WO2024211577A1 - Hybrid polymeric systems and methods of use thereof - Google Patents

Abstract

Disclosed is a hybrid polymeric system containing (a) a polymer matrix containing polymeric particles dispersed within the polymer matrix, and (b) therapeutic, diagnostic, nutraceutical, and/or prophylactic agents encapsulated in the polymeric particles, for these agents. The polymer matrix and the polymeric particles have different degradation rates, such that the degradation rate of the polymer matrix is less than that of at least one of the polymeric particles, such that when the hybrid polymeric system is administered to a subject in need thereof, the hybrid polymeric system remains at the site of administration, while the encapsulated polymeric particles degrade to release these agents. The hybrid polymeric system is particularly suited for progressive and/or chronic diseases or disorders that require prolonged periods of release of therapeutic, prophylactic, or diagnostic agents, and diseases or disorders that require repeated administration of these agents.

Description

HYBRID POLYMERIC SYSTEMSAND METHODS OF USE THEREOF

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Provisional Application No. 63/494,288 filed April 5, 2023, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention is in the field of delivery of therapeutic, prophylactic, and/or diagnostic agents, particularly hybrid polymeric systems for the release, preferably programmed release, of these agents to an organ or tissue.

BACKGROUND OF THE INVENTION

Prolonged delivery of one or more therapeutic, prophylactic, and/or diagnostic agents at the site of administration has been a focus of clinical and scientific research for several years, due to problems with inadequate retention and/or delivery systems at the site of implantation, particularly within the body of a subject. While the encapsulation of more therapeutic, prophylactic, and/or diagnostic agents into sustained delivery systems can achieve prolonged drug duration, the delivery vehicle can degrade prematurely leading to the release of these agents prior to the full time period required for their therapeutic, prophylactic, and/or diagnostic effects to be exerted at a particular organ or tissue. This means that patients have to undergo repeated, and sometimes very invasive surgical procedures for effective treatment. Examples include treating a range of progressive diseases that require multi-modal and/or repeated administration of therapeutic, prophylactic, and/or diagnostic agents, such as such as growth factor and small molecule delivery to the heart during open heart surgery, postoperative cancer treatment after tumor resection, wound healing therapy for burn patients when repeated administration is associated with pain.

In light of these limitations, it has been a long-standing goal to develop a delivery system that can deliver therapeutic, prophylactic, and/or diagnostic agents locally for prolonged periods of time, while limiting or eliminating systemic and local side effects.

It is therefore an object of the present invention to provide platforms, such as biocompatible platforms, for the local delivery of therapeutic, prophylactic, and/or diagnostic agents over a prolonged period of time.

It is also an object of the present invention to provide platforms, such as biocompatible platforms, for the local delivery of therapeutic, prophylactic, and/or diagnostic agents over a prolonged period of time, following a single administration.

It is also an object of the present invention to provide platforms, such as biocompatible platforms, for the multi-modal local delivery of therapeutic, prophylactic, and/or diagnostic agents over a prolonged period of time, following a single administration.

SUMMARY OF THE INVENTION

Disclosed is a hybrid polymeric system containing (a) a polymer matrix containing polymeric particles dispersed within the polymer matrix, and (b) therapeutic, diagnostic, and/or prophylactic agents encapsulated in the polymeric particles. The hybrid polymeric system is utilized for local delivery of the therapeutic, diagnostic, and/or prophylactic agents encapsulated in the polymeric particles.

The polymer matrix and the polymeric particles have different degradation rates, such that the degradation rate of the polymer matrix is less than that of at least one of the polymeric particles. As such, when the hybrid polymeric system is administered to a subject in need thereof, the hybrid polymeric system remains at the site of administration, while the encapsulated polymeric particles degrade to release the therapeutic, prophylactic, or diagnostic agents. The hybrid polymeric system can be in the form of a single-layered or multi-layered film, membrane, or patch, and is unidirectional (j.e., release drug through only one side), or multidirectional (i.e., release drug through at least two sides).

The mechanical properties ( g., Young’s modulus) of the polymer matrix are designed to be comparable to that of the organ or tissue on/in which the polymeric system is being implanted. These mechanical properties can be achieved by fine-tuning the covalent crosslinking density, crosslinker ratio (such as the amount of polymers to be covalently crosslinked with those not being crosslinked), adding porogens, and/or altering the time for crosslinking. In preferred forms, the polymer matrix is formed by covalent crosslinking of polymers (z.e., precursor polymers). In some forms, the polymer matrix contains (i) covalently crosslinked polyalkylene oxides such as poly(ethylene glycol) (PEG) or (ii) covalently crosslinked acrylamide polymers such as poly(acrylamide), and optionally polysaccharides such as alginates forming interpenetrating networks. Preferably, the polymer matrix is a hydrogel.

In some forms, the polymeric particles have a core containing polymers and a therapeutic, prophylactic and/or diagnostic agent dispersed within the polymers, with an optional polymeric shell or coating partially or completely surrounding the core containing these agents.

In some preferred forms, the polymeric particles contain a core space defined by a shell. In these forms, the core contains a therapeutic, prophylactic and/or diagnostic agent. In the case of non-spherical shapes, the polymeric particles contain a discrete core space defined by a shell, and the polymeric particles can include a base and a cap. The base and the cap may be formed from the same or different polymers. Preferred polymers for making the polymeric particles include polyesters, particularly poly hydroxy acids, such as poly(lactic acid-co-glycolic acid) (PLGA).

Polymeric particles of the same or different polymer composition, and/or having the same or different agent(s) may be combined within one hybrid polymeric system, as further described below.

In some forms, polymeric particles containing the same polymer and enclosing the same agent are combined within a single hybrid polymeric system. In some forms, polymeric particles containing different polymers and enclosing the same agent are combined within a single hybrid polymeric system. In some forms, polymeric particles containing the same polymer and enclosing different agent(s) are combined within a single hybrid polymeric system. In some forms, polymeric particles containing different polymers and enclosing different agents are combined within a single hybrid polymeric system.

In each of the hybrid polymeric systems described above, the polymeric particles can be designed (e.g., via a selection of polymers and/or physical properties) so that the polymeric particles have similar degradation rates and release the agents at about the same time. In another form in each of the hybrid polymeric systems described above, the polymeric particles can be designed e.g., via a selection of polymers and/or physical properties) so that a subset of the polymeric particles possesses a first degradation rate and releases the agents at a first time, and another subset of the polymeric particles possesses a second degradation rate and releases the agents at a second time. In these forms, the first degradation rate is different from the second degradation rate and, consequently, the first release time is different from the second release time.

In some forms, the release time(s) of the agents can be tailored so that multiple drugs are released at different time points that coincide with different physiological processes of an organ/tissue, such as the healing stages. In a non-limiting example, a hybrid polymeric system containing polymeric particles was designed for sequential delivery of different agents post-myocardial infarction. By encapsulating three drugs — Neuregulin-1 (NRG1) for immediate post-MI repair, Vascular Endothelial Growth Factor (VEGF) for angiogenesis during the recovery phase, and a TGF-fl inhibitor to prevent late-stage fibrosis — within PLGA microparticles in a hybrid polymeric system, targeted and timed therapeutic interventions were achieved. In vitro testing with cardiac spheres subjected to hypoxic conditions demonstrated the system's efficacy, with the drug-loaded hybrid polymeric system significantly enhancing cell survival, promoting angiogenesis, and reducing fibrosis. Also disclosed are methods of using the hybrid polymeric system. The hybrid polymeric system is particularly suited for progressive and/or chronic diseases or disorders that require prolonged periods of release of therapeutic, prophylactic, or diagnostic agents, and diseases or disorders that require repeated administration of these agents. The studies demonstrate that the structure of the polymeric particles and polymeric compositions thereof may be used to provide tunable controlled release formulations. Therefore, in some forms, the hybrid polymeric system releases these agents at different time periods, including pulsatile and/or multi-modal release of these agents. Release times include between about 1 day and about 1 year.

The hybrid polymeric system can be formulated for administration via routes that include: buccal, by placement in the buccal cavity for uptake through the mouth; mucosal, e.g. , intranasally or intravaginal administration, or direct application to a mucous membrane in the subject; direct application to an organ or tissue of a subject, such as intracranial; subcutaneous; intramuscular; intraperitoneal; transdermal, intratumoral administration, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A is a schematic showing the microfabrication of the coreshell PLGA-microparticles (PLGA-MPs). Figure IB is a schematic of the microfahrication of the tough hydrogel patch for encapsulating the PLGA- MPs. Figure 1C is a schematic of the MP-laden hydrogel patch attached to the injured epicardium. Figure ID is a line graph of the programmed release kinetics of fluorescent dextran through varying PLGA chemistry.

Figure 2 is a photo showing StampEd Assembly of polymer Layers (SEAL) microparticle arrays of different release profiles patterned in a small hydrogel patch.

Figures 3A and 3B are photos of the encapsulation of SEAL microparticles in the hydrogel patch. Figure 3A is an image showing complete particle encapsulation even when the patch is stretched four times the original length. Figure 3B are time course images of embedded SEAL particle degradation within the hydrogel patch over a 3 -month incubation. Figure 4 is a schematic showing the application of the hybrid polymeric system in different surgical sites.

Figures 5A and 5B are photos showing the hybrid polymeric system implanted on rat hearts using a 6-0 prolene surgical suture (Figure 5A) and a bridging chitosan adhesive layer (Figure 6B).

Figures 6A and 6B show mechanical testing the particle loaded hydrogel patch. The mechanical property using the final formulation matches Young’s modulus of the native myocardium (with Young’s modulus around 20-100kPa).

Figure 7 is a schematic of the fabrication method designed for the encapsulation of SEAL particles in the hydrogel network.

Figures 8A and 8B are images showing failed encapsulation using a softer hydrogel formation (Figure 8A), and successful encapsulation using the final formulation and the instant fabrication method (Figure 8B).

FIGs. 9A, 9B, and 9C are images (FIG. 9A), a line graph (FIG. 9B), and bar graphs (FIG. 9C) of a biomechanical characterization of a hybrid system described herein for prolonged surgical implantation. The biomechanical testing setup involved storage conditions at 4°C to assess storability and exposure to 37°C in a cyclic stretching bioreactor simulating the dynamic mechanical environment of a contracting heart. FIG. 9A shows representative images of the patch pre- and post-application of tensile stress, demonstrating structural integrity and flexibility. FIG. 9B shows representative force-extension curves obtained from tensile testing of patches under various conditions. FIG. 9C shows analyses of Young's Modulus from the tensile data, indicating the material's elasticity, and measurement of the elongation at the break point.

FIGs. 10A and 10B are a schematic of a cytotoxicity assay setup (FIG. 10A) and quantitative analysis of cell viability from a toxicity study (FIG. 10B).

FIGs. 11A and 11B are a schematic representation (FIG. 11A) illustrating a sequential therapy model employing three distinct drugs, each administered at specific time points post-myocardial infarction (MI) based on the temporal phases of cardiac remodeling post-MI, and a bar graph (FIG. 11B) showing quantitative analysis of cell viability per sphere across different treatment conditions.

FIGs. 12A-12L show in vivo validation in a myocardial infarction rodent model induced by left anterior descending (LAD) ligation. FIG. 12A is a schematic of surgical implantation of a hybrid system. FIG. 12B shows an experimental design and timeline of the four cohorts involved in the in vivo study. FIG. 12C shows representative images of LAD ligation and patch implantation. FIG. 12D is an image of an ultrasound procedure in rats. (FIG. 12E shows representative images of rats’ hearts from all groups at the 1 -month endpoint, providing visual evidence of the patch's position and integrity over time. FIGs. 12F-12I are line graphs showing quantification of survival rates of animals within each group (FIG. 12F), weight change of animals over the course of the in vivo study across different groups an indicator of overall health (FIG. 12G), quantitative analysis of cardiac injury biomarkers, including Troponin 1 and Creatine Kinase-MB (CK-MB), extracted from serum samples collected at various time points throughout the study (FIGs. 12H and 121). FIG. 12 J shows representative M-mode echocardiography images captured at baseline and then weekly postimplantation up to the 1 -month endpoint, as visual indicator of cardiac motion. FIGs. 12K and 12L are line graphs showing quantification of ejection fraction and fractional shortening at longitudinal and short axis of the heart at corresponding time points for assessing cardiac function over time.

FIGs. 13A and 13B are images (FIG. 13A) and a bar graph (FIG. 13B) showing an evaluation of postoperative surgical adhesion across experimental cohorts at 4-week endpoint. FIG. 13A contains representative images showing the thoracic cavity upon re-entry, delineating the presence of adhesions between the myocardium or implanted patch and chest wall. Each photograph is annotated to identify the heart, chest wall, and position of the implanted patch, with the specific sites of adhesion indicated by arrows. FIG. 13B shows a quantitative analysis of the incidence of surgical adhesion, expressed as a percentage, among the study cohorts at the 4- week endpoint, with sample sizes (n>6) for each group.

DETAILED DESCRIPTION OF THE INVENTION

I. Definitions

“About,” as relates to numerical values described herein, refers to a value that is ±10% of the specified value. Specific values within this range are ±1%, ±2%, ±3%, ±4%, ±5%, ±6%, ±7%, ±8%, ±9%, and ±10%.

As used herein, “microdevice” refers to microstructures with diverse or complex three-dimensional geometric shapes which cannot be formed using standard techniques such as emulsion or solvent evaporation techniques. The microdevices may have one or more internal compartments, with an outer shell that is formed by solvent and/or heat bonding of discrete powder or suspensions to form the desired shape and dimension. The microdevices may have diverse compartment geometries, external shell geometries, or diverse geometries of both the compartment and the external shell. For example, the compartment and the shell may have the same geometric shape, such as a cube-shaped compartment, and a cube-shaped shell. The compartment and the shell may have different geometric shapes, such as the compartment may be a cube, while the shell may be star-shaped, or a cone. The devices may be formed by bringing together a “base” device and a cap. Although described with reference to “a compartment”, it is understood that there may be multiple compartments, of the same or different dimensions and shapes.

The microdevices have microscale external dimensions, such as a length, width, height, or diameter, up to less than one centimeter in at least one dimension, more preferably having a maximum diameter between 1 micrometer (pm) and 1000 pm. As used herein, the “diameter” of a non- spherical microdevice refers to the largest linear distance between two points on the surface of the microdevice, or between two points of a non-spherical compartment. When referring to multiple microdevices or multiple compartments, the diameter of the microdevices or compartments typically refers to the average diameter of the microdevices. Diameter of microdevices or compartments can be measured using a variety of techniques, including, but not limited to, optical or electron microscopy. The diameter of microdevices can measured with dynamic light scattering. For spherical microparticles, the “diameter” is used in the art-recognized definition.

As used herein “base”, or “bases” in a context of a microdevice refers to the base of the microdevice.

As used herein, “cap” or “caps” refers to a structure that is used to cap the base or bases. The cap may have any geometric shape, and the geometric shape may be the same as that of the base, or different.

“Additive manufacturing” or “3D printing” as used herein refers to a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes or thicknesses. In some embodiments, “3D printing” uses an extruded or solvent based polymer-containing ink (e.g., PLGA, poly(L-lactide) (“PLLA”), etc.) that is jetted or extruded through a nozzle and solidified into a desired shape. The shape can be controlled in the x, y and z directions.

The term “biocompatible” as used herein refers to one or more materials that are neither themselves toxic to the host (e.g., an animal or human), nor degrade (if the material degrades) at a rate that produces monomeric or oligomeric subunits or other byproducts at toxic concentrations in the host.

The term “biodegradable” as used herein means that the materials degrade or break down into their component subunits in the body, as a function of hydrolysis and/or enzymatic degradation.

The terms “effective amount” or “therapeutically effective amount” means a quantity sufficient to alleviate or ameliorate one or more symptoms of a disorder, disease, or condition being treated, or to otherwise provide a desired pharmacologic and/or physiologic effect. Such amelioration only requires a reduction or alteration, not necessarily elimination. The precise quantity will vary according to a variety of factors such as subject-dependent variables (e.g., age, immune system health, weight, etc.), the disease or disorder being treated, as well as the route of administration, and the pharmacokinetics and pharmacodynamics of the agent being administered.

“Hydrophilic,” as used herein, refers to molecules which have a greater affinity for, and thus solubility in, water as compared to organic solvents. The hydrophilicity of a compound can be quantified by measuring its partition coefficient between water (or a buffered aqueous solution) and a water-immiscible organic solvent, such as octanol, ethyl acetate, methylene chloride, or methyl tert-butyl ether. If after equilibration a greater concentration of the compound is present in the water than in the organic solvent, then the compound is considered hydrophilic.

“Hydrophobic,” as used herein, refers to molecules which have a greater affinity for, and thus solubility in, organic solvents as compared to water. The hydrophobicity of a compound can be quantified by measuring its partition coefficient between water (or a buffered aqueous solution) and a water-immiscible organic solvent, such as octanol, ethyl acetate, methylene chloride, or methyl tert-butyl ether. If after equilibration a greater concentration of the compound is present in the organic solvent than in the water, then the compound is considered hydrophobic.

“Micromolding,” as used herein, generally refers to processes suitable for manufacturing parts or devices on a microscale, or processes suitable for manufacturing parts or devices having features or tolerances on a microscale. Exemplary techniques include, but are not limited to, lithography.

The term “small molecule,” as used herein, generally refers to an organic molecule that is less than about 2500 g/mol in molecular weight, such as between 100 Da and 2500 Da. Small molecules are non-polymeric and/or non-oligomeric.

II. Hybrid polymeric systems

Disclosed is a hybrid polymeric system containing (a) a polymer matrix containing polymeric particles dispersed within the polymer matrix, and (b) therapeutic, diagnostic, and/or prophylactic agents encapsulated in the polymeric particles. Preferably, the hybrid polymeric system is utilized for local delivery of the therapeutic, diagnostic, and/or prophylactic agents encapsulated in the polymeric particles. In some preferred forms, the polymer matrix is formed by covalent crosslinking of polymers (/.<?., precursor polymers), and composition is designed to have mechanical properties (e.g., Young’s modulus, elasticity, and toughness) suitable for administering to a given organ or tissue. To demonstrate a material's high elasticity and mechanical toughness, Young's modulus and elongation at break are two key factors. Young’s modulus assesses the material's stiffness and its ability to return to its original shape after deformation, indicating elasticity. Elongation at break measures the material's capacity to stretch before failing, reflecting mechanical toughness. These measurements are shown in Figure 9C, showing that the hybrid polymeric systems possess both desired properties, and can be tailored to achieve the properties desirable for specific tissues, organs, etc. These mechanical properties can be achieved by fine-tuning the covalent crosslinking density, crosslinker ratio (such as the amount of polymers to be covalently crosslinked with those not being crosslinked), adding porogens, and/or altering the time for crosslinking. Preferably, the polymer matrix and the polymeric particles have different degradation rates, such that the degradation rate of the polymer matrix is less than that of at least one of the polymeric particles. As such, when the hybrid polymeric system is administered to a subject in need thereof, the hybrid polymeric system remains at the site of administration, while the encapsulated polymeric particles degrade to release the therapeutic, prophylactic, or diagnostic agents.

The hybrid polymeric system is particularly suited for progressive and/or chronic diseases or disorders that require prolonged periods of release of therapeutic, prophylactic, or diagnostic agents, and diseases or disorders that require repeated administration of these agents. Therefore, in some forms, the hybrid polymeric system releases these agents at different time periods, including pulsatile and/or multi-modal release of these agents.

The hybrid polymeric system can be in the form of a single-layered or multi-layered film, membrane, or patch, and is unidirectional (i.e., release drug through only one side), or multi-directional (i.e., release drug through at least two sides).

A. Polymeric particles

1. Shape and size

The polymeric particles disclosed herein have diverse three- dimensional geometries, and may be free of, or contain an internal cavity. In preferred forms, the internal cavity forms a discrete core space defined polymers forming the polymeric particles. In some forms, this core space is defined by a shell containing the polymers forming the polymeric particles. In some forms, this core space contains a therapeutic, prophylactic and/or diagnostic agent.

In some forms, the polymeric particles have a core containing polymers and a therapeutic, prophylactic and/or diagnostic agent dispersed within the polymers. For example, the core can contain any of the agents to be delivered discussed below, such as drugs or vaccines. Optionally, in these forms, the polymeric particles further contain a polymeric shell or coating partially or completely surrounding the core containing the polymers with agents dispersed therein.

Microdevices have a complex three-dimensional (3D) geometry, which includes complex geometrical shapes and micron-sized objects. Exemplary geometrical shapes include a sphere, ellipsoid, and non-spherical shapes such as cube, cuboid, cone, tetrahedron, square pyramid, hexagonal pyramid, star, cylinder, rectangular prism, triangular prism, pentagonal prism, octahedron, and diamond.

The microdevices may be of any complex 3D geometry. The core of the microdevices, if present, may have any complex 3D geometry. The geometry of the microdevices and discrete core space, if present, may be governed by the end use of the microdevices. For example, if the microdevices are for drug or vaccine delivery, the microdevice shells may be cuboid, cube, spherical, or ellipsoid in shape, and have a cube-, cuboid-, spherical-, or ellipse-shaped discrete core space. If the microdevices are for fluid transfer, then the microdevices may be cuboid in shape, and have internal fluid channels with kinks, turns, or a vertically serpentine arrangement.

In the case of non-spherical shapes, the polymeric particles that contain a discrete core space defined by a shell, the polymeric particles can include a base and a cap. The base may be formed from one polymer, while the cap may be formed from another polymer. In one example, the cap may be of the same polymer composition as that used for forming the base but with chemically modified ends. In another example, the cap may be formed of a polymer that differs from the polymer used for forming the base by inclusion of different monomers, or having a different degree of polymerization, or a different co-polymer ratio, or a different blend.

Micron-sized objects generally have external dimensions, such as a length, width, height, or diameter, each between 1 micrometer (pm) and 1000 pm, 1 micrometer (pm) and 550 pm, 1 micrometer (pm) and 500 pm, 1 micrometer (pm) and 450 pm, 1 micrometer (pm) and 400 pm, between 1 pm and 350 pm, between 1 pm and 300 pm, between 1 pm and 250 pm, between 1 pm and 200 pm, between 1 pm and 150 pm, and between 1 pm and 100 pm. In some forms, the micron-sized objects generally have external dimensions, such as a length, width, height, or diameter, each between 10 pm and 1000 pm, 10 pm and 550 pm, 10 pm and 500 pm, 10 pm and 450 pm, 10 pm and 400 pm, between 10 pm and 350 pm, between 10 pm and 300 pm, between 10 pm and 250 pm, between 10 pm and 200 pm, between 10 pm and 150 pm, between 1 pm and 100 pm, between 25 pm and 1000 pm, 25 pm and 550 pm, 25 pm and 500 pm, 25 pm and 450 pm, 25 pm and 400 pm, between 25 pm and 350 pm, between 25 pm and 300 pm, between 25 pm and 250 pm, between 25 pm and 200 pm, between 25 pm and 150 pm, between 25 pm and 100 pm, between 50 pm and 1000 pm, 50 pm and 550 pm, 50 pm and 500 pm, 50 pm and 450 pm, 50 pm and 400 pm, between 50 pm and 350 pm, between 50 pm and 300 pm, between 50 pm and 250 pm, between 50 pm and 200 pm, between 50 pm and 150 pm, and between 50 pm and 100 pm. For example, external dimensions for a cuboid-shaped microdevice may be about 250 pm, about 300 pm, or about 400 pm for length, about 250 pm, about 300 pm, or about 400 pm for width, and about 250 pm, about 300 pm, or about 400 pm for height.

If a discrete core space is present, the discrete core space generally has nanoscale to microscale dimensions, such as a length, width, height, or diameter, each between 10 nanometers (nm) and 850 pm, between 10 nm and 800 pm, between 10 nm and 750 pm, between 10 nm and 700 pm, between 10 nm and 650 pm, between 10 nm and 600 pm, between 10 nm and 550 pm, between 10 nm and 500 pm, between 10 nm and 450 pm, between 10 nm and 400 pm, between 10 nm and 350 pm, between 10 nm and 300 pm, between 10 nm and 250 pm, between 10 nm and 200 pm, between 10 nm and 150 pm, between 10 nm and 100 pm, between 10 nm and 50 pm, between 10 nm and 10 pm.

Exemplary dimensions for a cube- or cuboid-shaped hollow core include length, width, and height of about 10 pm, about 20 pm, about 30 pm, about 40 pm, about 50 pm, about 60 pm, about 70 pm, about 80 pm, about 90 pm, about 100 pm, about 110 pm, about 120 pm, or about 130 pm, or about 140 pm, about 150 pm, about 200 pm, about 250 pm, or about 300 pm. For example, dimensions for a cuboid-shaped hollow core may be about 100 pm, about 150 pm, about 200 pm, or about 250 pm for length, about 100 pm, about 150 pm, about 200 pm, or about 250 pm for width, and about 100 pm, about 150 pm, about 200 pm, or about 250 pm for height.

2. Polymers

Preferred polymers for forming the polymeric particles are those that are biocompatible and biodegradable. The polymeric particles can be made with hydrophobic polymers, hydrophobic polymers blended with hydrophilic polymers, amphiphilic polymers, or mixtures thereof.

Examples of classes of suitable hydrophobic polymers include polyesters (such as polyhydroxy acids), poly anhydrides, poly(ortho)esters, poly(/?-dioxanone), poly (polyurethane), polycarbonate, polyphosphate, polyphosphonate, and a combination thereof. Preferably, the hydrophobic polymers include polyesters, preferably linear aliphatic polyesters. Specific examples of suitable hydrophobic polymers include, but are not limited to, poly(lactic acid-co-glycolic acid), poly(lactic acid), poly(glycolic acid), poly(caprolactone), poly(pentadecalactone), poly(hydroxybutyrate-co- hydroxy valerate), poly (hydroxybutyrate), polybutylene succinate, and a combination thereof. Preferably, the polymeric particles contain poly(lactic acid-co-glycolic acid).

Hydrophilic polymers include cellulosic polymers such as starch and polysaccharides, hydrophilic polypeptides, poly(amino acids) such as poly- L-glutamic acid (PGS), gamma-polyglutamic acid, poly-L-aspartic acid, poly-L-serine, or poly-L-lysine, polyalkylene oxides such as polyethylene glycol (PEG), and poly(ethylene oxide) (PEO), poly(oxyethylated polyol), poly(olefinic alcohol) such as poly(vinyl alcohol), polyvinylpyrrolidone, poly(hydroxyalkylmethacrylamide), poly(hydroxyalkylmethacrylate), and copolymers thereof.

Biodegradable polymers can include polymers that are insoluble or sparingly soluble in water that are converted chemically or enzymatically in the body into water-soluble materials. Biodegradable polymers can include soluble polymers crosslinked by hydrolyzable cross-linking groups to render the crosslinked polymer insoluble or sparingly soluble in water.

Amphiphilic polymers are polymers containing a hydrophobic polymer block and a hydrophilic polymer block. The hydrophobic polymer block can contain one or more of the hydrophobic polymers above or a derivative or copolymer thereof. The hydrophilic polymer block can contain one or more of the hydrophilic polymers above or a derivative or copolymer thereof.

B. Polymer matrix

Preferred polymers for forming the polymer matrix are those that are biocompatible and biodegradable. The polymer matrix can be made with hydrophobic polymers, hydrophobic polymers blended with hydrophilic polymers, amphiphilic polymers, or mixtures thereof. Examples of polymers for forming the polymer matrix can be selected from the hydrophilic and/or hydrophobic polymers described above for forming the polymeric matrix, with the proviso that the polymer matrix degrades more slowly than the polymeric particles, as illustrated in the examples in the Example section below.

In some forms, the polymer matrix contains polyalkylene oxides such as poly(ethylene glycol) (PEG); polysaccharides such as alginates, glucosaminoglycans, celluloses, and dextrans; poly(oxyethylated polyol); poly(olefinic alcohol) such as poly(vinyl alcohol); poly(N-vinylpyrrolidone); acrylic or acrylate, and alkacrylic or alkacrylate polymers such as poly(acrylic acid), poly(methacrylic acid), poly(hydroxyethyl acrylate); poly(N,N-dimethylaminoethyl methacrylate), poly(hydroxyalkyl methacrylate) e.g. poly(hydroxyethyl methacrylate); acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; and poly(4-vinylpyridine); blends, and copolymers of these polymers. Preferably, the polymer matrix contains polyalkylene oxides such as poly(ethylene glycol) (PEG); polysaccharides such as alginates, acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; or combinations thereof. In some forms, the polymer matrix contains polyalkylene oxides such as poly(ethylene glycol) (PEG). In some forms, the polymer matrix contains acrylamide polymers such as poly (acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide.

In some forms, the polymer matrix contains poly alkylene oxides such as poly(ethylene glycol) (PEG) and polysaccharides such as alginates.

In some forms, the polymer matrix contains acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide and polysaccharides such as alginates.

In some forms, polymers forming the matrix have a weight average molecular weight between 12.5 kDa to 25 kDa, such as 12.5 kDa, 13 kDa, 14 kDa, 15 kDa, 16 kDa, 17 kDa, 18 kDa, 19 kDa, 20 kDa, 21 kDa, 22 kDa, 23 kDa, 24 kDa, and 25 kDa.

The polymer matrix can be formed via covalent crosslinking of a subset of the polymers disclosed herein. For instance, poly(ethyl glycol) diacrylate, or poly(acrylamide) can be crosslinked to form the polymer matrix. In some forms, the crosslinking is performed in the presence of a second polymer (e.g. , a polysaccharide such as an alginate), to form interpenetrating networks in which the second polymer is not involved in covalent crosslinking. The covalent crosslinking can be formed employing crosslinking agents. Suitable crosslinking agents include, but are not limited to, an energy source (such as an electron beam, UV light, or heat); peroxides; and/or photoinitiators (such as dimethylhydroxyacetophenone (DMHA), 2,4,6-trimethylbenzoyldiphenylphosphone oxide (TPO), hydroxylcyclohexylphenylketone (CPK), 2,2-dimethoxy-2- phenylacetophenone (DMPA), benzophenone, 2,2-diethyloxyactetophenone, 2,4-diethylthiozanthone, isopropylthioxanthone, 2,4,6- trimethylbenzoyldiphenylphosphine oxide dimethylhydroxyacetophenone, ethyl(2,4,6-trimethylbenzoyl) phenylphosphinate, 2-phenylbenzophenone, methyl-o-benzoyl-benzoate, and methylbenzoylformate, or a combination thereof); or combinations thereof.

In some forms, the polymer matrix is a hydrogel. In some forms, the polymer matrix has high elasticity and mechanical toughness. In some forms, the polymer matrix has a Young’s modulus between 1 kPa to 150 kPa, such as 1 kPa, 2 kPa, 3 kPa, 4 kPa, 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, 100 kPa, 110 kPa, 120 kPa, 130 kPa, 140 kPa, and 150 kPa.

In some forms, the elongation at break can be between 1.5 and 10, such as 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, and 10.

The size of the polymer matrix can be based on the tissue or organ on or in which the hybrid polymeric system will be delivered. In preferred forms, the polymer matrix has macrodimensions, i.e., having one or more dimensions (length, width, height, and/or diameter) greater than 1 mm and less than 20 cm.

C. Agents to be delivered

The polymeric particles can be used for carrying, presenting, and/or delivering therapeutic agents, diagnostic agents, and/or prophylactic agents. Preferably, these agents are in a discrete core space defined by the polymers forming the polymeric particles. In some forms, this core space is defined by a shell containing the polymers forming the polymeric particles.

In some forms, the agents can be, independently, nucleic acids, proteins, peptides, lipids, polysaccharides, small molecules, or a combination thereof. Some specific classes of agents include, but are not limited to, vaccines, anticancer agents, analgesics/antipyretics, antiasthamatics, antibiotics, antidiabetics, antifungal agents, antihypertensive agents, antiinflammatories, antianxiety agents, immunomodulatory agents, antiarthritic agents, anticoagulants, antiparkinson agents, and antiviral agents.

According to some forms, the composition and methods described herein are compatible with one or more therapeutic, diagnostic, and/or enhancement agents, such as drugs, nutrients, microorganisms, in vivo sensors, and tracers. In some forms, the active substance is a therapeutic, nutraceutical, prophylactic or diagnostic agent. While much of the specification describes the use of therapeutic agents, other agents listed herein are applicable.

Agents can include, but are not limited to, any synthetic or naturally occurring biologically active compound or composition of matter which, when administered to a subject (e.g., a human or nonhuman animal), induces a desired pharmacologic, immunogenic, and/or physiologic effect by local and/or systemic action. For example, useful or potentially useful within the context of certain forms are compounds or chemicals traditionally regarded as drugs, vaccines, and biopharmaceuticals. Certain such agents may include molecules such as proteins, peptides, hormones, nucleic acids, gene constructs, etc., for use in therapeutic, diagnostic, and/or enhancement areas, including, but not limited to medical or veterinary treatment, prevention, diagnosis, and/or mitigation of disease or illness (e.g., HMG co-A reductase inhibitors (statins) like rosuvastatin, nonsteroidal anti-inflammatory drugs like meloxicam, selective serotonin reuptake inhibitors like escitalopram, blood thinning agents like clopidogrel, steroids like prednisone, antipsychotics like aripiprazole and risperidone, analgesics like buprenorphine, antagonists like naloxone, montelukast, and memantine, cardiac glycosides like digoxin, alpha blockers like tamsulosin, cholesterol absorption inhibitors like ezetimibe, metabolites like colchicine, antihistamines like loratadine and cetirizine, opioids like loperamide, protonpump inhibitors like omeprazole, anti(retro)viral agents like entecavir, dolutegravir, rilpivirine, and cabotegravir, antibiotics like doxycycline, ciprofloxacin, and azithromycin, anti-malarial agents, and synthroid/levothyroxine); substance abuse treatment e.g., methadone and varenicline); family planning (<?.g., hormonal contraception); performance enhancement (e.g., stimulants like caffeine); and nutrition and supplements (e.g., protein, folic acid, calcium, iodine, iron, zinc, thiamine, niacin, vitamin C, vitamin D, and other vitamin or mineral supplements).

In certain forms, the active substance is one or more specific therapeutic agents. As used herein, the term “therapeutic agent” or also referred to as a “drug” refers to an agent that is administered to a subject to treat a disease, disorder, or other clinically recognized condition, or for prophylactic purposes, and has a clinically significant effect on the body of the subject to treat and/or prevent the disease, disorder, or condition. Such treatment only requires a reduction or alteration in one or more symptoms of a disorder, disease, or condition between treated, not necessarily elimination. Listings of examples of known therapeutic agents can be found, for example, in the United States Pharmacopeia (USP), Goodman and Gilman’s The Pharmacological Basis of Therapeutics, 10th Ed., McGraw Hill, 2001 ; Katzung, B. (ed.) Basic and Clinical Pharmacology, McGraw-Hill/ Appleton & Lange; 8th edition (September 21, 2000); Physician’s Desk Reference (Thomson Publishing), and/or The Merck Manual of Diagnosis and Therapy, 17th ed. (1999), or the 18th ed (2006) following its publication, Mark H. Beers and Robert Berkow (eds.), Merck Publishing Group, or, in the case of animals, The Merck Veterinary Manual, 9th ed., Kahn, C.A. (ed.), Merck Publishing Group, 2005; and “Approved Drug Products with Therapeutic Equivalence and Evaluations," published by the United States Food and Drug Administration (F.D.A.) (the “Orange Book"). Examples of drugs approved for human use are listed by the FDA under 21 C.F.R. §§ 330.5, 331 through 361, and 440 through 460, incorporated herein by reference; drugs for veterinary use are listed by the FDA under 21 C.F.R. §§ 500 through 589, incorporated herein by reference. In certain forms, the therapeutic agent is a small molecule. Exemplary classes of therapeutic agents include, but are not limited to, analgesics, anti-analgesics, anti-inflammatory drugs, antipyretics, antidepressants, antiepileptics, antipsychotic agents, neuroprotective agents, anti-proliferatives, anti-cancer agents (including chemotherapeutic agents, checkpoint inhibitor agents, stimulator of interferon genes (STING) agonists, antihistamines, antimigraine drugs, hormones, prostaglandins, antimicrobials (including antibiotics, antifungals, antivirals, antiparasitics), antimuscarinics, anxioltyics, bacteriostatics, immunosuppressant agents, immunostimulatory agents, sedatives, hypnotics, antipsychotics, bronchodilators, anti-asthma drugs, cardiovascular drugs, anesthetics, anti-coagulants, inhibitors of an enzyme, steroidal agents, steroidal or non-steroidal anti-inflammatory agents, corticosteroids, dopaminergics, electrolytes, gastro-intestinal drugs, muscle relaxants, nutritional agents, vitamins, parasympathomimetics, stimulants, anorectics and anti-narcoleptics. Nutraceuticals can also be incorporated into the drug delivery device. These may be vitamins, supplements such as calcium or biotin, or natural ingredients such as plant extracts or phytohormones.

In some forms, the therapeutic agent is one or more antimalarial drugs. Exemplary antimalarial drugs include quinine, lumefantrine, chloroquine, amodiaquine, pyrimethamine, proguanil, chlorproguanil- dapsone, sulfonamides such as sulfadoxine and sulfamethoxypyridazine, mefloquine, atovaquone, primaquine, halofantrine, doxycycline, clindamycin, artemisinin and artemisinin derivatives. In some forms, the antimalarial drug is artemisinin or a derivative thereof. Exemplary artemisinin derivatives include artemether, dihydroartemisinin, arteether and artesunate. In certain embodiments, the artemisinin derivative is artesunate.

In another form, the therapeutic agent is an immunosuppressive agent. Exemplary immunosuppressive agents include glucocorticoids, cytostatics (such as alkylating agents, antimetabolites, and cytotoxic antibodies), antibodies (such as those directed against T-cell receptors or 11-2 receptors), drugs acting on immunophilins (such as cyclosporine, tacrolimus, and sirolimus) and other drugs (such as interferons, opioids, TNF binding proteins, mycophenolate, and other small molecules such as fingolimod).

In certain forms, the therapeutic agent is a hormone or derivative thereof. Non-limiting examples of hormones include insulin, growth hormone (e.g., human growth hormone), vasopressin, melatonin, thyroxine, thyrotropin-releasing hormone, glycoprotein hormones (e.g., luteinzing hormone, follicle-stimulating hormone, thyroid-stimulating hormone), eicosanoids, estrogen, progestin, testosterone, estradiol, cortisol, adrenaline, and other steroids.

In some forms, the therapeutic agent is a small molecule drug having molecular weight less than about 2500 Daltons, less than about 2000 Daltons, less than about 1500 Daltons, less than about 1000 Daltons, less than about 750 Daltons, less than about 500 Daltons, less or than about 400 Daltons. In some cases, the therapeutic agent is a small molecule drug having molecular weight between 200 Daltons and 400 Daltons, between 400 Daltons and 1000 Daltons, between 200 Daltons and 2500 Daltons, between 400 Daltons and 2500 Daltons, or between 500 Daltons and 2500 Daltons.

In some forms, the therapeutic agent is a STING agonist. STING is a cytosolic receptor that senses both exogenous and endogenous cytosolic cyclic dinucleotides (CDNs), activating TBK1/IRF3 (interferon regulatory factor 3), NF-KB (nuclear factor KB), and STAT6 (signal transducer and activator of transcription 6) signaling pathways to induce robust type I interferon and proinflammatory cytokine responses. STING is encoded by the TMEM173 gene. It works as both a direct cytosolic DNA sensor (CDS) and an adaptor protein in Type I interferon signaling through different molecular mechanisms. It has been shown to activate downstream transcription factors STAT6 and IRF3 through TBK1, which are responsible for antiviral response and innate immune response against intracellular pathogen. Any STING agonists known in the art can be used in accordance with the compositions and methods. The STING agonist can be a nucleic acid, a protein, a peptide, a polymer, or a small molecule. The STING agonist can be natural or synthetic. In some embodiments, the STING agonist is hydrophilic.

Suitable STING agonists include cyclic dinucleotides (CDNs) or non- cyclic dinucleotide agonists. Cyclic purine dinucleotides such as, but not limited to, cGMP, cyclic di-GMP (c-di-GMP), cAMP, cyclic di-AMP (c-di- AMP), cyclic-GMP-AMP (cGAMP), cyclic di-IMP (c-di-IMP), cyclic AMPIMP (cAIMP), and any analogue thereof, can be used. The CDNs may have 2’3’, 2’5’, 3’3’, or 3’5’ bonds linking the cyclic dinucleotides, or any combination thereof. For example, 2’ 3 ’-cGAMP or 3’3 ’-cGAMP can be used. Cyclic purine dinucleotides may be modified via standard organic chemistry techniques to produce analogues of purine dinucleotides. Suitable purine dinucleotides include, but are not limited to, adenine, guanine, inosine, hypoxanthine, xanthine, isoguanine, or any other appropriate purine dinucleotide known in the art. The cyclic dinucleotides may be modified analogues. Any suitable modification known in the art may be used, including, but not limited to, phosphorothioate, biphosphorothioate, fluorinate, and difluorinate modifications.

In some forms, the cyclic dinucleotides may include modified cyclic dinucleotides, such as a compound of the formula:

In further forms, R1 and R2 may be independently 9-purine, 9-adenine, 9- guanine, 9-hypoxanthine, 9-xanthine, 9-uric acid, or 9-isoguanine.

Suitable STING agonists include stereoisomers of cyclic purine dinuclotides (e.g., substantially pure Rp,Rp or Rp,Sp diastereomers thereof). c-di-AMP, c-di-GMP, c-di-IMP, c-AMP-GMP, c- AMP-IMP, and c-GMP- IMP, and analogs thereof including, but not limited to, phosphorothioate analogues, referred to herein as “thiophosphates” can be used. Phosphorothioates are a variant of normal nucleotides in which one of the nonbridging oxygens is replaced by a sulfur. The sulfurization of the intemucleotide bond dramatically reduces the action of endo- and exonucleases, including 5' to 3' and 3' to 5' DNA POL 1 exonuclease, nucleases SI and Pl , RNases, serum nucleases and snake venom phosphodiesterase. In addition, the potential for crossing the lipid bilayer increases.

A phosphorothioate linkage is inherently chiral. The skilled artisan will recognize that the phosphates in this structure may each exist in R or S forms. Thus, Rp,Rp, Sp,Sp, and Rp,Sp forms are possible. In each case, preferred are substantially pure Rp,Rp and Rp,Sp diastereomers of these molecules.

Suitable cyclic purine dinuclotides also include 2'-O-substituent forms of CDNs, and in particular CDN thiophosphates. Additional stability and bioavailability can be provided by the substitution of the 2'-OH of the ribose moiety. Substituent groups amenable herein include without limitation, halogen, hydroxyl, alkyl, alkenyl, alkynyl, acyl ( — C(0)R_aa), carboxyl ( — C(0)0-R_aa), aliphatic groups, alicyclic groups, alkoxy, substituted oxy (-0-R_aa), aryl, aralkyl, heterocyclic radical, heteroaryl, heteroarylalkyl, amino ( — N(Rbb)(Rcc)), imino(=NRbt>), amido ( — C(0)N(R_bb)(Rcc) or — N(Rbb)C(O)Raa), azido (— N₃), nitro (— N0₂), cyano ( — CN), carbamide ( — OC(0)N(Rbb)(Rcc) or — N(Rbb)C(Q)OR_aa), ureido ( — N(Rbb)C(O)-N(Rbb)(Rcc)), thioureido (— N(Rbb)C(S)N(R_bb)(Rcc)), guanidinyl ( — N(Rbb)C(=NRbb)N(Rbb)(Rcc)), amidinyl ( — C(=NRbb)N(Rbb)(Rcc) or — N(Rbb)C(=NRbb)(R_aa)), thiol (— SR_bb), sulfinyl ( — S(O)Rbb), sulfonyl ( — S(0)2Rb) and sulfonamidyl ( — S(0)2N(Rbb)(Rcc) or — N(Rbb)S(0)2Rbb). Wherein each Raa, Rbb and R_cc is, independently, H, an optionally linked chemical functional group or a further substituent group such as, H, alkyl, alkenyl, alkynyl, aliphatic, alkoxy, acyl, aryl, aralkyl, heteroaryl, alicyclic, heterocyclic and heteroarylalkyl. Suitable cyclic purine dinuclotides also include S-substituent forms of CDNs, and in particular CDN thiophosphates, which can advantageously provide prodrugs with improved bioavailability.

Non-cyclic dinucleotide agonists may also be used, such as 5,6- Dimethylxanthenone- 4-acetic acid (DMXAA; also known as Vadimezan or ASA404), or any other non-cyclic dinucleotide agonist known in the art.

Exemplary STING agonists include, but are not limited to, STING agonist-1, ML RR-S2 CD A, ML RR-S2c-di-GMP, ML-RR-S2 cGAMP, 2’ 3’ -c-di-AM(PS)2, 2’3’-cGAMPdFHS, 3'3'-cGAMPdFSH, cAIMP, cAIM(PS)2, 3’3’-cAIMP, 3’3’-cAIMPdFSH, 2’2’-cGAMP, 2’3’- cGAM(PS)2, 2'3'-cGsAsMP (bisphosphothioate analog of 2'3'-cGAMP), 3’3’-cGAMP, c- di-AMP, 2’3’-c-di-AMP, 2’3’-c-di-AM(PS)2, c-di-GMP, 2’3’-c-di-GMP, c-di-IMP, c-di-UMP, MK-2118, GSK3745417, TAK-676, CRD5500, SB 11325, SB 11396, TTI-10001, MAVU-104 (ENPP1 inhibitor), Dispiro diketopiperzine (DSDP) see Antiviral research. 2017 Nov 1 ; 147:37-46), Benzo[b][l,4]thiazine-6-carboxamide (indirect STING agonist), a-Mangostin (human STING-pref erring agonist), Benzamide and its analogues (see ACS Infect Dis 2019;5;l 139-49), Bicyclic benzamides, and Benzothiophene derivatives. Suitable STING agonists also include those disclosed in US 2016/0287623, WO 2019/183578, WO 2019/069270, WO 2019/069275, U.S. 9,695,212, U.S. 9,724,408, U.S. 10,450,341, WO 2019/079261, WO 2018/234805, WO 2018/234808, WO 2018/067423 and Ramanjulu JM., et al., Nature, 564(7736):439-443 (2018) which discloses amidobenzimidazole (ABZI) compounds as STING agonists, all of which are hereby incorporated by reference in their entirety.

In a preferred form, the STING agonist is selected from the group including cGAMP, DMXAA, MK-1454, MK-2118, E7766, MIW815 (ADU- S100), BMS-986301, GSK3745417, IMSA-101, SYNB 1891 (E.coli), SITX- 285.

The STING agonists can be functionalized, for example with ether, ester, or amide linkage, if desired. For example, DMXAA can be modified to DMXAA ester, DMXAA ether, or DMXAA amide.

In some forms, the therapeutic agent is selected from the group composed of active pharmaceutical agents such as insulin, nucleic acids, peptides, bacteriophage, DNA, mRNA, human growth hormone, monoclonal antibodies, adalimumab, epinephrine, GLP-1 Receptor agonists, semaglutide, liraglutide, dulaglitide, exenatide, factor VIII, small molecule drugs, progestin, vaccines, subunit vaccines, recombinant vaccines, polysaccharide vaccines, and conjugate vaccines, toxoid vaccines, influenza vaccine, shingles vaccine, prevnar pneumonia vaccine, mmr vaccine, tetanus vaccine, hepatitis vaccine, HIV vaccine Ad4-env Clade C, HIV vaccine Ad4-mGag, dna vaccines, ma vaccines, etanercept, infliximab, filgastrim, glatiramer acetate, rituximab, bevacizumab, any molecule encapsulated in a nanoparticle, epinephrine, lysozyme, glucose-6-phosphate dehydrogenase, other enzymes, certolizumab pegol, ustekinumab, ixekizumab, golimumab, brodalumab, gusellu,ab, secikinumab, omalizumab, tnf-alpha inhibitors, interleukin inhibitors, vedolizumab, octreotide, teriperatide, crispr cas9, insulin glargine, insulin detemir, insulin lispro, insulin aspart, human insulin, antisense oligonucleotides, and ondansetron.

In some forms, the component described herein comprises two or more types of therapeutic agents.

In some forms, the therapeutic agent may be present at a concentration below a minimal concentration generally associated with an active therapeutic agent (e.g., at a microdose concentration). For example, in some forms, the tissue interfacing component comprises a first therapeutic agent (e.g., a steroid) at a relatively low dose (e.g., without wishing to be bound by theory, low doses of therapeutic agents such as steroids may mediate a subject’s foreign body response(s) (e.g., in response to contact by a tissue interfacing components) at a location internal to a subject). In some forms, the concentration of the therapeutic agent is a microdose less than or equal to 100 pg and/or 30 nMol. In other forms, however, the therapeutic agent is not provided in a microdose and is present in one or more amounts listed above.

A specific combination of agents can be proteins (e.g., growth factors such as epidermal growth factors, vascular endothelial growth factors) and small molecules (e.g. , anti-fibrotic agents such as TGF-P inhibitors).

The agents are released from the hybrid polymeric system in one or more time periods, which are the same or different in duration and/or time of release. In some forms, the agents are released at multiple times or time periods, with a release time independently selected from about 1 day, about 4 days, about 8 days, about 11 days, about 15 days, about 18 days, about 97 days, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, and about 1 year. Preferably, the hybrid polymeric system releases the agent in a pulsatile pattern with no burst release between pulsed releases.

Polymeric particles of the same or different polymer composition, and/or having the same or different agent(s) may be combined within one hybrid polymeric system. In some forms, polymeric particles enclosing the same or different agent(s) are combined within a single hybrid polymeric system. In some forms, polymeric particles differing in polymer composition may be combined within a single hybrid polymeric system.

In some forms, polymeric particles containing the same polymer and enclosing the same agent are combined within a single hybrid polymeric system. In some forms, polymeric particles containing different polymers and enclosing the same agent are combined within a single hybrid polymeric system.

In some forms, polymeric particles containing the same polymer and enclosing different agent(s) are combined within a single hybrid polymeric system. In some forms, polymeric particles containing different polymers and enclosing different agents are combined within a single hybrid polymeric system.

In each of the hybrid polymeric systems described above, the polymeric particles can be designed so that the polymeric particles have similar degradation rates and release the agents at about the same time. In another form in each of the hybrid polymeric systems described above, the polymeric particles can be designed so that a subset of the polymeric particles possesses a first degradation rate and releases the agents at a first time, and another subset of the polymeric particles possesses a second degradation rate and releases the agents at a second time. In these forms, the first degradation rate is different from the second degradation rate and, consequently, the first release time is different from the second release time, e.g., the second release time occurs later than the first release time.

In some forms, the release time(s) of the agents can be tailored so that multiple drugs are released at different time points that coincide with different physiological processes of an organ/tissue, such as the healing stages. In a non-limiting example, a hybrid polymeric system containing polymeric particles was designed for sequential delivery of different agents post-myocardial infarction. By encapsulating three drugs — proteins (e.g., neuregulins (particularly neuregulin- 1 ) for immediate post-Ml repair, vascular endothelial growth factor (VEGF) for angiogenesis during the recovery phase, and a TGF-P inhibitor (e.g., pirfenidone) to prevent late- stage fibrosis — within polymeric microparticles (e.g., PLGA microparticles) in a hybrid polymeric system, targeted and timed therapeutic interventions were achieved. In vitro testing with cardiac spheres subjected to hypoxic conditions demonstrated the system's efficacy, with the drug-loaded hybrid polymeric system significantly enhancing cell survival, promoting angiogenesis, and reducing fibrosis. Additional examples of anti-fibrotic agents that can be provided with the polymeric particles include, but are not limited to, TGF-P inhibitors (such as tranilast, losartan, glitazones, imatinib mesylate, pirfenidone, and halofuginone), rapamycin, retinoic acid, penicillamine, colchicine, captopril, enalapril, telmisartan, epigallocatechin gallate, cyclosporine, nintedanib, metformin, antagomirs (e.g,, lademirsen) or drugs targeting interleukin 11 or NKD2 (WNT signaling pathway inhibitor). Nintedanib is a multi-tyrosine kinase inhibitor which blocks FGF receptor- 1 , VEGF receptor-2, and PDGF receptor-a and P52. Thus, other anti-fibrotic kinase inhibitors could also be used.

The rate of release of agent(s) incorporated within the polymeric particles can be tuned by the molecular weight (e.g., number- averaged molecular weight of the polymer or co-polymer, weight- averaged molecular weight of the polymer or co-polymer), poly dispersity index of the polymer or co-polymer, chain end functionality of the polymer or co-polymer, the ratio of co-polymers, or a combination thereof. In some forms, the release kinetics can be tuned by the shell composition including 1) blending different ratios of hydrophobic polymers e.g., PLGA, PLA, or PGA), and 2) blending different ratios of hydrophilic polymer, hydrophobic polymer, salts. The release kinetics can also be tuned by the wall thickness of a surface eroding polymer, such as polyanhydride or polyorthoester. Accordingly, the hybrid polymeric system can contain a population of polymeric particles that are homogeneous in terms of their polymer composition (and therefore, properties) and/or incorporated agent(s). In some forms, the hybrid polymeric system contains two or more (e.g., 2, 3, 4, 5 or more) populations of polymeric particles that are heterogeneous in terms of their polymer composition (and therefore, properties) and/or incorporated agent(s). In some forms, the hybrid polymeric system contains two or more (e.g., 2, 3, 4, 5 or more) different agents.

III. Methods of Making and Reagents therefor

A. Hybrid polymeric systems and polymer matrix

The hybrid polymeric system can be made by dispersing the polymeric particles within a solvent containing a precursor polymer used to form the polymer matrix. The polymeric particles can be randomly dispersed or dispersed in an array. In some forms, the solvent contains peroxides or photoinitiators to initiate crosslinking. Covalent crosslinking can be initiated by exposing the solvent to an energy source, such as an electron beam, UV light, or heat. As discussed above, covalent crosslinking can also be performed in the presence of a second polymer e.g., a polysaccharide such as an alginate), to form interpenetrating networks in which the second polymer is not involved in covalent crosslinking. Upon covalent crosslinking, the precursor polymer forms a crosslinked polymer in the polymer matrix.

B. Polymeric particles

Where the therapeutic, prophylactic, or diagnostic agent is or can be dispersed within the polymer forming the polymeric particles, the polymeric particles can be prepared via methods that include, but are not limited to, self-assembly; crosslinking; solvent evaporation and/or emulsion encapsulation (such as single emulsion solvent evaporation or multiemulsion solvent evaporation); hot melt particle formation; solvent removal; spray drying; phase inversion; microfluidics; coacervation; low temperature casting; molecular dispersion or phase separated dispersion techniques; nanoprecipitation, or solid phase encapsulation techniques.

Where the therapeutic, prophylactic, or diagnostic agent is or can be dispensed in a discrete core space defined by a polymeric shell, the polymeric particles can be prepared via methods that include, but are not limited to, three-dimensional printing, micromolding, nanoimprint lithography, micro-imprint lithography, solvent-assisted micro-molding, micro-fluidic contact printing, micro-contact hot printing, step and flash imprint lithography, or a combination thereof.

StampEd Assembly of polymer Layers (SEAL)

The polymeric particles (such as the microdevices) can be produced using StampEd Assembly of polymer Layers (SEAL). See McHugh KJ., et al., Science, 357(6356): 1138- 1142 (2017). The SEAL method creates an array of compartment- shell polymer devices. First, the polymer of choice, e.g., PLGA, is melt pressed using a prefabricated silicone mold. The mold is then transferred to another substrate where it is peeled off, leaving behind an array of polymer bases. These are then filled with any drug or other agents using an inkjet piezoelectric nozzle and then dried. Caps are then aligned with the base devices and sealed. The resulting array of compartment- shell microdevices are then removed from the base and stored until use. 1. Molds

In some embodiments, molds are formed as follows. Two or more silicon molds with complementary patterns is etched using standard microfabrication techniques. Polydimethylsiloxane (PDMS) is then cured on the surface of each silicon wafer to produce inverse elastomeric molds. A polymer is then heated and pressed into the PDMS molds to produce laminar microstructure components of interest.

The first layer is then delaminated onto a separate surface, such as glass, using heat-assisted microtransfer molding. Subsequent layers of the final structure are then assembled using a layer-by-layer sintering process under microscopic alignment to produce a large array of microstructures. This process draws on elements from existing technology, including laminated object manufacturing, microfabrication-based surface patterning, and thermal bonding of PLGA, to create polymeric microdevices with well- defined geometry.

2. Layer-by- Layer Alignment and Sintering

To ensure high-fidelity microdevice fabrication, a technique to align layers during sintering with high precision is used. In some embodiment, this approach uses a photomask aligner (MA4, Karl Suss, Sunnyvale, CA) retrofitted with a Peltier heater, temperature controller, relay, and voltage source to enable simultaneous alignment and thermal bonding. The mask holder vacuum is applied to hold a glass slide containing the first microstructure layer facing down while the next layer, still in the PDMS mold, is held on the wafer chuck. After optically aligning adjacent features using the mask aligner’s microscope and alignment knobs, the layers are brought into contact and heated to just above the polymer’ s glass transition temperature for up to 3 minutes. The sealing process is continuously monitored during this time by observing the disappearance of light diffraction patterns.

As two layers came into contact, the small air gap between them produces diffraction that resolves when the heated polymer flows to close the gap. After cooling samples to room temperature, the PDMS micromold containing the second layer is peeled off to yield a multi-layered microstructure. Individual microdevices are then removed from the glass slide.

3. Filling and Capping

The micromolded microdevice shells/bases are filled prior to sealing using a BioJet Ultra inkjet piezoelectric nozzle that can rapidly dispense picoliter volumes of a drug or other agent into a microdevice compartment. To seal the filled devices, a cap mold is aligned, sealed with the shell/base, and delaminated. The resulting array of compartment-shell devices is then removed from the base and stored until use.

4. Removing Scrum

In some cases, the polymer used to fill the micromolds forms a “scrum” at the top which should be removed before capping.

IV. Methods of Using

The hybrid polymeric system described herein, can be used as a versatile platform for the delivery of one or more therapeutic, prophylactic, or diagnostic agents. Given their demonstrated long-term release kinetics, the disclosed hybrid polymeric system is particularly suited for progressive and/or chronic diseases or disorders that require prolonged periods of release of therapeutic, prophylactic, or diagnostic agents, and diseases or disorders that require repeated administration of these agents. The hybrid polymeric system can be used to deliver an effective amount of one or more of these agents. The amount of agent to be administered can be readily determined by the prescribing physician and is dependent on the age and weight of the patient and the disease or disorder to be treated.

Preferred methods of administration include: buccal, by placement in the buccal cavity for uptake through the mouth; mucosal, e.g., intranasally or intravaginal administration, or direct application to a mucous membrane in the subject; direct application to an organ or tissue of a subject, such as intracranial; subcutaneous; intramuscular; intraperitoneal; transdermal, intratumoral administration, etc. The hybrid polymeric system can be administered as implants (such as films, membranes, or patches), capsules, tablets, etc. The films, membranes, or patches can be single-layered, multi-layered, unidirectional (i.e. , release drug through only side), multi-directional (i.e.. release drug through at least two sides), or a combination thereof. Preferably, the hybrid polymeric system is administered in a solid or semi-solid form.

Formulations containing polymeric particles of the same polymeric composition but enclosing different agents may be formulated to provide two or more different agents simultaneously as the polymer degrades. The formulations may be useful for combination therapies, for co-delivery of drugs, with only a single administration.

Formulations containing polymeric particles with different polymeric composition but enclosing the same agent(s) may be formulated for providing two or more pulsatile releases at two or more time points following a single administration. As shown in the Examples, such formulations can be useful for delivering therapeutics such as growth factors and small molecules to the heart during open heart surgery. A single administration of such formulations, allow for mimicking the repeat administration of drug or other agent as the timing of the pulsatile releases of incorporated agent(s) may be tuned.

Formulations containing polymeric particles with different polymeric composition and enclosing different agents may be formulated for providing two or more pulsatile releases at two or more time points as polymers of the different compositions degrade, releasing the different (e.g., 2, 3, 4, 5, or more) agents. Based on the composition of the microdevices, the formulations may release the two or more agents with each pulsatile release, or release only one type of agent with one release, and another type of agent with the subsequent release, following a single administration.

These formulations may be useful delivering therapeutic, prophylactic, or diagnostic agents to an organ or tissue selected from heart, stomach, liver, colon, kidney, brain, spinal column, dura, pleura, oral cavity, throat, esophagus, uterus, ovaries, breast, urinary tract, skeletal muscles, bones, vascular system (arteries and veins), nerves, skin, subcutaneous tissue, lungs, gastrointestinal tract, bladder, cartilage, tendon, ligaments, eye (e.g., cornea of the eye), etc. ; or optionally one or more of these organs or tissues postoperative cancer treatment.

V. Prophetic examples

Preparation of hybrid polymeric systems containing a polymer matrix formed from poly(ethylene glycol) tetra acrylate (PEGTA), polymers with functional groups capable of participating click chemistry (click chemistry hydrogels), other interpenetrating hydrogels, or fiber reinforced composite tough hydrogels, and polymeric particles containing different types of PLGA, PLA, or combinations of these dispersed within the polymer matrix. The polymeric particles will encapsulate therapeutic, prophylactic, or diagnostic agents. Examples of these agents will include small molecules, peptides, and cancer vaccines. The polymer matrix will have a Young’s modulus between 1 kPa to 150 kPa and be comparable to that of tissues or organs such as the heart, stomach, colon, subcutaneous tissue, lungs, gastrointestinal tract, bladder, etc.

Examples

Example 1: A Hybrid Polymeric System for Programmed Drug Release to the Heart

Development of a hybrid polymeric drug depot system composed of a tough hydrogel network and embedded core-shell microparticles. Polylactic-co-glycolic acid (PLGA), an FDA-approved polymer with high biocompatibility was used to construct core-shell microparticles for drug loading. Briefly, soft lithography and replica molding techniques were employed to mold PLGA into arrays of cubic microparticles with cavities as previously described (McHugh KJ, et al., Science, 357(6356): 1138-1142 (2017); Lu X, et al., Sci Transl A/e<L; 12(556):eaaz6606 (2020)).). Drug compounds (e.g., growth factors and small molecules) and stabilizing excipients were filled into the particle cores using a piezoelectric dispenser. The loaded particles were sealed with a cap layer using previously established microfabrication method termed stamped assembly of polymer layers (SEAL)(McHugh KJ, et al., Science, 357(6356): 1138-1142 (2017)). A multimodal drug delivery system was designed by patterning PLGA-MP arrays with different release profiles within a single device (Figure 1A).

A tough hydrogel patch served as a high-capacity depot for encapsulating the PLGA microparticles (PLGA-MPs). A dual interpenetrating network of alginate and Poly(ethylene glycol) diacrylate (PEGDA) was crosslinked to fabricate the hydrogel patch (Figure IB). Adhesion to the injured epicardium can be achieved by unilateral coupling of the amine-rich bridging polymer chitosan to the dissipative alginate network, or through surgical suturing (Blacklow et al., Sci Adv., 5(7):eaaw3963 (2019)). Once implanted, these sealed PLGA-MPs can release individual cargo in a pulsatile pattern with no burst release (Figure 1C).

Programmed codelivery of multimodal compounds in different therapeutic windows after myocardial infarction

The modularity of this platform makes it easily compatible with delivering combination therapy of multi-dosing regimens within a single administration. Delivery time and duration can be precisely controlled by tuning the molecular weight (MW), chain-end functionality, and copolymer ratio of the PLGA cap. To achieve the delivery regimen in line with the timedependent remodeling of the damaged myocardium, programmed release kinetics can be achieved by patterning MPs that can release cargos on day 1 (fabricated with AP81 PLGA cap), day 7 (fabricated with 502H PLGA cap), and day 14 (fabricated with 502HCC PLGA cap), demonstrated by the delivery of fluorescently labeled dextran macromolecules from corresponding MPs (Figure ID). Figure ID shows accumulative release of different fluorescent macromolecules from corresponding microparticles on the same device measured at different time points to demonstrate differential release time windows can be achieved. To achieve sequential and combination therapy for myocardial infarction, three compounds including neuregulin 1 (NRG1), vascular endothelial growth factor (VEGF), and TGF- 0 Small Molecule Inhibitor (pirfenidone) were filled in the microparticles, targeting three consecutive post-MI pathological phases (inflammatory, proliferative, and regenerative phases). Mechanical and toxicity tests demonstrated ideal biocompatibility and slow degradation profiles of the polymeric system.

In conclusion, this hybrid polymeric system simultaneously provides mechanical support to the injured myocardium through the tough hydrogel matrix and enables controlled drug delivery for cardiac regeneration through the core-shell microparticles. The hybrid polymeric system described in the above study offers a fully programmable design for localized cardiac drug delivery. The device implantation can go hand in hand with routine surgical procedures such as coronary artery bypass grafting and serve as a reinforcement for postoperative cardiac repair and regeneration. The findings of this study can provide new knowledge necessary for evaluating the temporal effect of cardiac regenerative therapies. This platform also holds great potential for treating a range of progressive diseases that require multimodal or repeated administration of therapeutics.

Example 2: Release Profiles of SEAL Microparticle Arrays

As a separate extension of the SEAL microparticle technology, a hybrid polymeric system can serve as an implantable device for localized drug delivery, which cannot be achieved by the previously SEAL method alone. A key difference lies in the capacity of the hybrid polymeric system to deliver the SEAL microparticles to surgical sites and enable the immobilization of these particles on the surface of soft tissue. This hybrid polymeric system simultaneously provides mechanical support to the surgical sites (e.g., injured myocardium) through the tough hydrogel matrix and enables controlled drug delivery through the embedded core-shell microparticles. Additional advantages of the hybrid polymeric system are described in the experiments below.

Study 1: High Delivery Efficacy of the Hybrid Polymeric System

The hybrid polymeric system overcame the previous injectability challenges underlying SEAL microparticle administration. Arrays of microparticles were patterned and embedded in a small hydrogel patch to achieve high drug loading (Figure 2). In the current design, 144 microparticles can be delivered in 12x12 arrays within a patch of 1cm² , with room for optimization. The footprint of the patch can be easily tuned based on desired microparticle numbers.

Study 2: Immobilization of Microparticles on Surgical Sites

The SEAL microparticles were encapsulated in the hydrogel patch (Figure 3A). As shown in Figure 3A, complete particle encapsulation occurs even when the patch is stretched four times the original length. Figure 3B is a line graph showing time course images of embedded SEAL particle degradation within the hydrogel patch over a 3 -month incubation. The hybrid polymeric system can immobilize SEAL microparticles in surgical sites until they fully degrade. The interpenetrating hydrogel network has a slower degradation rate than PLGA, offering a depot system for securing the microparticles in place and extending their release time. The hydrogel formulation is tuned to have high toughness to prevent microparticle detachment caused by patch rupture. This depot system will enhance microparticle retention on targeted tissue site and facilitate longterm release of therapeutics.

Study 3: Compatibility with Different Surgical Procedures

The hybrid polymeric system offers a fully programmable design for localized cardiac drug delivery. As shown in Figure 4, the device implantation can go hand in hand with routine surgical procedures such as coronary artery bypass grafting (for cardiac implantation) and endoscopy (for GI tract implantation). This system can be used for treating a range of progressive diseases that require multimodal or repeated administration of therapeutics, such as growth factor and small molecule delivery to the heart during open heart surgery, postoperative cancer treatment after tumor resection, wound healing therapy for burn patients when repeated administration is associated with pain.

Adhesion to the target organ can be achieved by unilateral coupling of the amine-rich bridging polymer chitosan to the dissipative alginate network. Additionally, the hydrogel matrix is tough enough to provide the holding power for both prolene and silk sutures. For surgical sites that are difficult to adhere to, such as the GI tract, the patch can be secured with biodegradation sutures. For example, Figures 5A and 5B are photos showing the hybrid polymeric system implanted on rat hearts using a 6-0 prolene surgical suture (Figure 5A) and a bridging chitosan adhesive layer (Figure 5B). This demonstrates that fixation to surgical sites can be achieved by unilateral coupling of the amine-rich bridging polymer chitosan to the dissipative alginate network, or through fasteners such as sutures and staples, showing the versatility of the disclosed hybrid polymeric compositions and implantation methods.

Example 3: Mechanical Toughness, Elasticity, and Degradation Rate of Hybrid Polymeric System.

To achieve safe encapsulation and immobilization of the SEAL microparticles, a hydrogel network with high toughness is desired. The patch needs to be long-lasting and durable, and it should be resistant to rupture to prevent SEAL particle escape and associated risks. Therefore, high mechanical toughness is a key design feature. Additionally, as the patch will be implanted onto soft tissue, it needs to withstand tensile stress and mechanical deformations involved in dynamic tissue motions, such as the contraction of the heart. Therefore, high elasticity is another required feature. More specifically, the hydrogel is required to have a slower degradation rate compared to PLGA, in order to immobilize SEAL particles in place till complete particle degradation. The patch can be degradable, eliminating the need for surgical removal. However, most hydrogels do not exhibit both high toughness and elasticity. The majority of previously reported tough hydrogel patches often contain polyacrylamide (PAAm). Although PAAm is relatively nontoxic to humans, the acrylamide monomer can be adsorbed via dermal exposure and inhalation, and it is a known neurotoxin and a potential carcinogen. Therefore, an objective was to develop a safe replacement for PAAm. The PEG-based hydrogels of the present study offer a great option due to their safety for in vivo delivery, tunable thermal or UV crosslinking methods, and commercial accessibility (to ensure less batch-to-batch variation). A number of PEG-based formulations were screened as shown below in Table 1. A list of PEG-based hydrogels was formed through photopolymerization or thermal- polymerization methods to screen required crosslinking time and mechanical property.

Table 1 : List of Tested Formulations for the Patch Design

Table 1 (continued): List of Tested Formulations for the Patch Design

As a result, the dual interpenetrating network of alginate and PEGDA (MN=20000) demonstrated the most optimal features, including (1) low toxicity, (2) high hydrophilicity and high Permeability for hydrophilic molecules, (3) low swelling ratio (5% swelling ratio and reaches equilibrium in 2 hours in the air-liquid interface) (4) have Young’s modulus ideal for cardiac applications (normally ranges from 10 kPA-100 kPa), and (5) short UV crosslinking time for preserving drug bioactivity. Figures 6A and 6B show the observations mechanical testing the particle loaded hydrogel patch. The mechanical property using the final formulation matches young’s modulus of the native myocardium (with Young’s modulus around 20- lOOkPa) (Figure 6B).

Fabrication method for the encapsulation of SEAL particles in the hydrogel network

Figure 7 is a schematic showing the fabrication method designed for the encapsulation of SEAL particles in the hydrogel network. Figures 8A and 8B are pictures showing failed encapsulation using a softer hydrogel formation (Figure 8A), and successful encapsulation using the final formulation and the instant fabrication method (Figure 8B). The tough hydrogel network enables a 100% SEAL particle encapsulation rate using the fabrication method that is compatible with our formulation. Using a hydrogel lacking toughness, or simply mixing the particles in hydrogel will cause a low encapsulation rate and escape of particles from the patch during implantation, as shown in Figure 3A.

Example 4: In vitro and in vivo assessments of surgical implantation and microparticle embedding. Case study: cardiac implantation.

To assess the applicability of the disclosed hybrid polymeric systems for delivery of agents, e.g., therapeutic delivery, comprehensive studies were conducted to extensively characterize their surgical applications. The current results, which highlight its efficacy in cardiac implantation through in vitro and in vivo assessments, underscore the system's applicability in a much wider range of medical applications. Designed for long-term surgical implantation and microparticle embedding, the system was tailored to meet the therapeutic delivery needs across diverse tissues and organs. The modularity of the system facilitates the customization of several aspects to meet the demands of a broad spectrum of medical applications and specific tissue needs. These customizable aspects include: (1) size, shape, and thickness: tailoring the patch's size, shape, and thickness to align with the dimensions and topography of various tissue sites ensures optimal fit and integration, (2) microparticle patterning: fine-tuning the number of microparticles within the patch can meet the therapeutic requirements of each site, (3) release kinetics: incorporating microparticles with varied release profiles, tailored to address different pathological processes, and (4) mechanical properties: the patch’s mechanical characteristics, such as tensile strength and elasticity, are adjustable based on the patch’s composition. This customization is realized by altering the ratios of polymers and crosslinkers and fine-tuning the crosslinking intensity or density. By allowing for such a high degree of customization, the system’s performance can be tailored for each specific application. The characterizations on tensile strength, elasticity, and biocompatibility confirm the system's robustness, functionality, and wide-ranging compatibility within the physiological environment throughout the desired therapeutic timeframe. In the extensive in vivo investigation, the hybrid polymeric system was tailored to facilitate precise cardiac repair after myocardial infarction (MI), illustrating its capacity for therapeutic intervention through targeted, phase-specific drug delivery. The hybrid polymeric system tailored to cardiac application was designed with a focus on elasticity and mechanical toughness, which are tailored through the patch’s composition using an interpenetrating network. Additionally, the release kinetics are adjusted to span a given time post-surgery (e.g., 1-month post-surgery), aligning with the timeframe in which recurrent myocardial infarctions (MI) commonly occur. In some specific instances, the patch is formulated in the form of a hydrogel. In a rodent myocardial infarction (MI) model induced by Left Anterior Descending Coronary Artery (LAD) ligation, this advanced system, engineered to sequentially release therapeutic compounds (Neuregulin- 1 , VEGF, and a TGF-|3 inhibitor), has proven to significantly enhance survival rates, improve cardiac function, and reduce injury markers following device implantation post-MI. Overall, the findings described here and elaborated on below not only confirm the system's multifunctional capabilities, but also establish a foundation for its application across a diverse range of therapeutic scenarios.

The hybrid polymeric systems employed in this example were developed following the steps described in Example 1 above, and tested as described below.

Mechanical Characterization of the Hybrid System Patch for Long- Term Surgical Implantation and Microparticle Embedding The biomechanical integrity of an implantable drug delivery system plays an important role for its efficacy and longevity. The results show that the hybrid polymeric patch exhibits an initial Young's modulus of over 100 KPa (FIG. 9B). While these findings were initially demonstrated in the context of cardiac implantation, the implications extend beyond, covering a spectrum of tissues and organs where such mechanical properties are desirable. Additional examples of tissues and organs where these mechanical properties are applicable include: (1) skin, patches that exhibit similar elasticity to skin can conform to body movements, providing comfort and promoting healing, (2) cartilage, interventions in the knee or other joints, materials that mimic the mechanical properties of cartilage can help restore function and delay or prevent the onset of degenerative diseases, (3) tendons and ligaments, high tensile strength and elasticity can withstand the forces of movement and support healing, (4) herniated tissues, reinforcement or bridging of herniated tissue, materials with appropriate tensile strength can prevent recurrence and support tissue integration, (5) cornea, patches with suitable elasticity can maintain the eye’s curvature and transparency, and (6) lungs, the lung’s unique requirements for elasticity and mechanical integrity make materials with high Young’s modulus ideal for facilitating gas exchange. This versatility ensures the patch’ s capability to comply with the mechanical movements inherent to diverse anatomical sites while preserving its structural integrity. Notably, after a month of storage at 4°C, the Young’s modulus exhibited a minor reduction to about 80 Kpa. Despite this decrease, the patch still demonstrates suitable biomechanical compatibility with various tissue types. Without wishing to be bound by theory, it is believe that this mechanical profile aligns with the requirements of various other tissues, making the patch compatible for multiple clinical applications beyond cardiac implantation, such as in vascular grafts, wound healing, and soft tissue repair.

To evaluate the patch’s long-term viability for diverse clinical uses, an in vivo testing protocol was implemented using a balloon system actuated by a ventilator. This approach, originally conceived to replicate the dynamic contraction of the heart, is adaptable to model the mechanical stresses relevant to other organs, such as the lungs during respiration, the gastrointestinal tract during peristalsis, or the bladder during expansion and contraction.

Subjecting the patch (e.g. , hydrogel patch) to 2 million cycles of stretching, in a setting that closely mirrors the physiological conditions (37°C and humid environment), allowed for the assessment of its exceptional durability and fatigue resistance. The patch demonstrated significant antifatigue characteristics, maintaining structural integrity and functional performance throughout the testing period. The feature not only demonstrated its applicability for cardiac therapy but also highlights its suitability for a myriad of other implantation sites.

Long-Term Biocompatibility and Low Toxicity

The assessment of an implantable device’s biocompatibility and toxicity profile is an important aspect in the engineering of medical devices. To accurately evaluate these parameters, Human Umbilical Vein Endothelial Cells (HUVECs) within a transwell system was utilized. The choice of HUVECs is due to their representativeness of endothelial functionality across various vascularized tissues, not limited to cardiac applications. This model provides an effective proxy for examining the interaction between the engineered patch and the endothelial lining of blood vessels, which is very important for a wide range of organ systems.

The results (FIG. 10B) show a markedly low cytotoxicity of the hybrid patch, showcasing its superior biocompatibility when compared to polyacrylamide (PAAm) hydrogel patches, a commonly referenced material in biomedical engineering. These results reveal the hybrid patch’s enhanced safety profile, demonstrating its viability as a preferred material for diverse implantation scenarios.

Design of a Cardiac Combination Therapy Using a Hybrid System and in vivo Validation in a Rodent Model of Myocardial Infarction The current application of this system to a cardiac condition provides an example of its potential for surgical and therapeutic use, addressing its versatility with targeted, stage-specific drug delivery.

The treatment of myocardial infarction (MI) necessitates a multifaceted approach, particularly given the complex progressive nature of cardiac remodeling. Many of the current controlled delivery systems lack the sophistication to release multiple drugs at different time points tailored to the stages of cardiac healing. This study presents a hybrid polymeric system designed for sequential drug delivery post-MI, demonstrating its applicability for targeted and/or sequential/staged therapy in progressive diseases. By encapsulating three drugs — Neuregulin-1 (NRG1) for immediate post-MI repair, Vascular Endothelial Growth Factor (VEGF) for angiogenesis during the recovery phase, and a TGF-P inhibitor to prevent late-stage fibrosis — within PLGA microparticles in the hybrid patch, targeted, timed therapeutic interventions were achieved (FIG. 11A). In vitro testing with cardiac spheres subjected to hypoxic conditions demonstrated the system’s efficacy, with the drug-loaded patch significantly enhancing cell survival, promoting angiogenesis, and reducing fibrosis (FIG. 11B). The data highlight not only the system’ s potential for cardiac repair but also its adaptability to other therapeutic contexts requiring staged drug delivery.

Extensive in vivo validation of hybrid polymeric systems were performed utilizing a rodent model of MI established via left anterior descending (LAD) artery ligation (FIG. 12A), a method acknowledged for its clinical relevance in simulating MI conditions.

The experimental design includes four cohorts (FIGs. 12B and 12C): a baseline group subjected to LAD ligation to represent the untreated acute MI phenotype, a group receiving systemically administered soluble drugs at predetermined intervals via tail vein injection, a control group undergoing LAD ligation followed by the implantation of an empty patch to evaluate the biomaterial’s intrinsic effects and the surgical intervention, and finally, a treatment group subjected to LAD ligation and subsequent implantation of a drug-eluting hybrid patch.

Notably, the drug-eluting and the empty patch cohorts demonstrated enhanced survival rates and attenuated weight loss compared to their untreated and soluble drug counterparts (FIGs. 12F and 12G), implicating a potential biomechanical stabilization effect imparted by the patch substrate itself. Cardiac injury markers, including Troponin I, Troponin T, and Creatine Kinase-MB (CK-MB), were quantitatively assessed using a luminex assay (FIGs. 12H and 121). The cohort treated with the drug-eluting patch exhibited significantly reduced biomarker levels, indicative of ameliorated cardiac injury.

Functional cardiac assessments were performed weekly via echocardiography (FIG. 12J), with parameters such as ejection fraction (FIG. 12K) and fractional shortening (FIG. 12L) being monitored longitudinally. The cohort receiving the drug-eluting patch exhibited a decelerated decline in these critical functional indices, implying effective therapeutic delivery and a contributory role of the patch in maintaining cardiac function post-MI. Histopathological analysis corroborated the therapeutic efficacy of the patch. In the treated cohort, there was a notable diminution in infarct size coupled with augmented capillary density in the peri-infarct region. Additionally, a pronounced reduction in fibrotic deposition was observed, attributable to the orchestrated release of the TGF- beta inhibitor.

In sum, the in vivo validation conducted with our rodent model post- LAD ligation highlights our engineered system's substantial promise as an implantable solution designed to restore cardiac function and facilitate tissue regeneration.

The data presented in this non-limiting example not only validated the hybrid system’s adaptability but also uncovered surprising results related to its application in preventing surgical adhesions. At the outset, the investigation was not centered on the adhesion effects; however, observations during the study revealed a significant reduction in surgical adhesion with the drug-loaded patch compared to other groups (FIG. 13B). Regarding the release of anti-fibrotic agents, the unforeseen discovery was that the drug-loaded patch significantly reduced the heart's adhesion to the chest wall and extended beyond our original anticipations. This unexpected finding is particularly compelling because the formation of surgical adhesions is a time-sensitive process. This technology offers a distinct opportunity to mitigate this challenge through the temporally controlled release of anti-fibrotic factors, elevating its potential impact beyond initial expectations and marking a significant advancement in surgical recovery. This unexpected outcome, attributed to the timed release of anti-fibrotic agents and reduced collagen deposition, emphasizes the system's added value in enhancing post-surgical recovery. Unexpected Reduction in Surgical Adhesion

This study revealed a surgical finding on the complex issue of surgical adhesion, a prevalent complication that can severely undermine the outcomes of surgical interventions. Surgical adhesions are fibrous bands that form between tissues and organs following surgery, often leading to discomfort, pain, restricted mobility, and sometimes necessitating additional surgical procedures to resolve. These adhesions can significantly detract from the quality of post-surgical recovery, making their prevention a priority in surgical and postoperative care.

In a comparative analysis among different groups within this study (FIGs. 13A and 13B), the drug-encapsulated patch demonstrated a remarkable ability to reduce surgical adhesion. In contrast to control groups where empty patches without drug loading adhered to the chest wall, the group implanted with the drug-loaded patch showed a drastically different outcome. Not only was there a significant reduction in adhesion, but the patch also maintained a smooth surface of the material upon inspection after a 4-week endpoint in an open-chest model, demonstrating less fibrosis encapsulation.

Mechanism Behind Reduced Adhesion

Without wishing to be bound by theory, it is believed that this notable reduction in adhesion can be attributed to the strategic design of the patch, which incorporates a timed-release mechanism for an anti-fibrotic factor. The inclusion of a TGF-P inhibitor in the patch's formulation plays an important role in this process of reducing fibrosis. TGF-p, a cytokine involved in cellular proliferation and differentiation, plays a dual role in the healing process. While it aids in early wound healing by promoting cell growth and differentiation, its prolonged activity can lead to excessive collagen deposition, contributing to fibrosis and adhesion formation. By timing the release of the TGF-P inhibitor to coincide with the phase when fibrotic signaling becomes detrimental, the patch effectively counteracts the formation of adhesions without compromising the initial stages of wound healing. The smooth surface of the material observed after 4 weeks, coupled with the reduced attachment, demonstrated the efficacy of the system in preventing the excessive deposition of collagen. This approach not only mitigates the risk of surgical adhesions but also enhances the quality of post- surgical recovery by maintaining the integrity and functionality of the surgical site.

Implications for Broad Application in Surgery

The implementation of our hybrid polymeric system extends beyond cardiac surgery, offering transformative potential across a spectrum of surgical disciplines where adhesions pose a significant risk.

In surgeries where adhesion poses a significant risk, such as abdominal, pelvic, and other surgeries, implementing this hydrogel patch could drastically enhance wound healing processes and post-surgical recovery. In abdominal surgeries, such as procedures for treating endometriosis, where adhesions can lead to chronic pain and fertility issues. In such cases, the conventional approach might involve the use of physical barriers or gels to prevent tissue adhesion post-surgery, yet these solutions often offer limited efficacy and lack the ability to deliver targeted therapeutic agents. Our hybrid polymeric system could be strategically implanted at the site of intervention to deliver a precise sequence of anti-inflammatory and anti-fibrotic agents. Unlike traditional anti-adhesive materials that passively attempt to reduce adhesion formation by acting as physical barriers, our system actively releases drugs in a targeted manner. For instance, an initial release of anti-inflammatory drugs could reduce acute post-operative inflammation, followed by the timed release of TGF-P inhibitors to prevent excessive fibrotic tissue formation.

When compared to other anti-adhesive materials, such as hyaluronic acid-based gels or oxidized regenerated cellulose films, the disclosed hybrid polymeric systems stand out for their multifunctionality and active therapeutic role. Specifically, the hybrid polymeric systems not only serve as an anti-adhesive barrier but also provide important mechanical support to tissues. Moreover, the hybrid polymeric systems facilitate the co-delivery of other therapeutic agents, such as those that promote tissue regeneration and angiogenesis. This dual capability of mechanical reinforcement and combined therapeutic effects highlights the advanced multifunctional nature of the systems. By actively modulating the biological processes involved in adhesion formation, the disclosed systems offer a more effective solution compared to traditional materials that serve only as passive barriers. This proactive approach not only prevents adhesions but also facilitates healthier tissue regeneration and healing.

By leveraging targeted drug delivery, tunability, and the disclosed system's active role in modulating healing processes, the disclosed systems offer a superior alternative to existing anti-adhesive materials. This innovation not only has the potential to improve surgical outcomes, but also to redefine postoperative care in various surgical fields, marking a step forward in approaches to surgical healing and recovery.

Furthermore, the disclosed systems find applicability in oncological surgery, especially for postoperative care following tumor resection. They can adeptly deliver anti-cancer drugs directly to the surgical site, where drug- filled particles are uniformly distributed within the targeted area via its hydrogel depot. This approach can facilitate a focused and effective postoperative treatment regimen, thereby reducing the likelihood of tumor recurrence and improving outcomes for patients undergoing tumor resection.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

We claim:

1. A hybrid polymeric system comprising:

(a) a polymer matrix comprising polymeric particles dispersed within the polymer matrix, and

(b) therapeutic, diagnostic, and/or prophylactic agents encapsulated in the polymeric particles, wherein the polymer matrix and the polymeric particles have different degradation rates, and the degradation rate of the polymer matrix is less than that of at least one of the polymeric particles.

2. The hybrid polymeric system of claim 1, wherein the polymeric particles are formed by 3D printing, micromolding, lithography (such as nanoimprint lithography), or a combination thereof.

3. The hybrid polymeric system of claim 1 or 2, wherein the polymeric particles comprise core-shell particles.

4. The hybrid polymeric system of any one of claims 1 to 3, wherein the polymeric particles comprise a shell that defines a discrete core space containing the therapeutic, diagnostic, nutraceutical, and/or prophylactic agents.

5. The hybrid polymeric system of claim 4, comprising a polymeric cap sealed to the shell to enclose the discrete core space.

6. The hybrid polymeric system of any one of claims 1 to 5, wherein the polymeric particles are microdevices.

7. The hybrid polymeric system of any one of claims 1 to 6, wherein the polymeric particles comprise at least one external dimension of between 1 pm and 1000 pm.

8. The hybrid polymeric system of any one of claims 1 to 7, wherein the polymeric particles are non-spherical.

9. The hybrid polymeric system of any one of claims 1 to 8, wherein the polymeric particles comprise polyesters (such as polyhydroxyacids), poly anhydrides, poly(ortho)esters, polyip-dioxanone), poly (poly urethane), polycarbonate, polyphosphate, polyphosphonate, and a combination thereof.

10. The hybrid polymeric system of any one of claims 1 to 9, wherein the polymeric particles comprise polyesters, preferably linear aliphatic polyesters.

11. The hybrid polymeric system of any one of claims 1 to 10, wherein the polymeric particles comprise poly(lactic acid-co-glycolic acid), poly(lactic acid), poly(glycolic acid), poly(caprolactone), poly(pentadecalactone), poly(hydroxybutyrate-co-hydroxyvalerate), poly(hydroxybutyrate), polybutylene succinate, and a combination thereof.

12. The hybrid polymeric system of any one of claims 1 to 11, wherein the polymeric particles comprise poly(lactic acid-co-glycolic acid).

13. The hybrid polymeric system of any one of claims 1 to 12, wherein the polymer matrix comprises polyalkylene oxides such as poly(ethylene glycol) (PEG); polysaccharides such as alginates, glucosaminoglycans, celluloses, and dextrans; poly (oxy ethylated polyol); poly(olefinic alcohol) such as poly(vinyl alcohol); poly(N-vinylpyrrolidone); acrylic or acrylate, and alkacrylic or alkacrylate polymers such as poly(acrylic acid), poly(methacrylic acid), poly(hydroxyethyl acrylate); poly(N,N- dimethylaminoethyl methacrylate), poly(hydroxy alkyl methacrylate) e.g. poly (hydroxy ethyl methacrylate); acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; and poly(4-vinylpyridine); and copolymers thereof.

14. The hybrid polymeric system of any one of claims 1 to 13, wherein the polymer matrix comprises polyalkylene oxides such as poly(ethylene glycol) (PEG); polysaccharides such as alginates, acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; or combinations thereof.

15. The hybrid polymeric system of any one of claims 1 to 14, wherein the polymer matrix comprises polyalkylene oxides such as poly(ethylene glycol) (PEG).

16. The hybrid polymeric system of any one of claims 1 to 15, wherein the polymer matrix comprises acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide.

17. The hybrid polymeric system of claim 15 or 16, wherein the polymer matrix further comprises polysaccharides such as alginates.

18. The hybrid polymeric system of any one of claims 1 to 17, wherein the polymer matrix is formed by covalently crosslinking a subset of polymers within the matrix.

19. The hybrid polymeric system of claim 18, wherein the subset of polymers comprises polyalkylene oxides such as poly(ethylene glycol) (PEG); poly(oxyethylated polyol); poly(olefinic alcohol) such as poly(vinyl alcohol); poly(N-vinylpyrrolidone); acrylic or acrylate, and alkacrylic or alkacrylate polymers such as poly(acrylic acid), poly(methacrylic acid), poly(hydroxyethyl acrylate); poly(N,N-dimethylaminoethyl methacrylate), poly (hydroxy alkyl methacrylate) e.g. poly (hydroxy ethyl methacrylate); acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; and poly(4- vinylpyridine); blends and copolymers thereof.

20. The hybrid polymeric system of claim 18 or 19, wherein the subset of polymers comprises polyalkylene oxides such as poly(ethylene glycol) (PEG); acrylamide polymers such as poly(acrylamide), poly(hydroxyalkyl methacrylamide) e.g. poly(hydroxyethyl methacrylamide; or combinations thereof.

21. The hybrid polymeric system of any one of claims 18 to 20, wherein crosslinking is performed using crosslinking agents selected from an energy source (such as an electron beam, UV light, or heat); peroxides; and/or photoinitiators (such as dimethylhydroxyacetophenone (DMHA), 2,4,6- trimethylbenzoyldiphenylphosphone oxide (TPO), hydroxylcyclohexylphenylketone (CPK), 2,2-dimethoxy-2- phenylacetophenone (DMPA), benzophenone, 2,2-diethyloxyactetophenone, 2,4-diethylthiozanthone, isopropylthioxanthone, 2,4,6- trimethylbenzoyldiphenylphosphine oxide dimethylhydroxyacetophenone, ethyl(2,4,6-trimethylbenzoyl) phenylphosphinate, 2-phenylbenzophenone, methyl-o-benzoyl-benzoate, and methylbenzoylformate, or a combination thereof); or combinations thereof.

22. The hybrid polymeric system of any one of claims 1 to 21, wherein the polymer matrix is a hydrogel.

23. The hybrid polymeric system of any one of claims 1 to 22, wherein the polymer matrix has high elasticity and mechanical toughness, preferably wherein the elasticity is determined using Young’s modulus, and mechanical toughness is determined using elongation at break.

24. The hybrid polymeric system of any one of claims 1 to 23, wherein polymers forming the matrix have a weight average molecular weight between 12.5 kDa to 25 kDa, such as 12.5 kDa, 13 kDa, 14 kDa, 15 kDa, 16 kDa, 17 kDa, 18 kDa, 19 kDa, 20 kDa, 21 kDa, 22 kDa, 23 kDa, 24 kDa, and 25 kDa.

25. The hybrid polymeric system of any one of claims 1 to 24, wherein the polymer matrix has a Young’s modulus between 1 kPa to 150 kPa, such as 1 kPa, 2 kPa, 3 kPa, 4 kPa, 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, 100 kPa, 110 kPa, 120 kPa, 130 kPa, 140 kPa, and 150 kPa.

26. The hybrid polymeric system of any one of claims 1 to 25 in the form of a single-layered or multi-layered film, membrane, or patch, and is unidirectional (z.e., release drug through only one side), or multi-directional (i.e. release drug through at least two sides).

27. The hybrid polymeric system of any one of claims 1 to 26, wherein the hybrid polymeric system releases the therapeutic, diagnostic, and/or prophylactic agents in one or more time periods, which are the same or different in duration and/or time of release.

28. The hybrid polymeric system of any one of claims 1 to 27, for local delivery of the therapeutic, diagnostic, and/or prophylactic agents at an organ or tissue.

29. The hybrid polymeric system of any one of claims 1 to 28, wherein the therapeutic, diagnostic, and/or prophylactic agents are released at multiple times or time periods, with a release time independently selected from about 1 day, about 4 days, about 8 days, about 11 days, about 15 days, about 18 days, about 97 days, about 1 month, about 2 months, about 3 months, about 4 months, about 5 months, about 6 months, and about 1 year.

30. The hybrid polymeric system of any one of claims 1 to 29, wherein the polymeric particles are configured to release the therapeutic, diagnostic, nutraceutical, and/or prophylactic agents at different time points corresponding to particular physiological processes (e.g. , healing stages) of an organ or tissue.

31. The hybrid polymeric system of any one of claims 1 to 30, wherein the therapeutic, diagnostic, nutraceutical, and/or prophylactic agents are selected from proteins and small molecules (e.g., anti-fibrotic agents such as TGF-P inhibitors).

32. The hybrid polymeric system of any one of claims 1 to 31 , wherein the therapeutic, diagnostic, and/or prophylactic agents are selected from growth factors and anti-fibrotic agents.

33. A method of delivering a therapeutic, prophylactic, nutraceutical, and/or diagnostic agent to a subject in need thereof, the method comprising administering to the subject the hybrid polymeric system of any one of claims 1 to 32.

34. The method of claim 33, comprising administering the hybrid polymeric system to an organ or tissue of the subject.

35. The method of claim 34, wherein the organ or tissue is selected from heart, stomach, liver, colon, kidney, brain, spinal column, dura, pleura, oral cavity, throat, esophagus, uterus, ovaries, breast, urinary tract, skeletal muscles, bones, vascular system (arteries and veins), nerves, skin, subcutaneous tissue, lungs, gastrointestinal tract, bladder, cartilage, tendon, ligaments, eye (e.g., cornea of the eye), etc.', or optionally one or more of these organs or tissues are involved in postoperative cancer treatment, myocardial infarction, etc.