WO2025091012A1

WO2025091012A1 - Improved silk leather and methods of making and using the same

Info

Publication number: WO2025091012A1
Application number: PCT/US2024/053221
Authority: WO
Inventors: Fiorenzo G. Omenetto; Marco LO PRESTI
Original assignee: Tufts University
Current assignee: Tufts University
Priority date: 2023-10-27
Filing date: 2024-10-28
Publication date: 2025-05-01
Anticipated expiration: 2026-04-27

Abstract

A host of new silk material formats are disclosed, all prepared from an initial liquid composition including both silk fibroin and polysaccharides. In some cases, particularly preferred material properties are achieved by the addition of glycerol. These various formats include liquids, whipped silk creams, silk meringues, and compressed/heat-compressed meringues. Among the useful end-uses for these materials is a silk leather comprising a tannic acid-treated fabric layer, which mimics the feel of conventional leather. Other uses include thermal insulation, absorption/gas sensing, biological scaffolding, and the like. A material that has material properties unexpectedly similar to mycelium is also disclosed.

Description

IMPROVED SILK LEATHER AND METHODS OF MAKING AND USING THE SAME CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the following provisional applications, which are hereby incorporated by reference in its entirety for all purposes: U.S. Patent Application Serial Number 63/593,776, filed October 27, 2023; and U.S. Patent Application Serial Number 63/658,745, filed June 11, 2024.

BACKGROUND

[0002] Sustainability in materials is an area of increasing interest. One material that is sustainable in a certain sense is leather, in that it can be reproduced and grown from animals. However, this material is not sustainable when it comes to humane treatment of animals. Alternatives to leather have been pursued for decades, but those alternatives have primarily been non-sustainable alternatives.

[0003] A need exists for alternatives to conventional leather as a material for use across the spectrum of applications where conventional leather is used.

SUMMARY

[0004] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin and a polysaccharide , wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

[0005] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin and a polysaccharide, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer. [0006] In some aspects, the present disclosure provides a method of forming a silk leather, including: whipping a liquid composition including silk fibroin and a polysaccharide, for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather includes a compressed silk meringue.

[0007] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

[0008] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

[0009] In some aspects, the present disclosure provides a method of forming a silk leather, including: whipping a liquid composition including silk fibroin, a polysaccharide, and a plasticizer for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather includes a compressed silk meringue. [0010] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

[0011] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

[0012] In some aspects, the present disclosure provides a method of forming a silk leather, including: whipping a liquid composition including silk fibroin, a polysaccharide, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather includes a compressed silk meringue.

[0013] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

[0014] In some aspects, the present disclosure provides a silk leather that is a layered structure including a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer including a compressed silk meringue, the compressed silk meringue including silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

[0015] In some aspects, the present disclosure provides a method of forming a silk leather, including: whipping a liquid composition including silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather includes a compressed silk meringue.

[0016] In some aspects, the present disclosure provides a conductive silk leather including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0017] In some aspects, the present disclosure provides a magnetic silk leather including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0018] In some aspects, the present disclosure provides a scented silk leather including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0019] In some aspects, the present disclosure provides a thermally -insulating silk leather having thermochromic reporting property throughout a bulk interior volume including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0020] In some aspects, the present disclosure provides a thermal insulator including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0021] In some aspects, the present disclosure provides a pH responsive silk leather including a pH responsive chemical distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather, and a tannic acid-treated fabric layer.

[0022] In some aspects, the present disclosure provides a humidity sensing leather including a pH responsive chemical and a pH altering agent distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather and a tannic acid-treated fabric layer, wherein measurable amounts of humidity solubilize at least a portion of the pH altering agent, thereby lowering the pH, thereby providing a measurable report of humidity.

[0023] In some aspects, the present disclosure provides a patterned silk leather including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0024] In some aspects, the present disclosure provides an electronic silk leather having an electronic component embedded therein including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0025] In some aspects, the present disclosure provides a semiconductor device-embedded silk leather having a semiconductor device embedded therein, including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0026] In some aspects, the present disclosure provides a haptic silk leather having a haptic switch embedded therein, including a compressed silk meringue, hot-pressed silk meringue, or silk leather as disclosed herein, and a tannic acid-treated fabric layer.

[0027] In some aspects, the techniques described herein relate to a tanned silk leather, the tanned silk leather having a tannic acid-treated fabric layer and a bulk volume of a compressed silk meringue or hot-compressed silk meringue and a surface layer of the compressed silk meringue or hot-pressed silk meringue, wherein the surface layer is formed from the same chemical composition as the bulk volume but includes at least one differing structural, mechanical, or chemical feature relative to the bulk volume.

[0028] In some aspects, the techniques described herein relate to an ultra lightweight silk down alternative including silk meringue and a tannic acid-treated fabric layer. [0029] In aspects, the disclosure herein relates to a liquid composition including a mixture of silk fibroin, a polysaccharide, and a plasticizer, wherein the liquid composition optionally has a water content of between 89% and 99%.

[0030] In aspects, the disclosure herein relates to whipped silk cream including silk fibroin, a polysaccharide, and a plasticizer, wherein the whipped silk cream optionally has a water content of between 50% and 95%.

[0031] In aspects, the disclosure herein relates to silk meringue including silk fibroin, a polysaccharide, and a plasticizer, wherein the silk meringue optionally has a water content of between 5% and 70%.

[0032] In aspects, the disclosure herein relates to compressed silk meringue including silk fibroin, a polysaccharide, and a plasticizer, wherein the compressed silk meringue optionally has a water content of between 2% and 50%.

[0033] In aspects, the disclosure herein relates to hot-pressed silk meringue including silk fibroin, a polysaccharide, and a plasticizer, wherein the hot-pressed silk meringue optionally has a water content of between 2% and 50%.

[0034] In aspects, the disclosure herein relates to a method of making a composition, the method including whipping a liquid composition including a mixture of silk fibroin, a polysaccharide, and a plasticizer for a predetermined whipping time to form a whipped silk cream. Optionally, the silk fibroin and the polysaccharide are whipped together before addition of the plasticizer; the silk fibroin and the plasticizer are whipped together before addition of the polysaccharide; or the polysaccharide and the plasticizer are whipped together before addition of the silk fibroin.

BRIEF DESCRIPTION OF THE FIGURES

[0035] The disclosure and the following detailed description of certain aspects thereof may be understood by reference to the following figures:

[0036] Figs. 1 A and IB depict silk leather of the disclosure.

[0037] Fig. 1C depicts a CO2 sensing reaction.

[0038] Fig. 2 depicts a mechanical comparison between Mycelium and Mysilkium.

[0039] Fig. 3 depicts mechanical properties of composite mysilkium and relative textile.

[0040] Fig. 4 depicts cream density.

[0041] Fig. 5 depicts cream water content.

[0042] Fig. 6 depicts meringue density.

[0043] Fig. 7 shows the solid compositions of the meringues obtained by varying the mass of SF and assuming a total removal of water from the cooking process. [0044] Fig. 8 provides data regarding various compositions and the ratio of SF. Gly, and XG in each composition.

[0045] Fig. 9a depicts the cream density for the compositions identified in Fig. 8.

[0046] Fig. 9b depicts the cream water content for the compositions identified in Fig. 8.

[0047] Fig. 10a depicts the syneresis (%) for the compositions identified in Fig. 8 and Fig. 10b depicts the relationship of density, water content, and syneresis to solid content.

[0048] Fig. 11 a depicts density variation of the cream as a function of whipping time.

[0049] Fig. l ib depicts the mechanical properties of the cream and their variation with whipping time through resistance toward compression (firmness).

[0050] Fig. 12 depicts overrun of the creams measured at different whipping times and using different plasticizers.

[0051] Fig. 13 depicts that the density of the cream reduces and can be controlled through whipping time.

[0052] Fig. 14 depicts the transition from random coils to P-sheet structure upon whipping.

[0053] Fig. 15 depicts the relationship of bubble size and overrun.

[0054] Fig. 16a depicts a photograph of SF:XG:Gly dried foam; Fig. 16b depicts densities; Fig. 16C depicts compressive strength; and Fig. 16D depicts the yield point using different ratios for SF:XG:Gly dried foams.

[0055] Fig. 17A depicts a comparison of the mechanical performance of xanthan and alginate-based silk foams; Fig. 17B depicts a comparison of the firmness of xanthan and alginate-containing silk creams; Fig. 17C depicts an experimental setup; and Fig. 17D depicts a temperature vs time plot of alginate foam vs. polystyrene.

[0056] Fig. 18 depicts photographs (A) and densities (B) of SF:XG:Gly 20:20:60 foams at different minutes of whipping.

[0057] Fig. 19A depicts photographs with the detail of the surface morphology of the foam and Fig. 19B) depicts its internal structure as a function of the whipping time obtained through fluorescent staining with rhodamine 6G.

[0058] Fig. 20 depicts foams fluorescent staining (ThT) to analyze the internal foam structure.

[0059] Fig. 21A depicts spectral features for ThT free in solution when excited at 365nm and Fig. 2 IB depicts spectral features for ThT bound to a P-sheet structure when excited at 365nm.

[0060] Fig. 22 depicts the emission of foams excited at 365nm displaying a color shift during the initial whipping phases.

[0061] Figs. 23A, 23B, and 23C depict foam materials as a substrate for algal growth. [0062] Fig. 24A depicts the chemical structure of tannic acid, Fig. 24B is a flowchart illustrating the process of organza modification, Fig. 24C is an FTIR spectra of control organza (top line), posttreatment (middle line), and tannic acid (lower line), Fig. 24D are macroscopic photographs of the fabric before treatment (left) and after treatment (right).

[0063] Fig. 25A is a plot of peel strength vs. displacement of the artificial leather samples made with control and modified fabric, Fig. 25B is a histogram illustrating the differences in performance in the first 40 mm of displacement (adhesive failure), Fig. 25C is a photograph of peeling on untreated organza, Fig. 25D is a photograph of organza treated with tannic acid, Fig. 25E is an SEM image of regions characterized by adhesive failure on untreated organza, and Fig. 25F is an SEM image of regions characterized by adhesive failure on organza treated with tannic acid.

DETAILED DESCRIPTION

[0064] Before the present invention is described in further detail, it is to be understood that the invention is not limited to the particular embodiments described. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. The scope of the present invention will be limited only by the claims. As used herein, the singular forms "a", "an", and "the" include plural embodiments unless the context clearly dictates otherwise.

[0065] In this application, unless otherwise clear from context, (i) the term “a” may be understood to mean “at least one”; (ii) the term “or” may be understood to mean “and/or”; (iii) the terms “comprising” and “including” may be understood to encompass itemized components or steps whether presented by themselves or together with one or more additional components or steps; and (iv) the terms “about” and “approximately” are used as equivalents and may be understood to permit standard variation as would be understood by those of ordinary skill in the art; and (v) where ranges are provided, endpoints are included.

[0066] Approximately: as used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).

[0067] Composition: as used herein, may be used to refer to a discrete physical entity that comprises one or more specified components. In general, unless otherwise specified, a composition may be of any form - e.g., gas, gel, liquid, solid, etc. In some embodiments, “composition” may refer to a combination of two or more entities for use in a single embodiment or as part of the same article. It is not required in all embodiments that the combination of entities result in physical admixture, that is, combination as separate co-entities of each of the components of the composition is possible; however many practitioners in the field may find it advantageous to prepare a composition that is an admixture of two or more of the ingredients in a pharmaceutically acceptable carrier, diluent, or excipient, making it possible to administer the component ingredients of the combination at the same time.

[0068] Improve, increase, or reduce: as used herein or grammatical equivalents thereof, indicate values that are relative to a baseline measurement, such as a measurement in a similar composition made according to previously known methods.

[0069] Substantially: as used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest. One of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if ever, go to completion and/or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to capture the potential lack of completeness inherent in many biological and chemical phenomena.

[0070] It should be apparent to those skilled in the art that many additional modifications beside those already described are possible without departing from the inventive concepts. In interpreting this disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. Variations of the term "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, so the referenced elements, components, or steps may be combined with other elements, components, or steps that are not expressly referenced. Embodiments referenced as "comprising" certain elements are also contemplated as "consisting essentially of" and "consisting of" those elements. When two or more ranges for a particular value are recited, this disclosure contemplates all combinations of the upper and lower bounds of those ranges that are not explicitly recited. For example, recitation of a value of between 1 and 10 or between 2 and 9 also contemplates a value of between 1 and 9 or between 2 and 10.

Definitions

[0071] As used herein, "low molecular weight" silk fibroin refers to silk fibroin that has been subjected to boiling during degumming or another processing step for a length of time of at least 30 minutes, thereby reducing the average molecular weight of the protein fragments. Examples of low molecular weight silk fibroin can be found at WO 2014/145002, which is incorporated herein in its entirety by reference.

[0072] As used herein, mysilkium refers to a material that is composed of at least 20% silk fibroin and which has one or more of the following material properties (e.g., compressive modulus, tensile strength, etc.) falling within 50%, within 25%, within 20%, within 15%, or within 10% of a native mycelium.

[0073] As used herein, "silk fibroin" refers to silk fibroin protein whether produced by silkworm, spider, or other insect, or otherwise generated (Lucas et al., Adv. Protein Chem., 13: 107-242 (1958)). Any type of silk fibroin can be used in different embodiments described herein. Silk fibroin produced by silkworms, such as Bombyx mori, is the most common and represents an earth-friendly, renewable resource. For instance, silk fibroin used in a silk film may be attained by extracting sericin from the cocoons of B. mori. Organic silkworm cocoons are also commercially available. There are many different silks, however, including spider silk (e.g., obtained from Nephila clavipes), transgenic silks, genetically engineered silks, such as silks from bacteria, yeast, mammalian cells, transgenic animals, or transgenic plants, and variants thereof, that can be used. See, e.g., WO 97/08315 and U.S. Pat. No. 5,245,012, each of which is incorporated herein by reference in their entireties.

Liquid Compositions

[0074] The present disclosure provides a liquid composition. Compositions disclosed herein may include a protein, at least one polysaccharide, and a plasticizer. In embodiments, the protein may be silk fibroin. In embodiments, the polysaccharide may be xanthan gum, an alginate, or another high molecular weight sugar, cellulose derivative (e.g., microcrystalline cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), combinations thereof, or the like. In embodiments, the polysaccharide may be a thickening agent. In embodiments, the polysaccharide may be carrageenan. Liquid compositions containing xanthan gum may be superior at obtaining silk leathers. It should be understood, however, that examples and embodiments throughout this Specification that reference xanthan gum as a component may comprise a different polysaccharide in place of, or in addition to, xanthan gum, such as an alginate. In some embodiments, selection of the particular polysaccharide or combination of polysaccharides used in the liquid composition may depend on the ultimate material properties desired. For example, in some aspects, alginate may be preferred if a free-standing leather material is desired. It is expressly contemplated that certain applications may require a combination of different polysaccharides within the same composition, such as a specific application requiring a whipped silk cream including silk fibroin, glycerol, xanthan gum, and alginate as the principal components.

[0075] In some aspects, the weight ratio of silk fibroin, polysaccharide, and plasticizer may have an impact on one or more of a mechanical property, a density, or a water content of a resulting material made from the composition. Without wishing to be bound by any particular theory, variations of the weight of the plasticizer may preferentially impact mechanical properties, variations of the weight of the polysaccharide or combination of polysaccharides may preferentially impact density, and variations of the weight of the silk fibroin may preferentially impact water content. [0076] In some embodiments, the liquid composition includes a mixture of silk fibroin and xanthan gum. In some aspects, the liquid composition includes a mixture of silk fibroin, xanthan gum, and a plasticizer. In some aspects, the liquid composition includes a mixture of silk fibroin, xanthan gum, and glycerol. In some aspects, the liquid composition includes a mixture of silk fibroin, xanthan gum, and a functionalizing agent. In some aspects, the liquid composition includes a mixture of silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent. In some aspects, the liquid composition includes a mixture of silk fibroin, xanthan gum, glycerol, and a functionalizing agent. In some aspects, the liquid composition includes a mixture of silk fibroin and a high molecular weight sugar (e.g., such as xanthan gum), and may optionally further include at least one of a plasticizer (e.g., such as glycerol) or a functionalizing agent.

[0077] The liquid composition can include other components that a skilled artisan will recognize are valuable in certain contexts. In certain cases, the liquid composition can further include glycerol. In certain cases, the liquid composition can further include a sensing agent. In certain case, the liquid composition can further include a therapeutically active agent. In certain cases, the liquid composition can include an aroma-providing compound.

[0078] The mixture of silk fibroin and polysaccharide (e.g., xanthan gum, alginate, etc.) includes a weight ratio of silk fibroin to polysaccharide of between 1 :4 and 20:1 or between 1 :2 and 10:1. For example, the mixture of silk fibroin and polysaccharide can include a weight ratio of silk fibroin to polysaccharide of at least 1 :4, at least 1 :3, or at least 1:2. For example, mixture of silk fibroin and polysaccharide can include a weight ratio of silk fibroin to polysaccharide of at most 20:1, at most 19: 1 , at most 18: 1 , at most 16:1 , at most 15: 1 , at most 14:1 , at most 12:1 , at most 1 1 :1 , or at most 10:1. [0079] The silk fibroin can be present in the liquid composition in an amount by weight of between 1% and 10% or between 3% and 7%. Without wishing to be bound by any particular theory, it is believed that the concentration of silk fibroin can impact the structural integrity of a resulting product. If the concentration is too low, the resulting product may not coalesce into a single physical structure, thereby failing to make an article at all. If the concentration is too high, the resulting product may form in a fashion with visible defects, cracks, and other imperfections. For example, the silk fibroin can be present in the liquid composition in an amount by weight of at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%. For example, the silk fibroin can be present in the liquid composition in an amount by weight of at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

[0080] The polysaccharide can be present in the liquid composition in an amount by weight of between 0.1% and 10.0%. For example, the polysaccharide can be present in the liquid composition in an amount by weight of at least 0.1%, at least 0.3%, at least 0.5%, at least 1.0%, at least 1.5%, at least 2.0%, at least 2.5%, at least 3.0%, at least 3.5%, at least 4.0%, at least 4.5%, at least 5.0%, at least

5.5%, at least 6.0%, at least 6.5%, at least 7.0%, at least 7.5%, at least 8.0%, at least 8.5%, at least

9.0%, or at least 9.5%. For example, the polysaccharide can be present in the liquid composition in an amount by weight of at most 10.0%, at most 9.5%, at most 9.0%, at most 8.5%, at most 8.0%, at most

7.5%, at most 7.0%, at most 6.5%, at most 6.0%, at most 5.5%, at most 5.0%, at most 4.5%, at most

4.0%, at most 3.5%, at most 3.0%, at most 2.5%, at most 2.0%, at most 1.5%, or at most 1.0%.

[0081] The plasticizer can be present in the liquid composition in an amount by weight of between 0.5% and 20.0%. For example, the plasticizer can be present in the liquid composition in an amount by weight of at least 0.5%, at least 1.0%, at least 1.5%, at least 2.0%, at least 2.5%, at least 3.0%, at least 3.5%, at least 4.0%, at least 4.5%, at least 5.0%, at least 5.5%, at least 6.0%, at least 6.5%, at least 7.0%, at least 7.5%, at least 8.0%, at least 8.5%, at least 9.0%, at least 9.5%, at least 10.0%, at least 12.0%, or at least 15.0%. For example, the plasticizer can be present in the liquid composition in an amount by weight of at most 20.0%, at most 18.5%, at most 17.5%, at most 16.0%, at most 15.0%, at most 14.0%, at most 13.0%, at most 12.5%, at most 11.0%, at most 10.0%, at most 8.0%, or at most 5.0%.

[0082] The plasticizer can be present in the liquid composition in an amount by weight of between 20.0% and 75.0%. For example, the plasticizer can be present in the liquid composition in an amount by weight of at least 20.0%, at least 25.0%, at least 30.0%, at least 35.0%, at least 40.0%, at least 45.0%, at least 50.0%, at least 55.0%, at least 60.0%, at least 65.0%, or at least 70.0%. For example, the plasticizer can be present in the liquid composition in an amount by weight of at most 75.0%, at most 70.0%, at most 65.0%, at most 60.0%, at most 55.0%, at most 50.0%, at most 45.0%, at most 40.0%, at most 35.0%, at most 30.0%, at most 25.0%, or at most 20.0%.

[0083] Plasticizers can include at least one of polyols, esters, phthalates, terephthalates, trimellitates, adipates, sebacates, organophosphates, ethanolamines, waxes, resins, or glycerols. The plasticizer can be selected from the group consisting of glycerol, 1 ,2-pentanediol, 1,5-pentanediol, 1,2,6-hexanetriol, and mixtures thereof. In some cases, the plasticizer is glycerol. In some cases, the plasticizer is 1,2- pentanediol. In some cases, the plasticizer is 1,5-pentanediol. In some cases, the plasticizer is 1,2,6- hexanetriol. In some cases, the plasticizer is at least one of xylitol, alditol, 1 ,2-pentanediol, 1,5- pentanediol, 1,2,6-hexanetriol, oleoyl-glycerol, cottonseed oil, di(ethylene glycol), tri(ethylene glycol), di(propylene glycol), tri(propylene glycol), or a vegetable oil.

[0084] Without wishing to be bound by any particular theory, it is believed that the number or and/or separation between -OH substituents can strongly impact the material properties of the resulting composition. In some cases, the plasticizer comprises at least one -OH substituent. In some cases, the plasticizer comprises at least two -OH substituents, at least 3 -OH substituents, or more -OH substituents. In some cases, the at least two -OH substituents, the at least 3 -OH substituents, or the more -OH substituents are separated from one another on the plasticizer by at least 2 carbon atoms, at least 3 carbon atoms, or at least 4 carbon atoms.

[0085] In some cases, the plasticizer can be partly or wholly evaporated off during processing. In some cases, the plasticizer remains within the composition during processing.

[0086] The sensing agent can be present in an amount that is selected by the nature of the sensing agent and the nature of the desired sensing performance. Similarly, a therapeutically active agent can be present in an amount that is selected by the nature of the therapeutically active agent and the nature of the desired therapeutic outcome. Similarly, a colorant can be present in an amount that is selected by the nature of the coloring ability of the colorant and the nature of the desired coloring. Similarly, an aroma-providing compound can be present in an amount that is selected by the nature of the aromaproviding ability of the compound and the nature of the desired aroma performance. A skilled artisan will recognize that there will be differing lower and upper boundaries for the amount of sensing agent, therapeutically active agent, colorant, and/or aroma- providing compound that will be present based on the nature of the agent. The aforementioned additives, agents, colorants, etc. can optionally be foodsafe versions, which are identified as generally recognized as safe according to the US Food and Drug Administration. The additive can be inorganic, with uses such as fluorescent materials, lasing materials/media, absorbing/light responsive materials, temperature-sensitive materials, electrochemical materials, or combinations thereof.

[0087] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin. In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide. In an example, the polysaccharide is present in an amount by weight of between 10% and 32% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer, wherein the polysaccharide is optionally an alginate. In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 25% and 94% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer. In some examples, the plasticizer is present in an amount by weight of between 5% and 80% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer. In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide, and between 25% and 94% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer. [0088] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 50% and 70% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0089] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 15% and 25% of the total weight of the silk fibroin and the plasticizer is the silk fibroin, and between 75% and 85% of the total weight of the silk fibroin and the plasticizer is the plasticizer.

[0090] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 30% and 35% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 30% and 35% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 30% and 35% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0091] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0092] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0093] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 35% and 45% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0094] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 45% and 85% of the total weight of the silk fibroin and the polysaccharide is the silk fibroin, and between 15% and 55% of the total weight of the silk fibroin and the polysaccharide is the polysaccharide. [0095] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 45% and 55% of the total weight of the silk fibroin and the polysaccharide is the silk fibroin, and between 45% and 55% of the total weight of the silk fibroin and the polysaccharide is the polysaccharide.

[0096] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 55% and 65% of the total weight of the silk fibroin and the polysaccharide is the silk fibroin, and between 35% and 45% of the total weight of the silk fibroin and the polysaccharide is the polysaccharide.

[0097] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 65% and 75% of the total weight of the silk fibroin and the polysaccharide is the silk fibroin, and between 25% and 35% of the total weight of the silk fibroin and the polysaccharide is the polysaccharide.

[0098] In some aspects of the liquid composition or any of the downstream products or articles of manufacture disclosed herein, between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer, and between 55% and 65% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

[0099] The liquid composition has a high water content. In some cases, the liquid composition has a water content of between 89% and 99%.

[0100] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include multi-valent metal ions, such as calcium or copper. Where the polysaccharide is an alginate, the multi-valent metal ions may be present in a concentration of at least 10 mmol of the multi-valent metal ion per gram of the alginate and at most 250 mmol of the multi- valent metal ion per gram of the alginate, including but not limited to, at least 20 mmol, at least 30 mmol, at least 40 mmol, or at least 50 mmol, and at most 240 mmol, at most 225 mmol, at most 210 mmol, at most 200 mmol, at most 175 mmol, or at most 150 mmol. In some cases, the multi-valent metal ions are introduced in the form of CuCh. In some cases, the multi-valent metal ions are introduced in the form of CaCOa, which can reduce yellowing in downstream compositions.

[0101] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include a salt, such as a chloride salt. The salt may be present in a concentration of at least 10 mmol per gram of non-water component (e.g. , all non- water ingredients - non-water component can be replaced with a dry solids basis, as would be appreciated by a skilled artisan, if other solvents are used) and at most 500 mmol per gram of non-water component, including but not limited to, at least 25 mmol, at least 50 mmol, or at least 100 mmol, and at most 450 mmol, at most 400 mmol, at most 300 mmol, or at most 250 mmol.

[0102] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include shellac, such as in an amount by weight of between 0.1% and 50%.

[0103] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include a natural wax, such as in an amount by weight of between 0.1% and 50%.

[0104] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include lycopodium powder, such as in an amount by weight of between 0.1% and 50%.

[0105] In some aspects, the liquid composition or any of the downstream products or articles of manufacture disclosed herein may further include at least one of a conductive additive, a non- conductive additive, or a thermally-conductive additive (e.g., electrically insulating).

Whipped Silk Creams

[0106] Much like dairy milk can be whipped into a cream because of the emulsion-forming capacity of its high fat content, unexpectedly, silk fibroin solutions can be whipped up to a foam in the presence of high molecular weight sugars, such as xanthan gum or alginates. Foams obtained this way may be brittle and may display higher wettability towards organic solvents. Adding plasticizers to the composition may remove the brittleness and makes the foams more hydrophilic and encourages sponge-like behavior in water environments.

[0107] The present disclosure provides a whipped silk cream comprising silk fibroin and xanthan gum. In some aspects, the whipped silk cream comprises silk fibroin, xanthan gum, and a plasticizer. In some aspects, the whipped silk cream comprises silk fibroin, xanthan gum, and glycerol. In some aspects, the whipped silk cream comprises silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent. In some aspects, the whipped silk cream comprises silk fibroin, xanthan gum, glycerol, and a functionalizing agent. In some aspects, the whipped silk cream comprises silk fibroin, xanthan gum, and a functionalizing agent. In some aspects, the whipped silk cream comprises a mixture of silk fibroin and a high molecular weight sugar (e.g., such as xanthan gum), and may optionally further include at least one of a plasticizer (e.g., such as glycerol) or a functionalizing agent.

[0108] Compositionally, the whipped silk cream can contain the same components in the same amounts as the liquid composition, with the liquid composition being transformed by the whipping process into a whipped silk cream.

[0109] The whipped silk cream can have an irregular porosity. [0110] In some cases, the whipped silk cream can have an overrun that is comparable to the overrun of dairy whipped cream. Certain properties of the whipped silk cream may be associated with particular overrun values. In some aspects, the properties of the whipped silk cream at a particular overrun value may be variable based on if the particular overrun value is achieved before or after achieving a maximum overrun value. Maximum overrun values may depend on at least one of: the components included in the liquid composition, the weight ratio of one or more components in the liquid composition, the weight % of one or more components in the liquid composition, the amount of whipping time, or the temperature during whipping. In one example, liquid compositions including plasticizers may exhibit greater overrun relative to compositions lacking or having reduced amounts of plasticizers.

[0111] The whipped silk cream may exhibit an overrun of between 10% and 550%, between 20% and 550%, between 50% and 300%, between 10% and 100%, between 10% and 150%, between 10% and 300%, or between 100% and 300%. The whipped silk cream may exhibit an overrun of at least 10%, at least 50%, at least 100%, at least 200%, at least 300%, at least 400%, or at least 500%.

[0112] Given that the whipped silk cream is a downstream product from the liquid composition, the whipped silk cream can include any component or feature of the liquid composition, unless the context clearly dictates otherwise (e.g., if the feature relates specifically to being a liquid and not whipped). [0113] The whipped silk cream has a water content that can be tailored for specific uses. In some cases, the water content of the whipped silk cream is between 50% and 95%, including but not limited to, between 75% and 93%, between 87% and 92%, or between 88.5% and 91%, including non-recited combinations of the upper and lower limits of those ranges (e.g., between 88.5% and 95%, etc.).

Silk Meringue

[0114] The present disclosure provides a silk meringue comprising silk fibroin and xanthan gum. In some aspects, the silk meringue comprises silk fibroin, xanthan gum, and a plasticizer. In some aspects, the silk meringue comprises silk fibroin, xanthan gum, and glycerol. In some aspects, the silk meringue comprises silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent. In some aspects, the silk meringue comprises silk fibroin, xanthan gum, glycerol, and a functionalizing agent. In some aspects, the silk meringue comprises silk fibroin, xanthan gum, and a functionalizing agent. In some aspects, the silk meringue comprises a mixture of silk fibroin and a high molecular weight sugar (e.g., such as xanthan gum), and may optionally further include at least one of a plasticizer (e.g., such as glycerol) or a functionalizing agent.

[0115] The silk meringue is a baked whipped silk cream. The silk meringue may be alternatively described as a foam herein. Compositionally, the silk meringue can contain the same components in the same amounts as the liquid composition and the whipped silk cream, with significantly less water/moisture content. Without wishing to be bound by any particular theory, it is believed that the whipping process and baking process can both give distinct characteristics to the silk meringue disclosed herein, with unique pore structure and size being generated by varying compositional and/or processing parameters.

[0116] Given that the silk meringue is a downstream product from the whipped silk cream, the silk meringue can include any component or feature of the whipped silk cream, unless the context clearly dictates otherwise (e.g., the water content is much lower in silk meringues). Similarly, as both the silk meringue and the whipped silk cream derive from the liquid composition, the silk meringue can include any component or feature of the liquid composition, unless the context clearly dictates otherwise.

[0117] The silk meringue has a water content that can be tailored for specific uses. The silk meringue can have a water content of between 5% and 70%. In some cases, the silk meringue has a water content of at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 50%. In some cases, the silk meringue has a water content of at most 75%, at most 65%, at most 60%, at most 50%, at most 40%, or at most 25%.

Compressed Silk Meringue

[0118] The present disclosure provides a compressed silk meringue comprising silk fibroin and xanthan gum and, in many cases, glycerol. In some aspects, the compressed silk meringue comprises silk fibroin, xanthan gum, and a plasticizer. In some aspects, the compressed silk meringue comprises silk fibroin, xanthan gum, and glycerol. In some aspects, the compressed silk meringue comprises silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent. In some aspects, the compressed silk meringue comprises silk fibroin, xanthan gum, glycerol, and a functionalizing agent. In some aspects, the compressed silk meringue comprises silk fibroin, xanthan gum, and a functionalizing agent. In some aspects, the compressed silk meringue comprises a mixture of silk fibroin and a high molecular weight sugar (e.g., such as xanthan gum), and may optionally further include at least one of a plasticizer (e.g., such as glycerol) or a functionalizing agent.

[0119] Compositionally, the compressed silk meringue is generally the same as the silk meringue. Structurally, the compressed silk meringue has a reduced and/or compressed and/or damaged pore structure when compared with the silk meringue.

[0120] Many of the most preferred compressed silk meringues include glycerol, as its inclusion provides an impressive malleability, thereby allowing compression with the retention of the general material and pore structure of the silk meringue. Specifically, in some cases where glycerol is present, the compressed silk meringue is a mysilkium material. Specifically, in some cases where glycerol is present, the compressed silk meringue can be or can form a part of (e.g., one or two layers adhered to a fabric substrate) a silk leather. In an embodiment, meringues disclosed herein can be used as an alternative to polyurethane foams employed for artificial leathers.

[0121] Given that the compressed silk meringue is a downstream product from the silk meringue, the compressed silk meringue can include any component or feature of the silk meringue, unless the context clearly dictates otherwise (e.g., the porosity is reduced in the compressed silk meringue). Similarly, as all of the compressed silk meringue, the silk meringue, and the whipped silk cream derive from upstream entities, the compressed silk meringue can include any component or feature of the silk meringue, the whipped silk cream, or the liquid composition, unless the context clearly dictates otherwise.

[0122] The compressed silk meringue has a water content that can be tailored for specific uses. The compressed silk meringue has a water content of between 2% and 50%. In some cases, the compressed silk meringue has a water content of at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%. In some cases, the compressed silk meringue has a water content of at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, or at most 25%.

Hot-Pressed Silk Meringue

[0123] The present disclosure provides a hot-pressed silk meringue comprising silk fibroin and xanthan gum and, in many cases, glycerol. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, and glycerol. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, and a plasticizer. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, and glycerol. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, glycerol, and a functionalizing agent. In some aspects, the hot-pressed silk meringue comprises silk fibroin, xanthan gum, and a functionalizing agent. In some aspects, the hot-pressed silk meringue comprises a mixture of silk fibroin and a high molecular weight sugar (e.g., such as xanthan gum), and may optionally further include at least one of a plasticizer (e.g., such as glycerol) or a functionalizing agent.

[0124] Compositionally, the hot-pressed silk meringue is generally the same as the silk meringue. Structurally, the hot-pressed silk meringue has a reduced and/or compressed and/or damaged pore structure when compared with the silk meringue.

[0125] Many of the most preferred hot-pressed silk meringues include glycerol, as its inclusion provides an impressive malleability, thereby allowing compression with the retention of the general material and pore structure of the silk meringue. Specifically, in some cases where glycerol is present, the hot-pressed silk meringue is a mysilkium material. Specifically, in some cases where glycerol is present, the hot-pressed silk meringue can be or can form a part of (e.g., one or two layers adhered to a fabric substrate) a silk leather. In an embodiment, meringues disclosed herein can be used as an alternative to polyurethane foams employed for artificial leathers.

[0126] Without wishing to be bound by any particular theory, it is believed that the most effective bonding between layers of material disclosed herein involves interlinking with mechanical structures (e.g., fibers in a woven fabric)

[0127] In some cases, the hot-pressed silk meringue (or other material format disclosed herein) can be interlinked with fabric, but in other cases the hot-pressed silk meringue is interlinked with a metal mesh, a conducting mesh, an electronic component, an active interface, an insulating interface, or a simple coating.

[0128] Given that the hot-pressed silk meringue is a downstream product from the silk meringue, the hot-pressed silk meringue can include any component or feature of the silk meringue, unless the context clearly dictates otherwise (e.g., the porosity is reduced in the hot-pressed silk meringue). Similarly, as all of the hot-pressed silk meringue, the silk meringue, and the whipped silk cream derive from upstream entities, the hot-pressed silk meringue can include any component or feature of the silk meringue, the whipped silk cream, or the liquid composition, unless the context clearly dictates otherwise.

[0129] The hot-pressed silk meringue has a water content that can be tailored for specific uses. The hot-pressed silk meringue has a water content of between 2% and 50%. In some cases, the hot-pressed silk meringue has a water content of at least 2%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, or at least 30%. In some cases, the hot-pressed silk meringue has a water content of at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, or at most 25%.

Methods of Making

[0130] The present disclosure provides methods of making the various compositions, materials, and articles described herein.

[0131] In one case, the present disclosure provides a method of making a composition, such as a whipped silk cream. A method of making a whipped silk cream can include whipping a liquid comprising silk fibroin and xanthan gum (and, in many cases, plasticizer or functionalizing agent) for a predetermined whipping time to form the whipped silk cream. The predetermined whipping time can be between 5 minutes and 30 minutes, including but not limited to, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, or at least 10 minutes and at most 30 minutes, at most 25 minutes, at most 20 minutes, at most 15 minutes, or at most 10 minutes.

[0132] The whipping can be achieved with mechanical agitation action that is associated with the integration of air, as would typically be understood from the context of food preparation involving various dairy and egg products, among other things. In some cases, the whipping is performed with a whisk. The whipping can optionally be performed manually, though there may be advantages to automated whipping, such as increased speed, endurance, and the like. The whipping can be performed using conventional whipping equipment or machines, such as a stand mixer. The whisk itself can be composed of metal or the whisk can be non-metal (or a metal whisk coated with a non-metal material, in some cases). The whipping can be done within a mixing bowl, such as a metal mixing bowl, for example a stainless steel mixing bowl.

[0133] In one specific case, the whipping involves whipping of a heterogenous solution, in which water and glycerol are the liquid phase and the silk fibroin and xanthan gum are in powder form.

[0134] In some cases, the temperature of the whipping is maintained at room temperature or lower, including refrigerated temperatures of between 1 °C and 25 °C.

[0135] In another case, the present disclosure provides a method of making a composition, such as a silk meringue. A method of making a silk meringue can include baking the whipped silk cream (optionally along with any method steps involved in preparing the whipped silk cream itself) at a temperature of between 25 °C and 150 °C, between 30 °C and 120 °C, or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form the silk meringue. In an example, the baking is performed at a temperature of between 40 °C and 150 °C for a length of time of between 5 minutes and 24 hours.

[0136] In some cases, the present disclosure provides a method of making an article, such as a compressed silk meringue. A method of making a compressed silk meringue can include compressing the silk meringue with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours. In some cases, the compressing can be heat-compressing that is performed at an elevated temperature of between 80 °C and 200 °C. In some cases, the compressing can be performed with a calendar press. A method of making a compressed silk meringue can include compressing the silk meringue with a force of between 0.25 MPa and 25 MPa for a length of time of between 5 minutes and 6 hours.

[0137] In some cases, the methods disclosed herein can further include embossing an article. The embossed article, such as an embossed silk leather, can have an appearance strikingly similar to embossed conventional leather.

[0138] The properties of silk creams, silk meringues, silk foams (baked silk creams), and articles of manufacture made from or including the silk creams, meringues, and or foams can be tuned by selection of weight ratios of starting materials, identity of starting materials, conditions of making the creams, meringues, and foams, and the like.

[0139] In some aspects, a method of making a whipped silk cream having a desired whipped silk cream morphology, a silk meringue having a desired silk meringue morphology, a compressed silk meringue having a desired compressed silk meringue morphology, or a hot-pressed silk meringue having a desired hot-pressed silk meringue morphology may include selecting a silk concentration, a silk molecular weight distribution, a polysaccharide species, a polysaccharide concentration, a plasticizer species, a plasticizer concentration, a whipping speed, optionally a silk meringue baking temperature, optionally a compressed silk meringue compressing force, optionally a hot-pressed silk meringue hot- pressing force and temperature. The method may further include making the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot-pressed silk meringue using the silk concentration, the silk molecular weight distribution, the polysaccharide species, the polysaccharide concentration, the plasticizer species, the plasticizer concentration, the whipping speed, optionally the silk meringue baking temperature, optionally the compressed silk meringue compressing force, and optionally the hot-pressed silk meringue hot-pressing force and temperature.

[0140] For example, the density, water content, and syneresis of the creams can be varied based on the selected weight ratio of silk fibroin, polysaccharide, and plasticizer in the composition. For example, compositions to be used in food or pharmaceutical industries may be tuned to exhibit low syneresis, while compositions to be used in dried foams where mechanical stability is favored may be tuned to exhibit a higher amount of syneresis. In certain aspects, the polysaccharide may have the greatest impact on overall density, the silk fibroin may have the greatest impact on water content, and the plasticizer may have the greatest impact on syneresis. The discovery of these differential impacts enables the tuning of the composition in accordance with the desired application or the desired performance.

[0141] In another example, the properties of density, firmness, and overrun of the cream may vary with whipping time. For example, depending on the application, greater or less firmness may be desired, and whipping time may be used to tune the cream for the desired application.

[0142] In another example, the properties of a cream’ s density or overrun may be tuned by selection of a particular plasticizer species. In an aspect, higher numbers of -OH groups of a plasticizer, such as glycerol and 1-3-6 hexanetriol, reduces the whipping time to overrun plateau by efficiently facilitating a hydrogen bonding network between the silk fibroin and the polysaccharide. In another aspect, the distance of -OH groups in a plasticizer influences the air capacity of the foam - plasticizers such as diols (e.g., 1,2 and 1,5-pentanediol) exhibit slower cream growth with a significantly higher overrun when the OH groups are at a greater distance.

[0143] In some aspects, the properties of silk foams made from creams and/or meringues may also be tuned via the composition ratio. For example, varying the amount of plasticizer may have an effect on the foam’s compressive strength and/or yield point. In another example, varying the polysaccharide species or combination of polysaccharides may be useful in tuning the foam for certain applications. For example, xanthan gum may be useful for applications where the foam is compressed (e.g., silk leather) where alginate may be more useful for foams being used in their expanded state.

[0144] In some aspects, the properties of silk foams made from creams and/or meringues may also be impacted by additives, such as borate ions which improve mechanical properties while providing flame retardant and anti-fungal properties.

[0145] In some aspects, varying the whipping time may have an effect on the resultant dried foam, such as due to the distribution of bubble sizes or the open/closed cell morphology. For example, longer whipping times may result in denser foams. As whipping time increases, cell structure may transition from a closed cell structure to an open cell structure. Variation in internal structure of foams may have an impact on performance in certain applications, such as in leather applications.

[0146] In an example method of making a composition, a liquid composition including a mixture of silk fibroin, a polysaccharide, and a plasticizer is whipped for a predetermined whipping time to form a whipped silk cream. In a further optional aspect of the example, the silk fibroin and the polysaccharide are whipped together before addition of the plasticizer. In another optional aspect of the example, the silk fibroin and the plasticizer are whipped together before addition of the polysaccharide. In still another optional aspect of the example, the polysaccharide and the plasticizer are whipped together before addition of the silk fibroin.

[0147] In certain cases the order of addition may be important, for example where highly hydrophobic compounds are used (e.g., fatty acids or oils). In these cases, the methods may include whipping a liquid composition including the silk fibroin and the polysaccharide for a first length of time before adding the highly hydrophobic compounds (optionally a plasticizer) and continuing the whipping.

Articles of Manufacture

[0148] The present disclosure provides articles of manufactures that include or are made from one or more of the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, or hot-pressed silk meringues disclosed herein.

Silk Leather

[0149] The present disclosure provides a silk leather. The silk leather is a layered structure comprising a first fabric layer and a second material layer disposed adjacent to the first fabric layer. The second material layer comprises the compressed silk meringue or the hot-pressed silk meringue disclosed herein. The silk leather optionally includes a third material layer disposed adjacent to the first fabric layer on a surface opposing the surface to which the second material layer is adjacent. The third material layer comprises the compressed silk meringue or the hot-pressed silk meringue disclosed herein. In effect, the compressed or hot-pressed silk meringues form a "sandwich" around the first fabric layer. Referring to Fig. 1, the silk leather 100 comprises a first fabric layer 102 and a second material layer 104 disposed adjacent to the first fabric layer 102 (See Fig. 1A). In aspects, a silk leather 108 optionally includes a third material layer 110 disposed adjacent to the first fabric layer 102 on a surface opposing the surface to which the second material layer 104 is adjacent (See Fig. IB).

[0150] The first fabric layer can be composed of cotton fabric, including but not limited to, cotton jersey, cotton canvas, and the like; silk fabric; synthetic fabric, including but not limited to, polyester fabric, rayon fabric, nylon fabric, and the like; linen; organza; the like; and combinations thereof. In some examples, the first fabric layer may be treated with tannic acid. In some examples, the first layer may be a hydrophilic fabric. The first fabric layer may include exposed hydroxyl groups.

[0151] In the aspects described herein, a unitary portion of silk leather may homogenously exhibit a property or functionality throughout the silk leather, or it may heterogeneously include various portions exhibiting one or more properties or functionalities (e.g., conductive, magnetic, colored, scented, tanned, patterned/embossed/textured, sensing/responsive (e.g., gas, humidity, thermochromic, pH), absorbing, thermal insulator, biological scaffold, electronics, semiconductor device-embedded, haptic, impact-resistant, heat-resistant, cold-resistant, or the like).

[0152] The silk leather can be colored to mimic non-colored natural leather. In some cases, the silk leather can be colored to mimic artificially colored natural leather. In one specific case, an artificial leather color can be produced by polymerizing phloroglucinol.

[0153] In some cases, using very cold water in making the whipped silk cream from which a silk leather is made can cause a thin "skin" to form on the surface, which can provide a wrinkled texture that mimics the texture of leather.

[0154] The present disclosure provides a thermal insulator. The thermal insulator comprises, consists essentially of, or consists of the silk meringue disclosed herein. The thermal insulator can be made by any of the methods disclosed herein. In aspects, thermally-insulating silk leather may have a thermochromic reporting property throughout a bulk interior volume.

[0155] The present disclosure provides a sorbent and/or gas sensing material. The sorbent and/or gas sensing material can comprise, consist essentially of, or consist of the silk meringue described herein. The sorbent and/or gas sensing material can further include a sensing agent that undergoes a measurable change upon exposure to a gas of interest. The sorbent and/or gas sensing material can include as a sensing agent a dye that changes color upon exposure to the gas of interest. The sorbent and/or gas-sensing material can be made by any of the methods disclosed herein.

[0156] The present disclosure provides a biological scaffold. In general, the biological scaffold is intended for the purpose of receiving a population of cells for one or more of growth, proliferation, differentiation, carbon dioxide capture, biomineralization, biosynthesis, fermentation, the like, and combinations thereof. [0157] In one specific case, the biological scaffolds disclosed herein are particularly excellent for algae growth. Specifically, both marine and freshwater algae were seeded and successfully grown on scaffolds for at least a month at 90% relative humidity and under adequate lighting conditions.

[0158] In one particular case, the present disclosure provides a mysilkium material with material properties that closely mimic the material properties of mycelium. The mysilkium material can be used in applications where mycelium is currently used.

Functionalizing/Active Agents

[0159] The compositions described herein can include a functionalizing agent, an active agent, a therapeutic agent, or a combination thereof.

[0160] According to various embodiments, a variety of functionalizing agents may be used with the silk-containing embodiments described herein (e.g., silk membrane, silk composition, silk articles, silk matrix, silk foam, silk microsphere, liquid composition, whipped silk cream, silk meringue, compressed silk meringue, hot-pressed silk meringue, silk leather, silk powder, silk toner, edible silkbased films, etc.). It should be understood that the examples herein may recite one or a few silkcontaining embodiments but are applicable to any silk-containing embodiment, as applicable. In some embodiments, a functionalizing agent may be any compound or molecule that facilitates the attachment to and/or development (e.g., growth) of one or more endothelial cells on a silk membrane. In some embodiments, a functionalizing agent may be any compound or molecule that facilitates the attachment and/or development (e.g., growth) of one or more megakaryocytes and/or hematopoietic progenitor cells on a silk matrix and/or silk membrane. In some embodiments, a functionalizing agent may be or comprise an agent suitable for facilitating the production of one or more of white blood cells and red blood cells.

[0161] In some embodiments, a functionalizing agent may be or comprise a cell attachment mediator and/or an extracellular matrix protein, for example: collagen (e.g., collagen type I, collagen type III, collagen type IV or collagen type VI), elastin, fibronectin, vitronectin, laminin, fibrinogen, von Willebrand factor, proteoglycans, decorin, perlecan, nidogen, hyaluronan, and/or peptides containing known integrin binding domains e.g. “RGD” integrin binding sequence, or variations thereof, that are known to affect cellular attachment.

[0162] In some embodiments, a functionalizing agent may be any soluble molecule produced by endothelial cells. Non-limiting examples include fibroblast growth factor- 1 (FGF1) and vascular endothelial growth factors (VEGF).

[0163] According to some embodiments, a plurality of functionalizing agents may be used. For example, in some embodiments wherein production of platelets is desired, provided compositions may comprise the use of laminin, fibronectin and/or fibrinogen, and type IV collagen in order to facilitate the attachment and growth of endothelial cells on a silk membrane (e.g., a porous silk membrane) and/or attachment of megakaryocytes to a silk matrix.

[0164] In some embodiments, a functionalizing agent may be embedded or otherwise associated with a silk membrane and/or silk matrix such that at least a portion of the functionalizing agent is surrounded by a silk membrane and/or silk matrix as contrasted to a functionalizing agent simply being positioned along the surface of a silk membrane and/or silk matrix. In some embodiments, a functionalizing agent is distributed along and/or incorporated in substantially the entire surface area of a silk membrane/silk wall. In some embodiments, a functionalizing agent is distributed and/or incorporated only at one or more discrete portions of a silk membrane/wall and/or silk matrix. In some embodiments, a functionalizing agent is distributed in and/or along at least one of the lumen-facing side of a silk wall and the matrix-facing side of a silk wall.

[0165] According to various embodiments, any application-appropriate amount of one or more functionalizing agents may be used. In some embodiments, the amount of an individual functionalizing agent may be between about 1 pg/ml and 1,000 pg/ml (e.g., between about 2 and 1,000, 5 and 1,000, 10 and 1,000, 10 and 500, 10 and 100 pg/m l ). In some embodiments, the amount of an individual functionalizing agent may be at least 1 pg/ml (e.g., at least 5, 10, 15, 20 25, 50, 100, 200, 300 400, 500, 600, 700, 800, or 900 pg/ml ). In some embodiments, the amount of an individual functionalizing agent is at most 1,000 pg/ml (e.g., 900, 800, 700, 600, 500, 400, 300 200, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10, or 5 pg/ml ).

[0166] In some aspects, the composition comprises one or more sensing agents, such as a sensing dye. The sensing agents/sensing dyes are environmentally sensitive and produce a measurable response to one or more environmental factors. In some aspects, the environmentally- sensitive agent or dye may be present in the composition in an effective amount to alter the composition from a first chemical - physical state to a second chemical -physical state in response to an environmental parameter (e.g., a change in pH, light intensity or exposure, temperature, pressure or strain, voltage, physiological parameter of a subject, and/or concentration of chemical species in the surrounding environment) or an externally applied stimulus (e.g., optical interrogation, acoustic interrogation, and/or applied heat). In some cases, the sensing dye is present to provide one optical appearance under one given set of environmental conditions and a second, different optical appearance under a different given set of environmental conditions. Suitable concentrations for the sensing agents described herein can be the concentrations for the colorants and additives described elsewhere herein. A person having ordinary skill in the chemical sensing arts can determine a concentration that is appropriate for use in a sensing application of the inks described herein. [0167] In some aspects, the first and second chemical-physical state may be a physical property of the composition, such as mechanical property, a chemical property, an acoustical property, an electrical property, a magnetic property, an optical property, a thermal property, a radiological property, or an organoleptic property. Exemplary sensing dyes or agents include, but are not limited to, a pH sensitive agent, a thermal sensitive agent, a pressure or strain sensitive agent, a light sensitive agent, or a potentiometric agent.

[0168] Exemplary pH sensitive dyes or agents include, but are not limited to, cresol red, methyl violet, crystal violet, ethyl violet, malachite green, methyl green, 2-(p- dimethylaminophenylazo) pyridine, paramethyl red, metanil yellow, 4-phenylazodiphenylamine, thymol blue, metacresol purple, orange IV, 4-o-Tolylazo-o-toluindine, quinaldine red, 2,4- dinitrophenol, erythrosine disodium salt, benzopurpurine 4B, N,N-dimethyl-p-(m-tolylazo) aniline, p-dimethylaminoazobenene, 4,4'-bis(2- amino-l-naphthylazo)-2,2'-stilbenedisulfonic acid, tetrabromophenolphthalein ethyl ester, bromophenol blue, Congo red, methyl orange, ethyl orange, 4-(4-dimethylamino-l-naphylazo)-3- methoxybenesulfonic acid, bromocresol green, resazurin, 4- phenylazo-l-napthylamine, ethyl red 2- (1-dimethylaminophenyazo) pyridine, 4-(p- ethoxypehnylazo)-m-phenylene-diamine monohydrochloride, resorcin blue, alizarin red S, methyl red, propyl red, bromocresol purple, chlorophenol red, p-nitrophenol, alizarin 2-(2,4- dinitrophenylazo) l-napthol-3,6-disulfonic acid, bromothymol blue, 6,8-dinitro-2,4-(lH) quinazolinedione, brilliant yellow, phenol red, neutral red, m- nitrophenol, cresol red, turmeric, metacresol purple, 4,4'-bis(3-amino-l-naphthylazo)-2,2'- stilbenedisulfonic acid, thymol blue, p- naphtholbenzein, phenolphthalein, o-cresolphthalein, ethyl bis(2,4-dimethylphenyl) ethanoate, thymolphthalein, nitrazine yellow, alizarin yellow R, alizarin, p- (2,4-dihydroxyphenylazo) benzenesulfonic acid, 5,5'-indigodisulfonic acid, 2,4,6-trinitrotoluene, 1,3,5-trinitrobenezne, and clayton yellow.

[0169] Exemplary light responsive dyes or agents include, but are not limited to, photochromic compounds or agents, such as triarylmethanes, stilbenes, azasilbenes, nitrones, fulgides, spiropyrans, napthopyrans, spiro-oxzines, quinones, derivatives and combinations thereof.

[0170] Exemplary potentiometric dyes include, but are not limited to, substituted amiononaphthylehenylpridinium (ANEP) dyes, such as di-4-ANEPPS, di-8-ANEPPS, and N-(4- Sulfobutyl)-4-(6-(4-(Dibutylamino)phenyl)hexatrienyl)Pyridinium (RH237).

[0171] Exemplary temperature sensitive dyes or agents include, but are not limited to, thermochromic compounds or agents, such as thermochromic liquid crystals, leuco dyes, fluoran dyes, octadecylphosphonic acid.

[0172] Exemplary pressure or strain sensitive dyes or agents include, but are not limited to, spiropyran compounds and agents. [0173] Exemplary chemi-sensitive dyes or agents include, but are not limited to, antibodies such as immunoglobulin G (IgG) which may change color from blue to red in response to bacterial contamination.

[0174] In some aspects, the compositions comprise one or more additive, dopant, or biologically active agent suitable for a desired intended purpose. In some aspects, the additive or dopant may be present in the composition in an amount effective to impart an optical or organoleptic property to the composition. Exemplary additives or dopants that impart optical or organoleptic properties include, but are not limited to, dyes/pigments, flavorants, aroma compounds, granular or fibrous fillers.

[0175] Additionally or alternatively, the additive, dopant, or biologically active agent may be present in the composition in an amount effective to "functionalize" the composition to impart a desired mechanical property or added functionality to the composition. Exemplary additive, dopants, or biologically active agent that impart the desired mechanical property or added functionality include, but are not limited to: environmentally sensitive/sensing dyes; active biomolecules; conductive or metallic particles; micro and nanofibers (e.g., silk nanofibers for reinforcement, carbon nanofibers); nanotubes; inorganic particles (e.g., hydroxyapatite, tricalcium phosphate, bioglasses); inorganic particles drugs (e.g., antibiotics, small molecules or low molecular weight organic compounds); proteins and fragments or complexes thereof (e.g., enzymes, antigens, antibodies and antigen-binding fragments thereof); DNA/RNA (e.g., siRNA, miRNA, mRNA); cells and fractions thereof (viruses and viral particles; prokaryotic cells such as bacteria; eukaryotic cells such as mammalian cells and plant cells; fungi).

[0176] In some aspects, the additive or dopant comprises a flavoring agent or flavorant.

[0177] Exemplary flavorants include ester flavorants, amino acid flavorants, nucleic acid flavorants, organic acid flavorants, and inorganic acid flavorants, such as, but not limited to, diacetyl, acetylpropionyl, acetoin, isoamyl acetate, benzaldehyde, cinnamaldehyde, ethyl propionate, methyl anthranilate, limonene, ethyl decadienoate, allyl hexanoate, ethyl maltol, ethylvanillin, methyl salicylate, manzanate, glutamic acid salts, glycine salts, guanylic acids salts, inosinic acid salts, acetic acid, ascorbic acid, citric acid, fumaric acid, lactic acid, malic acid, phosphoric acid, tartaric acid, derivatives, and mixtures thereof.

[0178] In some aspects, the additive or dopant comprises an aroma compound. Exemplary aroma compounds include ester aroma compounds, terpene aroma compounds, cyclic terpenes, and aromatic aroma compounds, such as, but not limited to, geranyl acetate, methyl formate, metyl acetate, methyl propionate, methyl butyrate, ethyl acetate, ethyl butyrate, isoamyl acetate, pentyl butrate, pentyl pentanoate, octyl acetate, benzyl acetate, methyl anthranilate, myrecene, geraniol, nerol, citral, cironellal, cironellol, linalool, nerolidol, limonene, camphor, menthol, carone, terpineol, alpha-lonone, thujone, eucalyptol, benzaldehyde, eugenol, cinnamaldehyde, ethyl maltol, vanillin, anisole, anethole, estragole, thymol.

[0179] In some aspects, the additive or dopant comprises a colorant, such as a dye or pigment. In some aspects, the dye or pigment imparts a color or grayscale to the composition. The colorant can be different than the sensing agents and/or sensing dyes below. Any organic and/or inorganic pigments and dyes can be included in the inks. Exemplary pigments suitable for use in the present disclosure include International Color Index or C.I. Pigment Black Numbers 1 , 7, 1 1 and 31 , C.I. Pigment Blue Numbers 15, 15 : 1 , 15 :2, 15 :3, 15 :4, 15 :6, 16, 27, 29, 61 and 62, C.I. Pigment Green Numbers 7, 17, 18 and 36, C.I. Pigment Orange Numbers 5, 13, 16, 34 and 36, C.I. Pigment Violet Numbers 3, 19, 23 and 27, C.I. Pigment Red Numbers 3, 17, 22, 23, 48: 1 , 48:2, 57: 1 , 81 : 1 , 81 :2, 81 :3, 81 :5, 101 , 1 14, 122, 144, 146, 170, 176, 179, 181 , 185, 188, 202, 206, 207, 210 and 249, C.I. Pigment Yellow Numbers 1 , 2, 3, 12, 13, 14, 17, 42, 65, 73, 74, 75, 83, 30, 93, 109, 1 10, 128, 138, 139, 147, 142, 151 , 154 and 180, D&C Red No. 7, D&C Red No. 6 and D&C Red No. 34, carbon black pigment (such as Regal 330, Cabot Corporation), quinacridone pigments (Quinacridone Magenta (228-0122), available from Sun Chemical Corporation, Fort Lee, N.J.), diarylide yellow pigment (such as AAOT Yellow (274- 1788) available from Sun Chemical Corporation); and phthalocyanine blue pigment (such as Blue 15 :3 (294-1298) available from Sun Chemical Corporation). The classes of dyes suitable for use in present invention can be selected from acid dyes, natural dyes, direct dyes (either cationic or anionic), basic dyes, and reactive dyes. The acid dyes, also regarded as anionic dyes, are soluble in water and mainly insoluble in organic solvents and are selected, from yellow acid dyes, orange acid dyes, red acid dyes, violet acid dyes, blue acid dyes, green acid dyes, and black acid dyes. European Patent 0745651 , incorporated herein by reference, describes a number of acid dyes that are suitable for use in the present disclosure. Exemplary yellow acid dyes include Acid Yellow 1 International Color Index or C.I. 10316); Acid Yellow 7 (C.I. 56295); Acid Yellow 17 (C.I. 18965); Acid Yellow 23 (C.I. 19140); Acid Yellow 29 (C.I. 18900); Acid Yellow 36 (C.I. 13065); Acid Yellow 42 (C.I. 22910); Acid Yellow 73 (C.I. 45350); Acid Yellow 99 (C.I. 13908); Acid Yellow 194; and Food Yellow 3 (C.I. 15985). Exemplary orange acid dyes include Acid Orange 1 (C.I. 13090/1); Acid Orange 10 (C.I. 16230); Acid Orange 20 (C.I. 14603); Acid Orange 76 (C.I. 18870); Acid Orange 142; Food Orange 2 (C.I. 15980); and Orange B.

[0180] Exemplary red acid dyes include Acid Red 1. (C.I. 18050); Acid Red 4 (C.I. 14710); Acid Red 18 (C.I. 16255), Acid Red 26 (C.I. 16150); Acid Red 2.7 (C.I. as Acid Red 51 (C.I. 45430, available from BASF Corporation, Mt. Olive, N.J.) Acid Red 52 (C.I. 45100); Acid Red 73 (C.I. 27290); Acid Red 87 (C. 1. 45380); Acid Red 94 (C.I. 45440) Acid Red 194; and Food Red 1 (C.I. 14700). Exemplary violet acid dyes include Acid Violet 7 (C.I. 18055); and Acid Violet 49 (C.I. 42640). Exemplary blue acid dyes include Acid Blue 1 (C.I. 42045); Acid Blue 9 (C.I. 42090); Acid Blue 22 (C.I. 42755); Acid Blue 74 (C.I. 73015); Acid Blue 93 (C.I. 42780); and Acid Blue 158A (C.I. 15050). Exemplary green acid dyes include Acid Green 1 (C.I. 10028); Acid Green 3 (C.I. 42085); Acid Green 5 (C.I. 42095); Acid Green 26 (C.I. 44025); and Food Green 3 (C.I. 42053). Exemplary black acid dyes include Acid Black 1 (C.I. 20470); Acid Black 194 (Basantol® X80, available from BASF Corporation, an azo/1 :2 CR-complex.

[0181] Exemplary direct dyes for use in the present disclosure include Direct Blue 86 (C.I. 74180); Direct Blue 199; Direct Black 168; Direct Red 253; and Direct Yellow 107/132 (C.I. Not Assigned). [0182] Exemplary natural dyes for use in the present disclosure include Alkanet (C.I. 75520,75530); Annatto (C.I. 75120); Carotene (C.I. 75130); Chestnut; Cochineal (C.I.75470); Cutch (C.I. 75250, 75260); Divi-Divi; Fustic (C.I. 75240); Hypemic (C.I. 75280); Logwood (C.I. 75200); Osage Orange (C.I. 75660); Paprika; Quercitron (C.I. 75720); Sanrou (C.I. 75100) ; Sandal Wood (C.I. 75510, 75540, 75550, 75560); Sumac; and Tumeric (C.I. 75300). Exemplary reactive dyes for use in the present disclosure include Reactive Yellow 37 (monoazo dye); Reactive Black 31 (disazo dye); Reactive Blue 77 (phthalo cyanine dye) and Reactive Red 180 and Reactive Red 108 dyes. Suitable also are the colorants described in The Printing Ink Manual (5th ed., Leach et al. eds. (2007), pages 289-299. Other organic and inorganic pigments and dyes and combinations thereof can be used to achieve the colors desired.

[0183] In addition to or in place of visible colorants, compositions provided herein can contain ETV fluorophores that are excited in the ETV range and emit light at a higher wavelength (typically 400 nm and above). Examples of ETV fluorophores include but are not limited to materials from the coumarin, benzoxazole, rhodamine, napthalimide, perylene, benzanthrones, benzoxanthones or benzothiaxanthones families. The addition of a UV fluorophore (such as an optical brightener for instance) can help maintain maximum visible light transmission. The amount of colorant, when present, generally is between 0.05% to 5% or between 0. 1 % and 1 % based on the weight of the composition.

[0184] For non- white compositions, the amount of pigment/dye generally is present in an amount of from at or about 0.1 wt% to at or about 20 wt% based on the weight of the composition. In some applications, a non-white ink can include 15 wt% or less pigment/dye, or 10 wt% or less pigment/dye or 5 wt% pigment/dye, or 1 wt% pigment/dye based on the weight of the composition. In some applications, a non-white ink can include 1 wt% to 10 wt%, or 5 wt% to 15 wt%, or 10 wt% to 20 wt% pigment/dye based on the weight of the composition. In some applications, a non-white ink can contain an amount of dye/pigment that is 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15%, 16 wt%, 17 wt%, 18 wt%, 19 wt% or 20 wt% based on the weight of the composition. [0185] For white compositions, the amount of white pigment generally is present in an amount of from at or about 1 wt% to at or about 60 wt% based on the weight of the composition. In some applications, greater than 60 wt% white pigment can be present. Preferred white pigments include titanium dioxide (anatase and rutile), zinc oxide, lithopone (calcined coprecipitate of barium sulfate and zinc sulfide), zinc sulfide, blanc fixe and alumina hydrate and combinations thereof, although any of these can be combined with calcium carbonate. In some applications, a white ink can include 60 wt% or less white pigment, or 55 wt% or less white pigment, or 50 wt% white pigment, or 45 wt% white pigment, or 40 wt% white pigment, or 35 wt% white pigment, or 30 wt% white pigment, or 25 wt% white pigment, or 20 wt% white pigment, or 15 wt% white pigment, or 10 wt% white pigment, based on the weight of the composition. In some applications, a white ink can include 5 wt% to 60 wt%, or 5 wt% to 55 wt%, or 10 wt% to 50 wt%, or 10 wt% to 25 wt%, or 25 wt% to 50 wt%, or 5 wt% to 15 wt%, or 40 wt% to 60 wt% white pigment based on the weight of the composition. In some applications, a nonwhite ink can an amount of dye/pigment that is 5%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55%, 56 wt%, 57 wt%, 58 wt%, 59 wt% or 60 wt% based on the weight of the composition.

[0186] In some aspects, the additive or dopant comprises a conductive additive. Exemplary conductive additives include, but are not limited to graphite, graphite powder, carbon nanotubes, and metallic particles or nanoparticles, such as gold nanoparticles. In some aspects, the conductive additive is biocompatible and non-toxic.

[0187] In some aspects, the additive is a biologically active agent. The term “biologically active agent” as used herein refers to any molecule which exerts at least one biological effect in vivo. For example, the biologically active agent can be a therapeutic agent to treat or prevent a disease state or condition in a subject. Biologically active agents include, without limitation, organic molecules, inorganic materials, proteins, peptides, nucleic acids (e.g., genes, gene fragments, gene regulatory sequences, and antisense molecules), nucleoproteins, polysaccharides, glycoproteins, and lipoproteins. Classes of biologically active compounds that can be incorporated into the composition provided herein include, without limitation, anticancer agents, antibiotics, analgesics, anti-inflammatory agents, immunosuppressants, enzyme inhibitors, antihistamines, anti-convulsants, hormones, muscle relaxants, antispasmodics, ophthalmic agents, prostaglandins, anti-depressants, anti-psychotic substances, trophic factors, osteoinductive proteins, growth factors, and vaccines. [0188] The term “active agent” may also be used herein to refer to a biological sample (e.g., a sample of tissue or fluid, such as for instance blood) or a component thereof, and/or to a biologically active entity or compound, and/or to a structurally or functionally labile entity.

[0189] Exemplary active agents include, but are not limited to, therapeutic agents, diagnostic agents (e.g., contrast agents), and any combinations thereof. In some embodiments, the active agent present in a silk matrix (e.g., a silk microsphere), composition, or the like can include a labile active agent, e.g., an agent that can undergo chemical, physical, or biological change, degradation and/or deactivation after exposure to a specified condition, e.g., high temperatures, high humidity, light exposure, and any combinations thereof. In some embodiments, the active agent present in the silk matrix (e.g., a silk microsphere), composition, or the like can include a temperature-sensitive active agent, e.g., an active agent that will lose at least about 30% or more, of its original activity or bioactivity, upon exposure to a temperature of at least about 10° C. or above, including at least about 15° C. or above, at least about room temperature or above, or at least about body temperature (e.g., about 37° C.) or above.

[0190] The active agent can be generally present in the silk matrix (e.g., a silk microsphere), composition, or the like in an amount of about 0.01% (w/w) to about 70% (w/w), or about 0.1% (w/w) to about 50% (w/w), or about 1% (w/w) to about 30% (w/w). The active agent can be present on a surface of the silk matrix (e.g., a silk microsphere), composition, or the like and/or encapsulated and dispersed in the silk matrix (e.g., a silk microsphere), composition, or the like homogeneously or heterogeneously or in a gradient. In some embodiments, the active agent can be added into the silk solution, which is then subjected to the methods described herein for preparing a silk matrix (e.g., a silk microsphere), composition, or the like. In some embodiments, the active agent can be coated on a surface of the silk matrix (e.g., a silk microsphere), composition, or the like. In some embodiments, the active agent can be loaded in a silk matrix (e.g., a silk microsphere), composition, or the like by incubating the silk microsphere in a solution of the active agent for a period of time, during which an amount of the active agent can diffuse into the silk matrix (e.g., a silk microsphere), composition, or the like, and thus distribute within the silk matrix (e.g., a silk microsphere), composition, or the like.

[0191] In some aspects, the additive is a therapeutic agent. As used herein, the term “therapeutic agent” means a molecule, group of molecules, complex or substance administered to an organism for diagnostic, therapeutic, preventative medical, or veterinary purposes. As used herein, the term “therapeutic agent” includes a “drug” or a “vaccine.” This term include externally and internally administered topical, localized and systemic human and animal pharmaceuticals, treatments, remedies, nutraceuticals, cosmeceuticals, biologicals, devices, diagnostics and contraceptives, including preparations useful in clinical and veterinary screening, prevention, prophylaxis, healing, wellness, detection, imaging, diagnosis, therapy, surgery, monitoring, cosmetics, prosthetics, forensics and the like. This term can also be used in reference to agriceutical, workplace, military, industrial and environmental therapeutics or remedies comprising selected molecules or selected nucleic acid sequences capable of recognizing cellular receptors, membrane receptors, hormone receptors, therapeutic receptors, microbes, viruses or selected targets comprising or capable of contacting plants, animals and/or humans. This term can also specifically include nucleic acids and compounds comprising nucleic acids that produce a therapeutic effect, for example deoxyribonucleic acid (DNA), ribonucleic acid (RNA), nucleic acid analogues (e.g., locked nucleic acid (LNA), peptide nucleic acid (PNA), xeno nucleic acid (XNA)), or mixtures or combinations thereof, including, for example, DNA nanoplexes, siRNA, microRNA, shRNA, aptamers, ribozymes, decoy nucleic acids, antisense nucleic acids, RNA activators, and the like. Generally, any therapeutic agent can be included in the composition provided herein.

[0192] The term “therapeutic agent” also includes an agent that is capable of providing a local or systemic biological, physiological, or therapeutic effect in the biological system to which it is applied. For example, the therapeutic agent can act to control infection or inflammation, enhance cell growth and tissue regeneration, control tumor growth, act as an analgesic, promote anti-cell attachment, and enhance bone growth, among other functions. Other suitable therapeutic agents can include anti-viral agents, hormones, antibodies, or therapeutic proteins. Other therapeutic agents include prodrugs, which are agents that are not biologically active when administered but, upon administration to a subject are converted to biologically active agents through metabolism or some other mechanism. Additionally, a silk-based drug delivery composition can contain one therapeutic agent or combinations of two or more therapeutic agents.

[0193] A therapeutic agent can include a wide variety of different compounds, including chemical compounds and mixtures of chemical compounds, e.g., small organic or inorganic molecules; saccharines; oligosaccharides; polysaccharides; biological macromolecules, e.g., peptides, proteins, and peptide analogs and derivatives; peptidomimetics; antibodies and antigen binding fragments thereof; nucleic acids; nucleic acid analogs and derivatives; an extract made from biological materials such as bacteria, plants, fungi, or animal cells; animal tissues; naturally occurring or synthetic compositions; and any combinations thereof. In some aspects, the therapeutic agent is a small molecule.

[0194] The term “bioactivity,” as used herein in reference to an active agent, generally refers to the ability of an active agent to interact with a biological target and/or to produce an effect on a biological target. For example, bioactivity can include, without limitation, elicitation of a stimulatory, inhibitory, regulatory, toxic or lethal response in a biological target. The biological target can be a molecule or a cell. For example, a bioactivity can refer to the ability of an active agent to modulate the effect/activity of an enzyme, block a receptor, stimulate a receptor, modulate the expression level of one or more genes, modulate cell proliferation, modulate cell division, modulate cell morphology, or any combination thereof. In some instances, a bioactivity can refer to the ability of a compound to produce a toxic effect in a cell. Exemplary cellular responses include, but are not limited to, lysis, apoptosis, growth inhibition, and growth promotion; production, secretion, and surface expression of a protein or other molecule of interest by the cell; membrane surface molecule activation including receptor activation; transmembrane ion transports; transcriptional regulations; changes in viability of the cell; changes in cell morphology; changes in presence or expression of an intracellular component of the cell; changes in gene expression or transcripts; changes in the activity of an enzyme produced within the cell; and changes in the presence or expression of a ligand and/or receptor (e.g., protein expression and/or binding activity). Methods for assaying different cellular responses are well known to one of skill in the art, e.g., western blot for determining changes in presence or expression of an endogenous protein of the cell, or microscopy for monitoring the cell morphology in response to the active agent, or FISH and/or qPCR for the detection and quantification of changes in nucleic acids. Bioactivity can be determined in some embodiments, for example, by assaying a cellular response.

[0195] In reference to an antibody, the term “bioactivity” includes, but is not limited to, epitope or antigen binding affinity, the in vivo and/or in vitro stability of the antibody, the immunogenic properties of the antibody, e.g., when administered to a human subject, and/or the ability to neutralize or antagonize the bioactivity of a target molecule in vivo or in vitro. The aforementioned properties or characteristics can be observed or measured using art-recognized techniques including, but not limited to, scintillation proximity assays, ELISA, ORIGEN immunoassay (IGEN), fluorescence quenching, fluorescence ELISA, competitive ELISA, SPR analysis including, but not limited to, SPR analysis using a BIAcore biosensor, in vitro and in vivo neutralization assays (see, for example, International Publication No. WO 2006/062685), receptor binding, and immunohistochemistry with tissue sections from different sources including human, primate, or any other source as needed. In reference to an immunogen, the “bioactivity” includes immunogenicity, the definition of which is discussed in detail later. In reference to a virus, the “bioactivity” includes infectivity, the definition of which is discussed in detail later. In reference to a contrast agent, e.g., a dye, the “bioactivity” refers to the ability of a contrast agent when administered to a subject to enhance the contrast of structures or fluids within the subject's body. The bioactivity of a contrast agent also includes, but is not limited to, its ability to interact with a biological environment and/or influence the response of another molecule under certain conditions. [0196] As used herein, the term “small molecule” can refer to compounds that are “natural productlike,” however, the term “small molecule” is not limited to “natural product-like” compounds. Rather, a small molecule is typically characterized in that it contains several carbon — carbon bonds, and has a molecular weight of less than 5000 Daltons (5 kDa), preferably less than 3 kDa, still more preferably less than 2 kDa, and most preferably less than 1 kDa. In some cases it is preferred that a small molecule have a molecular weight equal to or less than 700 Daltons.

[0197] Exemplary therapeutic agents include, but are not limited to, those found in Harrison’s Principles of Internal Medicine, 13th Edition, Eds. T.R. Harrison et al. McGraw-Hill N.Y., NY; Physicians’ Desk Reference, 50th Edition, 1997, Oradell New Jersey, Medical Economics Co.; Pharmacological Basis of Therapeutics, 8th Edition, Goodman and Gilman, 1990; United States Pharmacopeia, The National Formulary, ETSP XII NF XVII, 1990, the complete contents of all of which are incorporated herein by reference.

[0198] Therapeutic agents include the herein disclosed categories and specific examples. It is not intended that the category be limited by the specific examples. Those of ordinary skill in the art will recognize also numerous other compounds that fall within the categories and that are useful according to the present disclosure. Examples include a radiosensitizer, a steroid, a xanthine, a beta-2-agonist bronchodilator, an anti-inflammatory agent, an analgesic agent, a calcium antagonist, an angiotensinconverting enzyme inhibitors, a beta-blocker, a centrally active alpha- agonist, an alpha- 1 -antagonist, an anticholinergic/antispasmodic agent, a vasopressin analogue, an anti arrhythmic agent, an antiparkinsonian agent, an antiangina/antihypertensive agent, an anticoagulant agent, an antiplatelet agent, a sedative, an ansiolytic agent, a peptidic agent, a biopolymeric agent, an antineoplastic agent, a laxative, an antidiarrheal agent, an antimicrobial agent, an antifungal agent, a vaccine, a protein, or a nucleic acid. In a further aspect, the pharmaceutically active agent can be coumarin, albumin, steroids such as betamethasone, dexamethasone, methylprednisolone, prednisolone, prednisone, triamcinolone, budesonide, hydrocortisone, and pharmaceutically acceptable hydrocortisone derivatives; xanthines such as theophylline and doxophylline; beta-2-agonist bronchodilators such as salbutamol, fenterol, clenbuterol, bambuterol, salmeterol, fenoterol; antiinflammatory agents, including antiasthmatic anti-inflammatory agents, antiarthritis antiinflammatory agents, and nonsteroidal antiinflammatory agents, examples of which include but are not limited to sulfides, mesalamine, budesonide, salazopyrin, diclofenac, pharmaceutically acceptable diclofenac salts, nimesulide, naproxene, acetaminophen, ibuprofen, ketoprofen and piroxicam; analgesic agents such as salicylates; calcium channel blockers such as nifedipine, amlodipine, and nicardipine; angiotensin converting enzyme inhibitors such as captopril, benazepril hydrochloride, fosinopril sodium, trandolapril, ramipril, lisinopril, enalapril, quinapril hydrochloride, and moexipril hydrochloride; beta- blockers (i.e., beta adrenergic blocking agents) such as sotalol hydrochloride, timolol maleate, esmolol hydrochloride, carteolol, propanolol hydrochloride, betaxolol hydrochloride, penbutolol sulfate, metoprolol tartrate, metoprolol succinate, acebutolol hydrochloride, atenolol, pindolol, and bisoprolol fumarate; centrally active alpha-2-agonists such as clonidine; alpha- 1 -antagonists such as doxazosin and prazosin; anticholinergic/antispasmodic agents such as dicyclomine hydrochloride, scopolamine hydrobromide, glycopyrrolate, clidinium bromide, flavoxate, and oxybutynin; vasopressin analogues such as vasopressin and desmopressin; antiarrhythmic agents such as quinidine, lidocaine, tocainide hydrochloride, mexiletine hydrochloride, digoxin, verapamil hydrochloride, propafenone hydrochloride, flecainide acetate, procainamide hydrochloride, moricizine hydrochloride, and disopyramide phosphate; antiparkinsonian agents, such as dopamine, L-Dopa/Carbidopa, selegiline, dihydroergocryptine, pergolide, lisuride, apomorphine, and bromocryptine; antiangina agents and antihypertensive agents such as isosorbide mononitrate, isosorbide dinitrate, propranolol, atenolol and verapamil; anticoagulant and antiplatelet agents such as Coumadin, warfarin, acetylsalicylic acid, and ticlopidine; sedatives such as benzodiazapines and barbiturates; ansiolytic agents such as lorazepam, bromazepam, and diazepam; peptidic and biopolymeric agents such as calcitonin, leuprolide and other LHRH agonists, hirudin, cyclosporin, insulin, somatostatin, protirelin, interferon, desmopressin, somatotropin, thymopentin, pidotimod, erythropoietin, interleukins, melatonin, granulocyte/macrophage-CSF, and heparin; antineoplastic agents such as etoposide, etoposide phosphate, cyclophosphamide, methotrexate, 5 -fluorouracil, vincristine, doxorubicin, cisplatin, hydroxyurea, leucovorin calcium, tamoxifen, flutamide, asparaginase, altretamine, mitotane, and procarbazine hydrochloride; laxatives such as senna concentrate, casanthranol, bisacodyl, and sodium picosulphate; antidiarrheal agents such as difenoxine hydrochloride, loperamide hydrochloride, furazolidone, diphenoxylate hdyrochloride, and microorganisms; vaccines such as bacterial and viral vaccines; antimicrobial agents such as penicillins, cephalosporins, and macrolides, antifungal agents such as imidazolic and triazolic derivatives; and nucleic acids such as DNA sequences encoding for biological proteins, and antisense oligonucleotides.

[0199] Anti-cancer agents include alkylating agents, platinum agents, antimetabolites, topoisomerase inhibitors, antitumor antibiotics, antimitotic agents, aromatase inhibitors, thymidylate synthase inhibitors, DNA antagonists, farnesyltransferase inhibitors, pump inhibitors, histone acetyltransferase inhibitors, metalloproteinase inhibitors, ribonucleoside reductase inhibitors, TNF alpha agonists/antagonists, endothelinA receptor antagonists, retinoic acid receptor agonists, immunomodulators, hormonal and antihormonal agents, photodynamic agents, and tyrosine kinase inhibitors. [0200] Antibiotics include aminoglycosides (e.g., gentamicin, tobramycin, netilmicin, streptomycin, amikacin, neomycin), bacitracin, corbapenems (e.g., imipenem/cislastatin), cephalosporins, colistin, methenamine, monobactams (e.g., aztreonam), penicillins (e.g., penicillin G, penicillinV, methicillin, natcillin, oxacillin, cioxacillin, dicloxacillin, ampicillin, amoxicillin, carbenicillin, ticarcillin, piperacillin, mezlocillin, azlocillin), polymyxin B, quinolones, and vancomycin; and bacteriostatic agents such as chloramphenicol, clindanyan, macrolides (e.g., erythromycin, azithromycin, clarithromycin), lincomyan, nitrofurantoin, sulfonamides, tetracyclines (e.g., tetracycline, doxycycline, minocycline, demeclocyline), and trimethoprim. Also included are metronidazole, fluoroquinolones, and ritampin.

[0201] Enzyme inhibitors are substances which inhibit an enzymatic reaction. Examples of enzyme inhibitors include edrophonium chloride, N-methylphysostigmine, neostigmine bromide, physostigmine sulfate, tacrine, tacrine, 1 -hydroxy maleate, iodotubercidin, p- bromotetramiisole, 10- (alpha-diethylaminopropionyl)-phenothiazine hydrochloride, calmidazolium chloride, hemicholinium-3,3,5-dinitrocatechol, diacylglycerol kinase inhibitor I, diacylglycerol kinase inhibitor II, 3 -phenylpropargylamine, N°-monomethyl-Larginine acetate, carbidopa, 3- hydroxybenzylhydrazine, hydralazine, clorgyline, deprenyl, hydroxylamine, iproniazid phosphate, 6- MeO-tetrahydro-9H-pyrido-indole, nialamide, pargyline, quinacrine, semi carb azide, tranylcypromine, N,N-diethylaminoethyl-2,2-diphenylvalerate hydrochloride, 3 - isobutyl- 1- methylxanthne, papaverine, indomethacind, 2-cyclooctyl-2 -hydroxy ethylamine hydrochloride, 2,3- dichloro-a-methylbenzylamine (DCMB), 8,9-dichloro-2,3,4, 5 -tetrahydro- lH-2-benzazepine hydrochloride, p-amino glutethimide, p-aminoglutethimide tartrate, 3- iodotyrosine, alpha- methyltyrosine, acetazolamide, dichlorphenamide, 6-hydroxy-2- benzothiazolesulfonamide, and allopurinol.

[0202] Antihistamines include pyrilamine, chlorpheniramine, and tetrahydrazoline, among others.

[0203] Anti-inflammatory agents include corticosteroids, nonsteroidal anti-inflammatory drugs (e.g., aspirin, phenylbutazone, indomethacin, sulindac, tolmetin, ibuprofen, piroxicam, and fenamates), acetaminophen, phenacetin, gold salts, chloroquine, D-Penicillamine, methotrexate colchicine, allopurinol, probenecid, and sulfinpyrazone.

[0204] Muscle relaxants include mephenesin, methocarbomal, cyclobenzaprine hydrochloride, trihexylphenidyl hydrochloride, levodopa/carbidopa, and biperiden.

[0205] Anti-spasmodics include atropine, scopolamine, oxyphenonium, and papaverine.

[0206] Analgesics include aspirin, phenybutazone, idomethacin, sulindac, tolmetic, ibuprofen, piroxicam, fenamates, acetaminophen, phenacetin, morphine sulfate, codeine sulfate, meperidine, nalorphine, opioids (e.g., codeine sulfate, fentanyl citrate, hydrocodone bitartrate, loperamide, morphine sulfate, noscapine, norcodeine, normorphine, thebaine, nor- binaltorphimine, buprenorphine, chlomaltrexamine, funaltrexamione, nalbuphine, nalorphine, naloxone, naloxonazine, naltrexone, and naltrindole), procaine, lidocain, tetracaine and dibucaine. [0121] Ophthalmic agents include sodium fluorescein, rose bengal, methacholine, adrenaline, cocaine, atropine, alphachymotrypsin, hyaluronidase, betaxalol, pilocarpine, timolol, timolol salts, and combinations thereof. [0207] Prostaglandins are art recognized and are a class of naturally occurring chemically related long- chain hydroxy fatty acids that have a variety of biological effects.

[0208] Anti-depressants are substances capable of preventing or relieving depression.

[0209] Examples of anti-depressants include imipramine, amitriptyline, nortriptyline, protriptyline, desipramine, amoxapine, doxepin, maprotiline, tranylcypromine, phenelzine, and isocarboxazide.

[0210] Trophic factors are factors whose continued presence improves the viability or longevity of a cell trophic factors include, without limitation, platelet-derived growth factor (PDGP), neutrophilactivating protein, monocyte chemoattractant protein, macrophage- inflammatory protein, platelet factor, platelet basic protein, and melanoma growth stimulating activity; epidermal growth factor, transforming growth factor (alpha), fibroblast growth factor, platelet- derived endothelial cell growth factor, insulin- like growth factor, glial derived growth neurotrophic factor, ciliary neurotrophic factor, nerve growth factor, bone growth/cartilage- inducing factor (alpha and beta), bone morphogenetic proteins, interleukins (e.g., interleukin inhibitors or interleukin receptors, including interleukin 1 through interleukin 10), interferons (e.g., interferon alpha, beta and gamma), hematopoietic factors, including erythropoietin, granulocyte colony stimulating factor, macrophage colony stimulating factor and granulocyte- macrophage colony stimulating factor; tumor necrosis factors, and transforming growth factors (beta), including beta-1, beta-2, beta-3, inhibin, and activin.

[0211] Hormones include estrogens (e.g., estradiol, estrone, estriol, diethylstibestrol, quinestrol, chlorotrianisene, ethinyl estradiol, mestranol), anti-estrogens (e.g., clomiphene, tamoxifen), progestins (e.g., medroxyprogesterone, norethindrone, hydroxyprogesterone, norgestrel), antiprogestin (mifepristone), androgens (e.g, testosterone cypionate, fluoxymesterone, danazol, testolactone), antiandrogens (e.g., cyproterone acetate, flutamide), thyroid hormones (e.g., triiodothyronne, thyroxine, propylthiouracil, methimazole, and iodixode), and pituitary hormones (e.g., corticotropin, sumutotropin, oxytocin, and vasopressin). Hormones are commonly employed in hormone replacement therapy and / or for purposes of birth control. Steroid hormones, such as prednisone, are also used as immunosuppressants and anti-inflammatories. In some aspects, the additive is an agent that stimulates tissue formation, and/or healing and regrowth of natural tissues, and any combinations thereof. Agents that increase formation of new tissues and/or stimulates healing or regrowth of native tissue at the site of injection can include, but are not limited to, fibroblast growth factor (FGF), transforming growth factor-beta (TGF-beta, platelet-derived growth factor (PDGF), epidermal growth factors (EGFs), connective tissue activated peptides (CTAPs), osteogenic factors including bone morphogenic proteins, heparin, angiotensin II (A-II) and fragments thereof, insulin-like growth factors, tumor necrosis factors, interleukins, colony stimulating factors, erythropoietin, nerve growth factors, interferons, biologically active analogs, fragments, and derivatives of such growth factors, and any combinations thereof.

[0212] In some aspects, the silk composition can further comprise at least one additional material for soft tissue augmentation, e.g., dermal filler materials, including, but not limited to, poly (methyl methacrylate) microspheres, hydroxylapatite, poly(L-lactic acid), collagen, elastin, and glycosaminoglycans, hyaluronic acid, commercial dermal filler products such as BOTOX® (from Allergan), DYSPORT®, COSMODERM®, EVOLENCE®, RADIESSE®,RESTYLANE®, JUVEDERM® (from Allergan), SCULPTRA®, PERLANE®, and CAPTIQEIE®, and any combinations thereof.

[0213] In some aspects, the additive is a wound healing agent. As used herein, a “wound healing agent" is a compound or composition that actively promotes wound healing process.

[0214] Exemplary wound healing agents include, but are not limited to dexpanthenol; growth factors; enzymes, hormones; povidon-iodide; fatty acids; anti-inflammatory agents; antibiotics; antimicrobials; antiseptics; cytokines; thrombin; angalgesics; opioids; aminoxyls; furoxans; nitrosothiols; nitrates and anthocyanins; nucleosides, such as adenosine; and nucleotides, such as adenosine diphosphate (ADP) and adenosine triphosphate (ATP); neutotransmitter/neuromodulators, such as acetylcholine and 5- hydroxy tryptamine (serotonin/5- HT); histamine and catecholamines, such as adrenalin and noradrenalin; lipid molecules, such as 5 sphingosine-1 -phosphate and lysophosphatidic acid; amino acids, such as arginine and lysine; peptides such as the bradykinins, substance P and calcium gene- related peptide (CGRP); nitric oxide; and any combinations thereof.

[0215] In certain aspects, the active agents provided herein are immunogens. In one aspect, the immunogen is a vaccine. Most vaccines are sensitive to environmental conditions under which they are stored and/or transported. For example, freezing may increase reactogenicity (e.g., capability of causing an immunological reaction) and/or loss of potency for some vaccines (e.g., HepB, and DTaP/IPV/FQB), or cause hairline cracks in the container, leading to contamination. Further, some vaccines (e.g., BCG, Varicella, and MMR) are sensitive to heat. Many vaccines (e.g., BCG, MMR, Varicella, Meningococcal C Conjugate, and most DTaP-containing vaccines) are light sensitive. See, e.g., Galazka et al., Thermostability of vaccines, in Global Programme for Vaccines & Immunization (World Health Organization, Geneva, 1998); Peetermans et al., Stability of freeze-dried rubella virus vaccine (Cendehill strain) at various temperatures, 1 J. Biological Standardization 179 (1973). Thus, the compositions and methods provided herein also provide for stabilization of vaccines regardless of the cold chain and/or other environmental conditions. [0216] In some aspects, the additive is a cell, e.g., a biological cell. Cells useful for incorporation into the composition can come from any source, e.g., mammalian, insect, plant, etc. In some aspects, the cell can be a human, rat or mouse cell. In general, cells to be used with the compositions provided herein can be any types of cells. In general, the cells should be viable when encapsulated within compositions. In some aspects, cells that can be used with the composition include, but are not limited to, mammalian cells (e.g. human cells, primate cells, mammalian cells, rodent cells, etc.), avian cells, fish cells, insect cells, plant cells, fungal cells, spore cells, bacterial cells, and hybrid cells. In some aspects, exemplary cells that can be used with the compositions include platelets, activated platelets, stem cells, totipotent cells, pluripotent cells, and/or embryonic stem cells. In some aspects, exemplary cells that can be encapsulated within compositions include, but are not limited to, primary cells and/or cell lines from any tissue. For example, cardiomyocytes, myocytes, hepatocytes, keratinocytes, melanocytes, neurons, astrocytes, embryonic stem cells, adult stem cells, hematopoietic stem cells, hematopoietic cells (e.g. monocytes, neutrophils, macrophages, etc.), ameloblasts, fibroblasts, chondrocytes, osteoblasts, osteoclasts, neurons, sperm cells, egg cells, liver cells, epithelial cells from lung, epithelial cells from gut, epithelial cells from intestine, liver, epithelial cells from skin, etc., and/or hybrids thereof, can be included in the silk/platelet compositions disclosed herein. Those skilled in the art will recognize that the cells listed herein represent an exemplary, not comprehensive, list of cells. Cells can be obtained from donors (allogenic) or from recipients (autologous). Cells can be obtained, as a non-limiting example, by biopsy or other surgical means known to those skilled in the art.

[0217] In some aspects, the cell can be a genetically modified cell. A cell can be genetically modified to express and secrete a desired compound, e.g. a bioactive agent, a growth factor, differentiation factor, cytokines, and the like. Methods of genetically modifying cells for expressing and secreting compounds of interest are known in the art and easily adaptable by one of skill in the art.

[0218] Differentiated cells that have been reprogrammed into stem cells can also be used.

[0219] For example, human skin cells reprogrammed into embryonic stem cells by the transduction of Oct3/4, Sox2, c-Myc and Klf4 (Junying Yu, et. ah, Science , 2007, 318 , 1917-1920 and Takahashi K. et. ah, Cell , 2007, 131 , 1-12).

[0220] For the avoidance of doubt, the components listed in this section are combinable with all forms of composition described herein, including liquid composition, whipped silk cream, any form of silk meringue, silk leather, or a combination thereof.

Conductive Silk Leather

[0221] The present disclosure provides a conductive silk leather. Conductive silk leathers may be used to power embedded lights, for central processing for distributed sensors, and as a component of circuitry. In aspects, a unitary portion of silk leather may include portions that are conductive and portions that are not conductive.

[0222] Conductive silk leathers can be used with any other product or article of manufacture described herein. For example, the conductive silk leather can further include sorbent and/or gas sensing material, such as for example to provide a safety garment for a hazardous environment with embedded, powered lights and gas sensing capabilities. In another example, conductive silk leathers can be used with magnetic silk leathers, described elsewhere herein, to form a multi-functional item with magnetic and conductive properties. In some aspects, the conductive silk leather may also include materials, such as magnetic particles or chromium oxide, to render it both conductive and magnetic. Conductive silk leathers can be used with or include a thermal insulator to provide items with conductive and thermal insulation properties.

[0223] The conductive silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, at least one of a plurality of graphite flakes or a graphene powder is distributed within the compressed silk meringue or the hot-pressed silk meringue of the conductive silk leather. The graphite flakes or graphene powder may be added before or during the whipping process, or after whipping. In one example, graphite flakes or graphene powder are added when the whipped silk cream reaches a particular overrun value. The graphite flakes or graphene powder may be added before or during meringue formation or may be added before or during compression or hot-pressing the meringue.

[0224] In some aspects, the conductive silk leather includes a conductive ink. For example, the conductive ink is printed on a surface of the compressed silk meringue or the hot-pressed silk meringue. In another example, the conductive ink is printed between layers of the compressed silk meringue or the hot-pressed silk meringue or printed and subsequently embedded within the compressed silk meringue or the hot-pressed silk meringue. In yet another example, the conductive ink is printed between the compressed silk meringue or the hot-pressed silk meringue and a fabric layer. The conductivity is patterned into an electronic circuit. The resistivity of the conductive silk leather is at most IkQ, at most 0.7k , at most 0.5k , or at most O.lkQ.

[0225] For the avoidance of doubt, the conductive silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the conductive silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein. Magnetic Silk Leather

[0226] The present disclosure provides a magnetic silk leather. The magnetic silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, at least one of a plurality of magnetic particles or a plurality of chromium oxide particles is distributed within the compressed silk meringue or the hot-pressed silk meringue. The plurality of magnetic particles or plurality of chromium oxide particles may be added before or during the whipping process, or after whipping. In one example, plurality of magnetic particles or plurality of chromium oxide particles are added when the whipped silk cream reaches a particular overrun value. The plurality of magnetic particles or plurality of chromium oxide particles may be added before or during meringue formation or may be added before or during compression or hot-pressing the meringue. In an aspect, a magnetic field may be applied at any point during the processing of the liquid composition to a silk whipped cream and silk meringues. Magnetic silk leathers can block RFID signals or be a building block for products such as robots, games, home organizing/decor, or the like.

[0227] The magnetic silk leather can be tailored to have a specific polarity at a surface of the magnetic silk leather. In some cases, the polarity is North. In some cases, the polarity is South.

[0228] In some cases, the magnetic material may be manipulated prior to curing, such that a specific magnetic configuration is locked into the magnetic silk leather. Conceptually, applications involving ferrofluids such as generating different patterns could be applied to creation of magnetic silk foams/meringues/leathers. In general, a magnetic field could be applied at any step of the methods disclosed herein with the intention of manipulating magnetic particles located within one or more of the compositions disclosed herein.

[0229] In some cases, the magnetic silk leather can be used as an external surface for a robot (e.g., a “robot skin”).

[0230] For the avoidance of doubt, the magnetic silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the magnetic silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Scented Silk Leather

[0231] The present disclosure provides a scented silk leather. The scented silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, a plurality of aromatic compounds are distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the scented silk leather. [0232] The aromatic compounds may include emulsions, oils, alcohols, scented powder, or the like. The character of the aromatic compounds can impact the processing and the methods disclosed herein may afford different processing requirements. Both oil and alcohols can be freely incorporated into creams during the whipping, especially if the fragrance is concentrated (e.g., such as if the oil/alcohol is less than 5% of total volume). For adsorbing the fragrance on a dry material (e.g., meringue or leather), both oils and alcohols may be useful, but the permeability of the material would be controlled by the nature and content of the plasticizer. For example, foams with no glycerol (e.g., pure silk fibroin and xanthan gum) display a higher oil sorption capacity.

[0233] Applying an additional volume of the aromatic compound to a surface of the scented silk leather, such as by spraying, wiping, submerging, or other application method, may at least partly recharge the scented silk leather, thereby extending the lifetime of aroma release. In some cases, alcohol-based aroma compounds can be particularly effective at recharging scented silk leathers.

[0234] The aromatic compounds may be added before or during the whipping process, or after whipping. In one example, aromatic compounds are added when the whipped silk cream reaches a particular overrun value. The aromatic compounds may be added before or during meringue formation or may be added before or during compression or hot-pressing the meringue.

[0235] The silk foam can exhibit heterogeneous domains of scent such that scent intensity can be distributed based on foam particles. Through compression, gradients of scent may be generated. In one aspect, the scented silk leather exhibits pressure-sensitive aroma release.

[0236] The ability of a silk leather to become scented, maintain scent, release/dispense/disperse scent, and/or recharge scent may depend on factors such as the components of the liquid composition, the density, the water content, the presence of other agents/additives in the silk leather, or the like. Likewise, the release profile of scents may depend on similar factors.

[0237] For the avoidance of doubt, the scented silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the scented silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein. pH Responsive Silk Leather

[0238] The present disclosure provides a pH-responsive silk leather. The pH-responsive silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, a pH-responsive chemical is distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH-responsive silk leather. The pH-responsive chemical may be added before or during the whipping process, or after whipping. In one example, a pH-responsive chemical is added when the whipped silk cream reaches a particular overrun value. The pH-responsive chemical may be added before or during meringue formation or may be added before or during compression or hot- pressing the meringue. pH-responsive silk leather may be useful in worn garments such as to alert a wearer of certain ambient or precipitating pollutants.

[0239] For the avoidance of doubt, the pH-responsive silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the pH-responsive silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Humidity Sensing Silk Leather

[0240] The present disclosure provides a humidity sensing silk leather. The humidity sensing silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, a pH responsive chemical (e.g., o-cresolphtalein) and a pH altering agent (e.g., sodium carbonate) are distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the humidity sensing silk leather. In aspects, measurable amounts of humidity solubilize at least a portion of the pH altering agent, thereby lowering the pH, thereby providing a measurable report of humidity. At least one of the pH responsive chemical or the pH altering agent may be added before or during the whipping process, or after whipping. In one example, at least one of the pH responsive chemical or the pH altering agent are added when the whipped silk cream reaches a particular overrun value. At least one of the pH responsive chemical or the pH altering agent may be added before or during meringue formation or may be added before or during compression or hot-pressing the meringue. Humidity sensing silk leathers may be useful, for example, as a component of a humidor box.

[0241] For the avoidance of doubt, the humidity sensing silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the humidity sensing silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot- pressed silk meringues, or methods disclosed elsewhere herein.

Patterned Silk Leather

[0242] The present disclosure provides a patterned silk leather. The patterned silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. Patterned silk leathers may exhibit any pattern or texture, such as for example to mimic reptile skin in appearance and/or feeling. Certain patterns or textures may provide an aesthetic quality and/or a function/property to silk leather, such as improved grip, anti-bacterial, anti-fouling, water-repellent, waterproof, dustrepellent, or the like. The dimensions of the patterns may be nano-, micro-, or macro-scale.

[0243] Examples of suitable surface patterns include, but are not limited to: leather mimicking patterns, which mimics a variety of different leathers, including alligator leather, crocodile leather, snake leather, cow leather, stingray leather, ostrich leather; a water-resistant or water-proof pattern; tessellating patterns; optically-active patterns, such as diffraction patterns; plant patterns, geometric patterns, letters and numbers, or the like.

[0244] For the avoidance of doubt, the patterned silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the patterned silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Electronic Embedded Silk Leather

[0245] The present disclosure provides an electronic silk leather having an electronic component embedded therein. The electronic silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. In aspects, the electronic component or a second electronic component is embedded between the silk layer and the fabric layer in the electronic silk leather. In aspects, the electronic component or a third electronic component is embedded within the silk layer in the electronic silk leather. In aspects, the electronic silk leather further comprises a power supply coupled to the electronic component. For example, the power supply may be a rechargeable battery, a wired disposable battery holder, fiber-shaped solar cells (e.g., perovskite solar cells), or a combination thereof. In aspects, the electronic component comprises an RFID tag. In aspects, the electronic component comprises wiring. The present disclosure also provides a silk cream or silk meringue having electronics distributed throughout. In aspects, the silk cream or silk meringue may be a variable density filler material having electronic functionalization. In embodiments, electronic components may include light emitting devices such as LEDs or electroluminescent wires. Such components may be useful in fashion and design applications as well as for powering sensing applications.

[0246] For the avoidance of doubt, the electronic silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the electronic silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein. Semiconductor Device Embedded Silk Leather

[0247] The present disclosure provides a semiconductor device-embedded silk leather having a semiconductor device embedded therein. The semiconductor device-embedded silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. The semiconductor device or a second semiconductor device may be embedded at a surface of the compressed silk meringue or the hot-pressed silk meringue. The semiconductor device or a third semiconductor device may be embedded within the compressed silk meringue or the hot-pressed silk meringue. The semiconductor device or a fourth semiconductor device may be embedded between the first fabric layer and the compressed silk meringue or the hot-pressed silk meringue. In aspects, the semiconductor device-embedded silk further comprises a power supply, as described elsewhere herein, coupled to the semiconductor devices. In aspects, the semiconductor device may be in communication with one or more electronic components in the silk leather.

[0248] For the avoidance of doubt, the semiconductor device-embedded silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the semiconductor device-embedded silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Haptic Silk Leather

[0249] The present disclosure provides a haptic silk leather having a haptic switch embedded therein. The haptic silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. The haptic switch or a second haptic switch may be embedded at a surface of the silk leather. The haptic switch or a third haptic switch may be embedded within the compressed silk meringue or the hot-pressed silk meringue. The haptic switch or a fourth haptic switch may be embedded between the first fabric layer and the compressed silk meringue or the hot-pressed silk meringue. In aspects, the haptic silk further comprises a power supply, as described elsewhere herein, coupled to the haptic switch. In aspects, the haptic switch may be in communication with one or more electronic components or semiconductor devices in the silk leather.

[0250] For the avoidance of doubt, the haptic silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the haptic silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein. Tanned Silk Leather

[0251] The present disclosure provides a tanned silk leather. The tanned silk leather can comprise, consist essentially of, or consist of any of the silk meringues described herein. The tanned silk leather may have a bulk volume of a compressed silk meringue or hot-compressed silk meringue and a surface layer of the compressed silk meringue or hot-pressed silk meringue. The surface layer may be formed from the same chemical composition as the bulk volume but includes at least one differing structural, mechanical, or chemical feature relative to the bulk volume. In an aspect, the surface layer includes a dye.

[0252] In an aspect, the surface layer comprises a material, such as a precursor material, that may mimic tanning products (e.g., absorb aniline/dyes). In some examples, the precursor reacts to form the surface layer. In aspects, the surface layer may be modified/re-shaped relative to the bulk volume, such as by surface patterning, to provide a material difference to the surface layer. Silk leathers subjected to processes akin to tanning (e.g., chemical treatment with aniline) may result in a relatively stiff material which may, for example, be relatively more processable for fashion industries.

[0253] For the avoidance of doubt, the tanned silk leathers described herein can wholly include or include features of the silk leathers disclosed elsewhere here. Similarly, the tanned silk leathers described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Fiber Fortified Silk Cream/Meringue

[0254] The present disclosure provides a silk cream or silk meringue having fibers distributed throughout, such as fibers/textiles described herein. In aspects, woven fabrics may be penetrated with the liquid composition or any of the downstream products described herein.

[0255] For the avoidance of doubt, the fiber fortified silk cream/meringue can wholly include or include features of the whipped silk creams or silk meringues disclosed elsewhere herein. Similarly, the fortified creams/meringues described herein can be made from, comprise, wholly include, or include features from the liquid compositions, whipped silk creams, silk meringues, compressed silk meringues, hot-pressed silk meringues, or methods disclosed elsewhere herein.

Ultra-Lightweight Silk Down Alternative

[0256] The present disclosure provides an ultra-lightweight silk down alternative comprising, consisting essentially of, or consisting of any of the silk meringues described herein. The ultralightweight silk down alternative is made from a regenerated silk fibroin solution made from a recycled regenerated silk fibroin article or a waste silk fabric. The ultra-lightweight silk down alternative may further include a plurality of heat-reflective particles and/or have a thermochromic reporting capability. Impact Distributing Foam

[0257] The present disclosure provides an impact-distributing foam comprising a silk meringue. The impact-distributing foam has one or more impact and/or strain sensors positioned within the impactdistributing foam. The one or more impact and/or strain sensors are selected from the group consisting of a PDA sensor, an accelerometer, a piezoelectric sensor, a vibration sensor, a piezoresistive sensor, or a strain gauge sensor. The impact-distributing foam has one or more strain sensors positioned within the impact-distributing foam. The density of the foam may be between 0.1 g/cm³ and 0.2 g/cm³, or between 0.01 g/cm³ and 0.05 g/cm³, r between 0.05 g/cm³ and 0.25 g/cm³. For example, the density of the foam is at least 0.01 g/cm³, at least 0.05 g/cm³, at least 0.1 g/cm³, at least 0.2 g/cm³, or at least 0.25 g/cm³. The density of the foam may be tuned by one or more factors such as the components included in the liquid composition, the weight ratio of one or more components in the liquid composition, the weight % of one or more components in the liquid composition, the amount of whipping time, or the temperature during whipping.

[0258] The foams described herein serve two related but distinct functional purposes at the same time. On the one hand, the foam protects an underlying item from impact. On the other hand, the foam protects embedded sensors from the environment. In this way, a variety of different impact sensors may be usable, which otherwise would not be due to stability.

Protected Item

[0259] The present disclosure provides a protected item comprising: an item to be protected; and protective shell comprising a silk meringue, a cured silk meringue, a compressed silk meringue, or a hot-compressed silk meringue. The protective shell is formed by surrounding and contacting the item to be protected with a precursor to the protective shell and curing the precursor to form the protective shell, wherein surrounding comprises fully encapsulating or encapsulating against a surface. For example, the item to be protected may be at least one of an electronics component, an aerospace component, a semiconductor chip, a semiconductor device, or a three-dimensional printed structure.

[0260] The protective shell renders the item to be protected resistant to an impact of between 100 Newtons (N) and 25,000N, between 200N and 15,000N, between 500N and 10,000N, or between 1 ,000N and 5,000N. The level of impact resistance of the protective shell may be tuned by one or more factors such as the components included in the liquid composition, the weight ratio of one or more components in the liquid composition, the weight % of one or more components in the liquid composition, the amount of whipping time, or the temperature during whipping. The level of impact resistance of the protective shell may be tuned to provide a protective shell that is substantially resistant to impact, a protective shell that is moderately resistant to impact (e.g., the protective shell sustains damage while the item does not sustain damage, an outer portion of the protective shell sustains severe damage while an inner portion sustains less damage and the item sustains no damage), or a protective shell is minimally resistant to impact.

[0261] The item to be protected is resistant to a temperature of between 80°F and 500°F, between 100°F and 400°F, or between 150°F and 300°F. The item to be protected is resistant to a temperature of between 0°F and -500°F, between -50°F and -400°F, or between -150°F and -300°F.

[0262] For certain items, the nature of the material when it is applied may be relevant, such as a water content for applications involving electronics.

[0263] In cases where moisture sensitivity is an issue, the whipped silk cream or silk meringue that is applied to the item can have a water content below a threshold value. In cases where low moisture is an issue, the whipped silk cream or silk meringue that is applied to the item can have a water content above a threshold value.

[0264] In some cases, the protective shell, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue can have one or more impact sensors distributed throughout for reporting impacts that exceed a given threshold. In some cases, the impact sensors and/or strain sensors are poly diacetylene (PDA) based sensors.

Open Cell Silk Foam

[0265] The present disclosure provides an open-cell silk foam. The inventors discovered that controlling the whipping during the making of the silk cream can control the nature of the pores that are created in eventual silk foams/meringues. If the whipping falls within a given window of whipping (i.e., exceeds a first whipping threshold, but does not exceed a second whipping threshold), an opencell pore structure is formed in the whipped silk cream, resulting in an open-cell silk foam/meringue when baked. The open cell foams are generally lighter, more white and reflective, and more permeable to organic solvents. In some embodiments, open cell foams may be preferable for fragrance release or other applications that include loading of the baked foam. Open cell foams may be useful for sensor applications where sensors have to interact with the environment, such as gas, humidity or pH sensors.

Closed Cell Silk Foam

[0266] The present disclosure provides a closed-cell silk foam. The inventors discovered that controlling the whipping during the making of the silk cream can control the nature of the pores that are created in eventual silk foams/meringues. If the whipping falls outside a given window of whipping (i.e., does not exceed a first whipping threshold or does exceed a second, higher whipping threshold), a closed-cell pore structure is formed in the whipped silk cream, resulting in a closed-cell silk foam/meringue when baked. A closed cell morphology may be useful for applications in which an element is added to the foam during whipping and it is desired to preserve the element (e.g., living organisms or mechanical/thermal sensors).

[0267] It should be appreciated that there are a host of end uses for the materials described herein. Examples include, but are not limited to, bio-responsive seating, body monitors, leather bracelets as health indicators, enzymatic bracelets, scented bracelets, sensing sofas, fluorescent foams, microelectronic heat dissipators, fuel cell electrode matrices, food flavoring, water purifiers, pool purifiers, ocean oil capture, an ultralight insulator alternative (e.g., alternative to goose down), a leather-like impact monitor, gas sensing personal protective equipment (PPE), and the like.

Silk Leather Including Tannic Acid-Treated Fabric

[0268] One of the mechanical issues with silk leather is the adhesion of the foam layer to the fabric layer, which may delaminate after repeated stress. To address this problem, a chemical modification of the textile’s surface may be employed to improve the adhesion between these two materials. Referring to Fig. 24a, tannic acid (TA) is a natural polyphenol found in woods such as oak, walnut, mahogany, as well as in Indian almond leaves and alder cones. Tannic acid is generally recognized as safe by the Food and Drug Administration and is not considered environmentally hazardous. Tannic acid may be used to produce a tannic acid-treated fabric or fabric layer. It should be understood that any hydrophilic fabric or fabric with exposed hydroxyl groups, including the fabrics disclosed herein, may be treated to produce the tannic acid-treated fabric. For example, organza may be treated with tannic acid to produce a tannic acid-treated organza. It should be understood that while the examples throughout this disclosure reference fabrics or fabric layers, any textile may be useful in this disclosure. It should be understood that while the examples throughout this disclosure reference tannic acid, other phenolic/polyphenolic compounds are contemplated in this disclosure.

[0269] As used herein, a “tannic acid-treated” fabric refers to a fabric that exhibits one or more characteristic IR peaks, as described below in Example 14. Without wishing to be bound by any particular theory, it is believed that the characteristic IR peaks can be achieved by either covalent modification or surface adsorption, but the specific mechanism does not change the basis for identifying a fabric as tannic acid-treated.

[0270] An improved silk leather can include structural features similar to the silk leather described elsewhere herein. The improved silk leather includes a layered structure having a first tannic acid- treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer. The second material layer includes a compressed silk meringue and/or a hot-pressed silk meringue, as described elsewhere herein.

[0271] Each of the silk leathers described herein, including silk leather 100, silk leather 108, conductive silk leather, magnetic silk leather, scented silk leather, pH responsive silk leather, patterned silk leather, electronic embedded silk leather, semiconductor device embedded silk leather, haptic silk leather, tanned silk leather, or other silk leather described herein can have its fabric layer substituted with a tannic acid-treated fabric layer, thereby producing an improved version of the respective silk leather having enhanced adhesion between the layers of the improved silk leather.

[0272] In general, a fabric can be modified by immersing the fabric in an aqueous solution of tannic acid for a predetermined tannic acid treatment length of time at a predetermined tannic acid treatment temperature. Such a treatment can modify the surface of the fabric by covalently modifying the surface to include tannic acid substitutions and/or adsorbing tannic acid onto a surface of the fabric. The tannic acid treatment provides enhanced adhesion between layers of an improved silk leather.

[0273] The predetermined tannic acid treatment length of time can vary based on the desired outcome, but in general, it is between 1 hour and 48 hours, including 24 hours. The predetermined tannic acid treatment temperature can be between 0 °C and 60 °C, including room temperature of between 20 °C and 25 °C.

[0274] In an embodiment, silk leather is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue includes silk fibroin and a polysaccharide, such as xanthan gum. In some embodiments, the compressed silk meringue includes silk fibroin, xanthan gum, and a plasticizer. In some embodiments, the compressed silk meringue includes silk fibroin, xanthan gum, and a functionalizing agent. In some embodiments, the compressed silk meringue includes silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent.

[0275] In embodiments, an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer may be at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m. In another embodiment, an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer. The pressure at which the improved silk leather is prepared may have an impact on adhesion strength. In some embodiments, increasing the pressure of the contact between the silk meringue and the tannic acid-treated fabric may result in an increased adhesion strength relative to an improved silk leather prepared at a lower pressure of contact between the silk meringue and the tannic acid-treated fabric. In some embodiments, increasing the pressure of the contact between the silk meringue and the tannic acid-treated fabric may result in an increased adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer that is at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid- treated fabric layer and the comparison second material layer is otherwise identical to the second material layer

[0276] In an embodiment, the silk leather may further include a third material layer disposed adjacent to the first tannic acid-treated fabric layer on a surface opposing the surface to which the second material layer is adjacent, the third material layer including the compressed silk meringue or a hot- pressed silk meringue including silk fibroin and a polysaccharide, such as xanthan gum. In some embodiments, the compressed silk meringue of the third layer includes silk fibroin, xanthan gum, and a plasticizer. In some embodiments, the compressed silk meringue of the third layer includes silk fibroin, xanthan gum, and a functionalizing agent. In some embodiments, the compressed silk meringue of the third layer includes silk fibroin, xanthan gum, a plasticizer, and a functionalizing agent.

[0277] In an embodiment, a method of forming a silk leather may include whipping a liquid composition comprising silk fibroin and a polysaccharide (e.g., xanthan gum), as described elsewhere herein, for a predetermined whipping time to form a whipped silk cream, as described herein. The whipped silk cream may be baked as described herein, such as at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue. The silk meringue may be compressed onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue. Compressing may be performed at an elevated temperature of between 80 °C and 200 °C and the compressed silk meringue is a hot-pressed silk meringue.

[0278] The aspects of the present disclosure described with respect to pressing and heat-pressing of silk meringues are applicable to the methods of making a silk leather, particularly the improved silk leather, as described herein. Where the disclosure describes pressing, it also expressly contemplates pressing atop a tannic-acid-treated fabric. Where the disclosure described hot-pressing, it also expressly contemplates hot-pressing atop a tannic-acid-treated fabric. [0279] In some cases, the pressing can include pressing the second material layer and the third material layer at different times. In some cases, the pressing can include pressing the second material layer and the third material layer at the same time.

[0280] In some cases, the hot-pressing can include hot-pressing the second material layer and the third material layer at different times. In some cases, the hot-pressing can include hot-pressing the second material layer and the third material layer at the same time.

[0281] Unless otherwise specified or indicated by context, the terms “a”, “an”, and “the” mean “one or more.” For example, “a molecule” should be interpreted to mean “one or more molecules.”

[0282] As used herein, “about”, “approximately,” “substantially,” and “significantly” will be understood by persons of ordinary skill in the art and will vary to some extent on the context in which they are used. If there are uses of the term which are not clear to persons of ordinary skill in the art given the context in which it is used, “about” and “approximately” will mean plus or minus <10% of the particular term and “substantially” and “significantly” will mean plus or minus >10% of the particular term.

[0283] As used herein, the terms “include” and “including” have the same meaning as the terms “comprise” and “comprising.” The terms “comprise” and “comprising” should be interpreted as being “open” transitional terms that permit the inclusion of additional components further to those components recited in the claims. The terms “consist” and “consisting of’ should be interpreted as being “closed” transitional terms that do not permit the inclusion of additional components other than the components recited in the claims. The term “consisting essentially of” should be interpreted to be partially closed and allowing the inclusion only of additional components that do not fundamentally alter the nature of the claimed subject matter.

[0284] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0285] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0286] Preferred aspects of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred aspects may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect a person having ordinary skill in the art to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0287] While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. For example, any of the features or functions of any of the embodiments disclosed herein may be incorporated into any of the other embodiments disclosed herein.

[0288] The following examples illustrate some embodiments and aspects of the invention. It will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be performed without altering the spirit or scope of the invention, and such modifications and variations are encompassed within the scope of the invention as defined in the claims which follow. The following examples do not in any way limit the invention.

[0289] EXAMPLES

[0290] Example 1. 4 mL of silk solution (boiled 30- 180 minutes) at a concentration of 3-7% was mixed with 100 mg of xanthan gum and whipped with a whisk for about ten minutes to obtain a silk cream that can be cooked at 60 °C overnight to obtain a foam. The foam has an irregular porosity, is brittle, has excellent buoyancy, low hydrophilicity and high affinity for organic solvents. The foams can be useful for several applications such as thermal insulators, substrates for gas sensing and biological scaffolds. As proof of the concept, a sponge was used to remove an organic phase (hexane) colored with a dye (oil red O) from a stirred aqueous phase. The sponge was tested as a substrate for gas sensing. In 1 mL chloroform, 2 mg of the pH sensor of bromothymol blue and triethanolamine were dissolved in different ratios to make a sensor for CO2. The sponges were dried and placed in a desiccator filled with gaseous CO2. After a short time (e.g., minutes), a color change was appreciated on the sponges whose speed depends on the quantity of triethanolamine (TEA). The reversible CO2 sensing reaction is depicted in Fig. 1C. Furthermore, the sensor is also reversible since, exposed to air, it partially returns to its original color. Different porosity in the SF:XG foam could modulate the sensitivity/responsiveness. Further, the amount of TEA may affect both the speed of color change and its partial recovery. [0291] Example 2. Artificial Leathers: By adding glycerol to the composition and following the same process (e.g., a process as detailed in Example 1), the foam obtained after cooking results in a soft material. By hot pressing the foam (0.5-3 Mpa at 150 ⁰ C for 30 minutes), a material whose properties are reminiscent of mycelium is obtained, therefore, this material is referred to as "mysilkium". Under these conditions, the foam also exhibits self-healing capabilities since sheets can be made from isolated foam fragments. The foam was subjected to mechanical tests comparing its properties to those of the mycelium. In some examples, polyphenols were added to the composition, but these do not cause significant changes in mechanical properties using these conditions. Young's modulus and tensile strength of the mycelium are at least an order of magnitude higher than those of the Mysilkium, while the elongation is roughly the same (Fig. 2).

[0292] To increase the mechanical properties of the mysilkium, a composite material was made by making "layered cakes" by adding a fabric between two layers of cream before cooking it. The composite foam was then pressed and heated as described previously. With this strategy, materials have been created that aesthetically and to the touch recall the mycelium or artificial skin, but whose mechanical properties are similar to the added fabric/tissue (Fig. 3).

[0293] Example 3. Additional Characterization

[0294] Cream and meringue densities: In 35mL of bidistilled water, 3 mL of glycerol (gly), 1 gram of xanthan gum (XG) and 250mg, 1.25g, 2.5g and 3.75 of silk fibroin (SF) powder (220 minute boiled) were added. Controls were also prepared with only XG (1g) and gly (3mL), and only SF (1g) and gly (3mL). All the samples were whipped for 12 minutes to obtain the “cream”. The cream was used to fill 7.5mL petri dishes and, after weighting the density of the cream was measured (Fig. 4).

[0295] Control with XG alone does not whip to cream but forms a sticky slime. Whip only SF and Gly forms a not very consistent cream with a density between 0.1-0.15 g/cm³. The addition of XG increases the density of the creams obtained to around 0.3g/cm³. Variations in the density of the creams could be more influenced by the amount of water used for whipping or by the whipping time.

[0296] The creams were subsequently baked at 60° C overnight and the weight was measured again. This allowed to estimate the water content of the different creams assuming that the glycerol (boiling point 290°C) is not lost during the baking process while all the water in the cream is removed.

[0297] The silk cream has the highest water content (73%) while the addition of XG reduces the water content (46-58%) (Fig. 5). This is likely due to a higher porosity obtained with XG. By increasing the amount of silk compared to XG, the water content of the cream slightly increases.

[0298] In general, after cooking overnight the cream to meringue, density is reduced by a factor of 10. The density of meringues made of SF is very low (below 0.02g/cm³). With the combinations of SF and XG the density of the meringues increases around 0.05g /cm³ for meringues with solid silk contents lower than 34% and reaches 0.06g/cm³ for meringue with solid SF contents of 44% (see Fig. 7). Fig. 7 shows the solid compositions of the meringues obtained by varying the mass of SF and assuming a total removal of water from the cooking process. From all compositions except the XG control, a cream has been obtained that can be cooked in meringue, and then processed using a hot press (150°C for 30minutes) at “mysilkium”.

[0299] As the SF content increases, the meringues become gradually stiffer and the same goes for the mysilkium obtained. The tactile perception of the material is comparable to an artificial leather. From a qualitative point of view, the mysilkium obtained with the composition SF21 : Gly63: XG17 had the best tactile properties in terms of softness, flexibility, elasticity and homogeneity. Samples with SF 34% and higher content tend to deform over time after being pressed to mysilkium, while with SF <34% content, they remain flat indefinitely.

[0300] Example 4: Alternatives to silk or xanthan gum

[0301] The ingredients used to prepare the foams were changed while maintaining a solid ratio of protein20:glycerol60:gum20. Silk Alternatives: Compositions were mixed, baked, and pressed following the same aforementioned process. A “mysilkium” with gelatin, soy protein, casein as protein alternatives and pluronics and PEG (65kDa) as synthetic alternative was obtained. Gelatin failed to form a cream. Soy protein formed a very liquid film that displayed high water content and stickiness after the hot-pressing process. Casein was the only protein alternative able to form a material similar to mysilkium although the homogeneity, softness and aesthetics were much lower compared to silk. PEG failed to form a cream. With pluronics (65KDa), a “mysilkium” was formed, but still with homogeneity, softness and aesthetics greatly inferior to those obtained with silk. Pluronic was chosen as an alternative because, like SF, is a polymer organized in an alternation of hydrophobic and hydrophilic domains.

[0302] Gum alternatives: Xanthan gum was substituted with pine rosin gum, Arabic gum and tragacanth gum. None of these where suitable to obtain a cream or meringue with similar properties to mysilkium. Guar gum may be used as an alternative to xanthan gum, though it showed inferior performance for the specific applications that were pursued in this disclosure (e.g., to obtain a silk cream that is compressible into other interesting material formats, like silk leather) when compared to xanthan gum.

[0303] Example 5. Properties related to composition: The density, water content and syneresis of the whipped creams using different compositions with tunability on some parameters has been characterized. Fig. 8 provides data regarding various compositions and the varying weight ratio of SF, Gly, and XG in each composition. Fig. 9a depicts the cream density for the compositions identified in Fig. 8 in g/cm³. Fig. 9b depicts the cream water content for the compositions identified in Fig. 8. Fig. 10a depicts the syneresis (%) for the compositions identified in Fig. 8 and Fig. 10b depicts the correlation of density, water content, and syneresis with the solid content. It is possible to tune the density (important for thermal and mechanical properties, water content (very narrow range, but important for cell cultures) and syneresis which affect cream stability overtime.

[0304] Different combinations of SF, XG, and Gly yield varying densities, water contents, and syneresis, indicating that the components have distinct effects on the overall properties of the mixture. [0305] The Pearson correlation coefficient for each component and each variable was calculated, revealing that the content of XG (r=0.82) is the component most closely related to the increase in density that can range between 0.09-0.28 g/cm³. The water content exhibits low variability (88.5% < x < 91%) with changes in composition, and SF (r=0.40) is correlated with the water content.

[0306] Syneresis refers to the spontaneous expulsion of water from a colloidal system, resulting in the contraction or shrinkage of the material. As shown in Fig. 10a, the water loss for every composition is minimal, being less than 3% for each combination. This low syneresis ensures stability and consistency, making this material particularly interesting for the food or pharmaceutical industries.

[0307] Lastly, Gly is the component most strongly correlated with syneresis. While high syneresis negatively impacts foam stability, creams with low glycerol content might initially appear more desirable. However, it's important to note that glycerol content is important for the mechanical performance of the dried foams, as disclosed herein.

[0308] Example 6: Cream firmness (20:60:20): The mechanical properties of the cream (compression) were measured as a function of whipping time. Figs. 1 la and 1 lb depicts an increase of firmness as the air content increases.

[0309] Example 7: Overrun and Baked Cream characterization: The composition 20:20:60 (SF:XG:Gly) exhibited the lowest density, so a detailed analysis of the whipping time was conducted. The properties were investigated by whipping at 200 rpm using a 6- wire whip over a duration ranging from 0 to 25 minutes. In Fig. 1 1A, the density variation of the cream is illustrated as a function of whipping time. The density fluctuation is a result of the varying amount of air incorporated into the foam during the whipping phase.

[0310] Additionally, the mechanical properties of the cream and their variation with whipping time through resistance toward compression (firmness) (Fig. 13) was measured. The findings indicate an increase in firmness as the density decreases or as the air content increases. The firmness of a cream, often indicative of its texture or consistency, holds significance not only in food applications but also in various industries. This quality is particularly relevant in sectors such as cosmetics and personal care products, pharmaceuticals, textile and fabric treatments, as well as art and craft supplies. With firmness controlled through whipping time, the silk cream exhibits a range of values spanning between 94 and 211 Pa, making it an appealing substrate for applications in cosmetics, pharmaceuticals, food, textiles, and fabrics. Given the mechanical properties of this silk foam, incorporating the silk cream into 3D printer materials was evaluated. The application of customized 3D food printing, for example, has gained attention in the culinary world for crafting intricate food designs and decorations. To indirectly gauge the air content of the cream, the overrun was evaluated, representing the increase in volume when air is incorporated during whipping. For the 20:20:60 composition, the volume increases up to 133% in 5 minutes (resulting in lower density) and then starts decreasing after 10 minutes due to excessive whipping. Similar to common whipped cream, over- whipping can lead to the separation of fat from the liquid, resulting in butter and buttermilk instead of whipped cream. This implies a parallel role played by silk in this process.

[0311] An additional method for controlling the cream's density/overrun involves using plasticizers other than glycerol. Overrun was measured using plasticizers with varying numbers or distances of - OH groups. The results show that the number of -OH groups affect the whipping time, while their distance influences the air capacity of the foam (Figure 12). This phenomenon occurs because a hydrogen bonding network is formed between the protein and sugars during the whipping process, and plasticizers aid in bridging these interactions. As a result, a higher number of -OH functionalities (such as glycerol and 1-3-6 hexanetriol) lead to faster interactions, reaching the overrun plateau in just a few minutes. On the other hand, diols (1,2 and 1,5 -pentanediol) exhibit slower cream growth (15-20 minutes) with a significantly higher overrun when the -OH groups are at a greater distance (150% vs. 500%).

[0312] Example 8: Foams FTTR characterization: Unwhipped foams display a considerable amount of random coils, but after few minutes of whipping (e.g., 2.5 min), silk turns to P-sheet structure with no further variation for longer whipping times, as seen in Fig. 14. This is attributable to silk’s shear thinning behavior.

[0313] Example 9: Foams optical characterization: The average bubble size decreases in the initial phase (5-10 min) corresponding to the highest overrun value, and then increases again and remains relatively stable during prolonged whipping (20-25 min), as depicted in Fig. 15.

[0314] Example 10: Foam physical characterization: Composition related analyses: Tests were conducted on the physical and mechanical properties of the foams (baked creams, Figure 16A) obtained with different composition ratios. The density decreased by a factor of 10 compared to its wet state (Figure 16B). Regarding the mechanical properties, the foam's compressive strength and yield point (Figure 16C, D) were assessed and found to be primarily influenced by the glycerol content.

[0315] In general, foams obtained with SF, XG, and glycerol are very soft and deformable, especially the 20:20:60 composition, making it ideal for a compressed material (the silk-leather). However, it may be less suitable for using the foam in its expanded state, as silk and xanthan gum foam tend to self-collapse within a few days.

[0316] To enhance the mechanical properties of the dried foam for potential applications in their expanded state, alternative sugars may be considered. For instance, using alginate instead of xanthan gum significantly increases the mechanical performance of both dried foams (Figure 17A) and creams (Figure 17B). There may be additional applications of alginate-based foams in their expanded state, such as thermal insulation. In Figure 17C, a setup for measuring the thermal conductivity of foam materials is presented. Briefly, two thermocouples are placed — one in contact with a hot plate with a surface temperature of 60°C and the other at a 2cm height with either the 20:20:60 silk-alginate foam or polystyrene in between — and the temperature is recorded in a time-resolved experiment. As shown in Figure 17D, the silk-alginate foam displays a very similar trend to polystyrene, which is known to have a thermal conductivity between 0.034 and 0.038 W/mK. Additives such as borate ions may further increase mechanical properties while providing flame retardant and anti-fungal properties.

[0317] Example 11: Whipping time related analysis: The creams with various compositions, including the 20:20:60 composition obtained at different whipping times, were subsequently baked at 60°C overnight and further characterized in their dried state. As depicted in Figure 18 A, the dried foams exhibit varying whiteness depending on the whipping time. This difference is likely attributed to the distribution of bubble sizes or the open/closed cell morphology, which may vary based on the whipping time (see Figure 19). The density, once again, is one-tenth of the density in the wet state and can be adjusted by the whipping time, ranging from 0.009 to 0.048 g/cm³ (Figure 18B). This value is notably low compared to other protein -based foams.

[0318] In Figure 19A, schematics and pictures illustrating the surface detail are presented, showing the proposed change in the internal architecture of the foam at different whipping times. As previously mentioned, the whiteness and the reflective and scattering properties of the foams change with whipping time. This aspect may be significant for leather applications as it may influence the tactile sensation of the compressed material.

[0319] In Figure 19B, the foam's internal structure was analyzed using fluorescent staining. It can be observed that the bubble size is poly disperse, but the average diameter ranges between millimeters and micrometers depending on the whipping duration, with variations in the internal structure corresponding to the overrun trend (the overrun value remains stable between 5 and 10 minutes, and so does the foam's internal structure). The smallest bubbles (around 100 pm) are obtained with a 7.5- minute whipping, and the cell structure transitions from a closed cell structure at 2.5 minutes to an open cell structure after 5 minutes of whipping. [0320] Example 12: Foams fluorescent staining (ThT): To better understand the internal foam structure, a fluorescent dye (ThT) was added (lOOmM) during the whipping phase and the dried foams were analyzed in reflection with BF and FITC filter (Fig. 20). ThT was chosen because is a staining agent for P-amyloids and shows different spectral features if it is free in solution or bound to a P-sheet structure when excited at 365 nm (Fig. 21A and 21B).

[0321] The emission of foams excited at 365 nm display a color shift during the initial whipping phases (Fig. 22). This is probably due to a different binding of the dye to the increasing P-sheet content in silk (due to its shear thinning behavior) and this is in accordance with the FTIR of baked foams.

[0322] Example 13: Algal growth: Foam materials in their wet state (cream) may be used as a substrate for algal growth as shown in figure 23. Two algal strains from fresh water (chlorella) (figure 23 A) and marine (coccolithophores) (figure 23B) environments were used to inoculate the cream. The creams were stored in a greenhouse at 90% of relative humidity and sunlight illumination for 9 days visibly observing cellular growth for both cases. Global photosynthesis consumes ten times more CO2 than net anthropogenic emissions, and microalgae account for nearly half of this consumption. The high efficiency of algal photosynthesis relies on a mechanism concentrating CO2, which enhances its fixation at a rate of 10-50 times higher than terrestrial plants. This high rate allows algae to convert up to 2.7 tons of CO2 per acre per day, making them a good candidate for use in agriculture as a carbonnegative process that can also produce products. However, despite the potential benefits, the annual production of commercialized microalgal biomass (13,600 t) is low compared to worldwide CO2 emissions(~40 Gt year^-1). Therefore, new technologies need to be developed to increase productivity and make it economically viable. It has been reported that carbon dioxide fixation by microalgae might become economically viable when production costs fall below $500 t^-1 ha^-1 year^-1. A key factor in achieving this is improving the photosynthetic conversion efficiency, which is currently between 1.5% and 6%. Increasing this efficiency would allow for higher productivity and lower costs.

[0323] Microalgae have a wide range of diversity, and developing a substance to enhance their growth could help with the development of new technologies for different purposes such as direct carbon capture, hydrogen production, biofuels, food for humans or livestock, and biodegradation/bioremediation, each requiring a specific algal strain. For instance, coccolithophores are an interesting option for carbon capture applications. Coccolithophores are single-celled algae that have calcareous plates called coccoliths. These plates are formed through a biomineralization process where CO2 is trapped as calcium carbonate, providing a permanent sink for carbon emissions. This makes them important in the marine carbon cycle and helps to mitigate the effects of greenhouse gas emissions. Other algae species fix CO2 into organic polymers that are converted back into CO2 in a short period, but coccolithophores provide a long-term solution for carbon storage. In order to improve the algal economy and overcome current technological limitations, a foam substrate for algal culturing may be used. This substrate has several advantages that can enhance algal growth (Fig 23C). The structural material of the foam can be consumed by the algae, providing them with nutrients and other biomolecules. The porous structure of the foam can also help to distribute light and gas more uniformly, which are currently limiting factors in algal culturing techniques. Additionally, the photosynthesis process can be enhanced by adding artificial antennas (fluorophores) to the foam structure, which fill the chlorophyll's orange gap and increase the available solar spectrum. This approach could also allow for out-of-water cultivation, as it only requires a humid environment or a greenhouse, potentially expanding the possibilities for a broader bio-based economy.

[0324] Example 14: A silk fabric (organza) was modified by immersing it in a 20% (w/v) aqueous solution of tannic acid for 24 hours at room temperature (Fig. 24b). Fig. 24d depicts a control organza on the left side and a tannic acid-treated organza on the right side. After treatment, the fabric acquired an orange-brownish coloration (Fig. 24d). Without wishing to be bound by any particular theory, it is believed that the change in coloration is due to a covalent or electrostatic interaction between the tannic acid and the hydroxyl groups in the silk fibers. In an embodiment, tannic acid treatment of fabric may result in a fabric that is covalently-modified to have tannic acid substituents. In another embodiment, tannic acid treatment may result in the adsorption of tannic acid onto the fabric surface.

[0325] To confirm the functionalization, the fabric was thoroughly washed with water and subjected to IR spectroscopy (Fig. 24c). In Fig. 24c, FTIR spectra of control organza (top line), post-treatment (middle line), and tannic acid (lower line) are depicted. The IR spectroscopy further confirmed the presence of characteristic tannic acid peaks in the tannic acid-treated fabric. Specifically, peaks were observed at 1313 cm ¹ and 1022 cm ¹, which are characteristic signals of esters, and 1192 cm ¹, corresponding to C-0 bonds, found in alcohol or ester groups. Additionally, there was a peak at 1443 cm'¹ associated with C-H bonds (asymmetric stretching). In embodiments, tannic acid-treated fabrics may be characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm ¹, 1192 cm ¹, and 1443 cm ¹. [0326] After functionalization, samples of silk leather were prepared following a procedure described elsewhere and herein. In brief, silk fibroin, xanthan gum, and glycerol in a mass ratio of 2:2:6 were mixed using a stand mixer for 5 minutes and hot-pressed onto both regular and modified (e.g., tannic acid-treated) organza to form an improved silk leather.

[0327] Subsequently, and referring to Fig. 25a, the adhesion of the silk leather layer to the textile substrate was measured through a T-Peel test on 100 x 30 mm strips (5 samples). Fig. 25a depicts a peel strength vs. displacement plot of the artificial leather samples made with control and modified fabric. The test resulted in an initial adhesive failure on both samples (failure between textile and foam) in the first 20-40 mm, followed by cohesive failure (internal foam failure). Regarding the first 40 mm of displacement, and referring to Fig. 25b, the adhesion values were 11.6 ± 2.5 N/m and 20.1 ± 4.3 N/m for control organza and TA-modified organza, respectively. Fig. 25b depicts a histogram illustrating the differences in performance in the first 40mm of displacement (adhesive failure).

[0328] In addition to the features described above and elsewhere herein, the present disclosure also includes the following clauses:

1. A silk leather that is a layered structure comprising a first fabric layer and a second material layer disposed adjacent to the first fabric layer, the first fabric layer comprising exposed hydroxyl groups, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin and a polysaccharide, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

2. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the first fabric layer comprising exposed hydroxyl groups, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin and a polysaccharide, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

3. The silk leather of either of the immediately preceding clauses, further comprising a third material layer disposed adjacent to the first tannic acid-treated fabric layer on a surface opposing the surface to which the second material layer is adjacent, the third material layer comprising the compressed silk meringue or a hot-pressed silk meringue comprising silk fibroin and the polysaccharide.

4. The silk leather of any one of the preceding clauses, wherein the first tannic acid-treated fabric layer is composed of cotton fabric; silk fabric; synthetic fabric; linen; organza; a hydrophilic fabric; or a combination thereof.

5. The silk leather of the immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of organza. 6. The silk leather of any one of the preceding clauses, wherein the first tannic acid-treated fabric layer is characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm ¹, 1192 cm ¹, and 1443 cm^-1.

7. The silk leather of any one of the preceding clauses, wherein the first tannic acid-treated fabric layer is covalently modified to have tannic acid substituents.

8. The silk leather of any one of clauses 1-6, wherein the tannic acid is adsorbed onto a surface of the first tannic acid-treated fabric layer.

9. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin and a polysaccharide for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; and compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

10. The method of the immediately preceding clause, wherein the compressing is performed at an elevated temperature of between 80 °C and 200 °C and the compressed silk meringue is a hot- pressed silk meringue.

11. The method of any one of clauses 9 to the immediately preceding clause, wherein the silk fibroin is present in the liquid composition in an amount by weight of between 1% and 10% or between 3% and 7%, including but not limited to, at least 1 %, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

12. The method of any one of clauses 9 to the immediately preceding clause, wherein the polysaccharide is present in the liquid composition in an amount by weight of between 0.1% and 10.0%, including but not limited to, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

13. The method of any one of clauses 9 to the immediately preceding clause, wherein the silk fibroin and polysaccharide are present in a weight ratio of between 1 :4 and 20: 1 or between 1 :2 and 10:1, including but not limited to, at least 1:4, at least 1 :3, or at least 1:2, and at most 20:1, at most 19:1, at most 18:1, at most 16:1, at most 15:1, at most 14:1, at most 12:1, at most 11 :1, or at most 10:1. 14. The method of any one of clauses 9 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise a plasticizer.

15. The method of the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 0.5% and 20.0%.

16. The method of clause 14, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 20.0% and 75.0%.

17. The method of any one of clauses 9 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise at least one of a sensing agent, a therapeutically active agent, a colorant, an aroma-providing compound.

18. The method of any one of clauses 9 to the immediately preceding clause, wherein the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot-pressed silk meringue has irregular porosity.

19. The method of any one of clauses 9 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

20. The method of any one of clauses 9 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the tannic acid-treated fabric layer but is otherwise identical to the tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the compressed silk meringue or the hot-pressed silk meringue.

21. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

22. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

23. The silk leather of either of the immediately preceding clauses, further comprising a third material layer disposed adjacent to the first tannic acid-treated fabric layer on a surface opposing the surface to which the second material layer is adjacent, the third material layer comprising the compressed silk meringue or a hot-pressed silk meringue comprising silk fibroin, a polysaccharide, and a plasticizer.

24. The silk leather of any one of the three immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of cotton fabric; silk fabric; synthetic fabric; linen; organza; a hydrophilic fabric; or a combination thereof.

25. The silk leather of the immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of organza.

26. The silk leather of any one of clauses 21 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm ¹, 1192 cm , and 1443 cm'¹.

27. The silk leather of any one of clauses 21 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is covalently modified to have tannic acid substituents.

28. The silk leather of any one of clauses 21 to clause immediately preceding the immediately preceding clause, wherein the tannic acid is adsorbed onto a surface of the first tannic acid-treated fabric layer.

29. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, and a plasticizer for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

30. The method of the immediately preceding clause, wherein the compressing is performed at an elevated temperature of between 80 °C and 200 °C and the compressed silk meringue is a hot- pressed silk meringue.

31. The method of any one of clauses 29 to the immediately preceding clause, wherein the silk fibroin is present in the liquid composition in an amount by weight of between 1 % and 10% or between 3% and 7%, including but not limited to, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

32. The method of any one of clauses 29 to the immediately preceding clause, wherein the polysaccharide is present in the liquid composition in an amount by weight of between 0.1% and 10.0%, including but not limited to, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

33. The method of any one of clauses 29 to the immediately preceding clause, wherein the silk fibroin and polysaccharide are present in a weight ratio of between 1 :4 and 20: 1 or between 1 :2 and 10:1, including but not limited to, at least 1:4, at least 1 :3, or at least 1:2, and at most 20:1, at most 19:1, at most 18:1, at most 16:1, at most 15:1, at most 14: 1, at most 12:1, at most 11 :1, or at most 10: 1.

34. The method of the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 0.5% and 20.0%.

35. The method of the clause immediately preceding the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 20.0% and 75.0%.

36. The method of any one of clauses 29 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise at least one of a sensing agent, a therapeutically active agent, a colorant, an aroma-providing compound.

37. The method of any one of clauses 29 to the immediately preceding clause, wherein the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot-pressed silk meringue has irregular porosity.

38. The method of any one of clauses 29 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

39. The method of any one of clauses 29 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the compressed silk meringue or the hot-pressed silk meringue.

40. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

41. A silk leather that is a layered structure comprising a first tannic acid- treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

42. The silk leather of either of the immediately preceding clauses, further comprising a third material layer disposed adjacent to the first tannic acid-treated fabric layer on a surface opposing the surface to which the second material layer is adjacent, the third material layer comprising the compressed silk meringue or a hot-pressed silk meringue comprising silk fibroin, a polysaccharide, and a functionalizing agent.

43. The silk leather of any one of the three immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of cotton fabric; silk fabric; synthetic fabric; linen; organza; a hydrophilic fabric; or a combination thereof.

44. The silk leather of the immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of organza.

45. The silk leather of any one of clauses 46 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm ¹, 1192 cm , and 1443 cm⁴.

46. The silk leather of any one of clauses 46 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is covalently modified to have tannic acid substituents.

47. The silk leather of any one of clauses 46 to the clause immediately preceding the immediately preceding clause, wherein the tannic acid is adsorbed onto a surface of the first tannic acid-treated fabric layer.

48. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

49. The method of the immediately preceding clause, wherein the compressing is performed at an elevated temperature of between 80 °C and 200 °C and the compressed silk meringue is a hot- pressed silk meringue.

50. The method of any one of clauses 48 to the immediately preceding clause, wherein the silk fibroin is present in the liquid composition in an amount by weight of between 1 % and 10% or between 3% and 7%, including but not limited to, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

51. The method of any one of clauses 48 to the immediately preceding clause, wherein the polysaccharide is present in the liquid composition in an amount by weight of between 0.1% and 10.0%, including but not limited to, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

52. The method of any one of clauses 48 to the immediately preceding clause, wherein the silk fibroin and polysaccharide are present in a weight ratio of between 1 :4 and 20: 1 or between 1 :2 and 10:1, including but not limited to, at least 1:4, at least 1 :3, or at least 1:2, and at most 20:1, at most 19: 1, at most 18: 1, at most 16: 1, at most 15: 1, at most 14: 1, at most 12:1, at most 11 :1, or at most 10:1.

53. The method of any one of clauses 48 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise a plasticizer.

54. The method of the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 0.5% and 20.0%.

55. The method of the clause immediately preceding the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 20.0% and 75.0%.

56. The method of any one of clauses 48 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise at least one of a sensing agent, a therapeutically active agent, a colorant, an aroma-providing compound.

57. The method of any one of clauses 48 to the immediately preceding clause, wherein the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot-pressed silk meringue has irregular porosity.

58. The method of any one of clauses 48 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m. 59. The method of any one of clauses 48 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the compressed silk meringue or the hot-pressed silk meringue.

60. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

61. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid- treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

62. The silk leather of either of the immediately preceding clauses, further comprising a third material layer disposed adjacent to the first tannic acid-treated fabric layer on a surface opposing the surface to which the second material layer is adjacent, the third material layer comprising the compressed silk meringue or a hot-pressed silk meringue comprising silk fibroin, polysaccharide, a plasticizer, and a functionalizing agent. 63. The silk leather of either of the immediately preceding clauses, wherein the first tannic acid- treated fabric layer is composed of cotton fabric; silk fabric; synthetic fabric; linen; organza, a hydrophilic fabric; or a combination thereof.

64. The silk leather of any one of the three immediately preceding clauses, wherein the first tannic acid-treated fabric layer is composed of organza.

65. The silk leather of any one of clauses 60 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm ¹, 1 192 cm^-1, and 1443 cm’¹.

66. The silk leather of any one of clauses 60 to the immediately preceding clause, wherein the first tannic acid-treated fabric layer is covalently modified to have tannic acid substituents.

67. The silk leather of any one of clauses 60 to the clause immediately preceding the immediately preceding clause, wherein the tannic acid is adsorbed onto a surface of the first tannic acid-treated fabric layer.

68. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

69. The method of the immediately preceding clause, wherein the compressing is performed at an elevated temperature of between 80 °C and 200 °C and the compressed silk meringue is a hot- pressed silk meringue.

70. The method of any one of clauses 68 to the immediately preceding clause, wherein the silk fibroin is present in the liquid composition in an amount by weight of between 1% and 10% or between 3% and 7%, including but not limited to, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%.

71. The method of any one of clauses 68 to the immediately preceding clause, wherein the polysaccharide is present in the liquid composition in an amount by weight of between 0.1% and 10.0%, including but not limited to, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, or at least 6%, and at most 10%, at most 9%, at most 8%, at most 7%, at most 6%, or at most 5%. 72. The method of any one of clauses 68 to the immediately preceding clause, wherein the silk fibroin and polysaccharide are present in a weight ratio of between 1 :4 and 20: 1 or between 1 :2 and 10: 1, including but not limited to, at least 1:4, at least 1 :3, or at least 1:2, and at most 20: 1, at most 19:1, at most 18:1, at most 16:1, at most 15:1, at most 14:1, at most 12:1, at most 11 :1, or at most 10:1.

73. The method of any one of clauses 68 to the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 0.5% and 20.0%.

74. The method of any one of clauses 68 to the clause preceding the immediately preceding clause, wherein the plasticizer is present in the liquid composition, whipped silk cream, silk meringue, compressed silk meringue, or hot-pressed silk meringue in an amount by weight of between 20.0% and 75.0%.

75. The method of any one of clauses 68 to the immediately preceding clause, wherein the liquid composition, the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot- pressed silk meringue further comprise at least one of a sensing agent, a therapeutically active agent, a colorant, an aroma-providing compound.

76. The method of any one of clauses 68 to the immediately preceding clause, wherein the whipped silk cream, the silk meringue, the compressed silk meringue, or the hot-pressed silk meringue has irregular porosity.

77. The method of any one of clauses 68 to the immediately preceding clause, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

78. The method of any one of the preceding clauses, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid- treated fabric layer and the comparison second material layer is otherwise identical to the compressed silk meringue or the hot-pressed silk meringue. 79. The silk leather or method of any one of the preceding clauses, wherein the compressed silk meringue is a hot-pressed silk meringue.

80. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, wherein between 3% and 32% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide, or wherein between 25% and 94% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer.

81. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin.

82. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 3% and 32% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide.

83. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 25% and 94% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer.

84. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 3% and 72% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, wherein between 3% and 32% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide, and wherein between 25% and 94% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer.

85. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the silk fibroin, wherein between 15% and 25% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the polysaccharide, and wherein between 50% and 70% of the total weight of the silk fibroin, the polysaccharide, and the plasticizer is the plasticizer.

86. The silk leather or method of any one of the preceding clauses, the compressed silk meringue having a water content of between 2% and 50%.

87. The silk leather or method of any one of the preceding clauses, the hot-pressed silk meringue having a water content of between 1 % and 50%.

88. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer comprises at least one -OH substituent.

89. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer comprises at least two -OH substituents, at least 3 -OH substituents, or more -OH substituents. 90. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the at least two -OH substituents, the at least 3 -OH substituents, or the more -OH substituents are separated from one another on the plasticizer by at least 2 carbon atoms, at least 3 carbon atoms, or at least 4 carbon atoms.

91. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer is selected from the group consisting of glycerol, 1 ,2-pentanediol, 1,5-pentanediol, 1,2,6-hexanetriol, and mixtures thereof.

92. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer is glycerol.

93. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer is 1 ,2-pentanediol.

94. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer is 1,5-pentanediol.

95. The silk leather or method of any one of clauses 21 to 39 or 60 to 78, wherein the plasticizer is 1,2,6-hexanetriol.

96. A conductive silk leather, comprising a compressed silk meringue or a hot-pressed silk meringue and a tannic acid-treated fabric layer.

97. The conductive silk leather of clause 96, wherein a plurality of graphite flakes is distributed within the compressed silk meringue or the hot-pressed silk meringue.

98. The conductive silk leather of clause 96, wherein a graphene powder is distributed within the compressed silk meringue of the hot-pressed silk meringue.

99. The conductive silk leather of clause 96, wherein a conductive ink is printed on a surface of the compressed silk meringue or the hot-pressed silk meringue.

100. The conductive silk leather of clause 96, wherein a conductive ink is printed between layers of the compressed silk meringue or the hot-pressed silk meringue or printed and subsequently embedded within the compressed silk meringue or the hot-pressed silk meringue.

101. The conductive silk leather of clause 96, wherein a conductive ink is printed between the compressed silk meringue or the hot-pressed silk meringue and the tannic acid-treated fabric layer.

102. The conductive silk leather of any one of clauses 96 to the immediately preceding clause, wherein the conductivity is patterned into an electronic circuit.

103. The conductive silk leather of any one of clauses 96 to the immediately preceding clause, wherein a resistivity of the conductive silk leather is at most 1 kQ, at most 0.7 kQ, at most 0.5 kQ, or at most 0. 1 k . 104. The conductive silk leather of any one of clauses 96 to the immediately preceding clause, wherein the conductive silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

105. A magnetic silk leather, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

106. The magnetic silk leather of clause 105, wherein a plurality of magnetic particles is distributed within the compressed silk meringue or the hot-pressed silk meringue.

107. The magnetic silk leather of any one of clauses 105 to the immediately preceding clause, wherein a plurality of chromium oxide particles is distributed within the compressed silk meringue or the hot-pressed silk meringue.

108. The magnetic silk leather of any one of clauses 105 to the immediately preceding clause, wherein the magnetic silk leather blocks RFID signals.

109. The magnetic silk leather of any one of clauses 107 to the immediately preceding clause, wherein the magnetic silk leather is or comprises the silk leather of any one clauses 1 to 95.

110. A scented silk leather, comprising the compressed silk meringue, hot- pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

111. The scented silk leather of clause 110, wherein a plurality of aromatic compounds are distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the scented silk leather.

112. The scented silk leather of any one of clauses 110 to the immediately preceding clause, wherein applying an additional volume of the aromatic compound to a surface of the scented silk leather at least partly recharges the scented silk leather, thereby extending the lifetime of aroma release.

113. The scented silk leather of any one of clauses 110 to the immediately preceding clause, wherein the scented silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

114. A thermally-insulating silk leather having thermochromic reporting property throughout a bulk interior volume, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid- treated fabric layer.

115. The thermally-insulating silk leather of the immediately preceding clause, wherein the thermally-insulating silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95. 116. A pH responsive silk leather comprising a pH responsive chemical distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather, and a tannic acid-treated fabric layer.

117. The pH responsive silk leather of the immediately preceding clause, wherein the pH responsive silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

118. A humidity sensing leather comprising a pH responsive chemical and a pH altering agent distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather and a tannic acid-treated fabric layer, wherein measurable amounts of humidity solubilize at least a portion of the pH altering agent, thereby lowering the pH, thereby providing a measurable report of humidity.

119. The humidity sensing silk leather of the immediately preceding clause, wherein the humidity sensing silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

120. A patterned silk leather, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

121. The patterned silk leather of the immediately preceding clause, comprising a surface pattern selected from the group consisting of: a leather mimicking pattern; a water-resistant or water-proof pattern; a tessellating pattern; an optically active pattern; and combinations thereof.

122. The patterned silk leather of either of the immediately preceding clauses, wherein the patterned silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

123. An electronic leather having an electronic component embedded therein, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

124. The electronic silk leather of the immediately preceding clause , wherein the electronic component or a second electronic component is embedded between the silk layer and the fabric layer in the electronic silk leather.

125. The electronic silk leather of any one of clauses 123 to the immediately preceding clause, wherein the electronic component or a third electronic component is embedded within the silk layer in the electronic silk leather.

126. The electronic silk leather of any one of clauses 123 to the immediately preceding clause, wherein the electronic silk leather further comprises a power supply coupled to the electronic component. 127. The electronic silk leather of the immediately preceding clause, wherein the power supply is a rechargeable battery, a wired disposable battery holder, or a combination thereof.

128. The electronic silk leather of any one of clauses 123 to the immediately preceding clause, wherein the electronic component comprises an RFID tag.

129. The electronic silk leather of any one of clauses 123 to the immediately preceding clause, wherein the electronic component comprises wiring.

130. The electronic silk leather of any one of clauses 123 to the immediately preceding clause, wherein the electronic silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

131. A semiconductor device-embedded silk leather having a semiconductor device embedded therein, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

132. The semiconductor device-embedded silk leather of the immediately preceding clause, wherein the semiconductor device or a second semiconductor device is embedded at a surface of the compressed silk meringue or the hot-pressed silk meringue.

133. The semiconductor device-embedded silk leather of any one of clauses 131 to the immediately preceding clause, wherein the semiconductor device or a third semiconductor device is embedded within the compressed silk meringue or the hot-pressed silk meringue.

134. The semiconductor device-embedded silk leather of any one of clauses 131 to the immediately preceding clause, wherein the semiconductor device or a fourth semiconductor device is embedded between the first tannic acid-treated fabric layer and the compressed silk meringue or the hot-pressed silk meringue.

135. The semiconductor device-embedded silk leather of any one of clauses 131 to the immediately preceding clause, wherein the semiconductor device-embedded silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

136. A haptic silk leather having a haptic switch embedded therein, comprising the compressed silk meringue, hot-pressed silk meringue, or silk leather of any of the preceding clauses, and a tannic acid-treated fabric layer.

137. The haptic silk leather of the immediately preceding clause, wherein the haptic switch or a second haptic switch is embedded at a surface of the silk leather.

138. The haptic silk leather of any one of clauses 136 to the immediately preceding clause, wherein the haptic switch or a third haptic switch is embedded within a compressed silk meringue or a hot-pressed silk meringue of the haptic silk leather. 139. The haptic silk leather of any one of clauses 136 to the immediately preceding clause, wherein the haptic switch or a fourth haptic switch is embedded adjacent to the first tannic acid- treated fabric layer of the haptic silk leather.

140. The haptic silk leather of any one of clauses 136 to the immediately preceding clause, wherein the haptic silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

141. A tanned silk leather, the tanned silk leather having a tannic acid-treated fabric layer and a bulk volume of a compressed silk meringue or hot-compressed silk meringue and a surface layer of the compressed silk meringue or hot-pressed silk meringue, wherein the surface layer is formed from the same chemical composition as the bulk volume but includes at least one differing structural, mechanical, or chemical feature relative to the bulk volume.

142. The tanned silk leather of the immediately preceding clause, wherein the surface layer includes a dye.

143. The tanned silk leather of clause 141, wherein the surface layer comprises a precursor that reacts to form the surface layer.

144. The tanned silk leather of any one of clauses 141 to the immediately preceding clause, wherein the surface layer is patterned.

145. The tanned silk leather of any one of clauses 141 to the immediately preceding clause, wherein the tanned silk leather is or comprises the silk leather of or made by the method of any one of clauses 1 to 95.

146. The silk leather or method of any one of clauses 1 to 95, wherein the polysaccharide is xanthan gum.

147. The silk leather or method of any one of clauses 1 to 95, wherein the polysaccharide is an alginate.

148. The silk leather or method of the immediately preceding clause, wherein the alginate is sodium alginate.

Claims

What is claimed: I/we claim:

3. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin and a polysaccharide for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; and compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

4. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

5. A silk leather that is a layered structure comprising a first tannic acid- treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and plasticizer, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

6. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, and a plasticizer for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

7. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid- treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

8. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40% , at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid-treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

9. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

10. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 15 Newtons/meter (N/m), at least 17 N/m, at least 20 N/m, at least 22 N/m, at least 25 N/m, at least 30N/m, at least 40 N/m, at least 50 N/m, at least 60 N/m, or at least 70 N/m.

11. A silk leather that is a layered structure comprising a first tannic acid-treated fabric layer and a second material layer disposed adjacent to the first tannic acid-treated fabric layer, the second material layer comprising a compressed silk meringue, the compressed silk meringue comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent, wherein an adhesion strength as measured by a T-Peel test between the first tannic acid-treated fabric layer and the second material layer is at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 80%, at least 100%, at least 120%, at least 140%, at least 160%, at least 180%, or at least 200% greater than a comparison adhesion strength between a comparison fabric layer and a comparison second material layer, wherein the comparison fabric layer lacks the tannic acid treatment of the first tannic acid- treated fabric layer but is otherwise identical to the first tannic acid-treated fabric layer and the comparison second material layer is otherwise identical to the second material layer.

12. A method of forming a silk leather, comprising: whipping a liquid composition comprising silk fibroin, a polysaccharide, a plasticizer, and a functionalizing agent for a predetermined whipping time to form a whipped silk cream; baking the whipped silk cream at a temperature of between 30 °C and 150 °C or between 50 °C and 80 °C for a length of time of between 2 hours and 24 hours to form a silk meringue; compressing the silk meringue onto a tannic acid-treated fabric layer with a force of between 0.25 MPa and 25 MPa for a length of time of between 15 minutes and 6 hours to form a silk leather, wherein the silk leather comprises a compressed silk meringue.

1 . A conductive silk leather, comprising a compressed silk meringue or a hot-pressed silk meringue and a tannic acid-treated fabric layer.

14. A pH responsive silk leather comprising a pH responsive chemical distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather, and a tannic acid-treated fabric layer.

15. A humidity sensing leather comprising a pH responsive chemical and a pH altering agent distributed throughout the compressed silk meringue or the hot-pressed silk meringue of the pH responsive leather and a tannic acid-treated fabric layer, wherein measurable amounts of humidity solubilize at least a portion of the pH altering agent, thereby lowering the pH, thereby providing a measurable report of humidity.

16. A tanned silk leather, the tanned silk leather having a tannic acid-treated fabric layer and a bulk volume of a compressed silk meringue or hot-compressed silk meringue and a surface layer of the compressed silk meringue or hot-pressed silk meringue, wherein the surface layer is formed from the same chemical composition as the bulk volume but includes at least one differing structural, mechanical, or chemical feature relative to the bulk volume.

17. The silk leather or method of any one of claims 1 to 16, wherein the polysaccharide is xanthan gum.

18. The silk leather or method of any one of claims 1 to 16, wherein the polysaccharide is an alginate.

19. The silk leather or method of the immediately preceding claim, wherein the alginate is sodium alginate.

20. The silk leather or method of any one of claims 1 to 16, wherein the first tannic acid-treated fabric layer and/or the tannic acid-treated fabric layer is composed of cotton fabric; silk fabric; synthetic fabric; linen; organza; a hydrophilic fabric; or a combination thereof.

21. The silk leather or method of any one of claims 1 to 16, wherein the first tannic acid-treated fabric layer and/or the tannic acid-treated fabric layer is composed of organza.

22. The silk leather or method of any one of claims 1 to 16, wherein the first tannic acid-treated fabric layer and/or the tannic acid-treated fabric layer is characterized by the presence of IR peaks at 1313 cm ¹, 1022 cm , 1192 cm^-1, and 1443 cm^-1.

23. The silk leather or method of any one of claims 1 tol6, wherein the first tannic acid-treated fabric layer and/or the tannic acid-treated fabric layer is covalently modified to have tannic acid substituents.

24. The silk leather or method of any one of claims 1 to 16, wherein the tannic acid is adsorbed onto a surface of the first tannic acid-treated fabric layer and/or the tannic acid-treated fabric layer.