WO2025222067A1 - A strong biodegradable adhesive for tissue repair - Google Patents

Abstract

Among the various aspects of the present disclosure is the provision of a biological adhesive and methods of use thereof. A biological adhesive is described that limits complications from anastomotic leaks and provides a faster, simpler, and safer solution over the use of sutures. Methods of using the biological adhesive in single and double-layer tape form are also described.

Description

TITLE OF THE INVENTION

A STRONG BIODEGRADABLE ADHESIVE FOR TISSUE REPAIR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional Application Serial No. 63/635,376 filed on April 17, 2024, which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.

MATERIAL INCORPORATED-BY-REFERENCE

[0003] The Sequence Listing, which is a part of the present disclosure, includes a computer-readable form comprising nucleotide and/or amino acid sequences of the present invention (file name 020714-WO_SEQ_LISTING. XML created on April 17, 2025; 4,096 bytes). The subject matter of the Sequence Listing is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0004] The present disclosure generally relates to hydrogel tissue adhesive compositions.

BACKGROUND OF THE INVENTION

[0005] In surgical procedures, achieving effective tissue repair and reconnection is of utmost importance to prevent post-operative complications such as seromas and hematomas. Failure to reestablish tissue contact can lead to complex post-operative management that may include additional interventions or in some cases revision surgeries. This not only increases patient morbidity and healthcare costs but also negatively impacts patient satisfaction due to compromised functional and aesthetic results. Despite the widespread use of surgery, with tens of millions of procedures performed annually, current standard post-operative techniques such as gentle tissue handling, surgical drains, negative pressure wound vacuums, progressive tension sutures, and external compression are each accompanied by various limitations. Surgical drains may fail, hinder early patient mobility, cause discomfort, and necessitate additional clinic visits. Negative pressure wound vacuums are beneficial but have limited applications and require ongoing maintenance. Progressive tension sutures are effective, but demand considerable surgical skill and may potentially prolong surgery duration and/or cause skin dimpling.

[0006] Uncontrolled bleeding from trauma or during surgery is a major global cause of death. Addressing surgical challenges, especially those like gastrointestinal issues, aortic ruptures, and wounds penetrating the heart, is notably challenging. While surgical sutures are the main technique used to mend these defects, they have significant shortcomings. They often lead to complications such as anastomotic leaks, which can escalate to infections, sepsis, and even death. Thus, there is a pressing need for an alternative to sutures that is faster, more affordable, simpler, and safer.

[0007] Many plastic surgery procedures create large surgical dead space. In an abdominoplasty, or ‘tummy tuck’ procedure, the soft tissue abdominal flap, superior to the abdominal rectus fascia, is elevated and advanced to improve aesthetic contour. When the remaining tissue layers are brought back together for wound closure, spaces have been created between each of the tissue planes. Hematomas and seromas are the most common complications following abdominoplasty, with some studies reporting up to 40%. These potential complications are classically prevented with the use of drains. The drains are typically removed after 1-2 weeks depending on output, but they pose problems for patients regarding comfort, possible nexus for infection, and lack of efficacy. The current trend in abdominoplasty procedures now favors drainless abdominoplasties, which use layers of stitches to carefully close each layer of the abdominal wall to eliminate the potential space. In the last few years, multiple large retrospective studies have shown similar or improved results compared to the classic drain methodology, including less fluid pocket formations, better pain control, and better body contour. Although the results seem positive, drainless abdominoplasties require increased operating room time and resources, leading to increased costs. In particular, stitches cause trauma to tissue directly and can create tension, dimpling, and decreased blood flow that can lead to poor wound healing. There is a need for an efficient drainless approach without complications for abdominoplasty.

[0008] Tissue adhesives, sealants, and hemostatic materials for tissue repair within the medical community prove distinct strengths but also notable limitations. Cyanoacrylate adhesives, such as Dermabond and SurgiSeal, are currently favored for their rapid bonding capabilities and microbial protection., but their inherent cytotoxicity limits their suitability for some procedures such as abdominoplasty. Fibrin sealants, known for emulating the body's clotting response, offer flexibility and are particularly well-suited for internal vascular connections, but are not well-suited for other non-vascular connections. BioGlue is a combination of bovine serum albumin with glutaraldehyde is noted for its robust bonding but the animal-derived components may trigger immunogenic reactions. Polyethylene glycol hydrogels, like FocalSeal and TissuGlu, are valued for their adaptability and biocompatibility, especially in the dynamic realm of vascular anastomosis, but lack tunability for customizing the adhesive for different surgical procedures.

SUMMARY OF THE INVENTION

[0009] Among the various aspects of the present disclosure is the provision of compositions of a biological adhesive and methods of use thereof.

[0010] One aspect of the present disclosure provides for a biological adhesive composition comprising a polymeric base, wherein the polymeric base comprises one or more synthetic polymers, one or more biopolymers, one or more polysaccharides, one or more polypeptides and/or one or more proteins, and wherein the polymeric base is modified by introducing hyaluronic acid or other functional moieties.

[0011] In some embodiments, the biological adhesive is implemented as one of a plug, patch, tape, or aerosol.

[0012] In some embodiments, the polymeric base comprises one or more polyester-based compounds, polysaccharides, or polypeptides.

[0013] In some embodiments, the polymeric base is produced by combining a plurality of monomers. [0014] In some embodiments, the monomers consist of one of epoxide, cyclic anhydride, lactide, and cyclic phosphate.

[0015] In some embodiments, the functional moieties comprise one or more of hydroxyl (-OH), carboxyl (-COOH), amino (-NH2), amino acid (- COOHNH2), sulfhydryl (-SH), N-hydroxysuccinimide ester, aldehyde, and catechol.

[0016] In some embodiments, the biological adhesive further comprises one or more phosphoester bonds which promote biodegradability.

[0017] In some embodiments, the biological adhesive is within a stiffness range of about 0.03 MPa to about 0.8 MPa.

[0018] In some embodiments, the biological adhesive is implemented as a single-layer tape comprising the biological adhesive on both sides of the tape.

[0019] In some embodiments, the biological adhesive is implemented as a double-layer tape comprising a layer of the biological adhesive and a layer of a hydrophobic polyester.

[0020] In some embodiments, the layer consisting of the hydrophobic polyester consists essentially of a soft polyester.

[0021] In some embodiments, the layer consisting of the hydrophobic polyester consists essentially of a stiff polyester.

[0022] Another aspect of the present disclosure provides a method for using the single-layer tape comprising adhering the single-layer tape to connect tissues during or after an abdominoplasty.

[0023] Yet another aspect of the present disclosure provides for a method for using the double-layer tape comprising adhering the double-layer tape to a laceration of an organ or artery.

[0024] Yet another aspect of the present disclosure provides for a biological adhesive comprising of a biopolymer or synthesized polymer base wherein the polymer base is modified by amino groups, resulting in a modified polymer, wherein the modified polymer is used to catalyze the ring-opening polymerization of functional a/[3-amino acid N-carboxyanhydrides, resulting in the generation of functional brush copolymers, and then the functional brush copolymers are cross-linked using appropriate cross-linkers.

DESCRIPTION OF THE DRAWINGS

[0025] Those of skill in the art will understand that the drawings, described below, are for illustrative purposes only. The drawings are not intended to limit the scope of the present teachings in any way.

[0026] FIG. 1 is one embodiment of the adhesive comprising distinctive reactive groups and N-hydrosuccinimide ester.

[0027] FIG. 2 illustrates the tunable biodegradability of the adhesive based on the number of included phosphoester bonds.

[0028] FIG. 3 illustrates, in one embodiment, the elasticity of the adhesive shown by way of a stress-strain curve.

[0029] FIG. 4 illustrates the preparation of the tissue adhesive in one embodiment comprising the synthesis of polyester, carboxyl, and N- hydroxysuccinimide ester.

[0030] FIG. 5 illustrates an H NMR spectrum of the polyester in one embodiment before and after synthesis of the tissue adhesive.

[0031] FIG. 6 illustrates, in one embodiment, the adhesion properties of the tissue adhesive given the carboxyl and NHS groups’ ability to quickly react with amino groups in the extracellular matrix of tissues.

[0032] FIG. 7 shows the results of LIVE/DEAD staining of HUVECs with the tissue adhesives at concentrations of 0, 7, 14, and 21 mg/mL, wherein green shows LIVE cells and red shows DEAD cells, and the scale bar is 100 pm.

[0033] FIG. 8 shows, in bar chart form, the results of an alamarBlue assay for cell viabilities after incubation with the tissue adhesives in some embodiments.

[0034] FIG. 9 shows the tissue adhesive, in one embodiment wherein the adhesive is a single layer with dual adhesive faces, undergoing a peel test when adhered to rat subcutaneous tissue.

[0035] FIG. 10 shows, in bar chart form, the results of peel testing of the tissue adhesive, in one embodiment, adhered to rat subcutaneous fascia compared to normal tissue and further compared to cyanoacrylate adhered to rat subcutaneous fascia.

[0036] FIG. 11 shows, in bar chart form, the results of peel testing of the tissue adhesive, in one embodiment, adhered to rat subcutaneous fat compared to normal tissue and further compared to cyanoacrylate adhered to rat subcutaneous fat.

[0037] FIG. 12 shows the tissue adhesive, in one embodiment wherein the adhesive is a single layer with dual adhesive faces, undergoing a shear test when adhered to rat subcutaneous tissue.

[0038] FIG. 13 shows, in bar chart form, the results of shear testing of the tissue adhesive, in one embodiment, adhered to rat subcutaneous fascia compared to cyanoacrylate adhered to rat subcutaneous fascia.

[0039] FIG. 14 shows, in bar chart form, the results of shear testing of the tissue adhesive, in one embodiment, adhered to rat subcutaneous fat compared to cyanoacrylate adhered to rat subcutaneous fat.

[0040] FIG. 15 shows temperature measurement comparisons, measured in Celsius, between three separate samples of the tissue adhesive, in one embodiment, applied in vivo, and three separate samples of cyanoacrylate applied in vivo.

[0041] FIG. 16 shows, over time, exothermic temperature reactions, measured in Celsius, between cyanoacrylate applied in vivo to the rectus abdominus fascia of a rat and the tissue adhesive, in one embodiment, applied in vivo to the rectus abdominus facia of a rat.

[0042] FIG. 17 demonstrates the cytocompatibility of the tissue adhesives, in one embodiment, wherein LIVE/DEAD staining is shown for RGD-supported endothelial cell attachment on the surface of hyaluronic acid hydrogels, RGD is shown at levels of 0, 0.01 , 0.1 , and 1 mM, and the scale bar is 200 pm.

[0043] FIG. 18 shows the synthesis of various polyesters using ringopening polymerization.

[0044] FIG. 19 shows an H NMR spectrum for synthesis and modification of a soft polyester in one embodiment.

[0045] FIG. 20 shows an H NMR (CDCI3) spectrum of a copolymer in one embodiment.

[0046] FIG. 21 shows the H NMR spectrum for synthesis and modification of a stiff polyester in one embodiment.

[0047] FIG. 22 illustrates the tissue adhesive in one embodiment wherein the adhesive is composed of a hydrophobic polyester layer and a hydrophilic polyester or polyacrylic-based copolymer layer.

[0048] FIG. 23 illustrates the synthesis of a hydrophilic polyacrylic-based copolymer layer which, in some embodiments, is one of a plurality of layers of the tissue adhesive.

[0049] FIG. 24 illustrates the synthesis of a methacrylated hyaluronic acidbased composite adhesive.

[0050] FIG. 25 illustrates the synthesis of a polyester-based composite adhesive.

[0051] FIG. 26 shows the tissue adhesive prepared as a cohesive and as an adhesive.

[0052] FIG. 27 shows the interaction between the tissue cohesive and the tissue adhesive.

[0053] FIG. 28 demonstrates the differences between the stiff polyester embodiment and the soft polyester embodiment by way of stress-strain curves.

[0054] FIG. 29 shows the H NMR spectrum of the polyester in certain embodiments before and after modifications by functional groups.

[0055] FIG. 30 shows the degradation profiles of the polyesters over time wherein the red line represents a polyester with 100% content of double bonds, the blue line represents a polyester with 46.5% content of double bonds, and the green line represents a polyester with 24.5% content of double bonds.

[0056] FIG. 31 shows both the results of LIVE/DEAD staining of HUVECs with the tissue adhesives at concentrations of 0, 1 , 10, and 50 mg/mL, wherein green shows LIVE cells and red shows DEAD cells, the scale bar is 100 pm, and a bar chart summarizing the results of an alamarBlue assay for cell viabilities after incubation with the tissue adhesives in some embodiments.

[0057] FIG. 32 demonstrates the adhesion properties of the tissue adhesive, in one embodiment, as applied to pigskin, wherein the adhesive comprises a soft hydrophobic polyester layer and a hydrophilic polyacrylic-based copolymer layer.

[0058] FIG. 33 demonstrates the adhesion properties of the tissue adhesive, in one embodiment, as applied to pigskin, wherein the adhesive comprises a stiff hydrophobic polyester layer and a hydrophilic polyacrylic-based copolymer layer.

[0059] FIG. 34 demonstrates the adhesive property of the tissue adhesive, in one embodiment, as applied to a rat liver, wherein the adhesive comprises a soft hydrophobic polyester layer and a hydrophilic polyacrylic-based copolymer layer.

[0060] FIG. 35 shows the tissue adhesive used in various applications including abdominoplasty, repair of a liver laceration, and repair of a heart laceration.

[0061 ] FIG. 36 shows the adhesion property of the tissue adhesive as applied on an artery, wherein the tissue adhesive comprises a methacrylated hyaluronic acid-based composite.

[0062] FIG. 37 shows the shear strength and interfacial toughness of the tissue adhesive, in one embodiment wherein the tissue adhesive comprises a methacrylated hyaluronic acid-based composite when applied on rat skin, muscle, fat, and heart tissue.

[0063] FIG. 38A is an image of the first stage of a rat abdominoplasty model, showing a lesion created in the rat’s abdomen.

[0064] FIG. 38B is an image of a second stage of a rat abdominoplasty model, in which the subcutaneous tissue is separated from the underlying muscle fascia.

[0065] FIG. 38C is an image of a third stage of a rat abdominoplasty model, in which the lesion is sutured. [0066] FIG. 38D is an ultrasound image of the rat abdominoplasty model showing a seroma formed on post-operation day (POD) 1 .

[0067] FIG. 38E is an ultrasound image of the rat abdominoplasty model after draining the seroma shown in FIG. 38D.

[0068] FIG. 39 is a schematic of hyaluronic acid (HA)-based tissue adhesive tape, along with an associated photo of a synthesized tissue tape.

[0069] FIG. 40A is a histological assessment of abdominal wall tissue in a rat seroma model. Masson's Trichrome staining was used to evaluate fibrosis, tissue architecture, and biomaterial integration, showing normal abdominal wall tissue showing organized muscle bundles, intact dermal and subcutaneous layers, and minimal collagen deposition. Lower panels show high-magnification views of the boxed regions, highlighting differences in extracellular matrix deposition, hydrogel presence, and inflammatory cell infiltration. Scale bar: 2 mm (top), 0.2 mm (bottom).

[0070] FIG. 40B is a histological assessment of abdominal wall tissue in a rat seroma model. Masson's Trichrome staining was used to evaluate fibrosis, tissue architecture, and biomaterial integration, showing, seroma model without treatment, demonstrating disrupted tissue architecture, fluid-filled cavities, and extensive collagen deposition (blue), indicative of fibrotic remodeling. Lower panels show high-magnification views of the boxed regions, highlighting differences in extracellular matrix deposition, hydrogel presence, and inflammatory cell infiltration. Scale bar: 2 mm (top), 0.2 mm (bottom).

[0071] FIG. 40C is a histological assessment of abdominal wall tissue in a rat seroma model. Masson's Trichrome staining was used to evaluate fibrosis, tissue architecture, and biomaterial integration, showing suture closure group showing partial restoration of tissue structure and reduced seroma formation, though with some collagen accumulation at the interface. Lower panels show high-magnification views of the boxed regions, highlighting differences in extracellular matrix deposition, hydrogel presence, and inflammatory cell infiltration. Scale bar: 2 mm (top), 0.2 mm (bottom).

[0072] FIG. 40D is a histological assessment of abdominal wall tissue in a rat seroma model. Masson's Trichrome staining was used to evaluate fibrosis, tissue architecture, and biomaterial integration, showing HA-based tissue adhesive tape treatment showing strong integration with surrounding tissue, reduced seroma cavity, and moderate collagen deposition, suggesting enhanced sealing and tissue remodeling. Lower panels show high-magnification views of the boxed regions, highlighting differences in extracellular matrix deposition, hydrogel presence, and inflammatory cell infiltration. Scale bar: 2 mm (top), 0.2 mm (bottom).

[0073] FIG. 41A is H&E staining of rat abdominal wall in a seroma model, showing normal abdominal wall showing well-organized tissue architecture, intact dermis and subcutis, and no evidence of seroma or inflammation. Lower panels show high-magnification views of boxed regions, highlighting differences in cellu larity , seroma cavity formation, hydrogel-tissue interface, and inflammatory response. Scale bar: 2 mm (top) and 0.2 mm (bottom).

[0074] FIG. 41 B is H&E staining of rat abdominal wall in a seroma model, showing seroma model without treatment, showing extensive tissue disruption, seroma cavity formation, and inflammatory infiltrate in the subcutaneous layer. Lower panels show high-magnification views of boxed regions, highlighting differences in cel lu larity , seroma cavity formation, hydrogel-tissue interface, and inflammatory response. Scale bar: 2 mm (top) and 0.2 mm (bottom).

[0075] FIG. 41 C is H&E staining of rat abdominal wall in a seroma model, showing suture closure group with partial tissue re-approximation and moderate inflammatory response; seroma formation is reduced but some disorganized remodeling is present. Lower panels show high-magnification views of boxed regions, highlighting differences in cellu larity , seroma cavity formation, hydrogeltissue interface, and inflammatory response. Scale bar: 2 mm (top) and 0.2 mm (bottom).

[0076] FIG. 41 D is H&E staining of rat abdominal wall in a seroma model, showing HA-based tissue adhesive tape treatment shows close tissue apposition, reduced seroma cavity, and direct interaction between tissue and adhesive material, with localized cellular response and remodeling. Lower panels show high-magnification views of boxed regions, highlighting differences in cellu larity , seroma cavity formation, hydrogel-tissue interface, and inflammatory response. Scale bar: 2 mm (top) and 0.2 mm (bottom).

DETAILED DESCRIPTION OF THE INVENTION

[0077] Addressing the absence of FDA-approved tissue adhesive compositions for preventing post-surgical complications, a highly adhesive and biodegradable tissue adhesive composition is disclosed. The disclosed tissue adhesive compositions offer precise control over surgical planes, optimized healing, and improved patient outcomes. The global market for conventional wound closure methods such as sutures, staples, and clips is growing rapidly. The disclosed tissue adhesives merge innovative polymer science with profound surgical expertise, and are designed to reduce surgical time and associated risks, ultimately enhancing surgical outcomes. The adaptability of the disclosed tissue adhesive as described herein renders the tissue adhesive useful in various medical contexts, including closing potential spaces in various surgeries and sealing all types of superficial wounds. The integration of the disclosed tissue adhesive compositions into surgical practice will enhance surgery-related tissue repair and reconnection.

[0078] The present disclosure is based, at least in part, on an adhesive for mending wet tissue defects, including, but not limited to wound closures. The biological adhesive is comprised of a base polymer that can be selected from synthesized and synthetic polymers, polysaccharides, polypeptides, and proteins, selected examples of which are illustrated in FIG. 18. In some nonlimiting embodiments, the base polymer is a soft polyester, as illustrated in FIGS. 19, 20, and 28. In other non-limiting embodiments, the base polymer is a stiff polyester, as illustrated in FIGS. 21 and 28.

[0079] In some aspects, the polymers may be modified by incorporating hyaluronic acid and/or functional moieties including but not limited to carboxyl and N-hydroxysuccinimide (NHS) ester groups, as illustrated in FIG. 4. The modification of the polymers enables the tissue adhesive to react quickly with amino groups in the tissue extracellular matrix and exhibit adhesion on wet and dynamic tissue surfaces, as illustrated in FIGS. 1 , 5, and 6.

[0080] As an alternative to incorporating functional moieties into the polymers, biopolymers and synthesized polymers can be modified by incorporating amino groups in some aspects. Once modified with the amino groups, the polymers can catalyze the ring-opening polymerization of functional a/[3-amino acid N-carboxyanhydrides, as illustrated in FIG. 18. This leads to the generation of functional brush copolymers that possess functional groups such as hydroxyl (-OH), carboxyl (-COOH), amino (-NH2), amino acid (-COOHNH2), sulfhydryl (-SH), N-hydroxysuccinimide ester, aldehyde, and catechol. These brush copolymers can then be cross-linked to form adhesive materials using appropriate cross-linkers.

[0081] In some non-limiting embodiments, the polymers consist of polyesters and are modified with carboxylate and NHS ester functional moieties, as illustrated in FIG. 29. The content of double bonds in these non-limiting embodiments may range from about 20% to about 100%. In general, a lower percentage of double bonds results in a faster degradation rate of the polyester, as illustrated in FIG. 30.

[0082] The polymers may further comprise one or more phosphoester bonds, which, in greater numbers, result in an increase in the biodegradability of the biological adhesive and, in lesser numbers, decrease the biodegradability of the biological adhesive, as illustrated in FIG. 2. The ability to control the degradation of the biological adhesive can help to limit inflammation, infection, and toxicity.

[0083] In some aspects, the biological adhesive comprises a polyester backbone with carboxyl and N-hydroxysuccinimide ester functional groups, as illustrated in FIG. 4. This exemplary embodiment is found to not affect cell viability in a statistically significant manner, as illustrated in FIGS. 7, 8, and 31.

[0084] In some aspects, the tissue adhesive demonstrates interfacial toughness comparable to cyanoacrylate as illustrated in FIGS. 9-11 , and shear strength comparable to cyanoacrylate, as illustrated in FIGS. 12-14.

[0085] In some aspects, the tissue adhesive, when applied in vivo, results in little to no increase in exothermic temperature as compared to cyanoacrylates which results in an about 1 .2 degree Celsius exothermic temperature increase when applied in vivo, as illustrated in FIGS. 15-16.

[0086] In some embodiments, the tissue adhesive has a stiffness ranging from about 0.03 to about 0.8 MPa. Such stiffness levels are significantly less than that of cyanoacrylates and are indicative of an enhanced compatibility with biological tissues.

[0087] In some further non-limiting embodiments the tissue adhesive includes conjugating an RGD peptide to a hyaluronic acid-based hydrogel which enhances endothelial cell adhesion in a dose-responsive manner, as illustrated in FIG. 17.

[0088] In some further, non-limiting embodiments, the tissue adhesive may comprise a hydrophilic adhesive layer, as illustrated in FIG. 22. The hydrophilic adhesive layer may comprise, by way of non-limiting example, a polyester layer or a polyacrylic-based copolymer layer. FIGS. 22-23, and 26. In one exemplary, non-limiting embodiment, the hydrophilic adhesive layer comprises hyaluronic acid, N-carboxyanhydride esters, cyclic carboxy anhydrides, and acrylic acid, as illustrated in FIG. 24. In another exemplary, nonlimiting embodiment, the hydrophilic adhesive layer comprises hyaluronic acid, functional polyester, and fiber, as illustrated in FIG. 25.

[0089] In some further, non-limiting embodiments, the tissue adhesive may comprise a hydrophobic cohesive layer, as illustrated in FIGS. 22 and 26. In some non-limiting embodiments, the hydrophobic cohesive layer comprises polyester, as illustrated in FIG. 22.

[0090] In some embodiments, by way of non-limiting example, by modulating the crosslinking density and altering the polymer’s chemical structure, the tissue adhesive can take the form of, inter alia, plugs, patches, tapes, and aerosols, as illustrated in FIG. 3.

[0091] In some embodiments, the disclosed hydrogel tissue adhesive compositions are used for the closure of wounds associated with surgical procedures such as abdominoplasties or other plastic surgeries. In some aspects, the disclosed hydrogel tissue adhesive compositions may be used in abdominoplasties for wound closure that obviates the use of surgical drains. In some aspects, the hydrogel tissue adhesive compositions include distinctive reactive groups including, but not limited to, carboxyl and N- hydrosuccinimide ester groups, as illustrated in FIG. 1 , that quickly react with amino groups in the tissue extracellular matrix and facilitate rapid and robust adhesion capabilities, even on wet and dynamic tissue surfaces. In various aspects, the disclosed hydrogel adhesives are effective in adhering several tissue types together, rendering these adhesives particularly useful in abdominoplasty and other surgeries, because such surgeries typically result in a variety of tissue types that are held together for proper healing.

[0092] In some aspects, the phosphoester bonds of the disclosed hydrogel tissue adhesive compositions facilitate tunable biodegradability, as illustrated in FIG. 2. Without being limited to any particular theory, the higher the density of phosphoester bonds in the hydrogel tissue adhesive composition, the higher the rate of biodegrading of the composition in use. In various aspects, this controlled biodegradation is selected to match the rate of the body’s natural healing process. In other aspects, the disclosed hydrogel tissue adhesive compositions are bioabsorbable, thereby reducing concerns of inflammation, infection, and toxicity associated with use. In other aspects, the crosslinking density and chemical structure of the polymers within the disclosed hydrogel tissue adhesive composition may be adjusted to tune the elasticity of adhesive elasticity of the composition, as illustrated in FIG. 3. In various aspects, the tunability of various characteristics of the polymers within the hydrogel tissue adhesive composition including, but not limited to, adhesion strength, biodegradability, and adhesive elasticity provide for a variety of adhesive forms including, but not limited to, plugs, patches, tapes, injectable adhesives, and aerosolized/spray adhesives for a variety of surgical applications. In some aspects, the hydrogel tissue adhesive composition provides an efficient, robust, and non-invasive method for repairing abdominoplasty surgical sites, thereby eliminating the need for traditional drains or internal stitches and reducing the occurrence of surgical complications.

[0093] Also provided are kits. Such kits can include an agent or composition described herein and, in certain embodiments, instructions for administration. Such kits can facilitate performance of the methods described herein. When supplied as a kit, the different components of the composition can be packaged in separate containers and admixed immediately before use. Components include, but are not limited to the adhesive compositions of the present disclosure. Such packaging of the components separately can, if desired, be presented in a pack or dispenser device which may contain one or more unit dosage forms containing the composition. The pack may, for example, comprise metal or plastic foil such as a blister pack. Such packaging of the components separately can also, in certain instances, permit long-term storage without losing activity of the components.

[0094] Kits may also include reagents in separate containers such as, for example, sterile water or saline to be added to a lyophilized active component packaged separately. For example, sealed glass ampules may contain a lyophilized component and in a separate ampule, sterile water, sterile saline each of which has been packaged under a neutral non-reacting gas, such as nitrogen. Ampules may consist of any suitable material, such as glass, organic polymers, such as polycarbonate, polystyrene, ceramic, metal, or any other material typically employed to hold reagents. Other examples of suitable containers include bottles that may be fabricated from similar substances as ampules and envelopes that may consist of foil-lined interiors, such as aluminum or an alloy. Other containers include test tubes, vials, flasks, bottles, syringes, and the like. Containers may have a sterile access port, such as a bottle having a stopper that can be pierced by a hypodermic injection needle. Other containers may have two compartments that are separated by a readily removable membrane that upon removal permits the components to mix. Removable membranes may be glass, plastic, rubber, and the like.

[0095] In certain embodiments, kits can be supplied with instructional materials. Instructions may be printed on paper or another substrate, and/or may be supplied as an electronic-readable medium or video. Detailed instructions may not be physically associated with the kit; instead, a user may be directed to an Internet web site specified by the manufacturer or distributor of the kit.

[0096] Definitions and methods described herein are provided to better define the present disclosure and to guide those of ordinary skill in the art in the practice of the present disclosure. Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art. [0097] In some embodiments, numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth, used to describe and claim certain embodiments of the present disclosure are to be understood as being modified in some instances by the term “about.” In some embodiments, the term “about” is used to indicate that a value includes the standard deviation of the mean for the device or method being employed to determine the value. In some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the present disclosure may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. The recitation of discrete values is understood to include ranges between each value.

[0098] In some embodiments, the terms “a” and “an” and “the” and similar references used in the context of describing a particular embodiment (especially in the context of certain of the following claims) can be construed to cover both the singular and the plural, unless specifically noted otherwise. In some embodiments, the term “or” as used herein, including the claims, is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive.

[0099] The terms “comprise,” “have” and “include” are open-ended linking verbs. Any forms or tenses of one or more of these verbs, such as “comprises,” “comprising,” “has,” “having,” “includes” and “including,” are also open-ended. For example, any method that “comprises,” “has” or “includes” one or more steps is not limited to possessing only those one or more steps and can also cover other unlisted steps. Similarly, any composition or device that “comprises,” “has” or “includes” one or more features is not limited to possessing only those one or more features and can cover other unlisted features.

[0100] 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 with respect to certain embodiments herein is intended merely to better illuminate the present disclosure and does not pose a limitation on the scope of the present disclosure otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the present disclosure.

[0101 ] Groupings of alternative elements or embodiments of the present disclosure disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[0102] All publications, patents, patent applications, and other references cited in this application are incorporated herein by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application, or other reference was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Citation of a reference herein shall not be construed as an admission that such is prior art to the present disclosure.

[0103] Having described the present disclosure in detail, it will be apparent that modifications, variations, and equivalent embodiments are possible without departing from the scope of the present disclosure defined in the appended claims. Furthermore, it should be appreciated that all examples in the present disclosure are provided as non-limiting examples.

EXAMPLES

[0104] The following non-limiting examples are provided to further illustrate the present disclosure. It should be appreciated by those of skill in the art that the techniques disclosed in the examples that follow represent approaches the inventors have found function well in the practice of the present disclosure, and thus can be considered to constitute examples of modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the present disclosure.

Example 1: Single Laver Tissue Adhesive with Dual Adhesive Faces

[0105] In one exemplary embodiment, the tissue adhesive is a hydrogel adhesive designed in a single-layer format with dual adhesive faces, which makes it particularly effective for bonding different types of tissues together. The adhesive layer consists of methacrylated hyaluronic acid, polyester fiber, acrylic acid, and NHS ester, as illustrated in FIG. 24. An illustration of the dual adhesive is provided at FIG. 37. The dual adhesive single layer demonstrates shear strength between 10 and 30 kPa when tested on rat tissue such as skin, muscle, fat, and heart, as illustrated in FIG. 37. In additional shear tests, the adhesive demonstrates shear strength of about 30 kPa on rat subcutaneous fascia and also on rat subcutaneous fat, as illustrated in FIGS. 12-14. The dual adhesive single layer further demonstrates interfacial toughness between 40 and 80 Jrrr² when tested on rat tissue such as skin, muscle, and heart, as illustrated in FIG. 37. In additional peel tests, the adhesive demonstrates interfacial toughness of about 400 Jrrr² on rat subcutaneous fascia and interfacial toughness of about 300 Jrrr² on rat subcutaneous fat, as illustrated in FIGS. 9-11 .

Example 2: Double Laver Tissue Adhesive with One Hydrophilic Laver and One Hydrophobic Laver

[0106] In a second exemplary embodiment, the tissue adhesive is a hydrogel designed in a double-layer format, as illustrated in FIG. 22. One layer is designed as a hydrophobic cohesive layer, preventing it from sticking to nearby tissues, as illustrated in FIGS. 22, 26, and 27.

[0107] The second layer is a hydrophilic adhesive layer optimal for tissue bonding, as illustrated in FIGS. 22, 26, and 27. The second layer comprises either polyester-based or polyacrylic-based copolymers, as illustrated in FIGS. 22, 23, and 25. The second layer of polyester-based adhesive comprises hyaluronic acid, functional polyester, and fiber, as illustrated in FIG. 25. The second layer may comprise methacrylated hyaluronic acid, polyester fiber, acrylic acid, and/or NHS ester as illustrated in FIG. 24. The second layer may further alternatively comprise acrylic acid, NHS ester, and/or polyester as illustrated in FIG. 23

[0108] The combination of the first and second layers is demonstrated to be useful in rats undergoing abdominoplasty procedures, liver laceration procedures, heart laceration procedures, and artery adhesion procedures, as illustrated in FIGS. 35 and 36.

[0109] This disclosure demonstrates the use of the double-layer tissue adhesive disclosed herein on pig skin wherein the hydrophobic polyester layer comprises soft polyester, and the hydrophilic adhesive layer comprises the polyacrylic-based copolymer layer, as illustrated in FIGS. 19, 32, and 34. This disclosure further demonstrates the use of the double-layer tissue adhesive disclosed herein on pig skin wherein the hydrophobic polyester layer comprises stiff polyester, and the hydrophilic adhesive layer comprises the polyacrylic copolymer layer, as illustrated in FIGS. 21 and 33.

Example 3: Cytotoxicity of Hydrogel Tissue Adhesive Composition

[0110] To assess the cytotoxicity of a hydrogel tissue adhesive composition, the following experiments were conducted. Human umbilical vein endothelial cells (HUVECS) were incubated with a hydrogel tissue adhesive composition at concentrations of 0, 7, 14, and 21 mg/mL for 24 hours. The hydrogel tissue adhesive composition comprised a brush polymer that included a biocompatible polyester backbone with carboxyl and N-hydroxysuccinimide ester (NHS) functional groups, as illustrated in FIG. 6. After 24 hours, LIVE/DEAD staining and AlamarBlue assays were used to measure cell viability post- incubation.

[0111] As shown in FIG. 7, the LIVE/DEAD staining did not reveal any differences in cell viability at the different adhesive concentrations (0, 7, 14, and 21 mg/mL). As illustrated in FIG. 8, the AlamarBlue assay did not detect a statistically significant difference in cell viability among the different treatment groups

Example 4: Adhesion Performance of Hydrogel Tissue Adhesive Composition

[0112] To assess the adhesive strength of a hydrogel adhesive provided in a single-layer format with dual adhesive faces, the following experiments were conducted. Both peel (FIG. 9) and shear (FIG. 12) tests were conducted using a universal testing machine on rat subcutaneous tissue adhered to fascia or fat using the disclosed hydrogel tissue adhesive composition in one aspect. Cyanoacrylate (Dermabond) adhesive, known for its strong adhesive properties, was similarly tested as a control.

[0113] FIGS. 10 and 11 summarize the results of the peel tests. The interfacial toughness of the disclosed tissue adhesive was comparable to that of cyanoacrylate for adhering subcutaneous tissue to fascia (FIG. 10) as well as for adhering subcutaneous tissue to fat (FIG. 11 ). (FIG. 11 ). As shown in FIG. 10, cyanoacrylate the disclosed tissue adhesive bonded subcutaneous tissue to fascia with a toughness of 394.7 J rrr², as compared to the toughness of 276.4 J rrr² achieved by the disclosed tissue adhesive. As shown in FIG. 11 , cyanoacrylate achieved a toughness of 294.2 J rrr² as compared to 340.9 J nr² achieved using the disclosed tissue adhesive when bonding subcutaneous tissue to fat.

[0114] FIGS. 13 and 14 summarize the results of the shear tests. No significant differences between the disclosed tissue adhesive composition were detected. FIG. 13 summarizes the shear test results for bonding subcutaneous tissue to fascia, in which cyanoacrylate achieved a shear strength of 25.0 kPa and the disclosed tissue adhesive achieved 28.7 kPa (P=0.76). FIG. 15 summarizes the shear test results for bonding subcutaneous tissue to fat, in which cyanoacrylate achieved a shear strength of 26.0 kPa and the disclosed tissue adhesive achieved 27.9 kPa (P=0. 86). [0115] The results of these experiments demonstrated the effectiveness of the disclosed hydrogel tissue adhesive compositions in securely bonding rat tissues, with interfacial toughnesses and shear strengths comparable to cyanoacrylate. Additional experiments (not shown) demonstrated that the disclosed hydrogel tissue adhesive compositions may be tuned to enhance the adhesive’s compatibility with biological tissues surrounding tissues (ranging from 0.03 to 0.8 MPa), as compared to cyanoacrylates, which are significantly stiffer.

Example 5 Thermal Production of Hydrogel Tissue Adhesive Composition

[0116] In the realm of tissue adhesives, exothermic reactions are often favored due to their rapid setting characteristics and robust bonding strength, as exemplified by cyanoacrylate adhesives. However, the formulation of tissue adhesives is typically adjusted to reduce the amount of heat released during the setting process and thereby prevent potential damage to tissues.

[0117] To characterize the thermal production of the disclosed hydrogel tissue adhesive composition, the following experiments were conducted. Similar amounts of cyanoacrylate adhesive (control) and the disclosed hydrogel tissue adhesive composition were applied to the rectus abdominus fascia of rats and the temperatures of the adhesives while setting were monitored using infrared video recording.

[0118] FIG. 15 shows representative frames of the infrared video of cyanoacrylate adhesive (left) and the disclosed hydrogel tissue adhesive composition (right) curing on the rat rectus abdominus fascia, with the temperatures of specific regions marked by circles shown as inset legends. FIG. 16 is a graph summarizing the temperatures of cyanoacrylate adhesive (blue)) and the disclosed hydrogel tissue adhesive composition (red) obtained using images similar to the representative frames of FIG. 15. The temperature increased from 27.8 to 29.0 °C for cyanoacrylates while curing. The disclosed hydrogel tissue adhesive composition was cured at a temperature similar to the local temperature at the rectus abdominus fascia. This attribute makes our adhesives particularly suitable for abdominoplasty, where the management of heat release is a concern. The absence of a temperature increase in the application area ensures that the disclosed hydrogel tissue adhesive composition can be used safely and effectively in surgeries where minimizing the thermal impact on tissues is of concern.

Example 6: Development of Hydrogel Tissue Adhesive Composition for Endothelial Cell Adhesion

[0119] To develop a hydrogel tissue adhesive composition optimized for adhesion to endothelial cells, the following experiments were conducted.

[0120] A variety of adhesive peptide sequences were conjugated to a hyaluronic acid-based hydrogel adhesive as described herein. The adhesive peptides were selected for high binding affinity to endothelial cells and included REDV (SEQ ID NO:1 ), HGGVRLY (SEQ ID NO:2), and RGD from fibronectin. Samples of the adhesives with conjugated adhesive peptides were cultured with endothelial cells and the quantity of bound endothelial cells was quantified using imaging with LIVE/DEAD staining.

[0121 ] FIG. 17 is a series of images of the endothelial cells cultured with samples of the hyaluronic acid-based hydrogel adhesive conjugated with differing concentrations of the RGD adhesive peptide. Endothelial cells adhered to the RGD-conjugated hydrogel adhesive in a dose-responsive manner.

[0122] Several additional adhesive peptides in the form of cyclic peptide binding sequences, such as cyclic CCHGGVRLYC (SEQ ID NO:3) and cyclic HGGVRLY (SEQ ID NO:2) have been synthesized. These cyclic peptides are characterized by increased rigidity compared to linear peptides, resulting in enhanced binding affinity and specificity for target molecules. The cyclic peptide binding sequences will be conjugated to the hyaluronic acid-based hydrogel adhesive as described above and evaluated for biocompatibility using endothelial cells. LIVE/DEAD staining will be used to determine cell viability and the alamarBlue assay to measure cell proliferation as described above. An optimal concentration of HGGVRLY (SEQ ID NO:2) will be identified that is associated with the highest level of cell proliferation using these experimental methods.

Example 7 Performance of Hydrogel Tissue Adhesive Composition in Rat

Abdominoplasty Model [0123] To assess the biocompatibility and functionality of the disclosed hydrogel adhesive in a rat abdominoplasty model, the following experiments will be conducted. A hydrogel tissue adhesive composition optimized for adhesion to endothelial cells, the following experiments will be conducted.

[0124] Rats will be allocated into three distinct groups: one with drains, one with sutures, and one with hydrogel adhesives. Each group will consist of 18 rats, totaling 54, with a staggered sacrifice schedule at 2, 4, and 12 weeks postoperation. This design will allow for comprehensive longitudinal analysis.

[0125] The rats will be monitored for seroma formation, a common postoperative complication. Ultrasound imaging will be to monitor post-operative fluid accumulation. Histological analyses, including Hematoxylin and Eosin, Masson's Trichrome, and Verhoeff-Van Gieson will be used to evaluate biocompatibility. Immunohistochemical analysis will be conducted to assess inflammatory cell densities, macrophage polarization (CD68 for pan macrophage; CD86 for proinflammatory, and CD206 for pro-regenerative), as well the presence of proliferating cells (Ki67), endothelial cells (CD31 ), progenitor cells (CD34), smooth muscle cells (alpha smooth muscle actin), and fibroblasts (P4HB). Extracellular matrix components, including collagen types l/IV, will be examined to evaluate fibrosis.

[0126] In the rat abdominoplasty model, a lesion was created in the rat’s abdomen, as shown in FIG. 38A. The subcutaneous tissue is then separated from the underlying muscle fascia, as shown in FIG. 38B. The lesion is then sutured, as shown in FIG. 38C.

[0127] In an initial experiment, the formation of a seroma on postoperation day (POD) 1 was detected using ultrasound imaging, as shown in FIG. 38D. After aspiration of about .8 mL of fluid, the seroma resolved, as shown in FIG. 38E.

Claims

CLAIMS What is claimed is:

1 . A biological adhesive composition comprising polymeric backbone and at least one functional group attached to the polymeric backbone, wherein: a. the polymeric backbone is selected from a polyester-based polymers, polyurethane polymers, polycarbonate polymers, polythio polymers, acrylate-based polymers, and polyether polymers, cellulose-based polymers, chitosan derivative polymers, alginate polymers, hyaluronic polymers, polypeptide polymers, and any combination thereof; and b. the at least one functional group is selected from a hydroxyl (- OH) moiety, a carboxyl (-COOH) moiety, an amino (-NH2) moiety, an amino acid (-COOHNH2) moiety, a sulfhydryl (-SH) moiety, a N-hydroxysuccinimide ester moiety, an aldehyde moiety, a catechol moiety and any combination thereof; wherein the at least one functional group is configured to bond to a biological cell or tissue.

2. The composition of claim 1 , wherein the biological adhesive composition is provided in a single layer format, with dual adhesive faces, wherein the adhesive layer consists of a methacrylated hyaluronic acid polymeric backbone and acrylic acid functional groups, and a polyester fiber polymeric backbone with NHS ester functional groups.

3. The composition of claim 1 , wherein the biological adhesive composition is provided in a double layer format comprising a hydrophobic cohesive layer and a hydrophilic adhesive layer, wherein the hydrophobic cohesive layer comprises a polyester backbone and the hydrophilic adhesive layer comprises a polyester-based copolymer or a polyacrylic copolymer.

4. The composition of claim 3, wherein the second layer is selected from: a. hyaluronic acid, functional polyester, and fiber; b. methacrylated hyaluronic acid, polyester fiber, acrylic acid, and NHS ester; and c. acrylic acid, NHS ester, and polyester.

5. The composition of claim 1 , wherein the composition is provided in the form of a plug, a patch, a one-sided tape, a two-sided tape, or an aerosol.

6. The composition of claim 1 , wherein the polymeric backbone comprises at least one of an epoxide, a cyclic anhydride, a lactide, a cyclic phosphate, and any combination thereof.

7. The composition of claim 1 , further comprising one or more phosphoester bonds to promote biodegradability.

8. The composition of claim 1 , further comprising a stiffness ranging from about 0.03 MPa to about 0.8 MPa.

9. The composition of claim 1 , wherein the composition is provided in the form a single layer tape comprising the biological adhesive applied to both sides of a tape substrate.

10. The biological adhesive of claim 1 , wherein the composition is provided in the form of a double layer tape comprising the biological adhesive applied to a first side of a tape substrate and a hydrophobic polyester applied to a second side of the tape substrate.

11 . The biological adhesive of claim 10, wherein the hydrophobic polyester consists essentially of a soft polyester.

12. The biological adhesive of claim 10, wherein the hydrophobic polyester consists essentially of a stiff polyester.

13. A method for connecting at least two tissues during an abdominoplasty using the single layer tape of Claim 9, the method comprising adhering the single layer tape to the at least two tissues during or after an abdominoplasty.

14. A method for repairing a laceration of an organ or artery using the double layer tape of Claim 10, the method comprising adhering the double layer tape to the laceration of the organ or artery.