Acrylated gelatin polymer compositions comprising cells

Abstract

The present disclosure provides improved polymer compositions, such as acrylated gelatin polymer compositions. In certain embodiments, the improved polymer compositions can be used for delivering one or more therapeutic agents, such as cells, to a target therapeutic area, such as the eye of a subject. In certain embodiments, the improved polymer compositions are hydrogels which comprises acrylated gelatin (e.g., GelMA, GelAC, GelGA, GelGMA) or polymerically crosslinked derivatives thereof.

Description

ACRYLATED GELATIN POLYMER COMPOSITIONS COMPRISING CELLSFIELD OF THE DISCLOSURE

[0001] The present disclosure provides improved acrylated gelatin polymer compositions, such as GelMA or GelAC polymer compositions. In certain embodiments, the improved polymer compositions can be used for delivering one or more therapeutic agents, such as cells, to a target therapeutic area, such as the eye of a subject. In certain embodiments, the improved polymer compositions are hydrogels which comprises gelatin methacryloyl (i.e., GelMA), gelatin acryloyl (GelAC), gelatin glycidyl acrylate (GelGA), gelatin glycidyl methacrylate (GelGMA), or polymerically crosslinked derivatives thereof.INTRODUCTION

[0002] Acrylated gelatin polymer compositions have emerged as an effective material for use in sealing, repairing, and / or treating injuries, defects, or diseases in the soft tissues of subject. The design and production of improved acrylated gelatin polymer compositions for this purpose is an active field of study.

[0003] There remains a need for improved acrylated gelatin polymer compositions, methods for producing acrylated gelatin polymer compositions, and therapeutic applications for acrylated gelatin polymer compositions.SUMMARY

[0004] The details of various embodiments of the present disclosure are set forth in the description below.

[0005] In certain embodiments, the present disclosure provides polymer compositions which comprise at least one chemically modified gelatin. In certain embodiments, the polymer composition comprises at least one acrylated gelatin. In certain embodiments, the polymer composition comprises from about 0.5% to about 15.0% w / v of chemically modified gelatin. In certain embodiments, the polymer composition comprises from about 0.5% to about 15.0% w / v of acrylated gelatin.

[0006] In certain embodiments, the polymer composition comprises at least one chemically modified gelatin (optionally an acrylated gelatin) and at least one polymer crosslinking initiator (e.g., photoinitiator). In certain embodiments, the polymer composition comprises: (i) at least one chemically modified gelatin (optionally an acrylated gelatin); (ii) at least one polymer crosslinking initiator; and (iii) a population of cells. In certain embodiments, the polymer composition comprises: (i) at least one acrylated gelatin; (ii) at least one polymer crosslinking initiator; and (iii) a population of cells. In certainembodiments, the polymer composition is a precursor polymer composition. In certain embodiments, the polymer composition is a gel polymer composition.

[0007] In certain embodiments, the polymer composition comprises from about 5 million cells / mL to about 20 million cells / mL of the cells. In certain embodiments, the polymer composition comprises from about 10 million cells / mL to about 15 million cells / mL of the cells. In certain embodiments, the polymer composition comprises about 10 million cells / mL or about 15 million cells / mL of the cells.

[0008] In certain embodiments, the polymer composition comprises at least one crosslinking initiator. In certain embodiments, the crosslinking initiator comprises one or more light-activated photo-initiators, optionally one or more photo-initiators activated by visible light. In certain embodiments, the polymer crosslinking initiator comprises eosin Y, N-vinylcaprolactam, triethanolamine, or any combination thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y disodium salt (EYDS), N- vinylcaprolactam (NVC), triethanolamine, or any combination thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y or eosin Y disodium salt (EYDS), N-Vinylpyrrolidone (NVP), triethanolamine, or any combination thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y or eosin Y disodium salt (EYDS), methylene bisacrylamide (MBA), triethanolamine, or any combination thereof.

[0009] In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y or eosin Y disodium salt (EYDS); (ii) from about 1.0 to about 5.0 pL / mL ofN- vinylcaprolactam (NVC) or N-Vinylpyrrolidone (NVP); and (iii) triethanolamine. In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y disodium salt (EYDS); (ii) about 5.0 pL / mL N-Vinylpyrrolidone (NVP); and (iii) about 1.5% v / v of triethanolamine.

[0010] In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y or eosin Y disodium salt (EYDS); (ii) from about 0.2% to about 0.3% methylene bisacrylamide (MBA); and (iii) triethanolamine. In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y disodium salt (EYDS); (ii) about 0.25% methylene bisacrylamide (MBA); and (iii) about 1.5% v / v of triethanolamine.

[0011] In certain embodiments, the chemically modified gelatin is an acrylated gelatin. In certain embodiments, the polymer composition comprises from about 0.5% to about 15.0% w / v of at least one acrylated gelatin. In certain embodiments, the polymer composition comprises from about 1.0% to about 10.0% w / v of at least one acrylated gelatin. In certainembodiments, the polymer composition comprises from about 1.0% to about 5.0% w / v of at least one acrylated gelatin.

[0012] In certain embodiments, the acrylated gelatin has a degree of functionalization from about 10-80%. In certain embodiments, the acrylated gelatin has a degree of functionalization from 30-60%. In certain embodiments, the acrylated gelatin has a degree of functionalization of about 30%, about 45%, or about 60%.

[0013] In certain embodiments, the chemically modified gelatin comprises gelatin methacryloyl (GelMA). In certain embodiments, the polymer composition comprises from about 0.5% to about 15.0% w / v of GelMA. In certain embodiments, the polymer composition comprises from about 2% to about 5.0% w / v of GelMA. In certain embodiments, the polymer composition comprises from about 2% to about 3.5% w / v of GelMA. In certain embodiments, the polymer composition comprises about 1.0% w / v of GelMA. In certain embodiments, the polymer composition comprises about 1.5% w / v of GelMA. In certain embodiments, the polymer composition comprises about 2.0% w / v of GelMA. In certain embodiments, the polymer composition comprises about 2.5% w / v of GelMA. In certain embodiments, the polymer composition comprises about 3.0% w / v of GelMA. In certain embodiments, the polymer composition comprises about 3.5% w / v of GelMA. In certain embodiments, the polymer composition comprises about 4.0% w / v of GelMA. In certain embodiments, the polymer composition comprises about 4.5% w / v of GelMA. In certain embodiments, the polymer composition comprises about 5.0% w / v of GelMA.

[0014] In certain embodiments, at least a portion of the GelMA has a degree of methacrylation (DoM) from about 10-80%. In certain embodiments, at least a portion of the GelMA has a degree of methacrylation (DoM) from 40-60% DoM. In certain embodiments, at least a portion of the GelMA has a degree of methacrylation (DoM) of about 40%. In certain embodiments, at least a portion of the GelMA has a degree of methacrylation (DoM) of about 60% DoM.

[0015] In certain embodiments, the GelMA has a degree of methacrylation from about 10- 80%. In certain embodiments, the GelMA has a degree of methacrylation from 40-60%. In certain embodiments, the GelMA has a degree of methacrylation of about 40% or about 60%.

[0016] In certain embodiments, at least a portion of the GelMA in the polymer composition has an average molecular weight from about 90 kDa to about 160 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has an average molecular weight of about 90 kDa, about 138 kDa, or about 160 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has an averagemolecular weight of about 90. In certain embodiments, at least a portion of the GelMA in the polymer composition has an average molecular weight of about 160 kDa.

[0017] In certain embodiments, the GelMA in the polymer composition has an average molecular weight of about 90 kDa, about 138 kDa, or about 160 kDa. In certain embodiments, the GelMA in the polymer composition has an average molecular weight of about 90 kDa. In certain embodiments, the GelMA in the polymer composition has an average molecular weight of about 160 kDa.

[0018] In certain embodiments, at least a portion of the GelMA in the polymer composition has about 60% DoM and an average molecular weight from about 90-160 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 60% DoM and an average molecular weight of about 90 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 60% DoM and an average molecular weight of about 160 kDa.

[0019] In certain embodiments, at least a portion of the GelMA in the polymer composition has about 40% DoM and an average molecular weight from about 90-160 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 40% DoM and an average molecular weight of about 90 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 40% DoM and an average molecular weight of about 160 kDa.

[0020] In certain embodiments, at least a portion of the GelMA in the polymer composition has about 10% DoM and an average molecular weight from about 90-160 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 10% DoM and an average molecular weight of about 90 kDa. In certain embodiments, at least a portion of the GelMA in the polymer composition has about 10% DoM and an average molecular weight of about 160 kDa.

[0021] In certain embodiments, the polymer composition comprises about 2.5% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa. In certain embodiments, the polymer composition comprises about 2.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa. In certain embodiments, the polymer composition comprises about 5.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa. In certain embodiments, the polymer composition comprises about 5.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa. In certain embodiments, the polymer composition comprises about 1.0% w / v of GelMA, having about 10% DoM and an average molecularweight of about 160 kDa. In certain embodiments, the polymer composition comprises about 2.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa. In certain embodiments, the polymer composition comprises about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa. In certain embodiments, the polymer composition comprises about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa about 2.5% of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa. In certain embodiments, the polymer composition comprises about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa. In certain embodiments, the polymer composition comprises about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa about 2.0% of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa.

[0022] In certain embodiments, the polymer composition comprises any combination of (a) about 2.5% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (b) about 2.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (c) about 5.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (d) about 5.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; (e) about 1.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa; (f) about 2.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa; (g) about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; (h) about 2.5% of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa; (i) about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; and (j) about 2.0% of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa.

[0023] In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture. In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 0.5% to about 5% w / v. In certain embodiments, the total GelMA in the polymer composition is from about 2% to about 5% w / v. In certain embodiments, the total GelMA in the polymer composition is from about 2% to about 4% w / v. In certain embodiments, total GelMA in the polymer composition is from about 3% to about 5% w / v. In certain embodiments, the total GelMA inthe polymer composition is from about 3% to about 4% w / v. In certain embodiments, the total GelMA in the polymer composition is from about 3.5% w / v.

[0024] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 60% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 10% DoM and an average molecular weight of about 160 kDa. In certain embodiments, the polymer composition comprises: (a) about 2.5% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa.

[0025] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa.

[0026] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; wherein the ratio of GelMA which has about 40% DoM and an average molecular weight of about 90 kDa to GelMA which has about 40% DoM and an average molecular weight of about 160 kDa is about 7:3.

[0027] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; wherein the ratio of GelMA which has about 40% DoM and an average molecular weight of about 90 kDa to GelMA which has about 40% DoM and an average molecular weight of about 160 kDa is about 7:3; and wherein the composition comprises about 2.5% w / v of GelMA.

[0028] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; wherein the ratio of GelMA which has about 40% DoM and an average molecular weight of about 90 kDa to GelMA which has about 40% DoM and an average molecular weight of about 160 kDa is about 7:3; and wherein the composition comprises about 3.0% w / v of GelMA.

[0029] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; wherein the ratio of GelMA which has about 40% DoM and an average molecular weight of about 90 kDato GelMA which has about 40% DoM and an average molecular weight of about 160 kDa is about 7:3; and wherein the composition comprises about 3.5% w / v of GelMA.

[0030] In certain embodiments, the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; wherein the ratio of GelMA which has about 40% DoM and an average molecular weight of about 90 kDa to GelMA which has about 40% DoM and an average molecular weight of about 160 kDa is about 7:3; and wherein the composition comprises about 4.0% w / v of GelMA.

[0031] In certain embodiments, the polymer composition comprises: (a) about 2.0-3.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) about 0.5-1.5% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

[0032] In certain embodiments, the polymer composition comprises: (a) about 2.5% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

[0033] In certain embodiments, the polymer composition comprises: (a) 2.45% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) 1.05% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

[0034] In certain embodiments, the polymer composition comprises: (a) about 2.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

[0035] In certain embodiments, the polymer composition comprises: (a) 2.1% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) 0.9% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

[0036] In certain embodiments, the GelMA is functionalized with at least one acrylate- PEG-arginine-glycine-aspartic acid-serine (acrylate-PEG -RGDS). In certain embodiments, the polymer composition comprises about 5.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa, and the GelMA is functionalized with at least one acrylate-PEG-arginine-glycine-aspartic acid-serine (acrylate-PEG -RGDS)

[0037] In certain embodiments, the chemically modified gelatin comprises gelatin acryloyl (GelAC).

[0038] In certain embodiments, at least one acrylated gelatin comprises gelatin glycidyl acrylate (GelGA). In certain embodiments, the polymer composition comprises from about 0.5% to about 5.0% w / v of GelGA. In certain embodiments, the polymer composition from about 1% to about 3.5% w / v of GelGA. In certain embodiments, the polymer composition about 1.0% w / v of GelGA, about 2.5% w / v of GelGA, or about 3.5% w / v of GelGA.

[0039] In certain embodiments, the GelGA has a degree of functionalization (DoF) from about 45-60%. In certain embodiments, the GelGA has a degree of functionalization of about 45% or about 60% DoF. In certain embodiments, the GelGA in the polymer composition has an average molecular weight of about 7 kDa, about 11.5 kDa, more than 11.5 kDa, about 48 kDa, or about 50 kDa or more.

[0040] In certain embodiments, the GelGA in the polymer composition comprises: (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; or (iv) any combination of (i)-(iii). In certain embodiments, the GelGA in the polymer composition comprises (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more.

[0041] In certain embodiments, the polymer composition comprises about 2.5% w / v of GelGA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGA has about 45% DoF. In certain embodiments, the polymer composition comprises about 1.0% w / v of GelGA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGA has about 45% DoF.

[0042] In certain embodiments, the GelGA in the polymer composition comprises about 90% of GelGA with an average molecular weight of about 11.5 kDa and about 10% of GelGA with an average molecular weight of more than 11.5 kDa. In certain embodiments, the polymer composition comprises about 2.5% w / v of GelGA which has a DoF of about60%, and (i) about 90% of the Gel GA has an average molecular weight of about 11.5 kDa; and (ii) about 10% of the Gel GA has an average molecular weight of more than 11.5 kDa. In certain embodiments, the polymer composition comprises about 3.5% w / v of Gel GA which has a DoF of about 60%, and (i) about 90% of the GelGA has an average molecular weight of about 11.5 kDa; and (ii) about 10% of the GelGA has an average molecular weight of more than 11.5 kDa.

[0043] In certain embodiments, the polymer composition comprises: (a) about 2.5% w / v of GelGA which has a DoF of about 60%, and (i) about 90% of the GelGA has an average molecular weight of about 11.5 kDa and (ii) about 10% of the GelGA has an average molecular weight of more than 11.5 kDa; and (b) about 2.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa.

[0044] In certain embodiments, the polymer composition comprises polymer composition comprises: (a) about 1.0% w / v of GelGA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; and (b) about 2.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa.

[0045] In certain embodiments, the at least one acrylated gelatin comprises gelatin glycidyl methacrylate (GelGMA). In certain embodiments, the polymer composition comprises about 10% w / v of GelGMA. In certain embodiments, the GelGMA has a degree of functionalization (DoF) of about 30% DoF. In certain embodiments, the GelGMA in the polymer composition has an average molecular weight of about 7 kDa, about 48 kDa, or about 50 kDa or more.

[0046] In certain embodiments, the GelGMA in the polymer composition comprises: (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an average molecular weight of about 48 kDa; or (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more. In certain embodiments, the GelGMA in the polymer composition comprises (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more.

[0047] In certain embodiments, the polymer composition comprises: about 10% w / v of GelGMA which has a DoF of about 30%, and (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an average molecularweight of about 48 kDa; and (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGMA has about 45% DoF.

[0048] In certain embodiments, the population of cells comprise an endothelial cell. In certain embodiments, the population of cells comprise a human umbilical vein endothelial cell (HUVEC). In certain embodiments, the population of cells comprise an epithelial cell. In certain embodiments, the population of cells comprise a human retinal pigment epithelium cell (HRPEC). In certain embodiments, the population of cells comprise a human retinal pigment epithelium cell (HRPEC) derived from induced pluripotent stem cells (iPSC). In certain embodiments, the population of cells comprise an ocular cell, or a pluripotent or embryonic stem cell derived ocular cell.

[0049] In certain embodiments, the polymer composition further comprises at least 0.1% (w / v) of a hydrophilic non-ionic surfactant. In certain embodiments, the hydrophilic nonionic surfactant comprises at least one poloxamer surfactant such as Pol oxamer 407. In certain embodiments, the composition comprises about 0.2% (w / v) of a poloxamer surfactant such as Poloxamer 407.

[0050] In certain embodiments, the present disclosure describes a precursor polymer composition, comprising a polymer composition of the present disclosure. In certain embodiments, the present disclosure describes a gel polymer composition formed by photocrosslinking a precursor polymer composition of the present disclosure. In certain embodiments, the present disclosure describes a hydrogel polymer composition formed by photocrosslinking a precursor polymer composition of the present disclosure.

[0051] In certain embodiments, the present disclosure provides a method for treating and / or repairing a defect, injury, and / or disease in a target soft tissue of a subject. In certain embodiments, the present disclosure provides a method for treating and / or repairing a defect, injury, and / or disease in a target soft tissue of a subject, said method comprising: providing a precursor polymer composition of the present disclosure; administering the precursor polymer composition onto or under a surface of the target soft tissue of the subject, optionally the location of the soft tissue defect, injury, and / or disease; and crosslinking the precursor polymer composition by exposing the polymer crosslinking initiator in the polymer composition to crosslinking conditions, wherein the crosslinking of the precursor polymer composition produces a gel polymer composition.

[0052] In certain embodiments, the present disclosure provides a method for treating a defect, injury, and / or disease in a target soft tissue of a subject, said method comprising providing a gel polymer composition of the present disclosure and administering the gelpolymer composition onto, under, or near a surface of the target soft tissue of the subject. In certain embodiments, the gel polymer composition is administered at location of the soft tissue defect, injury, and / or disease.

[0053] In certain embodiments, the target soft tissue is ocular tissue. In certain embodiments, the target soft tissue is subconjunctival ocular tissue or retinal ocular tissue. In certain embodiments, the polymer composition is applied onto or under the surface of the ocular tissue by subconjunctival injection, subretinal injection, or suprachoroidal injection.

[0054] In certain embodiments, the defect, injury, and / or disease of the target soft tissue comprises an ocular defect, injury and / or disease; optionally an ocular ulcer such as a corneal ulcer from infections, injuries, perforations, or other defects. In certain embodiments, the ocular defect, injury and / or disease comprises a retinal degeneration disease. In certain embodiments, the ocular defect, injury and / or disease comprises age-related macular degeneration (AMD). In certain embodiments, the ocular defect, injury and / or disease comprises retinitis pigmentosa. In certain embodiments, the ocular defect, injury and / or disease comprises geographic atrophy.BRIEF DESCRIPTION OF THE FIGURES

[0055] The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the present disclosure, as illustrated in the accompanying figures. The figures are not necessarily to scale or comprehensive, with emphasis instead being placed upon illustrating the principles of various embodiments of the present disclosure.

[0056] FIG. 1 provides an example of a reaction in which gelatin is modified with methacrylic anhydride (MA) to form a methacryloyl-substituted gelatin (GelMA).

[0057] FIG. 2 provides a method 100 for producing gel polymer compositions of the present disclosure.

[0058] FIG. 3 provides an example of a series of reactions to produce a GelMA hydrogel polymer composition from gelatin methacryloyl polymer precursors using a photoinitiator element and light energy.

[0059] FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 4E, and FIG. 4F present GFP+ cell imaging results for a transwell underside cell growth study using Human Umbilical Vein Endothelial Cells (HUVECs) and certain embodiments of hydrogel of the present disclosure.

[0060] FIG. 5A, FIG. 5B, and FIG. 5C present confocal imaging results for a transwell underside cell growth study using Human Umbilical Vein Endothelial Cells (HUVECs) and certain embodiments of hydrogel of the present disclosure.

[0061] FIG. 6A, FIG. 6B, FIG. 6C, FIG. 6D, FIG. 6E, and FIG. 6F present GFP+ cell imaging results for a transwell underside cell growth study using Human Umbilical Vein Endothelial Cells (HUVECs) and certain embodiments of hydrogel of the present disclosure.

[0062] FIG. 7A, FIG. 7B, and FIG. 7C present Calcein AM+ based imaging results for a transwell underside cell growth study using Human Retinal Pigment Epithelium Cells (HRPEC) and certain embodiments of hydrogel of the present disclosure.

[0063] FIG. 8A, FIG. 8B, and FIG. 8C present Calcein AM+ based imaging results for a transwell topside cell growth study using Human Retinal Pigment Epithelium Cells (HRPEC) and certain embodiments of hydrogel of the present disclosure.

[0064] FIG. 9A provides live-cell Calcein AM imaging results related to in vitro retinal cell growth studies for hydrogel cell delivery formulations (~20 million cells / mL) of the present disclosure. FIG. 9B provides measurement for fluid shear rates related to the extrusion of GelMA precursor polymer formulations through the small -diameter needle. FIG. 9C provides live-cell Calcein AM imaging results related to in vitro retinal cell growth studies for hydrogel cell delivery formulations (~1 million cells / mL) of the present disclosure. FIG. 9D provides live-cell imaging results (anti-CD73 and anti-rhodopsin) related to in vitro retinal cell growth studies for hydrogel cell delivery formulations of the present disclosure.

[0065] FIG. 10A provides study results for cell localization and migration studies for hydrogel formulations of the present disclosure. FIG. 10B provides study results for hydrogel degradation studies for hydrogel formulations of the present disclosure. FIG. 10C and FIG. 10D show images of retinal detachment related to hydrogel formulations of the present disclosure. FIG. 10E is an image of human RPE cell deposition onto native pig RPE layers.

[0066] FIG. 11 provides cell growth study results related to hydrogel formulations of the present disclosure.

[0067] FIG. 12A and FIG. 12B present H&E and IHC cell count results for in vivo cell growth studies using Human Retinal Pigment Epithelium Cells (HRPEC) and certain embodiments of hydrogel of the present disclosure.

[0068] FIG. 13 presents the results of a cellular aggregation and viability studies using certain embodiments of hydrogel of the present disclosure.

[0069] FIG. 14 A, FIG. 14B, FIG. 14C, FIG. 14D, and FIG. 14E, provide live-cell imaging results related to retinal cell growth studies for hydrogel cell delivery formulations of the present disclosure.

[0070] FIG. 15 shows imaging of cell flow through glass needle for PBS and G5(90 / 60) samples.

[0071] FIG. 16A, FIG. 16B, FIG. 16C, FIG. 16D, FIG. 16E, and FIG. 16F provide results comparing rabbit eyes after an injection of a formulation containing 1% GelMA (160 / 10) + 2.5% GelMA (90 / 60) + 375 k cell dose versus a suspension of cells or no cells following rapid retinal pigment epithelial (RPE) degeneration.

[0072] FIG. 17A, FIG. 17B, and FIG. 17C compares chemical and mechanical properties of various GelMA mixtures versus controls.DETAILED DESCRIPTIONI. POLYMER COMPOSITIONSGeneral

[0073] The present disclosure provides polymer compositions (e.g., acrylated gelatin polymer compositions) which have one or more advantages over compositions in current commercial use or known in the art. In certain embodiments, the polymer compositions have one or more of the following advantages relative to one or more composition in current commercial use or known in the art: (i) lower in cost; (ii) easier to produce; (iii) improved biocompatibility; (iv) faster and / or stronger crosslinking and stabilization; (v) easier and / or more stable application; (vi) stronger adhesion and / or retention to target surface; (vii) degradation characteristics which can be engineered and adjusted; (viii) a smooth surface once applied; and / or (ix) higher cell viability or improved delivery for an encapsulated cell. In certain embodiments, polymer compositions of the present disclosure facilitate stable and sustained delivery of one or more therapeutic agents or cells to a target tissue. In certain embodiments, polymer compositions of the present disclosure facilitate controlled and sustained release of the one or more therapeutic agents or cells over a period of time to the target tissue. In certain embodiments, polymer compositions of the present disclosure facilitate stable and sustained delivery and growth of cells at a target treatment site. As such, the polymer compositions of the present disclosure present clear improvements over compositions in current commercial use and currently known in the art.

[0074] The term "polymer composition" as used herein can refer to a precursor polymer composition (e.g., a polymer composition before crosslinking polymerization) and / or a gel polymer composition (e.g., a polymer composition after crosslinking polymerization), as provided by the corresponding context of the disclosure. Examples of gel polymercompositions include hydrogels, and polymer compositions with increased viscosity (e.g., soft gels) resulting from crosslinking polymerization in the polymer composition.

[0075] In general, reference to a polymer component in the present disclosure (e.g., GelMA, GelAC, GelGA, GelGMA) can refer to a polymer precursor component (e.g., monomer or precursor oligomer), a crosslinked form of the polymer component in an oligomer (e.g., crosslinked oligomer), and / or a polymerized form of the polymer component in a gel polymer composition (e.g., hydrogel polymer), according to the context within the present disclosure.

[0076] In certain embodiments, the polymer compositions comprise one or more chemically modified gelatins, such as gelatin methacryloyl (i.e., GelMA), gelatin acryloyl (GelAC), gelatin glycidyl acrylate (GelGA), gelatin glycidyl methacrylate (GelGMA), or combinations thereof. In certain embodiments, the polymer compositions comprise gelatin methacryloyl (GelMA). In certain embodiments, the polymer compositions comprise gelatin acryloyl (GelAC). In certain embodiments, the polymer compositions comprise gelatin glycidyl acrylate (GelGA). In certain embodiments, the polymer compositions comprise gelatin glycidyl methacrylate (GelGMA), or combinations thereof. In certain embodiments, the polymer compositions comprise chemically modified gelatin (e.g., acrylated gelatin) and one or more crosslinking agents. In certain embodiments, the polymer compositions comprise chemically modified gelatin (e.g., acrylated gelatin) and one or more polymer crosslinking initiators, such as light-activated photo-initiator elements. In certain embodiments, the polymer compositions comprise chemically modified gelatin (e.g., acrylated gelatin), one or more crosslinking agents, and one or more polymer crosslinking initiators, such as light- activated photo-initiator elements.

[0077] In certain embodiments, the polymer compositions comprise acrylated gelatin, such as gelatin methacryloyl (i.e., GelMA), and a second acrylated gelatin, such as gelatin acryloyl (GelAC), gelatin glycidyl acrylate (GelGA). In certain embodiments, the polymer compositions comprise a combination of GelMA and GelAC. In certain embodiments, the polymer compositions comprise a combination of GelMA and GelGA. In certain embodiments, the polymer compositions comprise a combination of GelMA and GelGMA. In certain embodiments, the polymer compositions comprise a combination of GelAC and GelGA. In certain embodiments, the polymer compositions comprise a combination of GelAC and GelGMA. In certain embodiments, the polymer compositions comprise a combination of GelGA and GelGMA.

[0078] In certain embodiments, the polymer compositions do not comprise a hydrolyzing enzyme. In certain embodiments, the polymer compositions do not comprise a glycosidase hydrolyzing enzyme.

[0079] In certain embodiments, the gel polymer composition is a hydrogel. A hydrogel generally comprises a crosslinked polymeric framework which encompasses a network of pores filled with an interstitial solvent (e.g., a fluid) which includes water. In certain embodiments, a hydrogel polymer composition has a water content of about 80% or more. In certain embodiments, a hydrogel polymer composition has a water content of more than about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or more than about 99%.

[0080] In certain embodiments, a polymer composition (e.g., hydrogel or hydrogel precursor) of the present disclosure (e.g., acrylated gelatin polymer composition) is a primary polymer composition, and can include or be combined with one of more secondary hydrogelforming polymers components (i.e., polymers or precursors thereof). In certain embodiments, a polymer composition (e.g., hydrogel or hydrogel precursor) of the present disclosure (e.g., acrylated gelatin polymer composition) is a primary polymer composition, and can include or be combined with one of more secondary hydrogel-forming polymers components selected from acrylamide, acrylic acid, alginate, alginate methacrylate, cellulose, chitosan, chitosan methacrylate, dimethacrylamide, methylenebisacrylamide, fibronectin, gelatin, gelatin methacrylate, glycol chitosan, glycol chitosan methacrylate, hexyl methacrylate, hyaluronic acid, hyaluronic acid methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, isopropyl acrylamide, isopropyl methacrylamide, laminin, methacrylamide, methacrylic acid, polyamide, polycaprolactone, polyethylene-glycol (PEG), polyethylene-terephthalate, polylactic acid, polyurethane, polyvinyl alcohol, polyethyleneoxide dimethacrylate, siloxanes, polysiloxanes, or oligomer, polymers, and / or combinations thereof. In certain embodiments, a secondary hydrogel polymer (formed from the secondary hydrogel-forming polymer precursors) is covalently crosslinked with the primary gel polymer composition (e.g., GelMA polymer composition). In certain embodiments, the secondary hydrogel polymer (formed from the secondary hydrogel -forming polymer precursors) is not covalently crosslinked with the primary gel polymer composition (e.g., GelMA polymer composition), such, for example, the secondary hydrogel polymer forming a polymer network that is interwoven with the polymer network of the primary gel polymer composition.

[0081] In certain embodiments, a polymer composition of the present disclosure comprises one or more biocompatible polymer components or polysaccharides. In certain embodiments, a polymer composition of the present disclosure comprises one or more biocompatible polymer components or polysaccharides selected from agarose, alginates, amylopectin, amylose, carrageenan, cellulose, chitin, chitosans, chondroitin sulfate, collagen, dermatan sulfate, dextran, elastin, elastin-like polypeptides (ELPs), tropoelastin, fibrin, fibrinogen, fibronectin, gelatin, glycogen, heparan, heparan sulfate, heparin, heparin sulfate, hyaluronans, hyaluronic acid, keratan sulfate, laminin, pectin, polyglycerol sebacate (PGS), polyethylene glycol (PEG), polylactic acid (PLA), polylysine, starch, thrombin, derivatives thereof, or a combination thereof.

[0082] In certain embodiments, a polymer composition of the present disclosure comprises one or more cell-adhesion agents selected from fibronectin, laminin, vitronectin, RGD, vixapatin, derivatives thereof, or a combination thereof.

[0083] In certain embodiments, a polymer composition of the present disclosure comprises one or more synthetic polymer components, such as a biocompatible synthetic polymer component. In certain embodiments, a polymer composition comprises one or more synthetic polymer components selected from polyurethanes, polysiloxanes, silicones, polyethylenes, polyvinyl pyrrolidones, polyhydroxy ethylmethacrylates (poly-HEMA), polymethyl methacrylates, polyvinyl alcohols, polyacrylic acids, polyacrylamides, polyethylene-co-vinyl acetates, polyethylene glycols, polymethacrylic acids, polylactic acids, polyglycolic acids, polylactide-co-glycolides, nylons, polyamides, polyanhydrides, polyethylene-co-vinyl alcohols, polycaprolactones, polyvinyl acetates, polyvinylhydroxides, polyethylene oxides, polyorthoesters, polyallyl amines, polyethylene imines, polylysines, polyarginines, derivatives thereof, or combinations and / or copolymers thereof.

[0084] In certain embodiments, a polymer composition of the present disclosure comprises one or more polymer components (e.g., monomers, precursors, polymers) which include a crosslinkable group. In certain embodiments, a polymer composition of the present disclosure comprises one or more polymer components which include a crosslinkable group selected from (or formed from reaction with) anhydrides, acid halides, carboxylic acids, diols, acrylic anhydrides, methacrylic anhydrides, acryloyl chlorides, acryloyl bromides, methacryloyl chlorides, methacryloyl bromides, acrylic acids, glycidyl methacrylates, methacrylic acids, dopamines, derivatives thereof, or combinations thereof.

[0085] In certain embodiments, a hydroxy ethyl methacrylate (HEMA) or polymer thereof can be present in a polymer composition at a concentration from about 1% and about 60% weight per volume (w / v).

[0086] In certain embodiments, a polymer composition of the present disclosure comprises one or more stabilizers and / or enhancers. In certain embodiments, a polymer composition of the present disclosure comprises one or more stabilizers and / or enhancers selected from polar amino acids (e.g., tyrosine, cysteine, serine, threonine, asparagine, glutamine, aspartic acid, glutamic acid, arginine, lysine, and histidine), amino acid analogues, amino acid derivatives, collagen, divalent cation chelators (e.g., ethylenediaminetetraacetic acid (EDTA) or salts thereof), or a combination thereof.

[0087] In certain embodiments, a polymer composition of the present disclosure can be clear and / or translucent. In certain embodiments, a polymer composition can be partially translucent or partially opaque. In certain embodiments, a polymer composition can be opaque.

[0088] In certain embodiments, the polymer compositions of the present disclosure can include the polymeric or therapeutic components, can be produced, can be analyzed or can be used as disclosed in US 20140377326, US 20150274805, US 20160175488, US 20170232138, US 20190022280 Al, WO 2020051133, and WO 2020081673, each of which is incorporated herein by reference in its entirety, insofar as each describes the composition, production, analysis and use of acrylated gelatin polymeric compositions such as GelMA hydrogels.Formulations

[0089] In certain embodiments, polymer compositions of the present disclosure comprises chemically-modified gelatin (e.g., acrylated gelatin such as GelMA).

[0090] In certain embodiments, polymer compositions of the present disclosure comprise combinations of precursor polymer components according from Table 1 (percentages are w / v concentration in the total precursor polymer formulation). Unless stated otherwise, GelMA materials in Table 1 are 160 / 80 (i.e., have 160 kDa molecular weight (MW) and 80% degree of methacrylation (DoM)).Table 1 - Examples of Precursor Polymer Compositions

[0091] In certain embodiments, polymer compositions of the present disclosure comprise combinations of precursor polymer components according from Table 2. % w / v = w / v concentration in the total precursor polymer formulation; MW = average molecular weight (kDa); % DoF = degree of functionalization (e.g., degree of methacrylation (DoM)); GAc* is acrylate-PEG-RGDS (arginine-glycine-aspartic acid-serine).Table 2 - Examples of Precursor Polymer Compositions

[0092] In certain embodiments, the polymer composition comprises GelMA having about 160 kDa molecular weight (MW). In certain embodiments, the polymer composition comprises GelMA having from about 80% to about 90% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 85% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 80% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 75% to about 85% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMAhaving from about 70% to about 80% degree of methacryl ati on (DoM). In certain embodiments, the polymer composition comprises GelMA having about 75% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 70% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 65% to about 75% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 60% to about 70% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 65% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 60% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 55% to about 65% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 50% to about 60% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 55% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 50% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 45% to about 55% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 40% to about 50% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 45% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 40% DoM. In certain embodiments, the polymer composition comprises GelMA having from about 35% to about 45% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 30% to about 40% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 35% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 30% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 25% to about 35% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 20% to about 30% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 25% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 20% DoM. In certain embodiments, the polymer composition comprises GelMA having from about 15% toabout 25% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having from about 10% to about 20% degree of methacrylation (DoM). In certain embodiments, the polymer composition comprises GelMA having about 15% DoM. In certain embodiments, the polymer composition comprises GelMA having about 10% DoM. In certain embodiments, the polymer composition comprises GelMA having about 5% DoM. In certain embodiments, the polymer composition comprises GelMA having about 10% to about 40% DoM. In certain embodiments, the polymer composition comprises GelMA having about 50% to about 80% DoM. In certain embodiments, the polymer composition comprises GelMA having about 10 to about 20% DoM. In certain embodiments, the polymer composition comprises GelMA having about 7% DoM. In certain embodiments, the polymer composition comprises GelMA having about 5% DoM. In certain embodiments, the polymer composition comprises GelMA having about 5% to about 40% DoM. In certain embodiments, the polymer composition comprises GelMA having about 5% to about 20% DoM. In certain embodiments, the polymer composition comprises GelMA having about 1% to about 10% DoM.

[0093] In certain embodiments, the polymer composition comprises about 15% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%. In certain embodiments, the polymer composition comprises about 10% w / v of GelMA having an average molecular weight of about 138 kDa and a DoM of about 10%. In certain embodiments, the polymer composition comprises about 5% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%. In certain embodiments, the polymer composition comprises about 5% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 80%. In certain embodiments, the polymer composition comprises about 5% w / v of GelMA having an average molecular weight of about 138 kDa and a DoM of about 10%.

[0094] In certain embodiments, the polymer composition comprises about 2.5% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%. In certain embodiments, the polymer composition comprises about 5% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%. In certain embodiments, the polymer composition comprises about 1% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 10%. In certain embodiments, the polymer composition comprises about 2% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 10%. In certainembodiments, the polymer composition comprises about 2% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%.

[0095] In certain embodiments, the polymer composition comprises about 5% w / v of Gel AC. In certain embodiments, the GelAC polymer is functionalized with 1.2% w / v acrylate-PEG-RGDS (arginine-glycine-aspartic acid-serine) having an average molecular weight of about 3.4 kDa.

[0096] In certain embodiments, the polymer composition comprises about 2.5% w / v of GelGA having a DoF (degree of functionalization) of about 45%, and a combination of molecular weights as follows: about 70% 7 kDA, about 20% 48 kDa, and about 10% greater than 50 kDa. In certain embodiments, the polymer composition comprises about 10% w / v of GelGA having a DoF (degree of functionalization) of about 30%, and a combination of molecular weights as follows: about 70% 7 kDA, about 20% 48 kDa, and about 10% greater than 50 kDa. In certain embodiments, the polymer composition comprises about 1% w / v of GelGA having a DoF (degree of functionalization) of about 45%, and a combination of molecular weights as follows: about 70% 7 kDA, about 20% 48 kDa, and about 10% greater than 50 kDa. In certain embodiments, the polymer composition comprises about 2.5% w / v of GelGA having a DoF (degree of functionalization) of about 60%, and a combination of molecular weights as follows: about 90% 11.5 kDA and about 10% greater than 11.5 kDa. In certain embodiments, the polymer composition comprises about 3.5% w / v of GelGA having a DoF (degree of functionalization) of about 60%, and a combination of molecular weights as follows: about 90% 11.5 kDA and about 10% greater than 11.5 kDa.

[0097] In certain embodiments, the polymer composition comprises a first acrylated gelatin and a second acrylated gelatin.

[0098] In certain embodiments, the polymer composition comprises: (a) about 2.5% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%; and (b) about 1% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 10%.

[0099] In certain embodiments, the polymer composition comprises: (a) about 1.0% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%; and (b) about 2.5% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 40%. In certain embodiments, the polymer composition comprises: (a) 1.05% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%; and (b) 2.45% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 40%.

[0100] In certain embodiments, the polymer composition comprises: (a) about 1.0% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%; and (b) about 2.0% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 40%. In certain embodiments, the polymer composition comprises: (a) 0.9% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 40%; and (b) 2.1% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 40%.

[0101] In certain embodiments, the polymer composition comprises: (a) about 2.5% w / v of GelGA having a DoF (degree of functionalization) of about 60%, and a combination of molecular weights as follows: about 90% 11.5 kDA and about 10% greater than 11.5 kDa; and (b) about 2% w / v of GelMA having an average molecular weight of about 160 kDa and a DoM of about 10%.

[0102] In certain embodiments, the polymer composition comprises: (a) about 1% w / v of GelGA having a DoF (degree of functionalization) of about 45%, and a combination of molecular weights as follows: about 70% 7 kDA, about 20% 48 kDa, and about 10% greater than 50 kDa; and (b) about 2% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%.

[0103] In certain embodiments, the polymer composition comprises: (a) about 5.0% w / v of GelMA having an average molecular weight of about 90 kDa and a DoM of about 60%; and (b) about 1.2% w / v of acrylate-PEG-RGDS (arginine-glycine-aspartic acid-serine) having an average molecular weight of about 3.4 kDa.

[0104] In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture. In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 0.5% to about 5%. In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 2% to about 5%. In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 2% to about 4%. In certain embodiments, the polymer composition comprises a combination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 3% to about 5%. In certain embodiments, the polymer composition comprises acombination of a first GelMA mixture and a second GelMA mixture, wherein the total GelMA in the polymer composition is from about 3% to about 4%.

[0105] In certain embodiments, the polymer composition comprises from about 0.5% to about 3% of the first GelMA mixture. In certain embodiments, the polymer composition comprises from about 0.5% to about 3% of the second GelMA mixture. In certain embodiments, the polymer composition comprises from about 0.5% to about 3% of the first GelMA mixture, and about 0.5% to about 3% of the second GelMA mixture. In certain embodiments, the polymer composition comprises from about 0.5% to about 1.5% of the first GelMA mixture, and about 2% to about 3% of the second GelMA mixture. In certain embodiments, the polymer composition comprises from about 2% to about 3% of the first GelMA mixture, and about 0.5% to about 1.5% of the second GelMA mixture. In certain embodiments, the polymer composition comprises about 1% of the first GelMA mixture and about 2.5% of the second GelMA mixture.

[0106] In certain embodiments, the first GelMA mixture includes GelMA having a high average molecular weight (e.g., from 140 to 180 kDa, or about 160 kDa). In certain embodiments, the first GelMA mixture includes GelMA having a low degree of methacrylation (DOM) (e.g., from 5% to 40%, or about 10%). In certain embodiments, the first GelMA mixture includes GelMA having a high average molecular weight (e.g., from 140 to 180 kDa, or about 160 kDa) and a low DOM (e.g., from 5% to 40%, or about 10%). In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 40%. In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 20%. In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight of about 160 kDa and a DOM of about 10%.

[0107] In certain embodiments, the second GelMA mixture includes GelMA having a low average molecular weight (e.g., from 75 to 115 kDa, or about 90 kDa). In certain embodiments, the second GelMA mixture includes GelMA having a high degree of methacrylation (DOM) (e.g., from 50% to 80%, or about 60%). In certain embodiments, the second GelMA mixture includes GelMA having a low average molecular weight (e.g., from 75 to 115 kDa, or about 90 kDa) and a high DOM (e.g., from 50% to 80%, or about 60%). In certain embodiments, the second GelMA mixture includes GelMA having an average molecular weight from 75 to 115 kDa and a DOM from 50% to 80%. In certain embodiments, the second GelMA mixture includes GelMA having an average molecular weight from 80 to 115 kDa and a DOM from 50% to 70%. In certain embodiments, thesecond GelMA mixture includes GelMA having an average molecular weight of about 90 kDa and a DOM of about 60%.

[0108] In certain embodiments, the first GelMA mixture includes GelMA having a high average molecular weight (e.g., from 140 to 180 kDa, or about 160 kDa) and a low DOM (e.g., from 5% to 40%, or about 10%); and the second GelMA mixture includes GelMA having a low average molecular weight (e.g., from 75 to 115 kDa, or about 90 kDa) and a high DOM (e.g., from 50% to 80%, or about 60%). In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 40%; and the second GelMA mixture includes GelMA having an average molecular weight from 75 to 115 kDa and a DOM from 50% to 80%. In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 20%; and the second GelMA mixture includes GelMA having an average molecular weight from 80 to 100 kDa and a DOM from 50% to 70%. In certain embodiments, the first GelMA mixture includes GelMA having an average molecular weight of about 160 kDa and a DOM of about 10%; and the second GelMA mixture includes GelMA having an average molecular weight of about 90 kDa and a DOM of about 60%.

[0109] In certain embodiments, the polymer composition comprises from about 0.5% to about 3% w / v of a first GelMA mixture, which includes GelMA having a high average molecular weight (e.g., from 140 to 180 kDa, or about 160 kDa) and a low DOM (e.g., from 5% to 40%, or about 10%). In certain embodiments, the polymer composition comprises from about 0.5% to about 3% w / v of a second GelMA mixture, which includes GelMA having a low average molecular weight (e.g., from 75 to 115 kDa, or about 90 kDa) and a high DOM (e.g., from 50% to 80%, or about 60%). In certain embodiments, the polymer composition comprises: from about 0.5% to about 3% w / v of a first GelMA mixture, which includes GelMA having a high average molecular weight (e.g., from 140 to 180 kDa, or about 160 kDa) and a low DOM (e.g., from 5% to 40%, or about 10%); and from about 0.5% to about 3% w / v of a second GelMA mixture, which includes GelMA having a low average molecular weight (e.g., from 75-115 kDa, or about 90 kDa) and a high DOM (e.g., from 50% to 80%, or about 60%).

[0110] In certain embodiments, the polymer composition comprises from about 0.5% to about 1.5% w / v of a first GelMA mixture, which includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 40%; and from about 2% to about 3% w / v of a second GelMA mixture which includes GelMA having an averagemolecular weight from 75-115 kDa and a DOM from 50% to 80%. In certain embodiments, the polymer composition comprises from about 0.5% to about 1.5% w / v of a first GelMA mixture, which includes GelMA having an average molecular weight from 140 to 180 kDa and a DOM from 5% to 20%; and from about 2% to about 3% w / v of a second GelMA mixture which includes GelMA having an average molecular weight from 85-100 kDa and a DOM from 50% to 70%.[OHl] In certain embodiments, the polymer composition comprises about 1% w / v of a first GelMA mixture which includes GelMA having an average molecular weight of about 160 kDa and a DOM of about 10%; and about 2.5% w / v of a second GelMA mixture which includes GelMA having an average molecular weight of about 90 kDa and a DOM of about 60%.

[0112] In certain embodiments, the polymer composition comprises a combination of GelMA having about 10% DoM (e.g., GelMA 160 / 10) and GelMA having about 80% DoM (e.g., GelMA 160 / 80). In certain embodiments, the polymer composition comprises a combination of GelMA having about 10% DoM and GelMA having about 80% DoM, wherein the polymer composition comprises about 4 to 10% w / v of GelMA. In certain embodiments, the polymer composition comprises a combination of GelMA having about 10% DoM (e.g., GelMA 160 / 10) and GelMA having about 80% DoM (e.g., GelMA 160 / 80), wherein the ratio of 10% DoM GelMA and 80% DoM GelMA is from about 1 :9 to about 9: 1. In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 1:9. In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 2:8 (i.e., about 1:4). In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 3:7. In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 4:6 (i.e., about 2:3). In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 5:5 (i.e., about 1:1). In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 4:6 (i.e., about 2:3). In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 3:7. In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 2:8 (i.e., about 1 :4). In certain embodiments, the ratio of 10% DoM GelMA and 80% DoM GelMA is about 1 :9.

[0113] In certain embodiments, the polymer composition comprises glycidyl methacrylate-functionalized gelatin having about 45% DoM (e.g., GelGA 160 / 45). In certain embodiments, the polymer composition comprises glycidyl methacrylate-functionalized gelatin having about 45% DoM and 160 kDa (GelGA 160 / 45). In certain embodiments, thepolymer composition comprises glycidyl methacrylate-functionalized gelatin having about 45% DoM and 90 kDa (GelGA 90 / 45).

[0114] In certain embodiments, the polymer composition comprises a poloxamer surfactant (e.g., Poloxamer 407). In certain embodiments, the polymer composition comprises about 0.1-0.5% w / v (e.g., about 0.2% w / v) of a poloxamer surfactant (e.g., Poloxamer 407). In certain embodiments, the polymer composition comprises a tyloxapol surfactant. In certain embodiments, the polymer composition comprises about 0.1-0.5% w / v (e.g., about 0.1% w / v) of a tyloxapol surfactant.

[0115] In certain embodiments, the polymer composition comprises about 2% GelMA (10-40% DoM). In certain embodiments, the polymer composition comprises about 4% Gelatin Acrylate (10-40% DoM). In certain embodiments, the polymer composition comprises about 2% Gelatin Acrylate (10-40% DoM). In certain embodiments, the polymer composition comprises about 5-20% GelMA (10-40% DoM).

[0116] In certain embodiments, the polymer composition comprises about 4% GelMA (80% DoM) and about 0.2% (w / v) of a poloxamer surfactant (e.g., Poloxamer 407); optionally with a therapeutic agent (e.g., corticosteroid) or a cell. In certain embodiments, the polymer composition comprises about 4% GelMA (40% DoM) and about 0.2% (w / v) of a poloxamer surfactant (e.g., Poloxamer 407); optionally with a therapeutic agent (e.g., corticosteroid) or a cell. In certain embodiments, the polymer composition comprises about 4% GelMA (10% DoM) and about 0.2% (w / v) of a poloxamer surfactant (e.g., Poloxamer 407); optionally with a therapeutic agent (e.g., corticosteroid) or a cell. In certain embodiments, the polymer composition comprises about 20% GelMA (40% DoM); and about 0.2% (w / v) of a poloxamer surfactant (e.g., Poloxamer 407); optionally with a therapeutic agent (e.g., corticosteroid) or a cell.Chemically Modified Gelatin

[0117] Gelatin is a naturally derived, biocompatible mixture of peptides and proteins derived from collagen, which is a primary structural component of animal tissue (including ocular tissue, bones, and skin). Natural matrix peptides and proteins (e.g., denatured collagen) which can be used in the production of gelatin materials of the present disclosure can include gelatin components derived from animals including, but not limited to, pig, cow, horse, chicken, and fish. In certain embodiments, gelatin materials can be derived from connective tissue proteins, such as collagen. In certain embodiments, gelatin materials can be derived from bone, skin, or ocular tissues. In certain embodiments, gelatin materials can be prepared by acid hydrolysis and / or base hydrolysis of connective tissue proteins (e.g., collagen).

[0118] In certain embodiments, polymer compositions of the present disclosure comprise a chemically modified gelatin. In certain embodiments, the polymer compositions comprise acrylated gelatin. In certain embodiments, the polymer compositions comprise gelatin methacryloyl (i.e., GelMA). In certain embodiments, the polymer compositions comprise gelatin acryloyl (i.e., GelAC). In certain embodiments, the polymer compositions comprise gelatin glycidyl acrylate (i.e., GelGA). In certain embodiments, the polymer compositions comprise gelatin glycidyl methacrylate (i.e., GelGMA). In certain embodiments, a chemically modified gelatin can be included in precursor polymer compositions of the present disclosure. In certain embodiments, the chemically modified gelatin comprises a photo-crosslinkable derivative of gelatin. In certain embodiments, the chemically modified gelatin can be modified with an acrylic anhydride or acryloyl chloride (substituted or unsubstituted) to form an acryloyl-substituted gelatin. In certain embodiments, the chemically modified gelatin can be modified with one or more crosslinkable groups selected from methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, methacryloyl, catechol, ethylene oxide, or propylene oxide. In certain embodiments, the chemically modified gelatin can be modified with methacrylic anhydride (MA) (also known as methacryloyl anhydride) to form a methacryloyl-substituted gelatin (commonly referred to as gelatin methacryloyl, or GelMA). FIG. 1 provides an example of a reaction in which gelatin is modified with methacrylic anhydride to form a methacryloyl-substituted gelatin (GelMA).

[0119] In certain embodiments, acryloyl modification of gelatin can be performed by a synthesis reaction of gelatin with a functionalizing compound which comprises an acrylate group. In certain embodiments, methacryloyl modification of gelatin can be performed by a synthesis reaction of gelatin with methacrylic anhydride, methacryloyl chloride, 2- isocyanatoethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, methacrylic acid N-hydroxysuccinimide ester, allyl methacrylate, vinyl methacrylate, bis(2- methacryloyl)oxyethyl disulfide, 2-hydroxy-5-N-methacrylamidobenzoic acid, or combinations thereof.

[0120] As used herein, the terms “acryloyl-substituted gelatin” and “acrylated gelatin” can describe a gelatin having free amines (e.g., lysine, arginine, asparagine, or glutamine side chains) and / or free hydroxyls (e.g., serine, threonine, aspartic acid or glutamic acid side chains) that have been substituted with at least one acryloyl group, such as acrylamide, methacrylamide, hydroxyethyl acrylate (i.e., glycidyl acrylate), or hydroxyethyl methacrylate (i.e., glycidyl methacrylate). Generally, an acryloyl group is an a, P -unsaturated carbonyl compound represented by the formula H2C=CR’-C(=O)-R, where R’ can be, but is notlimited to: hydrogen, halogen, hydroxyl, C1-C5 alkoxy, C1-C5 alkyl, C3-C8 cycloalkyl, C1-C5 heteroalkyl, C3-C8 heterocycloalkyl, aryl, heteroaryl or amino group, each being optionally substituted with halogen, C1-C5 alkoxy, C1-C5 alkyl, C3-C8 cycloalkyl, C1-C5 heteroalkyl, C3- Cs heterocycloalkyl, aryl, heteroaryl or amino group. For acryloyl-substituted gelatins of the present disclosure, the R group includes a terminal amine and / or hydroxyl group on the gelatin which is subject to the acryloyl functionalization.

[0121] In certain embodiments, the R’ group of the acryloyl moiety is methyl, commonly referred to as a methacryloyl group. As used herein, the terms “methacryloyl-substituted gelatin”, “gelatin methacryloyl”, and “GelMA” can describe a gelatin having free amines (e.g., lysine, arginine, asparagine, or glutamine side chains) and / or free hydroxyls (e.g., serine, threonine, aspartic acid or glutamic acid side chains) that have been substituted with at least one methacryloyl group, such as methacrylamide groups (from free amines on the gelatin) and / or a methacrylate groups (from free hydroxyls on the gelatin).

[0122] As used herein, the terms “gelatin acryloyl”, and “GelAC” can describe a gelatin having free amines (e.g., lysine, arginine, asparagine, or glutamine side chains) and / or free hydroxyls (e.g., serine, threonine, aspartic acid or glutamic acid side chains) that have been substituted with at least one methacryloyl group, such as methacrylamide groups (from free amines on the gelatin) and / or a methacrylate groups (from free hydroxyls on the gelatin).

[0123] As used herein, the terms “gelatin glycidyl acrylate” and “GelGA” can describe an acrylated gelatin having free amines (e.g., lysine, arginine, asparagine, or glutamine side chains) and / or free hydroxyls (e.g., serine, threonine, aspartic acid or glutamic acid side chains) that have been substituted with at least one hydroxyethyl acryloyl group, such as a hydroxyethyl acrylate group (i.e., glycidyl acrylate group).

[0124] As used herein, the terms “gelatin glycidyl methacrylate” and “GelGMA” can describe an acrylated gelatin having free amines (e.g., lysine, arginine, asparagine, or glutamine side chains) and / or free hydroxyls (e.g., serine, threonine, aspartic acid or glutamic acid side chains) that have been substituted with at least one hydroxy ethyl methacryloyl group, such as a hydroxyethyl methacrylate group (i.e., glycidyl methacrylate group).

[0125] In certain embodiments, a chemically modified gelatin (e.g., acrylated gelatin) can be present in the polymer composition at a concentration from about 1% to about 60% weight per volume (w / v). In certain embodiments, a chemically-modified gelatin (e.g., acrylated gelatin) can be present in the polymer composition at a weight per volume concentration (w / v) of about 0.5%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, or about 60%. In certain embodiments, a chemically-modified gelatin (e.g., acrylated gelatin) can be present in the polymer composition at a weight per volume concentration (w / v) of from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 1-10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10-15%, about 15-20%, about 21-23%, about 23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%, about 33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about 43-46%, about 46-50%, about 40-50%, about 40-45%, about 45-50%, about 51-53%, about 53-56%, about 56-60%, about 50-60%, about 50-55%, or about 55-60%.

[0126] In certain embodiments, a polymer composition comprises acrylated gelatin (i.e., GelMA) with a degree of acryloyl substitution (i.e., methacryloyl functionalization). As used herein, the terms “degree of acryloyl substitution” and “degree of functionalization” (DoF) can describe the percentage of free amines and hydroxyls in a gelatin that have been substituted with acryloyl groups (i.e., functionalized). As used herein, the term “degree of methacryloyl substitution” (DoM) can describe the percentage of free amines and hydroxyls in a gelatin that have been substituted with methacryloyl groups. In certain embodiments, a polymer composition comprises acrylated gelatin with a degree of acryloyl substitution of at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, or at least about 90%. In certain embodiments, a polymer composition comprises acrylated gelatin with a degree of acryloyl substitution from about 10-99%. In certain embodiments, the degree of acryloyl substitution is from about 1- 5%, about 5-10%, about 10-15%, about 15-20%, about 20-25%, about 25-30%, about 30- 35%, about 35-40%, about 40-45%, about 45-50%, about 50-55%, about 55-60%, about 60- 65%, about 65-70%, about 70-75%, about 75-80%, about 80-85%, about 85-90%, about 90- 95%, or about 95-99%. In certain embodiments, a polymer compositions comprises GelMA with a degree of methacryloyl substitution of from about 1-5%, about 5-10%, about 10-15%, about 15-20%, about 20-25%, about 25-30%, about 30-35%, about 35-40%, about 40-45%,about 45-50%, about 50-55%, about 55-60%, about 60-65%, about 65-70%, about 70-75%, about 75-80%, about 80-85%, about 85-90%, about 90-95%, or about 95-99%.

[0127] In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylamide substitution (i.e., methacrylamide functionalization). In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylamide substitution of at least about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or at least about 90%. In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylamide substitution from about 20-90%. In certain embodiments, the degree of methacrylamide substitution is from about 1-5%, about 5-10%, about 10-15%, about 15-20%, about 20-25%, about 25-30%, about 30-35%, about 35-40%, about 40-45%, about 45-50%, about 50-55%, about 55-60%, about 60-65%, about 65-70%, about 70-75%, about 75-80%, about 80-85%, or about 85-90%. In certain embodiments, the degree of methacrylamide substitution can be measured using proton nuclear magnetic resonance. In certain embodiments, the degree of methacrylamide substitution can be measured using a fluoraldehyde assay.

[0128] In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylate substitution (i.e., methacrylate functionalization). In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylate substitution of at least about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or at least about 90%. In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylate substitution from about 20-90%. In certain embodiments, the degree of methacrylate substitution is from about 1-5%, about 5-10%, about 10-15%, about 15-20%, about 20-25%, about 25-30%, about 30-35%, about 35-40%, about 40-45%, about 45-50%, about 50-55%, about 55-60%, about 60-65%, about 65-70%, about 70-75%, about 75-80%, about 80-85%, or about 85-90%. In certain embodiments, the degree of methacrylate substitution can be measured using proton nuclear magnetic resonance. In certain embodiments, the degree of methacrylate substitution can be measured using a Fe(III)- hydroxamic acid-based assay. In certain embodiments, measurement of the degree of methacrylate substitution can include an aminolysis reaction (e.g., by exposure to a hydroxylamine solution) to convert methacrylate groups into N-hydroxymethacrylamide groups.

[0129] In certain embodiments, a polymer composition comprises GelMA with a degree of methacrylamide substitution and with a degree of methacrylate substitution. In certain embodiments, the ratio of methacrylamide substitution to methacrylate substitution in the GelMA is from about 1:1 to 99:1. In some embodiments, the ratio of methacrylamide substitution to methacrylate substitution is from about 1:1 to 2: 1, about 2:1 to 3 : 1, about 3 : 1 to 4:1, about 4:1 to 5:1, about 1:1 to 5:1, about 5:1 to 10:1, about 10:1 to 15:1, about 15:1 to 20:1, about 20:1 to 25:1, about 25:1 to 30:1, about 30:1 to 35:1, about 35:1 to 40:1, about 40:1 to 45:1, about 45:1 to 50:1, about 50:1 to 55:1, about 55:1 to 60:1, about 60:1 to 65:1, about 65:1 to 70:1, about 70:1 to 75:1, about 75:1 to 80:1, about 80:1 to 85:1, about 85:1 to 90:1, about 90:1 to 95:1, or about 95:1 to 99:1. In certain embodiments, the ratio of methacrylate substitution to methacrylamide substitution in the GelMA is from about 1:1 to 99:1. In some embodiments, the ratio of methacrylate substitution to methacrylamide substitution is from about 1:1 to 2:1, about 2:1 to 3:1, about 3:1 to 4:1, about 4:1 to 5:1, about 1:1 to 5:1, about 5:1 to 10:1, about 10:1 to 15:1, about 15:1 to 20:1, about 20:1 to 25:1, about 25:1 to 30:1, about 30:1 to 35:1, about 35:1 to 40:1, about 40:1 to 45:1, about 45:1 to 50:1, about 50:1 to 55:1, about 55:1 to 60:1, about 60:1 to 65:1, about 65:1 to 70:1, about 70:1 to 75:1, about 75:1 to 80:1, about 80:1 to 85:1, about 85:1 to 90:1, about 90:1 to 95:1, or about 95:1 to 99:1.

[0130] In certain embodiments, the polymer composition comprises GelMA with a methacryloyl modification of gelatin performed by a reaction of gelatin with methacrylic anhydride. In certain embodiments, the polymer composition comprises GelMA with a methacryloyl modification of gelatin performed by a reaction of gelatin with glycidyl methacrylate.

[0131] In certain embodiments, a gelatin can be functionalized with anchoring integrins and / or proteins (e.g., proteins which bind to the surface proteins of a target surface). Said functionalization can occur with polymeric linkers between the gelatin and integrin and / or protein.Crosslinking Agents

[0132] In certain embodiments, a polymer composition of the present disclosure comprises a crosslinking agent. As used herein, the phrase “crosslinking agent” can describe a substance which forms, promotes, or regulates intermolecular bonding (covalent, ionic, hydrogen) between polymeric units or chains to create a network of polymeric chains. Crosslinking agents typically exhibit one or more, optionally two or more, bonding functionalities which can create chemical bonds between two or more polymer chains.Crosslinking agents can include, for example, two vinyl bonds (tetrafunctionality), or three amines (trifunctionality).

[0133] In certain embodiments, a polymer composition comprises a crosslinking agent which can be used to activate or facilitate polymerization, gelation, and solidification of the polymer composition from a precursor polymer composition to a gel polymer composition. In certain embodiments, exposure of a polymer composition of the present disclosure (e.g., precursor polymer composition) to crosslinking conditions (e.g. exposure to visible light in the presence of a photoinitiator) can result in one or more acryloyl groups in the polymer composition (e.g., acryloyl-substituted gelatin and other acryloyl-based crosslinking agents) to react with other acryloyl groups to crosslink the polymer composition and form a gel polymer composition (e.g., acrylated gelatin hydrogel).

[0134] In certain embodiments, a polymer composition of the present disclosure (e.g., precursor polymer composition) comprises from about 1% and about 50% (w / v) of one or more crosslinking agents. In certain embodiments, the polymer composition comprises one or more crosslinking agents at a concentration (w / v) of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, or about 40%. In certain embodiments, the polymer composition comprises one or more crosslinking agents at a concentration (w / v) of no more than about 50%, about 45%, about 40%, about 35%, or about 30%. In certain embodiments, the polymer composition comprises one or more crosslinking agents at a concentration (w / v) of from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 1- 10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10- 15%, about 15-20%, about 21-23%, about 23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%, about 33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about 43-46%, about 46-50%, about 40-50%, about 40-45%, or about 45-50%.

[0135] In certain embodiments, a polymer composition of the present disclosure comprises one or more crosslinking agents selected from glutaraldehyde, epoxides (e.g., bisoxiranes), oxidized dextran, p-azidobenzoyl hydrazide, N-(a-maleimidoacetoxy)succinimide ester, p-azidophenyl glyoxal monohydrate, bis-((4-azidosalicylamido)ethyl)disulfide, bis(sulfosuccinimidyl)suberate, dithiobis(succinimidyl proprionate), disuccinimidyl suberate, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), ethoxylated trimethylpropane triacrylate, N-hydroxysuccinimide (NHS), derivatives thereof, or a combination thereof.

[0136] In certain embodiments, a polymer composition of the present disclosure comprises one or more crosslinking agents selected from polyethyleneoxide dimethacrylate, methylene bisacrylamide, methylene bis(2 -methylacrylamide), methylene diacrylate, methylene bis(2 -methylacrylate), diethylene glycol diacrylate, hexamethylene diacrylate, hexamethylene diisocyanate, oxybis(methylene) bis(2 -methylacrylate), oxybis(ethane-2,l- diyl) bis(2 -methylacrylate), trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2- hydroxy ethyl) isocyanurate triacrylate, isocyanuric acid tris(2 -acryloyloxyethyl) ester, ethoxylated trimethylolpropane triacrylate, pentaerythrityl triacrylate and glycerol triacrylate, phosphinylidynetris(oxyethylene) triacrylate derivatives thereof, or a combination thereof Polymer Crosslinking Initiator / Photo-initiator

[0137] In certain embodiments, a polymer composition comprises one or more polymer crosslinking initiators, such as photo-initiator elements. In certain embodiments, the polymer crosslinking initiator forms free-radicals when exposed to specific polymer crosslinking conditions (e.g., acidic conditions, basic conditions, high-salt conditions, low salt conditions, high temperature, agitation, solubility conditions, light exposure), wherein the free radicals can result in bond formation between reactive groups in the composition, such as vinyl-bond crosslinking between methacrylate groups in a GelMA polymer composition.

[0138] In certain embodiments, a polymer composition comprises one or more photoinitiator elements (i.e., a crosslinking initiator which is initiated or activated by absorbing a certain wavelength of light). In certain embodiments, precursor polymer compositions of the present disclosure comprise one or more photo-initiator elements. In certain embodiments, the photo-initiator element can be activated by exposure to light. In certain embodiments, light exposure can activate the photo-initiator to form free-radicals, wherein the free radicals can result in bond formation between reactive groups in the composition, such as vinyl-bond crosslinking between methacrylate groups in a GelMA polymer composition.

[0139] In certain embodiments, a photo-initiator element can be activated by exposure to one or more light sources selected from visible light sources (e.g., white or blue light), ultraviolet (UV) light sources, near-infrared (NIR) light sources, and fluorescent light sources. In certain embodiments, the photo-initiator element comprises a visible light- activated photo-initiator, such as a visible light-activated photo-initiator which is activated upon exposure to light having a wavelength from about 380 nm to about 740 nm. In certain embodiments, the visible light-activated photo-initiator can be activated upon exposure to light having a wavelength of from about 380-435 nm (i.e. violet light), about 435-500 nm (i.e. blue light), about 500-565 nm (i.e. green light), about 565-600 nm (i.e. yellow light), about600-650 nm (i.e. orange light), or about 650-740 nm (i.e. red light). In certain embodiments, the photo-initiator element comprises an ultraviolet light-activated photo-initiator. In certain embodiments, the photo-initiator element comprises a near-infrared (NIR) light-activated photo-initiator. In certain embodiments, the photo-initiator element comprises a white light- activated photo-initiator. In certain embodiments, the photo-initiator element comprises a blue light-activated photo-initiator.

[0140] In certain embodiments, a polymer composition comprises one or more photoinitiator elements selected from: methylene bisacrylamide (MBA), triethanolamine; 1-Vinyl- 2-pyrrolidone (NVP); N-vinylcaprolactam (NVC); Ethylene Glycol Diacrylate (EGDA); riboflavin; azobisisobutyronitrile; benzoyl peroxide; 1 -benzoylcyclohexanol; di -tert-butyl peroxide; Eosin Y (e.g., disodium salt), (2-(2,4,5,7-tetrabromo-6-oxido-3-oxo-3H-xanthen-9- yl) benzoate); 4,6-trimethylbenzoylphosphinate; triethanol amine; 2, 3 -diketo- 1,7,7- trimethylnorcamphane; 1 -phenyl- 1,2-propadi one; 2,4,6- trimethylbenzoyl-diphenylphosphine oxide; bis(2,6-dichlorobenzoyl)-(4-propylphenyl)phosphine oxide; 4,4’- bis(dimethylamino)benzophenone; 4,4’- bis(diethylamino)benzophenone; 2- chlorothioxanthen-9-one; 4-(dimethylamino)benzophenone; phenanthrenequinone; ferrocene; 2-hy droxy -4’ -(2 -hydroxy ethoxy)-2 -methylpropiophenone; 2 -hydroxy -2- methylpropiophenone; diphenyl(2,4,6 trimethylbenzoyl)phosphine oxide / 2 -hydroxy-2 - methylpropiophenone (blend); benzoin methyl ether; benzoin isopropyl ether; 2,2- diethoxyacetophenone; dibutoxyacetophenone; 2,2-dimethoxy-2-phenyl-l -phenylethanone; 2, 2-dimethoxy -2 -phenyl acetophenone; dibenzosuberenone; (benzene)tricarbonylchromium; resazurin; resorufin; benzoyltrimethylgermane; lithium phenyl-2,4,6-trimethyl- benzoylphospinate; camphorquinone; 2-methyl-l-(4-(methylthio)phenyl)-2- morpholinopropan-2-one; 2 -benzyl -2-(dimethylamino)-4’ -morpholinobutyrophenone; 2- benzyl-2-dimethylamino-l-(4-morpholinophenyl)butan-l-one; methybenzoylformate; bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide; bis(2,4-cylcopentadien-l-yl)-bis(2,6- difluoro-3-(lH-pyrrol-l-yl)-phenyl)titanium; 5,7-diiodo-3-butoxy-6-fluorone; 2, 4,5,7- tetraiodo-3-hydroxy-6-fluorone; 2,4,5,7-tetraiodo-3-hydroxy-9-cyano-6-fluorone; dimethoxyhydroxy-acetophenone; 2-naphthalene-sulfonyl chloride; 1 -phenyl- 1,2- propanedione-2-(O-ethoxy-carbonyl)oxime; 2-ethylthioxanthone; 2-isopropylthioxanthone; 2,4-diethyl thioxanthone; 2-tert-butyl thioxanthone; 2-chlorothioxanthone; 2-propoxy thioxanthone; methylphenylglycoxylate; phenyl 2 -hydroxy-2 -propyl ketone; 4- isopropylphenyl 2 -hydroxy-2 -propyl ketone; 4-n-dodecylphenyl 2-hydroxy-2 propyl ketone; 4-(2-hy droxy ethoxy)phenyl 2-hy droxy -2 -propyl ketone; l-[4-(2-hy droxy ethoxy)-phenyl]-2-hydroxy-2-methyl-l -propane- 1 -one); 4-(2-acryloyloxyethoxy)phenyl 2-hydroxy- 2-propyl ketone; derivatives thereof, or combinations thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y or eosin Y disodium salt (EYDS). In certain embodiments, a polymer crosslinking initiator comprises methylene bisacrylamide (MBA). In certain embodiments, the polymer crosslinking initiator comprises triethanolamine. In certain embodiments, a polymer composition comprises a combination of Eosin Y, triethanolamine, and / or vinyl caprolactam. In certain embodiments, the polymer crosslinking initiator comprises eosin Y disodium salt (EYDS), N-vinyl caprolactam (NVC), triethanolamine, or any combination thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y disodium salt (EYDS), N-Vinylpyrrolidone (NVP), triethanolamine, or any combination thereof. In certain embodiments, the polymer crosslinking initiator comprises eosin Y disodium salt (EYDS), methylene bisacrylamide (MBA), triethanolamine, or any combination thereof.

[0141] In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y or eosin Y disodium salt (EYDS), optionally about 50 pM eosin Y disodium salt (EYDS); (ii) from about 1.0 to about 5.0 pL / mL of N-vinyl caprolactam (NVC) or N- Vinylpyrrolidone (NVP), optionally from about 3.5 to about 5.0 pL / mL of NVP, optionally about 5.0 pL / mL of NVP; and (iii) triethanolamine, optionally about 1.5% v / v of triethanolamine.

[0142] In certain embodiments, the polymer crosslinking initiator comprises from about 0.2-0.3% methylene bisacrylamide (MBA). In certain embodiments, the polymer crosslinking initiator comprises about 0.25 methylene bisacrylamide (MBA).

[0143] In certain embodiments, the polymer crosslinking initiator comprises: (i) from about 40-60 pM eosin Y disodium salt (EYDS); (ii) from about 0.2-0.3% methylene bisacrylamide (MBA); and (iii) about 1.0-2.0% v / v of triethanolamine. In certain embodiments, the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y disodium salt (EYDS); (ii) about 0.25% methylene bisacrylamide (MBA); and (iii) about 1.5% v / v of triethanolamine.

[0144] In certain embodiments, a polymer composition comprises one or more photoinitiator elements selected from: acetophenone; anisoin; anthraquinone; anthraquinone-2- sulfonic acid, sodium salt monohydrate; (benzene) tricarbonylchromium; 4-(boc- aminomethyl)phenyl isothiocyanate; benzin; benzoin; benzoin ethyl ether; benzoin isobutyl ether; benzoin methyl ether; benzoic acid; benzophenyl-hydroxycyclohexyl phenyl ketone; 3, 3’, 4, 4’- benzophenone tetracarboxylic dianhydride; 4-benzoylbiphenyl; 2-benzyl-2-(dimethylamino)-4’- morpholino butyrophenone; 4,4’-bis(diethylamino)benzophenone; 4,4’- bis(dimethylamino)benzophenone; Michler’s ketone; camphorquinone; 2-chlorothioxanthen- 9-one; 5-dibenzosuberenone; (cumene)cyclopentadienyliron(II) hexafluorophosphate; dibenzosuberenone; 2,2-diethoxyacetophenone; 4,4 ’-dihydroxybenzophenone; 2,2- dimethoxy-2- phenylacetophenone; 4-(dimethylamino)benzophenone; 4,4’-dimethylbenzyl;2,5- dimethylbenzophenone; 3,4-dimethylbenzophenone; diphenyl(2,4,6- trimethylbenzoyl)phosphine oxide; 2 -hydroxy -2 -methylpropiophenone; 4’- ethoxyacetophenone; 2-ethylanthraquinone; ferrocene; 3’-hydroxyacetophenone; 4’- hydroxyacetophenone; 3 -hydroxybenzophenone; 4- hydroxybenzophenone; 1- hydroxycyclohexyl phenyl ketone; 2-hydroxy-2- methylpropiophenone; 2- methylbenzophenone; 3 -methylbenzophenone; methybenzoylformate; 2-methyl-4’- (methylthio)-2 -morpholinopropiophenone; 9, 10-phenanthrenequinone; 4’- phenoxyacetophenone; thioxanthen-9-one; triarylsulfonium hexafluoroantimonate salts; triarylsulfonium hexafluorophosphate salts; 3 -mercapto- 1 -propanol; mercapto- 1 -undecanol;1- mercapto-2 -propanol; 3 -mercapto-2 -butanol; hydrogen peroxide; benzoyl peroxide; 4, d’- dimethoxybenzoin; 2,2-dimethoxy-2-phenylacetophenone; dibenzoyl disulphides; diphenyldithiocarbonate; 2,2’-azobisisobutyronitrile; 2,2’-azobis[2-methyl-N-(2- hydroxyethyl)propionamide; camphorquinone; eosin; dimethylaminobenzoate; dimethoxy-2- phenyl-acetophenone; Quanta-cure ITX photosensitizer; Irgacures (e.g., 907, 2959, 651); Darocur 2959; ethyl-4-N,N-dimethylaminobenzoate; l-[-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-l-one; 1-hydroxy-cy cl ohexyl-phenyl -ketone; 2,4,6-trimethylbenzoyldiphenylphosphine oxide; diphenyl(2,4,6-trimethylbenzoyl)phosphine; 2-ethylhexyl-4-dimethylaminobenzoate; 2-hydroxy-2-methyl-l-phenyl-l -propanone; oligo[2- hydroxy-2-methyl-l-[4-(methylvinyl)phenyl]propanone] and propoxylated glyceryl triacrylate; benzil dimethyl ketal; benzophenone; blend of benzophenone and a-hydroxy- cyclohexyl-phenylketone; blend of Esacure KIP 150 and Esacure TZT; blend of Esacure KIP 150 and Esacure TZT; blend of Esacure KIP 150 and TPGDA; blend of phosphine oxide, Esacure KIP 150 and Esacure TZT; difunctional a-hydroxy ketone; ethyl 4- dimethylaminobenzoate; isopropyl thioxanthone; 2-hydroxy-2-methyl-phenylpropanone;2,4,6,- trimethylbenzoyldiphenyl phosphine oxide; 2,4,6-trimethyl benzophenone; blend of 4- methylbenzophenone and benzophenone; oligo(2-hydroxy-2-methyl-l-(4(l- methylvinyl)phenyl)propanone; oligo(2-hydroxy-2-methyl-l-4(l-methylvinyl)phenyl propanone and 2-hydroxy-2-methyl-l-phenyl-l-propanone; 4-methylbenzophenone; trimethylbenzophenone and methylbenzophenone; and water emulsion of 2,4,6-trimethylbenzoylphosphine oxide, alpha hydroxyketone, trimethylbenzophenone, and 4- methyl benzophenone.

[0145] In certain embodiments, a polymer composition comprises one or more cationic and / or anionic photo-initiator elements selected from: titanium tetrachloride, vanadium tetrachloride, bis(cyclopentadienyl)titanium dichloride, ferrocene, cyclopentadienyl manganese tricarbonyl, manganese decacarbonyl, diazonium salts, diaryliodonium salts (e.g., 3,3’-dinitrodiphenyliodonium hexafluoroarsenate, diphenyliodonium fluoroborate, 4- methoxydiphenyliodonium fluoroborate) and triarylsulfonium salts.

[0146] Photoinitiated polymerizations and photoinitiators are discussed in detail in Rabek, Mechanisms of Photophysical Processes and Photochemical Reactions in Polymers, New York: Wiley & Sons, 1987; and Fouassier, Photoinitiation, Photopolymerization, and Photocuring, Cincinnati, Ohio: Hanser / Gardner; Fisher et al., 2001, Annu. Rev. Mater. Res., 31 : 171; each of which is incorporated herein by reference in its entirety, insofar as each describes the use of polymerization and photoinitiators in the production of polymer compositions, including acryloyl gelatins such as GelMA hydrogels.

[0147] In certain embodiments, a polymer composition comprises a crosslinking agent or initiator which comprises one or more metal2+ions and / or metal3+ions. In certain embodiments, a polymer composition comprises a crosslinking agent which comprises one or more metal2+ions and / or metal3+ions selected from Fe2+, Fe3+, Ni2+, Zn2+, Cu2+, Ag2+, Au3+, Co2+, Co3+, Cr2, Cr3+, Cd2+, Mn2+, Mg2+, Pd2+, Pt2+, Al3+, or combinations thereof. In certain embodiments, a precursor polymer composition of the present disclosure comprises both one or more photoinitiators element and one or more metal2+ / 3+ions.

[0148] In certain embodiments, a polymer composition comprises a crosslinking agent or initiator which uses Click bioconjugation chemistry for polymeric crosslinking. In certain embodiments, the polymer composition comprises a crosslinking agent or initiator which uses Click bioconjugation chemistry selected from metal -catalyzed azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, strain-promoted alkyne-nitrone cycloaddition (e.g., Alkene / azide [3+2] cycloaddition, Alkene / tetrazine inverse-demand Diels-Alder, Alkene / tetrazole photoclick reaction), or a combination thereof.II. PHYSICAL, MECHANICAL AND STRUCTURAL CHARACTERISTICSViscosity, Shear strength and Shear resistance

[0149] The viscosity of a material is a measurement of the resistance of the material to deformation at a given rate. The viscosity of a fluid material is often correlated with the thickness and / or density of that material.

[0150] In certain embodiments, polymer compositions of the present disclosure can have a therapeutically effective viscosity. In certain embodiments, a polymer composition can have a viscosity which provides for strong adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a precursor polymer composition of the present disclosure can have a viscosity which provides for strong adhesion and high retention of the polymer composition on a target tissue of a subj ect. In certain embodiments, a precursor polymer composition can have a viscosity which is greater than water. In certain embodiments, a precursor polymer composition can have a viscosity which is equivalent to a paste. In certain embodiments, a gel polymer composition of the present disclosure can have a viscosity which provides for strong adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a precursor polymer composition can have a viscosity which is equivalent to water. In certain embodiments, a gel polymer composition can retain its shape and / or consistency on the surface of a target tissue for one or more hours, one or more days, or one or more weeks.

[0151] In certain embodiments, a polymer composition can have a viscosity from about 0.5 Pascal-seconds (Pa s) to about 300 Pa s at a low shear rate (e.g., at a shear rate of about 0.001 s'1to about 1 s'1). In certain embodiments, the polymer composition can have a viscosity from about 0.5-100 Pa s at a low shear rate. In certain embodiments, the polymer composition can have a viscosity, at a low shear rate, of from about 0.5-5 Pa s, about 5-10 Pa s, about 10-15 Pa s, about 15-20 Pa s, about 20-25 Pa s, about 25-30 Pa s, about 30-35 Pa s, about 35-40 Pa s, about 40-45 Pa s, about 45-50 Pa s, about 50-55 Pa s, about 55-60 Pa s, about 60-65 Pa s, about 65-70 Pa s, about 70-75 Pa s, about 75-80 Pa s, about 80-85 Pa s, about 85-90 Pa s, about 90-95 Pa s, about 95-100 Pa s, about 100-125 Pa s, about 125- 150 Pa s, about 150-175 Pa s, about 175-200 Pa s, about 200-225 Pa s, about 225-250 Pa s, about 250-275 Pa s, or about 275-300 Pa s.

[0152] Shear strength and / or resistance are measurements of the ability of a material to resist external shear stress (i.e., shear load) without failure (i.e. loss of adhesion or integrity). In certain embodiments, polymer compositions of the present disclosure can have a therapeutically effective shear strength. In certain embodiments, a polymer composition canhave a shear strength which provides for durable adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition of the present disclosure can have a shear strength which provides for durable adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition can have a shear strength which allows the polymer composition to retain its shape, adhesion, connectivity and / or consistency on the surface of a target tissue for one or more hours, one or more days, or one or more weeks.

[0153] In certain embodiments, a polymer composition can have shear strength from about 1 to about 360 kPa. In certain embodiments, the polymer composition can have shear strength from about 100-360 kPa. In certain embodiments, the polymer composition can have shear strength from about 200-360 kPa. In certain embodiments, the polymer composition can have a shear strength from about 1-20 kPa, about 20-40 kPa, about 40-60 kPa, about 60- 80 kPa, about 80-100 kPa, about 100-120 kPa, about 120-140 kPa, about 140-160 kPa, about 160-180 kPa, about 180-200 kPa, about 200-220 kPa, about 220-240 kPa, about 240-260 kPa, about 260-280 kPa, about 280-300 kPa, about 300-320 kPa, about 320-340 kPa, or about 340- 360 kPa.

[0154] In certain embodiments, the shear strength of a polymer composition can be measured using ASTM F2255-05, or a modified Lap Shear test variation thereof.Swelling and Water Content

[0155] In certain embodiments, the polymer composition comprises a gel. A gel generally comprises a crosslinked polymeric framework which encompasses a network of pores filled with an interstitial solvent (e.g., a fluid). In certain embodiments, the polymer composition comprises a hydrogel, wherein the interstitial fluid comprises water. In certain embodiments, the polymer composition comprises an alcogel, wherein the interstitial fluid comprises an alcohol (e.g., methanol, ethanol).

[0156] Swelling (i.e., an increase in volume) can occur in a gel when the gel material absorbs and retains additional interstitial fluid within the pore network of the gel. Likewise, shrinkage (i.e., a decrease in volume) can occur in a gel when the gel material expels interstitial fluid from the pore network of the gel. The ability and / or tendency of a gel material to swell and / or shrink in certain solvent environments will depend on the chemical nature of the polymer and the solvent (e.g., solubility, hydrophobicity, pore structure, affinity) and the elasticity of the polymer network of the gel. The swelling ratio of a gel is a measurement of the fractional increase in the weight of the gel due to fluid absorption (e.g., weight increase of a hydrogel from the absorption of water).

[0157] In certain embodiments, polymer compositions of the present disclosure can have a therapeutically effective swelling ratio and / or water content. In certain embodiments, a polymer composition can have a swelling ratio and / or water content which provides for strong adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition of the present disclosure can have a swelling ratio and / or water content which provides for strong adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition can have a swelling ratio and / or water content which allows the polymer composition to retain its shape, adhesion, connectivity and / or consistency on the surface of a target tissue for one or more hours, one or more days, or one or more weeks.

[0158] In certain embodiments, a polymer composition can have a swelling ratio from about 5% to about 50%. In certain embodiments, a polymer composition can have a swelling ratio of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, or about 40%. In certain embodiments, a polymer composition can have a swelling ratio of no more than about 50%, about 45%, about 40%, about 35%, about 30%, about 25%, about 20%, about 15%, or about 10%. In certain embodiments, a polymer composition has a swelling ratio of about 25% or less, about 20% or less, about 15% or less, or about 10% or less. In certain embodiments, a polymer composition can have a swelling ratio from about 1- 3%, about 3-6%, about 6-10%, about 1-5%, about 1-10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10-15%, about 15-20%, about 21-23%, about23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%, about33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about43-46%, about 46-50%, about 40-50%, about 40-45%, or about 45-50%. In certain embodiments, a polymer composition can have a short-term swelling ratio (i.e., a swelling ratio measured for about 1 to 24 hours) from about 1-3%, about 3-6%, about 6-10%, about 1- 5%, about 1-10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10-15%, about 15-20%, about 21-23%, about 23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%, about 33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about 43-46%, about 46-50%, about 40-50%, about 40-45%, or about 45-50%. In certain embodiments, a polymer composition can have a medium -term swelling ratio (i.e., a swelling ratio measured for about 1 to 7 days) from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 1-10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10-15%, about 15-20%, about 21-23%, about 23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%,about 33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about 43-46%, about 46-50%, about 40-50%, about 40-45%, or about 45-50%. In certain embodiments, a polymer composition can have a long-term swelling ratio (i.e., a swelling ratio measured for about 1 to 4 weeks, or more) from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 1-10%, about 5-10%, about 11-13%, about 13-16%, about 16-20%, about 10-20%, about 10-15%, about 15-20%, about 21-23%, about 23-26%, about 26-30%, about 20-30%, about 20-25%, about 25-30%, about 31-33%, about 33-36%, about 36-40%, about 30-40%, about 30-35%, about 35-40%, about 41-43%, about 43-46%, about 46-50%, about 40-50%, about 40-45%, or about 45-50%.

[0159] In certain embodiments, a hydrogel polymer composition can have a water content from about 5% to about 99%. In certain embodiments, a hydrogel polymer composition can have a water content from about 50% to about 99%. In certain embodiments, a hydrogel polymer composition can have a water content from about 65% to about 85%. In certain embodiments, a polymer composition can have a water content of at least about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80%. In certain embodiments, a polymer composition can have a swelling ratio of about 99% or less, about 95% or less, about 90% or less, about 85% or less, about 80% or less, about 75% or less, about 70% or less, about 65% or less, about 60% or less, about 55% or less, about 50% or less, about 45% or less, about 40% or less, about 35% or less, or about 30% or less. In certain embodiments, a polymer composition can have a water content from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 5-10%, about 1-10%, about 11-13%, about 13- 16%, about 16-20%, about 10-15%, about 15-20%, about 10-20%, about 21-23%, about 23- 26%, about 26-30%, about 20-25%, about 25-30%, about 20-30%, about 31-33%, about 33- 36%, about 36-40%, about 30-35%, about 35-40%, about 30-40%, about 41-43%, about 43- 46%, about 46-50%, about 40-45%, about 45-50%, about 40-50%, about 51-53%, about 53- 56%, about 56-60%, about 50-55%, about 55-60%, about 50-60%, about 61-63%, about 63- 66%, about 66-70%, about 60-65%, about 65-70%, about 60-70%, about 71-73%, about 73- 76%, about 76-80%, about 70-75%, about 75-80%, about 70-80%, about 81-83%, about 83- 86%, about 86-90%, about 80-85%, about 85-90%, about 80-90%, about 91-93%, about 93- 96%, about 96-99%, about 90-95%, about 95-99%, or about 90-99%.

[0160] In certain embodiments, a hydrogel polymer composition of the present disclosure permits controlled and sustained release of one or more therapeutic agents over a period of time. In certain embodiments, the hydrogel polymer composition allows for the release of atleast 1 pg / day, at least 2 pg / day, at least 3 pg / day, at least 4 pg / day, at least 5 pg / day, at least 6 pg / day, at least 7 pg / day, at least 8 pg / day, at least 9 pg / day, at least 10 pg / day, at least 11 pg / day, at least 12 pg / day, at least 13 pg / day, at least 14 pg / day, at least 15 pg / day, at least 16 pg / day, at least 17 pg / day, at least 18 pg / day, at least 19 pg / day, at least 20 pg / day, at least 25 pg / day, at least 30 pg / day, at least 35 pg / day, at least 40 pg / day, at least 45 pg / day, at least 50 pg / day, at least 60 pg / day, at least 70 pg / day, at least 80 pg / day, at least 90 pg / day, at least 100 pg / day, at least 150 pg / day, at least 200 pg / day, at least 250 pg / day, at least 300 pg / day, at least 350 pg / day, at least 400 pg / day, at least 450 pg / day, at least 500 pg / day, at least 600 pg / day, at least 700 pg / day, at least 800 pg / day, at least 900 pg / day, or at least 1000 pg / day of a therapeutic agent. In certain embodiments, the hydrogel polymer composition allows for the release of at least 10 pg / day of a therapeutic agent.Durability and Degradation

[0161] In certain embodiments, polymer compositions of the present disclosure can have a therapeutically effective rate of polymeric degradation (i.e. degradation rate). In certain embodiments, a polymer composition can have a degradation rate which provides for sustained adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition of the present disclosure can have a degradation rate which provides for sustained adhesion and high retention of the polymer composition on a target tissue of a subject. In certain embodiments, a gel polymer composition can have a degradation rate which allows the polymer composition to retain its shape, adhesion, connectivity and / or consistency on the surface of a target tissue for one or more hours, one or more days, or one or more weeks.

[0162] In certain embodiments, a polymer composition can have a degradation rate from 1-50 days. In certain embodiments, a polymer composition can have a degradation rate from about 1-3 days, about 3-6 days, about 6-10 days, about 1-5 days, about 1-10 days, about 5-10 days, about 11-13 days, about 13-16 days, about 16-20 days, about 10-20 days, about 10-15 days, about 15-20 days, about 21-23 days, about 23-26 days, about 26-30 days, about 20-30 days, about 20-25 days, about 25-30 days, about 31-33 days, about 33-36 days, about 36-40 days, about 30-40 days, about 30-35 days, about 35-40 days, about 41-43 days, about 43-46 days, about 46-50 days, about 40-50 days, about 40-45 days, or about 45-50 days.Biocompatibility

[0163] In certain embodiments, the polymer compositions of the present disclosure have biocompatibility with a target tissue of a subject. In certain embodiments, the biomechanicalproperties of the polymer compositions are similar and / or biocompatible to the biomechanical properties of a target tissue of a subject (e.g., the cornea of a subject).

[0164] In certain embodiments, the biocompatibility of a polymer compositions can be evidenced by low inflammatory response in a target tissue or subject. In certain embodiments, the biocompatibility of a polymer compositions can be evidenced by the survival rate of cells from a target tissue which are implanted or incorporated into a portion of the polymer composition.Shape

[0165] In certain embodiments, polymer compositions of the present disclosure can be formed as molded, stamped, or shaped gel compositions. Molded, stamped or shaped hydrogels can be prepared using, for example, the methods set forth in US 20050008675 or US 20040258729, each of which is incorporated herein by reference in its entirety, insofar as each describes the composition, production (including molding), analysis and use of hydrogels, including acrylated gelatin polymeric compositions such as GelMA hydrogels.

[0166] In certain embodiments, polymer compositions (e.g., hydrogel polymer compositions) of the present disclosure can be formed into cylinders, each cylinder having a length and a diameter. In certain embodiments, polymer compositions (e.g., hydrogel polymer compositions) of the present disclosure can be conformed to the shape of the target surface. In certain embodiments, the polymer composition is conformed to the convex, concave, or curved shape of a target surface.

[0167] In certain embodiments, polymer compositions can be formed into cylindrical rods. As used herein, “cylindrical rods” or “rods” describe cylinders which have a cylinder-length at least 3-times (3x) the cylinder-diameter. As non-limiting examples, a cylindrical rod can have: a length of about 3 mm and a diameter of about 0.75 mm; or a length of about 2.5 mm and a diameter of about 0.75 mm. In certain embodiments, hydrogel rods of the present disclosure can be about 3 mm in length and about 0.75 mm in diameter. In certain embodiments, hydrogel rods of the present disclosure can be about 6 mm in length and about 0.75 mm in diameter.

[0168] In certain embodiments, polymer compositions can be formed into cylindrical disks. As used herein, “cylindrical disks” or “disks” describe cylinders which have a cylinder-diameter at least 2-times (2x) the cylinder-length. As non-limiting examples, a cylindrical disk can have: a length of about 2.5 mm and a diameter of about 6 mm; or a length of about 2 mm and a diameter of about 6 mm.III. GEL PRODUCTION

[0169] In certain embodiments, polymeric compositions of the present disclosure (e.g., Acrylated gelatin polymer compositions) can be produced as described in the art, including Nichol et al., Biomaterials, 2010 Jul, 31(21): 5536-44; Assmann et al., Biomaterials, 2017, 140: 115-127; Noshadi et al., Biomater. Sci., 2017, 5: 2093-2105; each of which is incorporated herein by reference in its entirety, insofar as each describes the production of polymeric compositions, including acryloyl gelatin polymeric compositions such as GelMA hydrogels.

[0170] In certain embodiments, a polymer composition of the present disclosure can be formed by crosslinking two or more chemically modified gelatin components in a precursor polymer composition to form a gel polymer composition. In certain embodiments, a polymer composition of the present disclosure can crosslink, polymerize and / or gel under wet, aqueous and / or biological conditions to form a gel polymer composition. In certain embodiments, the crosslinking of the two or more chemically modified gelatin components is initiated, facilitated, or enabled when exposed to specific crosslinking conditions (e.g., acidic conditions, basic conditions, high-salt conditions, low salt conditions, high temperature, agitation, solubility conditions). In certain embodiments, the crosslinking of the two or more chemically modified gelatin components is initiated, facilitated, or enabled by a crosslinking agent. In certain embodiments, the crosslinking of the two or more chemically modified gelatin components is initiated, facilitated, or enabled by a crosslinking agent under specific crosslinking conditions.

[0171] In certain embodiments, the present disclosure provides methods for producing a gel polymer composition, such as a hydrogel polymer composition. In certain embodiments, the present disclosure provides methods for producing a Acrylated gelatin hydrogel polymer composition. FIG. 2 provides a method 100 for producing a gel polymer composition. In step 110, a precursor polymer composition comprising chemically modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA) is provided. In optional step 115, one or more additional chemically modified polymer precursors with cross-linkable groups (e.g., MeHA) is added to the precursor polymer composition. In step 120, a solution comprising one or more crosslinking agents and / or photoinitiators is added to the precursor polymer composition. In optional step 125, a therapeutic agent, cell, and / or particle (i.e., microparticle or nanoparticle) is added to the precursor polymer composition. In step 130, the precursor polymer composition is polymerized / crosslinked to produce a gel polymer composition.

[0172] In certain embodiments, methods for producing a gel polymer composition can include providing a precursor polymer composition comprising chemically modified gelatin with crosslinkable groups (e.g., acryloyl -substituted gelatin, GelMA). In certain embodiments, the chemically modified gelatin comprises acrylated gelatin. In certain embodiments, the chemically modified gelatin comprises gelatin methacryloyl (i.e. GelMA).

[0173] In certain embodiments, the precursor polymeric composition comprises one or more solvents or liquid vehicles, diluents, dispersion media, dispersing agents, granulating agents, binding agents, disintegrating agents, suspension agents, surface active agents, emulsifiers or emulsifying agents, isotonic agents, thickening agents, preservatives, solid binders, buffering agents, lubricants, coloring agents, coating agents, sweeteners, flavourings, perfuming agents, or combinations thereof.

[0174] In certain embodiments, the precursor polymeric composition comprises one or more solvents. In certain embodiments, the solvent comprises an aqueous solvent. Examples of aqueous solvents include, but are not limited to, distilled water, deionized water, saline, Dulbecco’s phosphate-buffered saline (DPBS), and Ringer’s solution. In certain embodiments, the solvent comprises DPBS. In certain embodiments, the solvent comprises an organic solvent. Examples of organic solvents include, but are not limited to, hexanes, benzene, toluene, acetone, diethyl ether, chloroform, dichloromethane, isopropanol, methanol, ethanol, n-propanol, and n-butanol.

[0175] In certain embodiments, a precursor polymer composition can be in a sprayable form. In certain embodiments, a precursor polymer composition can be in a high-viscosity form (e.g., paste-like viscosity). In certain embodiments, a precursor polymer composition can be in a low-viscosity form (e.g., liquid-like viscosity).

[0176] In certain embodiments, methods for producing a gel polymer composition can include a step of adding one or more additional chemically modified polymer precursors with cross-linkable groups to the precursor polymer composition. In certain embodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically-modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); and (ii) adding one or more additional chemically-modified polymer precursors with cross-linkable groups to the precursor polymer composition.

[0177] In certain embodiments, methods for producing a gel polymer composition can include a step of adding one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer composition. In certainembodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); and (ii) adding one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer composition. In certain embodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically-modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); (ii) adding one or more additional chemically-modified polymer precursors with cross-linkable groups to the precursor polymer composition; and (iii) adding one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer.

[0178] In certain embodiments, one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) can be added to the precursor polymer before one or more additional chemically modified polymer precursors with cross-linkable groups are added to the precursor polymer composition. In certain embodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically-modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); (ii) adding one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer; and (iii) adding one or more additional chemically-modified polymer precursors with cross-linkable groups to the precursor polymer composition.

[0179] In certain embodiments, a polymer composition comprises one or more polymer crosslinking initiators, (e.g., crosslinking initiator which forms free-radicals when exposed to specific polymer crosslinking conditions, such as acidic conditions, basic conditions, high- salt conditions, low salt conditions, high temperature, agitation, solubility conditions, and light exposure). In certain embodiments, a polymer composition comprises one or more photo-initiator elements (i.e., a crosslinking initiator which is initiated or activated by absorbing a certain wavelength of light). In certain embodiments, precursor polymer compositions of the present disclosure comprise one or more photo-initiator elements (i.e., a crosslinking initiator which is initiated or activated by visible light). In certain embodiments, the photo-initiator element can be activated by exposure to light. In certain embodiments, light exposure can activate the photo-initiator to form free-radicals, wherein the free radicals can result in bond formation between reactive groups in the composition, such as vinyl-bond crosslinking between methacrylate groups in a GelMA polymer composition. FIG. 3 provides an example of a series of reactions to produce a GelMA hydrogel polymer composition, inwhich: (i) a photo-initiator element is activated by light energy (hv) to form free-radicals (R*), which then initiate bond formation between reactive groups on separate gelatin methacryloyl polymer precursors, thereby forming a crosslinked GelMA polymer network. The continued reaction between reactive groups on gelatin methacryloyl components will results in the formation of a broader GelMA hydrogel polymer composition.

[0180] In certain embodiments, a photo-initiator element can be activated by exposure to one or more light sources selected from visible light sources (e.g., white or blue light), ultraviolet (UV) light sources, near-infrared (NIR) light sources, and fluorescent light sources. In certain embodiments, the photo-initiator element comprises a visible light- activated photo-initiator, such as a visible light-activated photo-initiator which is activated upon exposure to light having a wavelength from about 380 nm to about 740 nm. In certain embodiments, the visible light-activated photo-initiator can be activated upon exposure to light having a wavelength of from about 380-435 nm (i.e., violet light), about 435-500 nm (i.e. blue light), about 500-565 nm (i.e. green light), about 565-600 nm (i.e. yellow light), about 600-650 nm (i.e. orange light), or about 650-740 nm (i.e. red light). In certain embodiments, the photo-initiator element comprises an ultraviolet light-activated photoinitiator. In certain embodiments, the photo-initiator element comprises a near-infrared (NIR) light-activated photo-initiator. In certain embodiments, the photo-initiator element comprises a white light-activated photo-initiator. In certain embodiments, the photo-initiator element comprises a blue light-activated photo-initiator.

[0181] In certain embodiments, methods for producing a gel polymer composition can include a step of adding one or more a therapeutic agent and / or particle (i.e., microparticle or nanoparticle) to the precursor polymer composition. In certain embodiments, one or more a therapeutic agent and / or particle can be added to the precursor polymer before one or more additional chemically modified polymer precursors with cross-linkable groups are added to the precursor polymer composition. In certain embodiments, one or more a therapeutic agent and / or particle can be added to the precursor polymer before one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) are added to the precursor polymer composition. In certain embodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically-modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); (ii) optionally adding one or more additional chemically-modified polymer precursors with cross-linkable groups to the precursor polymer composition; (iii) adding oneor more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer; and (iv) optionally adding one or more therapeutic agent and / or particle.

[0182] In certain embodiments, a precursor polymer composition can be clarified, purified, or processed for quality and / or purity prior to any polymerizing / crosslinking step. In certain embodiments, a precursor polymer composition can be filtered. In certain embodiments, a precursor polymer composition can be lyophilized. In certain embodiments, a precursor polymer composition can be frozen for storage.

[0183] In certain embodiments, methods for producing a gel polymer composition can include a step of polymerizing / crosslinking the precursor polymer composition to produce a gel polymer composition. In certain embodiments, methods for producing a gel polymer composition can include: (i) providing a precursor polymer composition comprising chemically-modified gelatin with crosslinkable groups (e.g., acryloyl-substituted gelatin, GelMA); (ii) optionally adding one or more additional chemically-modified polymer precursors with cross-linkable groups to the precursor polymer composition; (iii) adding one or more crosslinking agents and / or polymer crosslinking initiators (e.g., photoinitiators) to the precursor polymer; (iv) optionally adding one or more therapeutic agent and / or particle; and (v) polymerizing / crosslinking the precursor polymer composition to produce a gel polymer composition.

[0184] In certain embodiments, the crosslinking of chemically modified gelatin components and any additional chemically modified polymer precursors is initiated, facilitated, or enabled by exposure to UV or visible light in the presence of a photoinitiator component. In certain embodiments, exposure to UV or visible light in the presence of a photoinitiator causes acryloyl groups on one chemically modified gelatin molecule to react with acryloyl groups on other chemically modified gelatin molecules to crosslink the acryloyl-substituted gelatin components and produce a gel (e.g., hydrogel). In certain embodiments, exposure to visible light in the presence of a photoinitiator causes methacryloyl groups on one methacryloyl gelatin molecule to react with methacryloyl groups on other methacryloyl gelatin molecules to crosslink the methacryloyl-substituted gelatin components and produce a gelatin methacryloyl (GelMA) hydrogel.

[0185] In certain embodiments, the polymer composition is exposed to a light source for a duration from 1-60 minutes. In certain embodiments, the polymer composition is exposed to a light source for a duration of 1 minute or more, 5 minutes or more, 10 minute or more, 15 minutes or more, 20 minute or more, 25 minutes or more, or 30 minutes or more. In certain embodiments, the polymer composition is exposed to a light source for a duration of 1 minuteor less, 5 minutes or less, 10 minute or less, 15 minutes or less, 20 minute or less, 25 minutes or less, or 30 minutes or less, 35 minutes or less, or 40 minutes or less. In certain embodiments, the polymer composition is exposed to a light source for a duration of about 5 seconds, about 10 seconds, about 15 seconds, about 20 seconds, about 25 seconds, about 30 seconds, about 35 seconds, about 40 seconds, about 45 seconds, about 50 seconds, about 55 seconds, about 60 seconds, about 65 seconds, about 70 seconds, about 75 seconds, about 80 seconds, about 85 seconds, about 90 seconds, about 95 seconds, about 100 seconds, about105 seconds, about 110 seconds, about 115 seconds, about 120 seconds, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes about 9 minutes, about 10 minutes, about 11 minutes, about 12 minutes, about 13 minutes, about 14 minutes, about 15 minutes, about 16 minutes, about 17 minutes, about 18 minutes, about 19 minutes, about 20 minutes, about 21 minutes, about 22 minutes, about 23 minutes, about 24 minutes, about 25 minutes, about 26 minutes, about 27 minutes, about 28 minutes, about 29 minutes, about 30 minutes, about 31 minutes, about 32 minutes, about 33 minutes, about 34 minutes, about 35 minutes, about 36 minutes, about 37 minutes, about 38 minutes, about 39 minutes, about 40 minutes, about 41 minutes, about 42 minutes, about 43 minutes, about 44 minutes, about 45 minutes, about 46 minutes, about 47 minutes, about 48 minutes, about 49 minutes, about 50 minutes, about 51 minutes, about 52 minutes, about 53 minutes, about 54 minutes, about 55 minutes, about 56 minutes, about 57 minutes, about 58 minutes, about 59 minutes, or about 60 minutes. In certain embodiments, the polymer composition is exposed to a light source for a duration of from about 1-3 minutes, about 3-6 minutes, about 6-10 minutes, about 1-5 minutes, about 1-10 minutes, about 5-10 minutes, about 11-13 minutes, about 13-16 minutes, about 16-20 minutes, about 10-20 minutes, about 10-15 minutes, about 15-20 minutes, about 21-23 minutes, about 23-26 minutes, about 26-30 minutes, about 20-30 minutes, about 20-25 minutes, about 25-30 minutes, about 31-33 minutes, about 33-36 minutes, about 36-40 minutes, about 30-40 minutes, about 30-35 minutes, about 35-40 minutes, about 41-43 minutes, about 43-46 minutes, about 46-50 minutes, about 40-50 minutes, about 40-45 minutes, about 45-50 minutes, about 51-53 minutes, about 53-56 minutes, about 56-60 minutes, about 50-60 minutes, about 50-55 minutes, or about 55-60 minutes.

[0186] In certain embodiments, a polymer composition can have a thickness from about 1 pm to about 10000 pm. In certain embodiments, a polymer composition can have a thickness from about 1-50 pm, about 50-100 pm, about 100-150 pm, about 150-200 pm, about 200-250 pm, about 250-300 pm, about 300-350 pm, about 350-400 pm, about 400-450 pm, about 450-400 m, about 400-450 pm, about 450-500 pm, about 500-550 pm, about 550-600 pm, about 600-650 pm, about 650-700 pm, about 700-750 pm, about 750-800 pm, about 800-850 pm, about 850-900 pm, about 900-950 pm, about 950-1000 pm, about 1000-1500 pm, about 1500-2000 pm, about 2000-2500 pm, about 2500-3000 pm, about 3000-3500 pm, about3500-4000 pm, about 4000-4500 pm, about 4500-4000 pm, about 4000-4500 pm, about4500-5000 pm, about 5000-5500 pm, about 5500-6000 pm, about 6000-6500 pm, about6500-7000 pm, about 7000-7500 pm, about 7500-8000 pm, about 8000-8500 pm, about8500-9000 pm, about 9000-9500 pm, or about 9500-10000 pm.

[0187] In certain embodiments, a precursor polymer composition can be cooled prior to or during crosslinking reactions. In certain embodiments, a precursor polymer composition can be cooled to a temperature of from about 0°C and about 30°C prior to or during crosslinking reactions. In certain embodiments, a precursor polymer composition can be cooled to a temperature of from about 0-5°C, about 5-10°C, about 0-10°C, about 10-15°C, about 15- 20°C, about 10-20°C, about 20-25°C, about 25-30°C, or about 20-30°C. In certain embodiments, a precursor polymer composition can be heated prior to or during crosslinking reactions. In certain embodiments, a precursor polymer composition can be heated to a temperature of from about 30°C and about 150°C prior to or during crosslinking reactions. In certain embodiments, a precursor polymer compositions can be heated to a temperature of from about 30-35°C, about 35-40°C, about 30-40°C, about 40-45°C, about 45-50°C, about 40-50°C, about 50-55°C, about 55-60°C, about 50-60°C, about 60-65°C, about 65-70°C, about 60-70°C, about 70-75°C, about 75-80°C, about 70-80°C, about 80-85°C, about 85- 90°C, about 80-90°C, about 90-95°C, about 95-100°C, about 90-100°C, about 100-105°C, about 105-110°C, about 100-110°C, about 110-115°C, about 115-120°C, about 110-120°C, about 130-135°C, about 135-140°C, about 130-140°C, about 140-145°C, about 145-150°C, or about 140-150°C.

[0188] Once crosslinking reactions are completed or halted, the resulting gel polymer materials can be clarified, purified, or processed for quality, purity, and / or therapeutic viability. In certain embodiments, a gel polymer composition can be dialyzed to remove any unreacted compounds from the gel mixture or structure. In certain embodiments, a gel polymer composition can be dialyzed with a dialysis buffer that comprises deionized water. In certain embodiments, a gel polymer composition can be filtered. In certain embodiments, a gel polymer composition can be dried. In certain embodiments, a gel polymer composition can be lyophilized. In certain embodiments, a gel polymer composition can be frozen for storage.

[0189] In certain embodiments, polymer compositions of the present disclosure can be formed, molded, extruded woven, or otherwise produced or processed into fibers, films, discs, fabrics, tubes, conduits, rods, rings, mesh, or any other form or shape for polymeric or gel materials known in the art. In certain embodiments, polymer compositions of the present disclosure can be formed, molded, extruded woven, or otherwise produced or processed into single layer structures or multi-layered structures (e.g., two layers, three layers, four layers, etc.).

[0190] In certain embodiments, a polymer composition of the present disclosure comprises macromolecular polymeric and / or fibrous elements which are interwoven or intertwined within the interstitial porous network of a polymer composition, but which are not chemically connected to the core crosslinked polymeric network. Non-limiting examples of such macromolecules include polycaprolactone, gelatin, gelatin methacrylate, alginate, alginate methacrylate, chitosan, chitosan methacrylate, glycol chitosan, glycol chitosan methacrylate, hyaluronic acid, hyaluronic acid methacrylate, and other non-crosslinked natural or synthetic polymeric chains. Gel materials which includes an interwoven macromolecular structure can be referred to as a composite structure or composite gel. Examples of hydrogel / fiber composites are described, for example, in Moutos et al. Nat.Mater., 2007, 6(2), p. 162-7; which is incorporated herein by reference in its entirety, insofar as it describes the composition, production, analysis and use of composite gel materials. In certain embodiments, a precursor polymer composition can be in a high-viscosity form (e.g., paste-like viscosity), and incorporated into a macromolecular polymeric matrix (e.g., fibrous mat or tissue matrix). In certain embodiments, a precursor polymer composition can be in a low-viscosity form (e.g., liquid-like viscosity), and incorporated into a macromolecular polymeric matrix (e.g., fibrous mat or tissue matrix).

[0191] In certain embodiments, a cross-linked polymer composition can have a substantially covalent matrix form. In certain embodiments, a cross-linked polymer composition can have an amorphous matrix form (i.e., matrix formed primarily through ionic and / or hydrogen bonding).

[0192] In certain embodiments, polymer compositions of the present disclosure can be formed as patterned gel compositions (e.g., a micropatterned hydrogel). Micropatterned hydrogels can be prepared using, for example, the methods set forth in US 6,423,252, which is incorporated herein by reference in its entirety, insofar as it describes the composition, production (including micropatterning), analysis and use of hydrogels, including acrylated gelatin polymeric compositions such as GelMA hydrogels. For example, the methodcomprises: (i) contacting a precursor polymer composition with a mold or surface which comprises a three-dimensional negative configuration (i.e., template) of a micropattern; and (ii) crosslinking and / or polymerizing the precursor polymer composition to produce a crosslinked gel polymer composition (e.g., GelMA hydrogel) which includes the micropattern on at least on surface of the hydrogel.

[0193] In certain embodiments, polymer compositions of the present disclosure can be formed as molded, stamped, or shaped gel compositions. Molded, stamped or shaped hydrogels can be prepared using, for example, the methods set forth in US 20050008675 or US 20040258729, each of which is incorporated herein by reference in its entirety, insofar as each describes the composition, production (including molding), analysis and use of hydrogels, including acrylated gelatin polymeric compositions such as GelMA hydrogels.IV. ADMINISTRATION AND TREATMENTSGeneral

[0194] Suturing, tissue transplantation, and the use of tissue adhesives are common treatments for defects and / or traumatic injuries to soft tissues (such as corneal or scleral tissues). However, each treatment carries risks and complications: (i) Suturing requires advanced surgical skill and early treatment, it often results in irregular stigmatisms, and can often lead to microbial entrapment and infection; (ii) Tissue grafting and transplantation require donor tissue (with associated high costs), advanced surgical skill, and present a high risk of immune reactions or full rejection of the grafted tissue; (iii) Tissue adhesives (such as cyanoacrylate glues, fibrin glues, or polyethylene-glycol (PEG)-based sealants) have limited effectiveness and adhesion (particularly in aqueous and physiological environments), have limited durability, can be difficult to apply and control texture, have a high probability of leaking, lack of biocompatibility (e.g., inflammatory) and possible toxicity, have a lack of translucence / transparency, have a high risk of infection (including risks related to high porosity), and have generally not received FDA safety approval for alleviating corneal defects or repairing corneal incisions, perforations or trauma.

[0195] There remains a need for improved polymer compositions which are effective in treating and / or sealing injuries, defects, and diseases to soft tissues in subjects (i.e., tissue of the body except bone).

[0196] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant composition for treating or repairing soft tissue in a subject. In certain embodiments, polymer compositions of the present disclosure can be used as a deliveryvehicle for administering a therapeutic agent for treating or repairing soft tissue in a subject. In certain embodiments, polymer compositions of the present disclosure can be used as a sealant composition for treating or repairing soft tissue in a subject, and as a delivery vehicle for administering a therapeutic agent for treating or repairing the soft tissue of the subject.

[0197] In certain embodiments, the methods and compositions of the present disclosure can be used to adhere, seal or treat target soft tissues of a subject. In certain embodiments, the methods and compositions of the present disclosure can be used to adhere, seal or treat one or more target soft tissues selected from: adipose tissue, bladder tissue, bone marrow, cardiovascular tissue (e.g., cardiac), dura mater, endocrine glands, gastrointestinal tissue, hair follicles, kidney tissue, liver tissue, lung tissue, lymph nodes, muscle tissue, neural / nerve tissue (e.g., peripheral nervous system), ocular tissue (e.g., corneal), oral tissue (e.g., craniofacial, odontic, periodontic), pancreatic tissue, renal tissue, skin tissue (e.g., for treatment of topical ulcers, such as diabetic ulcers), urethra tissue, vascular tissue. In certain embodiments, the methods and compositions of the present disclosure can be used to adhere, seal, or treat one or more target soft tissues in stressed and / or physiological environment, or similar applications which require elastic and / or adhesive compositions.

[0198] Polymer compositions (e.g., Acrylated gelatin polymer compositions) of the present disclosure may be administered by any route which results in a therapeutically effective outcome.

[0199] In certain embodiments, the method includes applying a pre-gelation polymer composition to an applicator; placing the applicator containing the pre-gelation polymer composition onto a surface of the target tissue of the subject; and crosslinking (e.g., photocrosslinking) the polymer composition by exposing the pre-gelation polymer composition to crosslinking conditions (e.g., visible light with a photoinitiator). In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target tissue without an applicator. In certain embodiments, application to the surface of a target tissue comprises application to an external surface of a target tissue (e.g., topical application). In certain embodiments, application to the surface of a target tissue comprises application / inj ection to a space directly below the surface of a target tissue (e.g., subconjunctival application to ocular tissue, subretinal application to ocular tissue).

[0200] In certain embodiments, a target soft tissue can be treated or sealed by applying a first layer which comprises a first polymer composition of the present disclosure which is engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity); and then applying a second layerwhich comprises a second polymer composition which is engineered to have different physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity). In certain embodiments, the method can include applying one or more additional layers (e.g., a third layer, a fourth layer, etc.), each of which comprises a polymer composition of the present disclosure which is engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity).

[0201] In certain embodiments, a target soft tissue can be treated by: (i) forming a preformed polymer composition by polymerizing a polymer composition of the present disclosure; and (ii) applying the pre-formed polymer composition onto a surface or under the surface (e.g., subconjunctival, subretinal) of the target tissue of the subject. In certain embodiments, application to the surface of a target tissue (e.g., onto or under the surface) comprises application / inj ection to a space directly below the surface of a target tissue (e.g., subconjunctival application to ocular tissue, subretinal application to ocular tissue). In certain embodiments, the pre-formed polymer composition can be engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity).

[0202] In certain embodiments, a target soft tissue can be treated by: (i) forming a preformed hydrogel polymer composition by polymerizing a polymer composition of the present disclosure; (ii) drying the hydrogel polymer by removing a substantial portion of interstitial fluid from the hydrogel (e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90 %, or at least 95% of interstitial fluid); (iii) applying the pre-formed polymer composition onto a surface or under the surface (e.g., subconjunctival, subretinal) of the target tissue of the subject; and (iv) optionally rehydrating the dried hydrogel polymer to a substantially hydrated form (e.g., e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90 %, or at least 95% of interstitial fluid volume). In certain embodiments, application to the surface of a target tissue (e.g., onto or under the surface) comprises application / inj ection to a space directly below the surface of a target tissue (e.g., subconjunctival application to ocular tissue, subretinal application to ocular tissue). In certain embodiments, the pre-formed polymer composition can be engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity).Therapeutic Compositions

[0203] In certain embodiments, polymer compositions of the present disclosure can be prepared as, or comprised in, therapeutic compositions. In certain embodiments, hydrogelpolymer compositions of the present disclosure can be prepared as, or comprised in, therapeutic compositions. In certain embodiments, acrylated gelatin hydrogel polymer compositions of the present disclosure can be prepared as, or comprised in, therapeutic compositions. Such compositions comprise one or more polymer composition of the present disclosure (including, optionally, one or more therapeutic agents or active ingredients) and one or more therapeutically acceptable excipients (e.g., carrier, solvent, or delivery vehicle).

[0204] Relative amounts of the polymer compositions (e.g., acrylated gelatin hydrogel polymer composition), a therapeutically acceptable excipient, and / or any additional ingredients in a therapeutic composition in accordance with the present disclosure may vary, depending upon the identity, size, and / or condition of the subject or tissue being treated and further depending upon the route by which the composition is to be administered or applied. In certain embodiments, a therapeutic composition comprises from 0.1% and 99% (w / v) of a polymer composition of the present disclosure in the volume of the therapeutic composition. In certain embodiments, a therapeutic composition comprises a polymer composition of the present disclosure at weight-per-volume concentration (w / v) of about 0.5%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 88%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99%. In certain embodiments, a therapeutic composition comprises a polymer composition of the present disclosure at weight-per-volume concentration (w / v) of from about 1-3%, about 3-6%, about 6-10%, about 1-5%, about 5-10%, about 1-10%, about 11-13%, about 13-16%, about 16- 20%, about 10-15%, about 15-20%, about 10-20%, about 21-23%, about 23-26%, about 26- 30%, about 20-25%, about 25-30%, about 20-30%, about 31-33%, about 33-36%, about 36- 40%, about 30-35%, about 35-40%, about 30-40%, about 41-43%, about 43-46%, about 46-50%, about 40-45%, about 45-50%, about 40-50%, about 51-53%, about 53-56%, about 56-60%, about 50-55%, about 55-60%, about 50-60%, about 61-63%, about 63-66%, about 66-70%, about 60-65%, about 65-70%, about 60-70%, about 71-73%, about 73-76%, about 76-80%, about 70-75%, about 75-80%, about 70-80%, about 81-83%, about 83-86%, about 86-90%, about 80-85%, about 85-90%, about 80-90%, about 91-93%, about 93-96%, about 96-99%, about 90-95%, about 95-99%, or about 90-99%.

[0205] In certain embodiments, therapeutic compositions and formulations of the present disclosure comprises, without limitation, saline, liposomes (e.g., unilamellar vesicles, multilamellar vesicles), lipid particles (including microparticles and nanoparticles), and / or polymeric particles (including microparticles and nanoparticles). In certain embodiments, therapeutic compositions and formulations of the present disclosure comprises a polymeric composition of the present disclosure which incorporates, without limitation, saline, liposomes, lipid particles (including microparticles and nanoparticles), polymeric particles (including microparticles and nanoparticles) or a combination thereof.

[0206] In certain embodiments, therapeutic compositions and formulations of the present disclosure are aqueous formulations (i.e., formulations which comprise water). In certain embodiments, therapeutic compositions and formulations of the present disclosure comprise water, sanitized water, or Water-for-inj ection (WFI).

[0207] In certain embodiments, therapeutic compositions and formulations of the present disclosure comprises one or more of the following: pH buffered solutions (e.g., phosphate buffered saline (PBS), HEPES, TES, MOPS), isotonic saline, Ringer’s solution, Balanced Salt Solution Plus (BSS+, Alcon), polyols (e.g., glycerol, propylene glycol, liquid polyethylene glycol), alginic acid, ethyl alcohol, and therapeutically acceptable mixtures thereof. In certain embodiments, therapeutic compositions and formulations of the present disclosure comprises phosphate buffered saline (PBS).

[0208] Formulations of the present disclosure can be used in any step of producing, processing, preparing, storing, expanding, or administering polymer compositions of the present disclosure.

[0209] In certain embodiments, therapeutic compositions of the present disclosure comprise one or more therapeutically acceptable excipient (e.g., a vehicle capable of suspending or dissolving the polymeric compound. Excipients may include, for example: anti adherents, antioxidants, binders, coatings, compression aids, disintegrants, dyes (colors), emollients, emulsifiers, fillers (diluents), film formers or coatings, flavors, fragrances, glidants (flow enhancers), lubricants, preservatives, printing inks, sorbents, suspension, ordispersing agents, sweeteners, and waters of hydration. Exemplary excipients include, but are not limited to: acetic acid, aluminum stearate, butylated hydroxytoluene (BHT), calcium carbonate, calcium chloride, calcium phosphate (dibasic), calcium stearate, carboxymethyl celluloses, croscarmellose, crosslinked polyvinyl pyrrolidone, citric acid, crospovidone, cysteine, ethylcellulose, gelatin, glucose, glucuronic acid, gluconic acid, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyl-butanedioic acid, inosite, lactose, magnesium chloride, magnesium stearate, maltitol, mannitol, methionine, methylcellulose, methyl paraben, microcrystalline cellulose, phosphoric acid, polyethylene glycol, polyvinyl pyrrolidone, povidone, pregelatinized starch, propyl paraben, retinyl palmitate, saccharose, shellac, silicon dioxide, sodium acetate, sodium carbonate, sodium bicarbonate, sodium carboxymethyl cellulose, sodium chloride, sodium citrate, sodium hydroxide, sodium phosphate, sodium starch glycolate, sorbitol, starch (corn), stearic acid, sucrose, talc, titanium dioxide, vitamin A, vitamin E, vitamin C, xylitol, zinc stearate, and combinations thereof. Therapeutic Agents

[0210] In certain embodiments, the polymer compositions of the present disclosure can include a therapeutic agent. In certain embodiments, the polymer compositions of the present disclosure can include a therapeutic agent as a delivery payload.

[0211] In certain embodiments, a polymer composition of the present disclosure can include a therapeutic agent at a concentration (w / v) from about 0% and about 40%. In certain embodiments, a precursor polymer composition of the present disclosure can include a therapeutic agent at a concentration (w / v) from about 0% and about 40%. In certain embodiments, a gel polymer composition of the present disclosure can include a therapeutic agent at a concentration (w / v) from about 0% and about 40%. In certain embodiments, a polymer compositions of the present disclosure can include a therapeutic agent at a concentration (w / v) from about 1-2%, about 2-4%, about 4-6%, about 6-8%, about 8-10%, about 1-5%, about 5-10%, about 1-10%, about 10-12%, about 12-14%, about 14-16%, about 16-18%, about 18-20%, about 10-15%, about 15-20%, about 10-20%, about 20-22%, about22-24%, about 24-26%, about 26-28%, about 28-30%, about 20-25%, about 25-30%, about20-30%, about 30-32%, about 32-34%, about 34-36%, about 36-38%, about 38-40%, about30-35%, about 35-40%, or about 30-40%.

[0212] In certain embodiments, a precursor polymer composition of the present disclosure can include a therapeutic agent at a concentration from about 0.1 mg / mL and about 500 mg / mL. In certain embodiments, a polymer compositions of the present disclosure can include a therapeutic agent at a concentration from about 0.1-0.5 mg / mL, about 0.5-1.0mg / mL, about 1.0-2.5 mg / mL, about 2.5-5.0 mg / mL, about 5.0-10.0 mg / mL, about 10.0-25.0 mg / mL, about 25.0-50.0 mg / mL, about 50.0-100.0 mg / mL, about 100-150 mg / mL, about 150-200 mg / mL, about 200-250 mg / mL, about 250-300 mg / mL, about 300-350 mg / mL, about 350-400 mg / mL, about 400-450 mg / mL, about 450-500 mg / mL, about 500-550 mg / mL, about 550-600 mg / mL, about 600-650 mg / mL, about 650-700 mg / mL, about 700- 750 mg / mL, about 750-800 mg / mL, about 800-850 mg / mL, about 850-900 mg / mL, about 900-950 mg / mL, or about 950-1000 mg / mL.

[0213] In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in less than 1 hour. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in less than 1 day. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in from about 0-2 hours, about 2-4 hours, about 4-6 hours, about 6-8 hours, about 8-10 hours, about 10-12 hours, about 12-16 hours, about 16-20 hours, about 20-24 hours, about 24-30 hours, about 30-36 hours, about 36-42 hours, or about 42-48 hours. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in less than 1 week. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in from about 0-2 days, about 2-4 days, about 4-6 days, about 6-8 days, about 8-10 days, about 10-12 days, about 12-16 days, about 16-20 days, about 20-24 days, about 24-30 days, about 30-35 days, about 35-40 days, about 40-45 days, about 45-50 days, about 50-55 days, or about 55-60 days. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in less than 1 month. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in less than 12 months. In certain embodiments, a polymer composition can deliver a therapeutic agent to a peak concentration in from about 0-1 months, about 1-2 months, about 2-3 months, about 3-4 months, about 4-5 months, about 5-6 months, about 6-7 months, about 7-8 months, about 8-9 months, about 9-10 months, about 10-11 months, or about 11-12 months.

[0214] In certain embodiments, the therapeutic agent comprises one or more of a growth factor, a hemostatic agent, analgesics, anesthetics, antifungals, antibiotics, antibacterials, antiinflammatories, antimicrobials, anthelmintics, antidotes, antiemetics, antihistamines, antihypertensives, antimalarials, antipsychotics, antipyretics, antiseptics, antiarthritics, antituberculotics, antitussives, antivirals, cardioactive drugs, cathartics, chemotherapeutic agents, a colored or fluorescent imaging agent, corticoids (such as steroids), antidepressants, depressants, diagnostic aids, diuretics, enzymes, expectorants, hormones, hypnotics, immunosuppressants, minerals, nutritional supplements, parasympathomimetics, potassiumsupplements, radiation sensitizers, a radioisotope, sedatives, sulfonamides, stimulants, sympathomimetics, tranquilizers, urinary anti-infectives, vasoconstrictors, vasodilators, vitamins, xanthine derivatives, organic molecules, small molecule inhibitors, glycosaminoglycans, organometallic agents, chelated metals or metal salts, peptide-based drugs, vitamins, nutritional supplements, glycoproteins (e.g., collagen), extracellular matrix proteins or fragments thereof, fibronectin, peptides and / or proteins, polysaccharides, carbohydrates (both simple and / or complex), proteoglycans, antigens, oligonucleotides (sense and / or antisense DNA and / or RNA), antibodies, nucleic acid sequences, gene therapy agents, triamcinolone acetonide, ovalbumin, or a combination thereof.

[0215] In certain embodiments, the therapeutic agent comprises one or more anti- acanthamoebal, antiviral and / or antibacterial agents. In certain embodiments, the therapeutic agent comprises one or more agent selected from acyclovir, valacyclovir, famciclovir, penciclovir, trifluridine, vidarabine, hydroxychloroquine, gatifloxacin, daptomycin, tigecycline, telavancin, chloramphenicol, fusidic acid, chlorohexidine, polyhexamethylene biguanide, propamidine, hexamidine, bacitracin, metronidazole, rifampin, ethambutol, streptomycin, isoniazid, silver nanoparticles, copper oxide nanoparticles, glycopeptides (e.g., teicoplanin, vancomycin), aminoglycosides (e.g., gentamycin, tobramycin, amikacin, netilmicin), cephalosporins (e.g., cefazolin, cefoxitin, cefotaxime, cefuroxime, moxalactam), macrolides (e.g., erythromycin), oxazolidinones (e.g., linezolid), quinolones, polymyxins, sulfonamides, tetracyclines, penems, carbapenems, monobactams, lincosamides, spectinomycin, clindamycin, ansamycins, daptomycin, nitrofurans, trimethoprim sulfamethoxazole, chitosan, penicillin, ciprofloxacin, or a combination thereof.

[0216] In certain embodiments, the therapeutic agent comprises one or more anti-fungal agents. In certain embodiments, the therapeutic agent comprises one or more agent selected from amphotericin B, natamycin, candicin, fllipin, hamycin, nystatin, rimocidin, voriconazole, imidazoles, triazoles, thiazoles, allylamines, echinocandins, benzoic acid, ciclopirox, flucytosine, griseofulvin, haloprogin, tolnaftate, undecylenic acid, and povidone iodine, or a combination thereof.

[0217] In certain embodiments, the therapeutic agent comprises one or more antimicrobial agents. In certain embodiments, the therapeutic agent comprises one or more antimicrobial agents selected from polymyxin B, vancomycin, cholera toxin, diphtheria toxin, lysostaphin, hemolysin, bacitracin, boceprevir, albavancin, daptomycin, enfuvirtide, oritavancin, teicoplanin, telaprevir, telavancin, guavanin 2, Maximin H5, derm ci din, cecropins, andropin, moricin, ceratotoxin, melittin, magainin, dermaseptin, brevinin-1, esculentins, buforin II,CAP18, LL37, baecin, apidaecins, prophenin, indolicidin, antimicrobial peptide (AMP) (e.g., Tet213), chlorhexidine, a chlorhexidine salt, triclosan, polymyxin, tetracycline, an amino glycoside (e.g., gentamicin, Tobramycin), rifampicin, erythromycin, neomycin, chloramphenicol, miconazole, a quinolone, penicillin, fusidic acid, cephalosporin, mupirocin, metronidazole, secropin, protegrin, bacteriolcin, defensin, nitrofurazone, mafenide, aracyclovir, clindamycin, lincomycin, sulfonamide, norfloxacin, pefloxacin, nalidizic acid, cinnamycin, anti -DEF A5, duramycin, nisin, pediocin, Abaecin, Ct-AMPl, Apidaecin IA, Apidaecin IB, Bactenecin, Bactenecin 5, Bactenecin 7, Bactericidin B-2, Aurein family, SMAP-29, Temporin B, Pleurocidin, Tachyplesin III, LL-37, Citropin 1.1, BMAP-27, BMAP-28, Agelaia-MP, Temporin lOLa, NA-CATH, Histatins, Latarcin, Halocidin, Bombinin, Cathelicidin, Malacidin, MP196, MS100a7al5, Murepavadin, Myticin, Mytilin, Paenibacterin, Pardaxin, Peptaibol, SAAP-148, Sarcotoxin, Stomoxyn, Tachyplesin, thioester-containing protein 1, Thionin, Alamethicin, Arenicin, dermorphins, deltorphins, dermaseptins, pseudin, bombesins, maculatins, LEAP2, Efrapeptin, Arylomycins, Capreomycin, Gramicidin B, Antiamoebin, Bacillomycin, Teixobactin, Tyrothricin, Viomycin, oxalic acid, or combinations thereof.

[0218] In certain embodiments, the therapeutic agent comprises one or more antiinflammatory agents. In certain embodiments, the therapeutic agent comprises one or more anti-inflammatory agent selected from steroidal anti-inflammatory drugs (e.g., prednisolone), corticosteroids (e.g., loteprednol etabonate), salicylates, non-steroidal anti-inflammatory drugs (e.g., bromfenac), mTOR inhibitors, calcineurin inhibitors, synthetic or natural antiinflammatory proteins, dexamethasone, 5 -fluorouracil, daunomycin, paclitaxel, curcumin, resveratrol, mitomycin, methylprednisolone, prednisolone, hydrocortisone, fludrocortisone, prednisone, celecoxib, ketorolac, piroxicam, diclorofenac, ibuprofen, and ketoprofen, rapamycin, cyclosporin, tacrolimus / FK-506, or a combination thereof.

[0219] In certain embodiments, the therapeutic agent comprises one or more growth factors. In certain embodiments, the therapeutic agent comprises a growth factor which comprises a recombinant hepatocyte growth factor or recombinant nerve growth factor. In certain embodiments, the therapeutic agent comprises one or more growth factors selected from Activins (e.g., Activin A, Activin B, Activin AB), Adrenomedullin (AM), albumin, alpha-2 macroglobulin, annexin, Angiopoietin (Ang), Artemin, Autocrine motility factor, Bone morphogenetic proteins (BMPs) (e g., BMP-1, BMP -2, BMP-3, BMP -4, BMP-5, BMP- 6, BMP-7, BMP-8, BMP-9), Brain-derived neurotrophic factor (BDNF), Ciliary neurotrophic factor family, Ciliary neurotrophic factor (CNTF), connective tissue activated peptides(CTAPs), Epidermal growth factor (EGF), Ephrins (e.g., Ephrin Al, Ephrin A2, Ephrin A3, Ephrin A4, Ephrin A5, Ephrin Bl, Ephrin B2, Ephrin B3), Erythropoietin (EPO), Fibroblast growth factor (FGF) (e.g, FGF1, FGF2, FGF3, FGF4, FGF5, FGF6, FGF7, FGF8, FGF9, FGF10, FGF11, FGF12, FGF13, FGF14, FGF15, FGF16, FGF17, FGF18, FGF19, FGF20, FGF21, FGF22, FGF23), basic fibroblast growth factor (bFGF), acidic fibroblast growth factor (aFGF), Fetal Bovine Somatotrophin (FBS), Glial cell line-derived neurotrophic factor (GDNF), Granulocyte colony-stimulating factor (G-CSF), Granulocyte macrophage colonystimulating factor (GM-CSF), Growth differentiation factors (GDF) (e.g, GDF1, GDF9), Heparin-binding growth factors, Hepatocyte growth factor (HGF), Hepatocyte growth factorlike protein (HGFLP), Hepatoma-derived growth factor (HDGF), Inhibins (e.g, Inhibin A, Inhibin B), Insulin, Insulin-like growth factor (IGF) (e.g, IGF-1, IGF-2), Interleukins (IL) (e.g, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-11, and IL-13), Keratinocyte growth factor (KGF), Leukemia inhibitory factor (LIF), Macrophage colony-stimulating factor (M- CSF), Macrophage-stimulating protein (MSP), Migration-stimulating factor (MSF), Myostatin, Neuregulins (NRG) (e.g, NRG1, NRG2, NRG3, NRG4), Neurotrophins (NT) (e.g, NT-1, NT -2, NT-3, NT -4), Neurturin, Nerve growth factor (NGF), osteogenic factors, Persephin, Placental growth factor (PGF), Platelet-derived growth factor (PDGF), Renalase (RNLS), stromal cell-derived factor- 1, T-cell growth factor (TCGF), Thrombopoietin (TPO), Transforming growth factor alpha (TGF-a), Transforming growth factor beta (TGF-P), Tumor necrosis factor-alpha (TNF-a), and Vascular endothelial growth factor (VEGF), anti- vascular endothelial growth factor (anti-VEGF) (e.g, bevacizumab, ranibizumab, aflibercept), and biologically active analogs, fragments, derivatives of such growth factors, or a combination thereof.

[0220] In certain embodiments, the therapeutic agent comprises one or hormone. In certain embodiments, the therapeutic agent comprises one or more hormones selected from: antimullerian hormone, mullerian inhibiting factor or hormone), adiponectin, adrenocorticotropic hormone, corticotropin, angiotensinogen, angiotensin, antidiuretic hormone, vasopressin, arginine vasopressin, atrial -natriuretic peptide, atriopeptin, calcitonin, cholecystokinin, corticotropin-releasing hormone, erythropoietin, follicle-stimulating hormone, gastrin, ghrelin, glucagon, gonadotropin-releasing hormone, growth hormone- releasing hormone, human chorionic gonadotropin, human placental lactogen, growth hormone, somatomedin, leptin, luteinizing hormone, melanocyte stimulating hormone, orexin, oxytocin, parathyroid hormone, prolactin, relaxin, secretin, somatostatin,thrombopoietin, thyroid-stimulating hormone, thyrotropin, thyrotropin-releasing hormone, or combinations thereof.

[0221] In certain embodiments, a polymer composition of the present disclosure can include one or more growth factors at a concentration (w / v) from about 0.001 pg / mL and about 2 g / mL. In certain embodiments, a polymer composition of the present disclosure can include one or more growth factors at a concentration (w / v) from about 0.001 pg / mL and about 1000 pg / mL. In certain embodiments, a polymer composition can include one or more growth factors at a concentration (w / v) from about 0.01 pg / mL and about 500 pg / mL. In certain embodiments, a polymer composition can include one or more growth factors at a concentration (w / v) from about 0.1 pg / mL and about 200 pg / mL. In certain embodiments, a polymer compositions can include one or more growth factors at a concentration (w / v) from about 0.1-0.5 pg / mL, about 0.5-1.0 pg / mL, about 1-2 pg / mL, about 2-4 pg / mL, about 4-6 pg / mL, about 6-8 pg / mL, about 8-10 pg / mL, about 10-12 pg / mL, about 12-14 pg / mL, about 14-16 pg / mL, about 16-18 pg / mL, about 18-20 pg / mL, about 20-22 pg / mL, about 22-24 pg / mL, about 24-26 pg / mL, about 26-28 pg / mL, about 28-30 pg / mL, about 30-35 pg / mL, about 35-40 pg / mL, about 40-45 pg / mL, about 45-50 pg / mL, about 50-55 pg / mL, about 55- 60 pg / mL, about 60-65 pg / mL, about 65-70 pg / mL, about 70-75 pg / mL, about 75-80 pg / mL, about 80-85 pg / mL, about 85-90 pg / mL, about 90-95 pg / mL, about 95-100 pg / mL, about 100-125 pg / mL, about 125-150 pg / mL, about 150-175 pg / mL, about 175-200 pg / mL, about200-225 pg / mL, about 225-250 pg / mL, about 250-275 pg / mL, about 275-300 pg / mL, about300-325 pg / mL, about 325-350 pg / mL, about 350-375 pg / mL, about 375-400 pg / mL, about400-425 pg / mL, about 425-450 pg / mL, about 450-475 pg / mL, about 475-500 pg / mL, about500-550 pg / mL, about 550-600 pg / mL, about 600-650 pg / mL, about 650-700 pg / mL, about700-750 pg / mL, about 750-800 pg / mL, about 800-850 pg / mL, about 850-900 pg / mL, about900-950 pg / mL, about 950-1000 pg / mL, about 1000-1100 pg / mL, about 1100-1200 pg / mL, about 1200-1300 pg / mL, about 1300-1400 pg / mL, about 1400-1500 pg / mL, about 1500- 1600 pg / mL, about 1600-1700 pg / mL, about 1700-1800 pg / mL, about 1800-1900 pg / mL, or about 1900-2000 pg / mL.

[0222] In certain embodiments, the therapeutic agent comprises one or more hemostatic agents (i.e., a material that promotes hemostasis) and / or immunosuppressive agents. In certain embodiments, the therapeutic agent comprises one or more agents selected from blood platelets, platelet-like nanoparticles (e.g., silicate nanoparticles), blood coagulation factors (e.g., thrombin, prothrombin), alkylating agents, antimetabolites, mycophenolate,cyclosporine, tacrolimus, rapamycin, or combinations thereof. In certain embodiments, the therapeutic agent comprises an anticoagulant or blood thinner (e.g., heparin).

[0223] In certain embodiments, a polymer composition of the present disclosure can incorporate or be coated with cells or cell -precursors of a target tissue. In certain embodiments, a polymer compositions can incorporate or be coated with one or more cells or cell-precursors of a target tissue selected from nerve cells, muscle cells, myocytes, cardiomyocytes, hepatocytes, keratinocytes, melanocytes, ameloblasts, fibroblasts, preosteoblasts, osteoblasts, osteoclasts, endothelial cells, epithelial cells, mesenchymal stem cells, neurolemmocytes (i.e., Schwann cells), embryonic stem cells, adult stem cells, pluripotent stem cells, multipotent stem cells, hematopoietic stem cells, adipose derived stem cells, bone marrow derived stem cells, osteocytes, neurocytes, or a combination thereof. In certain embodiments, a polymer composition can incorporate or be coated with endothelial cells (e.g., corneal endothelial cells). In certain embodiments, a polymer composition can incorporate or be coated with ocular cells. In certain embodiments, a polymer composition can incorporate or be coated with adherent cell types (i.e., cells that form cell-to-cell network, 3D vasculature). In certain embodiments, a polymer composition can incorporate or be coated with monolayer cell types (i.e., 2D). In certain embodiments, a polymer composition can incorporate or be coated with epithelial cells, endothelial cells, keratocytes, and combinations thereof. In certain embodiments, a polymer composition can incorporate or be coated with human umbilical vein endothelial cells (HUVEC) or vascular endothelial cells. In certain embodiments, a polymer composition can incorporate or be coated with human retinal pigment epithelium cells (HRPEC), human neuroepithelial cells, human photoreceptor cells, human corneal endothelial cells, human neural crest cells, human retinal ganglion cells, human limbal cells, human cardiomyocytes, human hepatocytes, human dermal cells, human gastrointestinal epithelial cells, human neurons, and human islet cells, human immune cells, and other therapeutic human cells.

[0224] In certain embodiments, cells or cell -precursors can be incorporated into or onto a polymer gel matrix by placing the polymer gel composition in a cell culture mixture for a duration of time. The culture time may differ depending upon the cells used, but can generally be 1 to 21 days. In certain embodiments, exposure of the polymer gel composition to cell cultures is repeated to increase the cell density in or on the gel matrix.

[0225] In certain embodiments, a polymer composition of the present disclosure can incorporate cells or cell-precursors according to the procedures disclosed in WO 2013040559; or Loessner et al., Nature protocols. 2016 Apr; 11(4): 727; each of which isincorporated herein by reference in its entirety, insofar as each describes the incorporation of cells or cell-precursors onto or into a gel matrix, such as an acrylated gelatin hydrogel. Therapeutic Applications

[0226] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in a subject. In certain embodiments, polymer compositions of the present disclosure can be used as a delivery vehicle for administering a therapeutic agent for treating and / or repairing soft tissue in a subject. In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in a subject, and as a delivery vehicle for administering a therapeutic agent for treating and / or repairing the soft tissue of the subject.

[0227] In certain embodiments, the methods and compositions of the present disclosure can be used to adhere, seal or treat one or more target soft tissues selected from ocular tissue (i.e. eyes), lung, cardiovascular, skin, kidney, bladder, urethra, dura mater, liver, gastrointestinal, or oral (i.e. mouth) tissue. In certain embodiments, the methods and compositions of the present disclosure can be used to adhere, seal or treat one or more target soft tissues in a stressed and / or physiological environment, or similar applications which require elastic and / or adhesive compositions.

[0228] In certain embodiments, the present disclosure provides methods for treating and / or repairing soft tissue in a subject using polymer compositions of the present disclosure. In certain embodiments, the present disclosure provides methods for treating and / or repairing a defect, injury, and / or disease in the soft tissue of a subject using polymer compositions of the present disclosure. In certain embodiments, the method includes: applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pregelation polymer composition onto a surface of a target soft tissue of the subject (e.g., location of soft tissue defect, injury, and / or disease); and crosslinking (e.g., photocrosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., photoinitiator and visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or soft tissue surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target soft tissue without an applicator. In certain embodiments, the pre- gelation polymer composition is applied on or near (e.g., on the same tissue or under thetissue) the target soft tissue. In certain embodiments, the pre-gelation polymer composition can have a strong, sustained adhesion and high retention on the target soft tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the target soft tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target soft tissue. In certain embodiments, the polymer composition is engineered to distribute a therapeutic agent to the target soft tissue. In certain embodiments, the shear thinning property of the polymer composition is utilized to deliver the polymer composition.

[0229] In certain embodiments, a polymer composition can improve the cell viability once injected into the soft tissue. In certain embodiments, the polymer composition is a scaffold for cells, wherein the function of the transplanted cells is improved through (i) direct action of the cells, (ii) supporting a secondary cell type for treating injuries, defects, or diseases of the soft tissue. In certain embodiments, the polymer composition improves the structure of restored tissue to recapitulate naturally occurring tissues.Ocular Injuries and Diseases

[0230] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing ocular soft tissue in the eye of a subject. In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing an ocular defect, ocular surface injury, or an ocular disease in the eye of a subject. In certain embodiments, the ocular defect, injury or disease is a corneal or scleral defect, injury or disease. In certain embodiments, the corneal or scleral injury is a laceration (partial- or full-thickness), perforation, incision (e.g., surgical incision), or similar surface trauma (such as trauma from a foreign object or projectile). In certain embodiments, the ocular defect, injury or disease is an ocular ulcer, such as a corneal ulcer from severe infections, injuries, perforations, or other defects. In certain embodiments, the target soft tissue is ocular tissue; optionally subconjunctival ocular tissue or retinal ocular tissue.

[0231] In certain embodiments, the present disclosure provides methods for treating an ocular defect, ocular surface injury, or an ocular disease in a subject with the polymer compositions of the present disclosure. In certain embodiments, the method includes applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pre-gelation polymer composition onto a surface of the eye of the subject; and crosslinking(e.g., photo-crosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or ocular surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target ocular tissue without an applicator. In certain embodiments, the pre-gelation polymer composition can have a strong, sustained adhesion and high retention on the ocular tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the ocular tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target ocular tissue (e.g., corneal tissue).

[0232] In certain embodiments, the applicator is a curved, concave surface. In certain embodiments, the applicator is a curved lens (e.g., contact lens). In certain embodiments, the curvature of the applicator is similar to the curvature of the target ocular surface.

[0233] In certain embodiments, an ocular defect, ocular surface injury, or an ocular disease in a target ocular tissue can be treated by: (i) forming a pre-formed polymer composition by polymerizing a polymer composition of the present disclosure; and (ii) applying the pre-formed polymer composition onto a surface or under the surface (e.g., subconjunctival, subretinal) of the target tissue of the subject. In certain embodiments, application to the surface of a target tissue comprises application / inj ection to a space directly below the surface of a target tissue (e.g., subconjunctival application to ocular tissue, subretinal application to ocular tissue). In certain embodiments, the pre-formed polymer composition can be engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity).

[0234] In certain embodiments, an ocular defect, ocular surface injury, or an ocular disease in a target ocular tissue can be treated by: (i) forming a pre-formed hydrogel polymer composition by polymerizing a polymer composition of the present disclosure; (ii) drying the hydrogel polymer by removing a substantial portion of interstitial fluid from the hydrogel (e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90 %, or at least 95% of interstitial fluid); (iii) applying the pre-formed polymer composition onto a surface or under the surface (e.g., subconjunctival, subretinal) of the target tissue of the subject; and (iv) optionally rehydrating the dried hydrogel polymer to a substantially hydrated form (e.g., e.g., at least 50%, at least 60%, at least 70%, at least 80%, at least 90 %, or at least 95% ofinterstitial fluid volume). In certain embodiments, application to the surface of a target tissue comprises application / inj ection to a space directly below the surface of a target tissue (e.g., subconjunctival application to ocular tissue, subretinal application to ocular tissue). In certain embodiments, the pre-formed polymer composition can be engineered to have specific physical, mechanical, structural, chemical and / or biological properties (e.g., elasticity, biodegradability, porosity).

[0235] In certain embodiments, the polymer composition improves (i) RPE monolayer formation, (ii) RPE function through preservation of photoreceptor structure and function, or (i) and (ii). In certain embodiments, the polymer composition restores or maintains vision. Oral Injuries and Diseases

[0236] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in the mouth of a subject. In certain embodiments, polymer compositions can be used for treating and / or repairing oral tissue associated with periodontal diseases, injuries or ailments. In certain embodiments, the periodontal disease, injury or ailment can include those associated with periodontal implants, including peri-implant diseases (PIDs) such as peri-implant mucositis (PIM) and peri-implantitis (PI). These ailments are often associated with inflammation (from bacterial accumulation and biofilm formation) of the soft tissues surrounding a periodontal implant, resulting in bleeding suppuration, erythema, swelling, and infection of the oral tissues, as well as possible progressive bone loss that can lead to implant failure.

[0237] In certain embodiments, polymer compositions of the present disclosure can be used to seal an area of soft tissue surrounding a periodontal implant. In certain embodiments, polymer compositions of the present disclosure can be used to deliver a therapeutic agent (e.g., antimicrobial or anti-inflammatory) to an area of soft tissue surrounding a periodontal implant. In certain embodiments, the polymer compositions comprise an osteoinductive agent. In certain embodiments, the polymer compositions comprise one or more osteoinductive agents selected from silicate nanoparticles (SNs), calcium salts, bioglass, hydroxyapatite, demineralized bone matrix (DBM), or combinations thereof. In certain embodiments, the polymer compositions comprise one or more silicate nanoparticles, including SNs that include one or more metals, such as calcium, aluminum, silver, gold, platinum, palladium, lithium, magnesium, sodium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, iridium, or combinations thereof. In certain embodiment, the silicate nanoparticles include laponite nanoparticles. In certainembodiments, the polymer compositions comprise one or more calcium salts, such as calcium phosphate, calcium sulfate, calcium hydroxide, calcium bromide, calcium fluoride, calcium iodide, calcium hydride, or combinations thereof.

[0238] In certain embodiments, the present disclosure provides methods for treating a defect, injury, or disease in the oral soft tissue of a subject, with the polymer compositions of the present disclosure. In certain embodiments, the method includes: applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pregelation polymer composition onto a surface of the oral soft tissue of the subject (e.g., soft tissue surrounding a periodontal implant); and crosslinking (e.g., photo-crosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or oral soft tissue surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target oral soft tissue without an applicator. In certain embodiments, the pre-gelation polymer composition can have a strong, sustained adhesion and high retention on the oral soft tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the oral soft tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target oral soft tissue (e.g., soft tissue surrounding a periodontal implant).Nerve Injuries and Diseases

[0239] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in the nervous system (e.g., central nervous system (CNS), peripheral nervous system (PNS)) of a subject. In certain embodiments, polymer compositions can be used for treating and / or repairing nerve tissue associated with traumatic injury or surgical damage, including Peripheral Nerve Injuries (PNI). Typical surgical interventions for these ailments (including suturing and / or commercial adhesives) are often associated with inflammation, heightened foreign body response (FBR), scaring, slower nerve regeneration, or loss of nerve function (partial or complete).

[0240] In certain embodiments, nerve tissue can be treated or sealed by applying a polymer composition of the present disclosure to the target nerve tissue. In certainembodiments, nerve tissue can be treated or sealed by applying a polymer composition of the present disclosure to the lumen of nerve conduits in the location of nerve injury.

[0241] In certain embodiments, the present disclosure provides methods for treating a defect, injury, or disease in the nerves or CNS tissue of a subject, with the polymer compositions of the present disclosure. In certain embodiments, the method includes: applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pre-gelation polymer composition onto a surface of the nerves or CNS tissue of the subject (e.g., nerves of the peripheral nervous system); and crosslinking (e.g., photocrosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or nerves / CNS tissue surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target nerves or CNS tissue without an applicator. In certain embodiments, the pre- gelation polymer composition can have a strong, sustained adhesion and high retention on the target nerves or CNS tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the target nerves or CNS tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target nerves or CNS tissue (e.g., nerves of the peripheral nervous system).

[0242] In certain embodiments, the polymer compositions of the present disclosure can include the polymeric or therapeutic components, or can be produced, analyzed or used by the methods (including for the treatment of nerve injuries) as disclosed in US 20190070338, which is incorporated herein by reference in its entirety, insofar as it describes the composition, production, analysis and use of acrylated gelatin polymeric compositions, such as GelMA hydrogels.Cardiovascular Injuries and Diseases

[0243] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in the cardiovascular system (e.g., heart) of a subject. In certain embodiments, polymer compositions can be used for treating and / or repairing cardiovascular tissue associated with traumatic injury or surgical damage, including cardiac tissue. Typical surgical interventionsfor these ailments (including suturing and / or commercial adhesives) are often associated with inflammation and infection, scaring, slower tissue regeneration, or loss of function (partial or complete).

[0244] In certain embodiments, vascular / cardiovascular tissue can be treated or sealed by applying a polymer composition of the present disclosure to the target vascular / cardiovascular tissue. In certain embodiments, vascular / cardiovascular tissue can be treated or sealed by applying a cell-laden hydrogel composition of the present disclosure to the target vascular / cardiovascular tissue. In certain embodiments, a cell-laden hydrogel composition comprises cells or cellular precursors which encourage or facilitate the repair, restoration, replacement, or regeneration of vascular / cardiovascular tissue (e.g., cardiac tissue). In certain embodiments, a cell-laden hydrogel composition comprises one or more cells or cellular precursors selected from: smooth muscle cells, cardiomyocytes, fibroblasts, mesenchymal stem cells, bone marrow stem cells, or a combination thereof. In certain embodiments, the cell-laden hydrogel composition is in the form of a mat, fabric, mesh, or other shape which is amenable to being used as a covering or transplant.

[0245] In certain embodiments, the present disclosure provides methods for treating a defect, injury, or disease in the cardiovascular tissue of a subject, with the polymer compositions of the present disclosure. In certain embodiments, the method includes: applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pre-gelation polymer composition onto a surface of the cardiovascular tissue of the subject (e.g., heart tissue); and crosslinking (e.g., photo-crosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or cardiovascular tissue surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target cardiovascular tissue without an applicator. In certain embodiments, the pre-gelation polymer composition can have a strong, sustained adhesion and high retention on the cardiovascular tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the cardiovascular tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target cardiovascular tissue (e.g., heart tissue).

[0246] In certain embodiments, the polymer compositions of the present disclosure can include the polymeric or therapeutic components, or can be produced, analyzed or used by the methods (including for the treatment of cardiovascular injuries) as disclosed in WO 2014063194, which is incorporated herein by reference in its entirety, insofar as it describes the composition, production, analysis and use of acrylated gelatin polymeric compositions, such as GelMA hydrogels.Lung Injuries and Diseases

[0247] In certain embodiments, polymer compositions of the present disclosure can be used as a sealant and / or therapeutic composition for treating and / or repairing soft tissue in the lungs of a subject. In certain embodiments, polymer compositions can be used for treating and / or repairing lung tissue associated with traumatic injury or surgical damage. Typical surgical interventions for these ailments (including suturing and / or commercial adhesives) are often associated with inflammation and infection, scaring, slower tissue regeneration, or loss of function (partial or complete).

[0248] In certain embodiments, lung tissue can be treated or sealed by applying a polymer composition of the present disclosure to the target lung tissue. In certain embodiments, lung tissue can be treated or sealed by applying a cell-laden hydrogel composition of the present disclosure to the target lung tissue. In certain embodiments, a cell-laden hydrogel composition comprises cells or cellular precursors which encourage or facilitate the repair, restoration, replacement, or regeneration of lung tissue. In certain embodiments, the cellladen hydrogel composition is in the form of a mat, fabric, mesh, or other shape which is amenable to being used as a covering or transplant.

[0249] In certain embodiments, the present disclosure provides methods for treating a defect, injury, or disease in the lung tissue of a subject, with the polymer compositions of the present disclosure. In certain embodiments, the method includes: applying a pre-gelation polymer composition of the present disclosure (e.g., a polymer composition comprising acryloyl-substituted gelatin) to an applicator; placing the applicator containing the pregelation polymer composition onto a surface of the lung tissue of the subject; and crosslinking (e.g., photo-crosslinking) the polymer composition by exposing the pre-gelation polymer composition to a crosslinking initiator (e.g., visible light). In certain embodiments, the method includes removing the applicator from the gel polymer composition and / or lung tissue surface after the polymeric crosslinking and / or gelation of the polymer composition is complete. In certain embodiments, the pre-gelation polymer composition is applied directly to the surface of the target lung tissue without an applicator. In certain embodiments, the pre-gelation polymer composition can have a strong, sustained adhesion and high retention on the lung tissue of the subject. In certain embodiments, the gel polymer composition can have a strong, sustained adhesion and high retention on the lung tissue of the subject. In certain embodiments, the polymer composition is engineered to present physical, mechanical, structural, chemical and / or biological properties (elasticity, water content) to match or resemble the target lung tissue.V. DEFINITIONS

[0250] At various places in the present disclosure, substituents, or properties of compounds of the present disclosure are disclosed in groups or in ranges. It is specifically intended that the present disclosure comprise each and every individual or sub-combination of the members of such groups and ranges.

[0251] Unless stated otherwise, the following terms and phrases have the meanings described below. The definitions are not meant to be limiting in nature and serve to provide a clearer understanding of certain aspects of the present disclosure.

[0252] Administering: As used herein, the term “administering” refers to providing a composition to a subject.

[0253] Amelioration'. As used herein, the term “amelioration” or “ameliorating” refers to a lessening of severity of at least one indicator of a condition or disease.

[0254] Animal: As used herein, the term “animal” refers to any member of the animal kingdom. In certain embodiments, “animal” refers to humans at any stage of development. In certain embodiments, “animal” refers to non-human animals at any stage of development. In certain embodiments, the non-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit, a monkey, a dog, a cat, a sheep, cattle, a primate, or a pig). In certain embodiments, animals comprise, but are not limited to, mammals, birds, reptiles, amphibians, fish, and worms. In certain embodiments, the animal is a transgenic animal, genetically engineered animal, or a clone.

[0255] Approximately: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. The term may refer to + / - 10% of the recited value. In certain embodiments, the term refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).

[0256] Associated with: As used herein, the terms “associated with,” “conjugated,”“linked,” “attached,” and “tethered,” when used with respect to two or more moieties, means that the moieties are physically associated or connected with one another, either directly or via one or more additional moieties that serves as a linking agent, to form a structure that is sufficiently stable so that the moieties remain physically associated under the conditions in which the structure is used, e.g., physiological conditions. An “association” need not be strictly through direct covalent chemical bonding. It may also suggest ionic or hydrogen bonding or a hybridization-based connectivity sufficiently stable such that the “associated” entities remain physically associated.

[0257] Biocompatible'. As used herein, the term “biocompatible” refers to a material which produces minimal or zero toxic, injurious, or immunological response in living tissue.

[0258] Biodegradable'. As used herein, the term “biodegradable” refers to a material which can decompose partially or fully under physiological conditions into biologically processable byproducts. For example, a material can be considered biodegradable if at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the material can decompose under physiological conditions within a desired period of time (e.g., minutes, hours, days, weeks, or months, depending on the nature of the material and physiological application). The term “biodegradable” can encompass the term “bioresorbable,” which describes a substance that decomposes under physiological conditions, breaking down to products that undergo bioresorption into the host subject (e.g., as metabolites of biochemical systems).

[0259] Biologically active'. As used herein, the term “biologically active” refers to a characteristic of any substance or material that has activity in a biological system and / or organism. For instance, a material that, when administered to an organism, has a biological effect on that organism, is considered to be biologically active.

[0260] Compound'. Compounds of the present disclosure comprise all of the isotopes of the atoms occurring in the intermediate or final compounds. “Isotopes” refers to atoms having the same atomic number but different mass numbers resulting from a different number of neutrons in the nuclei. For example, isotopes of hydrogen comprise tritium and deuterium. The compounds and salts of the present disclosure can be prepared in combination with solvent or water molecules to form solvates and hydrates by routine methods.

[0261] Cross-link: As used herein, the terms “cross-link” or “cross-linking” refer bond formation (e.g., covalent bond formation) that links one polymer unit to another polymer unit.

[0262] Direct Action of the Cells'. As used herein, the term “the direct action of the cells” means that the transplanted cells directly produce therapeutic molecules or directly treat structural defects leading to disease modification. For example, islet cells produce insulin, cardiomyocytes (cardiac muscle cells) contract the heart, and photoreceptors cells respond to light.

[0263] Encapsulate: As used herein, the term “encapsulate” means to enclose, surround or encase.

[0264] Engineered: As used herein, embodiments of the present disclosure are “engineered” when they are designed to have a feature or property, whether structural or chemical, that varies from a starting point or native molecule.

[0265] Effective Amount: As used herein, the term “effective amount” of an agent is an amount sufficient to effect beneficial or desired results, for example, clinical results, and, as such, an effective amount depends upon the context in which it is being applied. For example, in the context of administering an agent that treats an ocular trauma or disorder, an effective amount of an agent is, for example, an amount sufficient to achieve treatment of the ocular trauma or disorder, as compared to the response obtained without administration of the agent.

[0266] Feature: As used herein, a “feature” refers to a characteristic, a property, or a distinctive element.

[0267] In vitro'. As used herein, the term “zzz vitro" refers to events that occur in an artificial environment, e.g., in a test tube or reaction vessel, in cell culture, in a Petri dish, etc., rather than within an organism (e.g., animal, plant, or microbe).

[0268] In vivo'. As used herein, the term “zzz vivo" refers to events that occur within an organism (e.g., animal, plant, or microbe or cell or tissue thereof).

[0269] Modified'. As used herein “modified” refers to a changed state or structure of a molecule of the present disclosure. Molecules may be modified in many ways comprising chemically, structurally, and functionally. As used herein, embodiments of the disclosure are modified when they have or possess a feature or property, whether structural or chemical, that varies from a starting point or native molecule.

[0270] Non-human animal: As used herein, a “non-human animal” includes all animals (e.g., vertebrates) except Homo sapiens, including wild and domesticated species. Examples of non-human vertebrate animals include, but are not limited to, mammals, such as alpaca, banteng, bison, camel, cat, cattle, deer, dog, donkey, gayal, goat, guinea pig, horse, llama, mule, pig, rabbit, reindeer, sheep water buffalo, and yak. Non-human animals include non- human primates.

[0271] Pharmaceutically acceptable'. The terms “pharmaceutically acceptable” or “therapeutically acceptable” are employed herein to refer to those compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0272] Pharmaceutically acceptable excipients'. The terms “pharmaceutically acceptable excipient” or “therapeutically acceptable excipient”, as used herein, refer to an ingredient other than the polymeric compositions described herein (e.g., a vehicle capable of suspending or dissolving the polymeric compound) and having the properties of being substantially nontoxic and non-inflammatory in a subject.

[0273] Pharmaceutically acceptable salts'. The present disclosure also comprises pharmaceutically acceptable salts of the compounds described herein. As used herein, “pharmaceutically acceptable salts” refers to derivatives of the disclosed compounds wherein the parent compound is modified by converting an existing acid or base moiety to its salt form (e.g., by reacting the free base group with a suitable organic acid). Examples of pharmaceutically acceptable salts comprise, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. Representative acid addition salts comprise acetate, acetic acid, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzene sulfonic acid, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, di gluconate, dodecyl sulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy- ethanesulfonate, 4-(2 -hydroxy ethyl)- 1 -piperazineethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3- phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like.Representative alkali or alkaline earth metal salts comprise sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, comprising, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. The pharmaceutically acceptable salts of the present disclosure comprise the conventional non-toxic salts of the parent compound formed, for example, fromnon-toxic inorganic or organic acids. The pharmaceutically acceptable salts of the present disclosure can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile can be used.

[0274] Secondary Cells'. As used herein, the term “secondary cells” refers to cells that are mechanically or bimolecularly supported by the transplanted cells. The transplanted cells support can improve the secondary cell’s function, which then improves symptoms or decreases or alleviates or slows disease progression. An example of secondary cells supported by transplanted cells include retinal pigment epithelium (RPE), which improves photoreceptor health (the secondar cell) and lead to vision improvement. Another example includes myelin producing cells, which support neurons (the secondary cell).

[0275] Subject'. As used herein, the term “subject” refers to any organism to which a composition in accordance with the present disclosure may be administered, e.g., for experimental, diagnostic, prophylactic, and / or therapeutic purposes. Typical subjects comprise animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans) and / or plants. The subject or patient may seek or need treatment, require treatment, is receiving treatment, will receive treatment, or is under care by a trained professional for a particular disease or condition.

[0276] Substantially. As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest. One of ordinary skill in the arts will understand that biological and chemical phenomena rarely, if ever, go to completion and / or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to expressly capture the potential lack of completeness inherent in many biological and chemical phenomena. Likewise, the exclusion of the term “substantially” does not preclude the same potential lack of completeness inherent in many biological and chemical phenomena.

[0277] Synthetic. The term “synthetic” means produced, prepared, and / or manufactured by the hand of man. Synthesis of polynucleotides or polypeptides or other molecules of the present disclosure may be chemical or enzymatic.

[0278] Therapeutic Agent'. The term “therapeutic agent” refers to any agent that, when administered to a subject, has a therapeutic, diagnostic, and / or prophylactic effect and / or-n -elicits a desired biological and / or pharmacological effect. Examples of therapeutic agents include, but are not limited to oligonucleotides (e.g., sense and / or antisense DNA and / or RNA), proteins and polypeptides (e.g., hormones, growth factors), small molecules and pharmaceuticals, and cells (e.g., stem cells, epithelium cells).

[0279] Treating'. As used herein, the term “treating” refers to partially or completely alleviating, ameliorating, improving, relieving, preventing, delaying onset of, inhibiting progression of, reducing severity of, and / or reducing incidence of one or more symptoms or features of a particular infection, disease, disorder, and / or condition. Treatment may be administered to a subject who does not exhibit signs of a disease, disorder, and / or condition and / or to a subject who exhibits only early signs of a disease, disorder, and / or condition for the purpose of decreasing the risk of developing pathology associated with the disease, disorder, and / or condition.

[0280] Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments in accordance with the present disclosure described herein. The scope of the present disclosure is not intended to be limited to the above Description.

[0281] In the claims, articles such as “a,” “an,” and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that comprise “or” between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The present disclosure can include embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The present disclosure can include embodiments in which more than one, or the entire group members are present in, employed in, or otherwise relevant to a given product or process.

[0282] It is also noted that the term “comprising” is intended to be open and permits but does not require the inclusion of additional elements or steps. When the term “comprising” is used herein, the term “consisting of’ is thus also encompassed and disclosed.

[0283] The abbreviation, “e.g.,” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.,” is synonymous with the term “for example”.

[0284] The abbreviation, “i.e.,” is derived from the Latin id est, and is used herein to indicate a non-limiting rewording or clarification. Thus, the abbreviation “i.e.,” is synonymous with the term “that is”.

[0285] Where ranges are given, endpoints are comprised. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context of the disclosure and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or subrange within the stated ranges in different embodiments of the present disclosure, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise.

[0286] In addition, it is to be understood that any particular embodiment of the present disclosure that falls within the prior art may be explicitly excluded from any one or more of the claims. Since such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiment of the compositions of the present disclosure (e.g., any antibiotic, therapeutic or active ingredient; any method of production; any method of use; etc.) can be excluded from any one or more claims, for any reason, whether or not related to the existence of prior art.

[0287] It is to be understood that the words which have been used are words of description rather than limitation, and that changes may be made within the purview of the appended claims without departing from the true scope and spirit of the present disclosure in its broader aspects.

[0288] While the present disclosure has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the present disclosure.

[0289] All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, comprising definitions, will control. In addition, section headings, the materials, methods, and examples are illustrative only and not intended to be limiting.EXAMPLESExample 1. Preparation of gelatin methacryloyl (GelMA) precursor polymeric composition

[0290] GelMA precursor polymeric compositions can be synthesized as described in the art. For example, GelMA is synthesized by dissolving 10% (w / v) gelatin (e.g., porcinegelatin) in phosphate-buff ered saline (PBS), and then heated at 60°C for 20 minutes. The heating is followed by dropwise addition of 8% (v / v) methacrylic anhydride at 50°C for 3 hours (under continuous stirring), followed by dilution with PBS and dialysis at 40-50°C for about 7 days (using deionized water). The resulting mixture is filtered and lyophilized for 4 days. The resulting GelMA precursor polymeric composition can be stored at -80°C until further use.

[0291] In one alternative, GelMA is synthesized by dissolving 10 grams of gelatin from fish skin in 100 ml DPBS at 60°C for 30 minutes. 8% (v / v) methacrylic anhydride is then added to the solution dropwise under stirring at 60°C for 3 hours. An additional 300 ml DPBS is added to halt the reaction. The resulting mixture is dialyzed using a deionized water bath at 50°C for about 5 days to remove the unreacted methacrylic anhydride. The resulting solution is filtered and lyophilized for about 4 days.Example 2: Preparation of hydrogel polymeric composition

[0292] Hydrogel polymeric compositions can be synthesized as described in the art. For example, a freeze-dried GelMA precursor polymeric composition produced according to Example 1 is dissolved in PBS or (4-(2 -hydroxy ethyl)- 1 -piperazineethanesulfonic acid) buffered saline at concentrations of 5-25% (w / v). Either 2-hydroxy-4’-(2- hydroxy ethoxy)-2- methylpropiophenone or Eosin Y or Eosin Y disodium salt is added as a photoinitiator, and the mixture is dissolved at 20-80 °C. The amount of each element added is based on the desired physical, mechanical, structural, chemical and / or biological properties of the hydrogel polymeric composition. The resulting precursor polymeric composition is photocrosslinked via visible light irradiation (e.g., blue or white light) to form a GelMA hydrogel polymeric composition.

[0293] In one alternative, a GelMA hydrogel polymeric composition is synthesized by first dissolving 7-15% w / v of gelatin methacryloyl from Example 1 into a solution containing at least one photoinitiator element, such as a mixture of triethanolamine (about 2% w / v) and N-vinyl caprolactam (about 1.25% w / v), in distilled water at room temperature. A solution of Eosin Y disodium salt (0.5 mM) is then added to the gelatin methacryloyl solution, and the resulting precursor polymeric composition is then photocrosslinked under exposure to visible light (420-480 nm) for 120 seconds. The amount of each element added is based on the desired physical, mechanical, structural, chemical and / or biological properties of the hydrogel polymeric composition.

[0294] In one alternative, microparticles (e.g., micelles) which contain a therapeutic agent (e.g., ocular antibiotic such as ciprofloxacin) are incorporated into the GelMA precursor polymeric composition prior to photocrosslinking.

[0295] Porosity can be measured and analyzed by fabricating a freeze-dried, gold-sputter- coated hydrogel sample, which can then be imaged using a scanning electron microscope (SEM).

[0296] Samples can also be subjected to a range of mechanical tests, including elasticity, swelling, compression testing, texture, and tensile testing.

[0297] In one alternative, a GelMA hydrogel polymeric composition is formed on the surface of a target tissue. Resulting samples can be subjected to a range of mechanical and therapeutic tests, including adhesion, burst pressure, wound closure strength, shear strength, and durability / degradation rate.Example 3: Preparation of hydrogel polymeric composition

[0298] Hydrogel polymeric compositions were prepared according to the follow steps.

[0299] A photopolymerization initiator mixture was prepared comprising: 0.35 mg / mL of eosin Y (20% v / v), 12.5 mg / mL N-vinylcaprolactam, and 18.75 mg / mL triethanolamine (80% v / v), in phosphate buffer saline (PBS; pH 7), with pH adjustment using concentrated HC1 as needed.

[0300] Polymeric precursors were allowed to reach room temperature (RT) before their incorporation into a hydrogel polymeric precursor composition.

[0301] GelMA precursor materials (when applicable for a target formulation) were then added at the desired concentration (e.g., 4-20% w / v) into the hydrogel precursor mixture, and allowed to dissolve at 60°C for about 2 hours with occasional vortexing.

[0302] Once all precursor materials were fully dissolved into the hydrogel precursor mixture, a therapeuticagent (when applicable for a target formulation) was added at the desired concentration (e.g., 1-350 mg / mL). The mixture was maintained under stirring at 37°C until ready for polymerization.

[0303] Hydrogel disk samples were prepared by pipetting about 100 pL of hydrogel precursor mixture into individual poly(dimethyl siloxane) (PDMS) cylindrical molds positioned in wells of a 24-well non-treated plate. The polymer composition was then photocrosslinked using a Dolan-Jenner high-intensity LED illuminator (MI-LED-US-B1) equipped with a dual-arm gooseneck configuration (one arm above and one arm below, thus allowing for dual light exposure from top and bottom; incident ray 90°). Each arm outputs anaverage optical power of -100 mW / cm2(Xmax= 450, 540 nm), with light exposure times varying from 5 seconds to 4 minutes.

[0304] Hydrogel rod samples were prepared by dipping 0.75 mm inner-diameter borosilicate glass capillaries into the hydrogel precursor mixture, and then oscillating the capillary tubes until filled up to about 10 mm from the opening. The polymer composition was then photocrosslinked using a Dolan-Jenner high-intensity LED illuminator (MI-LED- US-B1) equipped with a dual-arm gooseneck configuration (one arm above and one arm below, thus allowing for dual light exposure from top and bottom; incident ray 90°). Each arm outputs an average optical power of -100 mW / cm2(Zmax= 450, 540 nm), with light exposure times of about 4 minutes. Hydrogel rods were extruded from the capillary tubes using a 0.5 mm diameter quartz rod, and then cut to size using calipers.Example 4: Transwell Underside Cell Growth study - HUVEC

[0305] Studies were completed to evaluate the ability of various hydrogel formulations to attach and deliver cells to a membrane with challenging gravitational requirements.

[0306] Populations of Human Umbilical Vein Endothelial Cells (HUVECs) were added to hydrogel precursor formulations G5(80) [5% GelMA, 80% DoM] as prepared in Example 3 in PBS. Cell concentrations were about 10 million HUVECs per mL (GFP+).

[0307] PET transwell inserts (0.4 pm pore size) were then incubated in serum containing endothelial growth media for 15 minutes. The inserts were dried with eye spears and 13.2 pL of each hydrogel precursor solution (containing HUVECs) was added to individual transwell undersides and exposed to 1 min of high intensity white light (Dolan-Jenner high-intensity LED illuminator MI-LED-US-B1 equipped with a dual -arm gooseneck configuration). The transwells were then inverted onto well plates, such that the hydrogels on each transwell underside were submerged in endothelial growth media supplemented with growth factors and serum. Free HUVECs (i.e., non-hydrogel encapsulated cells) were also added to endothelial growth media in the well plates as a control. Cell growth for each formulation was analyzed on after several days (e.g., Day 4 and Day 11) using GFP+ imaging, and using confocal imaging on Day 11. a) GFP+ Imaging Results

[0308] Results for GFP+ Imaging are shown in FIG. 4A-4F.

[0309] For G5(80) — After 4 days, samples showed HUVECs remained localized to the underside of the transwell (FIG. 4A), with strong endothelial cell viability and clear cellular network formation (see FIG. 4A), and only cell debris found localized on the well platebottom. After 11 days, G5(80) samples continued to show HUVECs localized to the underside of the transwell (FIG. 4B), with continued strong endothelial cell viability and clear cellular network formation (see arrow in FIG. 4B), and only cell debris found localized on the well plate bottom.

[0310] For the free cell control sample (i.e., no hydrogel) — After 4 days, control samples showed minimal HUVEC attachment to transwell underside (FIG. 4C), with most cells migrating to well bottom (FIG. 4D). Overall cell density was low. After 11 days, control samples continued to show low cell density and minimal cell network formation on the transwell underside (FIG. 4E), with viable cells remaining localized on the well plate bottom (FIG. 4F), with some cell elongation but minimal cell network formation. b) Confocal Imaging Results

[0311] On Day 11, hydrogel sample for G5(80) from Example 4(a) was stained for the following: Actin (cytoskeleton showing cell spreading and network formation);PECAM / CD31 (endothelial marker); and DAPI (nuclei). Stained samples were then subjected to confocal imaging; results are shown in FIG. 5A-5C.

[0312] G5(80) samples showed high HUVEC deposition on the underside of the transwell(FIG. 5 A and FIG. 5B), including formation of a dense cellular network with good cell distribution and no evidence of cell clumping.

[0313] Free cell (i.e., no hydrogel) control samples showed lower cell density and poor network formation (FIG. 5C) when compared to G5(80) samples. c) Additional Formulation Testing

[0314] Additional hydrogel formulations were analyzed according to the procedures of Example 4(a). Results for transwell underside imaging and analysis are shown in Table 3.Table 3 - GFP+ HUVEC Analysisd) Study Observations

[0315] Study results showed that HUVECs spread more effectively, created stronger cellular networks, and aggregated less within GelMA-based formulations, as compared to PEGDA-based formulations. Study results also showed that higher crosslinking densities (e.g., higher polymer concentration, higher DOM) generally did not promote for strong cell spreading and network formation. GelMA-based materials also provided stronger adhesion to the test surface (i.e., transwell undersurface) and deposit cells more effectively to form a dense cell network, even in challenging environments and growth conditions (e.g., against gravity).Example 5: Transwell Underside Cell Growth Study - HRPECs

[0316] Studies were completed to evaluate the ability of various hydrogel formulations to attach and deliver cells to a membrane in challenged gravity environments mimicking subretinal space.

[0317] Populations of Human Retinal Pigment Epithelium Cells (HRPEC) were added to the following hydrogel precursor formulations: (i) G5(80) [5% GelMA, 80% DoM]; and (ii) G4(80) [5% GelMA, 80% DoM] as prepared in Example 3 in PBS. Cell concentrations were about 20 million HRPECs per mL.

[0318] PET transwell inserts (0.4 pm pore size) were then incubated in serum containing DMEM / F-12 media (supplemented with 10% FBS) for 15 minutes. The inserts were dried with eye spears and 13.2 pL of each hydrogel precursor solution (containing HRPECs) was added to individual transwell undersides and exposed to 1 min of light. The transwells were then inverted onto well plates, such that the hydrogels on each transwell underside weresubmerged in DMEM / F-12 media (supplemented with 10% FBS). Cell growth for each formulation was imaged and analyzed after several days (e.g., Day 3, Day 8, Day 10, Day 20), which included the use of Calcein AM staining and imaging.

[0319] Results are shown in FIG. 7A-7C.

[0320] For G5(80) — After 8 days, samples showed well dispersed rounded cells, but also showed minimal cell spreading and no cell network formation (FIG. 7A).

[0321] For G4(80) — After 8 days, hydrogels were shown to have degraded / detached quickly, but were also shown to have provided a HRPEC monolayer with good coverage and viability, including zones of mature monolayer formation (FIG. 7B). After 20 days, mature HRPEC monolayer was shown to have formed over the entire transwell membrane surface (FIG. 7C). a) Study Observations

[0322] Study results showed that HRPECs have minimal spread and networking within hydrogel formulations that have a high degree of methacrylation, a high molecular weight, and / or a high polymer concentration of hydrogels. HRPECs had improved spread and networking within hydrogel formulations that had a lower degree of methacrylation and lower polymer concentration of hydrogels, thus allowing for effective HRPEC deposition and monolayer formation.

[0323] Also, PEG-based hydrogels such as PEGDA were generally shown to have poor bioadhesion and poor biodegradability (often being detached from underneath transwells in as little as 24-48 hours, see Table 3). Remaining HRPECs on the transwell surface were believed to be those that were trapped on the surface of the PEGDA hydrogel during the photopolymerization process. Cells were not able to attach or migrate through the PEGDA polymeric network, remaining trapped and only able to attach to neighboring cells.Example 6: Transwell Topside Cell Growth Study - HRPECs

[0324] Studies were completed to evaluate the ability of various hydrogel formulations to degrade and deliver cells to a membrane.

[0325] Populations of Human Retinal Pigment Epithelium Cells (HRPEC) were added to two hydrogel precursor formulations: (i) G5(10) [5% GelMA, 10% DoM]; and (ii) G5(80) [5% GelMA, 80% DoM] as prepared in Example 3 in PBS. Cell concentrations were about 20 million HRPECs per mL.

[0326] PET transwell inserts (0.4 pm pore size) were then incubated in serum containing DMEM / F-12 media (supplemented with 10% FBS) for 15 minutes. The inserts were driedwith eye spears and about 10 pL of each hydrogel precursor solution (containing HRPECs) was added to individual transwell topsides and exposed to 1 min of light. The transwells were then submerged in DMEM / F-12 media (supplemented with 10% FBS). Free HRPECs (i.e., no hydrogel) were also added to media in the well plates as a control.

[0327] After 24 hours, hydrogel samples were stained with Calcein AM and imaged for cell aggregation and viability (FIG. 8A). Samples were likewise analyzed after 3 days (FIG. 8B), and after 6 days (FIG. 8C).

[0328] At 24 hours (FIG. 8A) — Cell-only control samples showed uninhibited cell growth and monolayer formation. G5(10) samples showed hydrogels beginning to degrade, depositing HRPECs, and beginning to form monolayer networks. G5(80) samples showed no hydrogel degradation and no monolayer formation, with cells generally remaining rounded and suspended within the hydrogel.

[0329] At 3 days (FIG. 8B) — Cell-only control samples continued to show uninhibited cell growth and monolayer formation, with cells showing dense packing. G5(10) samples showed hydrogels mostly degraded, with deposited HRPECs forming a clear monolayer network similar to the control sample at 24 hours, and with few rounded, encapsulated cells remaining over the monolayer. G5(80) samples continued to show little hydrogel degradation and little monolayer formation, with cells generally remaining rounded and suspended within the hydrogel.

[0330] At 6 days (FIG. 8C) — Cell-only control samples continued to show uninhibited cell growth and monolayer formation, with packed cell density and networking. G5(10) samples showed degraded hydrogels, with a deposited HRPECs monolayer network similar in density and morphology to the control sample, and with few rounded cells remaining over the monolayer. G5(80) samples showed hydrogels beginning to degrade and early monolayer formation in certain regions (top right of FIG. 8C image for G5(80)), while other regions remained undegraded with no monolayer formation (lower left of FIG. 8C image for G5(80)), and with HRPECs remaining rounded and suspended within the hydrogel.Example 7: in vitro Retinal Cell Growth Studies

[0331] Studies were completed to evaluate a G5(10) [5% GelMA, 10% DoM] hydrogel formulation for facilitating in vitro delivery and cell growth of stem-cell derived retinal cells, including retinal pigment epithelial (RPE) cells and rod photoreceptor cells.a) Monolayer formation study

[0332] A G5(10) [5% GelMA, 10% DoM] hydrogel precursor formulation was prepared according to the general procedures in Example 3, with reduced concentrations of photopolymerization initiator mixture. A population of Human Retinal Pigment Epithelium Cells (HRPEC), derived from induced pluripotent stem cells (iPSC), was then added to the G5(10) hydrogel precursor formulation (~20 million cells / mL). iPSC-derived RPEs were also added to a saline solution as a control. About 200 pL of each formulation was injected (in PBS) through a MedOne Subretinal PolyTip® 38G (outer diameter) (41G inner diameter) subretinal cannula (with a standard 1 mL luer-lok plastic syringe) at a controlled rate of 200- 300 pL / min (flow rate controlled with a syringe pump) onto 6-well transwell plates with 0.4 pm polyester (polyethylene terephthalate) membranes. The polyester membranes were included to mimic a native Bruch's membrane; membrane is permeable to nutrients and proteins, but not to cells. The injected formulations were then photo crosslinked in 10 pL drops using white light.

[0333] After one week, live-cell imaging was completed using Calcein AM. Results are shown in FIG. 9A. Study results showed that RPE cells were able to slowly degrade the G5(10) hydrogel substrate after crosslinking and then migrate to the transwell membrane. The RPE cells had formed a clear cellular monolayer after one-week, mimicking target anatomic patterning of functional RPE cells (See FIG. 9A). The RPE cells delivered in the saline (control) formulation failed to form observable cellular monolayers after one week, despite being delivered at the same seeding density as the cells in the hydrogel formulation.

[0334] Fluid shear rates related to extrusion through the 38G (41G inner) small-diameter needle were measured during the sampled delivery. Results (see FIG. 9B) showed that GelMA pre-polymers can be shear thinning in precursor polymer solutions, thus enabling protective plug-flow dynamics through small diameter needles that protects the passenger cells. b) iPSC de-differentiation study

[0335] Precursor formulations from Example 7A were prepared at ~1 million cells / mL, and then injected (in PBS) onto 6-well transwell plates with 0.4 pm polyester (polyethylene terephthalate) membranes using the same delivery system and conditions as Example 7A. The injected formulations were then photo crosslinked in 10 pL drops using white light. After one week, live-cell imaging was completed using Calcein AM. Results are shown in FIG. 9C. Study results showed that RPE cells had formed a monolayer, with cells retaining a cuboidal morphology and pigmentation patterns that are characteristics of standard, healthy RPEmorphology. The RPE cells delivered in the saline (control) formulation became elongated and highly proliferative, and failed to retain their cuboidal morphology and RPE pigmentation patterns indicating de-differentiation.

[0336] Without being bound by theory, study observations show that the hydrogel substrate provides a localized and condensed environment for the RPE cells, thus enabling monolayer formation with the characteristic RPE morphology by reducing RPE dedifferentiation due to environmental factors. c) Rod photoreceptor delivery study

[0337] A G5(10) [5% GelMA, 10% DoM] hydrogel precursor formulation was prepared according to the general procedures in Example 3, with reduced concentrations of photopolymerization initiator mixture. A population of rod photoreceptor cells, derived from human retinal organoids (Lako Lab, Newcastle University), was then added to the G5(10) hydrogel precursor formulation. The formulations were then injected (in PBS) onto RPE monolayers in 6-well transwell plates with 0.4 pm polyester (polyethylene terephthalate) membranes, using the same delivery system and conditions as Example 7 A. The injected formulations were then photo crosslinked using white light.

[0338] After two weeks, live-cell imaging was completed using anti-CD73 and antirhodopsin imaging. Results are shown in FIG. 9D. Study results showed that rod photoreceptor cells (left, top of FIG. 9D) were localized over the RPE monolayer (left, bottom of FIG. 9D) and remained viable at two weeks, with both the rod photoreceptor cells and RPE cells expressing CD73. Only the rod photoreceptor cells were shown to express rhodopsin (right of FIG. 9D).Example 8: in vivo Retinal Cell Growth Studies

[0339] Studies were completed to evaluate cell localization and viability of retinal pigment epithelial cells (RPE) after a single subretinal (SR) injection in swine in one of three G5 [5% GelMA] hydrogel formulations polymerized in situ via intraocular procedure light.

[0340] Four test groups included 200 pl injections into 6 eyes (for each group, 24 eyes and 12 animals total):

[0341] Group 1 (Control): Saline + 200k RPE cells; Group 2: G5(10) [5% GelMA, 10% DoM] + 200k RPE cells; Group 3: G5(80) [5% GelMA, 80% DoM] + 200k RPE cells; Group 4: [5% GelMA, 80% DoM] G5(80) + IM RPE cells.

[0342] Animals in Groups 2-4 received a single SR injection of RPE with the designated hydrogel formulation. Group 1 was administered a single injection of RPE in saline ascontrol. Prednisone oral was given pre-op and throughout the study. For the injection, 38G / 41G MedOne subretinal needle equipped with 6-7 in extension tubing was used. Hydrogel precursors and cell mixtures were prepared fresh prior to each group. Constellation 23 G light pipe was used for radiation, which at max power emitted approximately 27 mW of light power (as measured at 517 nm).

[0343] All animals had ophthalmic examinations, color fundoscopy, and ocular coherence tomography (OCT) post-injection and on Days 1, Day 3, 7, 14, 21, 28 post-injection. All enrolled eyes were stained for STEM121 (transplanted human cells), Iba-1 (microglia / white blood cells), RPE65 (RPE cells), and DAPI (all nuclei).

[0344] Two eyes from each group were also selected for immunofluorescent staining. Blocks were sectioned sagittally (14 pm) at 5 levels across the eye: nasal, peripheral, midway between nasal and optic nerve head (ONH), ONH, midway between the ONH and temporal, and temporal peripheral. At least 10 slides / level were collected. Slides were scanned during acquisition for the cell depot. A series of 8-10 slides / eye was selected for IHC.

[0345] Results of observations related to cell migration to retina surface are shown in FIG. 10 A. The saline control formulations exhibited more cell migration (above 80%) and corresponding epiretinal adverse events due to poor cell localization (i.e., cells outside of subretinal area). This finding was confirmed by histological examination of the eye after day 28, in which vitreous cells were found, and subretinal hydrogel formulations exhibited minimal cell migrations of about 20% or below.

[0346] Results of observations related to hydrogel degradation after 28 days are shown in FIG. 10B. The Group 1 (control) did not include hydrogel. For Group 2, only about 33% of hydrogel remained after 28 days (i.e., about 67% lost). Group 3 and Group 4 had about 100% hydrogel remaining after 28 days (i.e., about 0% lost). After 28 days, hydrogels with high 80% methacrylation (Group 3 and Group 4) showed retinal detachment from underlying layers, as seen in FIG. 10C and FIG. 10D. Staining results did show successful human stem cell transplant onto native pig RPE layers, which were not disrupted (see FIG. 10E, wherein the arrows represent human cells).Example 9: Combination Formulation Study

[0347] A Gl(160 / 10)G2.5(90 / 60) blend was studied with various photoinitiator formulations (including triethanolamine (TEO A) at 1.5% v / v) and polymerization conditions. Table 4 presents study conditions and results for the various formulations.Table 4 - Combination Formulation Study

[0348] Rxn 3 was further studied. 10 M cells / mL were added to each of Rxn 3 and PBS (as control). The Rxn 3 sample and a portion of the PBS control were extruded onto a transwell surface, as well as unextruded PBS. After two weeks, Rxn 3 showed a healthy RPE monolayer growth, similar to the PBS controls, with the Rxn 3 sample providing a high cell count than either PBS control sample. Cell count results are show in FIG. 11.Example 10: in vivo Retinal Cell Growth Studies - v.2

[0349] Studies were completed to evaluate cell localization and viability of retinal pigment epithelial cells (RPE) after a single subretinal (SR) injection in swine in one of three formulations polymerized in situ via intraocular procedure light.

[0350] Three test groups included 50 pl injections into 6 eyes (gel formulations) or 3 eyes (saline control) - 15 eyes total

[0351] Group 1 (Control): Saline + 250k RPE cells (n=3); Group 2: Gl(160 / 10)G2.5(90 / 60) + 250k RPE cells (n=6); Group 3: Gl(160 / 10)G2.5(90 / 60) + 500k RPE cells (n=6).

[0352] Injection, sampling, and analysis was completed according to the general procedures described in Example 8, including: hematoxylin and eosin (H&E) staining for analyzing transplanted cell area, and Immunohistochemistry (IHC) staining for analyzing percent cell spread.

[0353] Results of H&E and IHC analysis after 14 days are shown in FIG. 12A (H&E) and FIG. 12B (IHC). Though the saline control and hydrogel 250K dose had the same number of starting cells before implantation, the hydrogel formulation showed a significantly higher number of cells that were successfully transplanted and allowed to proliferate.Example 11: Cell Viability Studies

[0354] Studies were completed to evaluate cell localization and viability of retinal pigment epithelial cells (RPE) after extrusion / inj ection though MedOne 38G subretinal cannula.

[0355] The following formulations were included in the study: (a) GA2.5(90% 11.5 / 60);(b) GMA10(70% 7 kDa, 20% 48 kDa, 10% greater than 50 kDa / 30); (c) GA2.5(70% 7 kDA, 20% 48 kDa, 10% greater than 50 kDa / 45); (d) GA3.5(70% 7 kDA, 20% 48 kDa, 10% greater than 50 kDa / 45); (e) GAI (70% 7 kDA, 20% 48 kDa, 10% greater than 50 kDa / 45) + G2 (90 / 60).

[0356] Samples were tested at 10 million cells / mL, with 100 uL / min constant extrusion speed using syringe pump and 1 minute crosslinking at 35 mW.

[0357] The GA2.5 Sample (a) did not provide cell encapsulation data, as the gel was too firm.

[0358] The GMA10 Sample (b), GA2.5 Sample (c), GA2.5 Sample (d), and GAI + G2 Sample (e) all showed healthy monolayer developed in both extruded and non-extruded samples after 12-14 days.

[0359] Extruded samples of GA2.5 Sample (c) and GAI + G2 Sample (e) were also compared with PBS extruded and PBS non-extruded. Imagining after 8 days of growth showed that both PBS samples had high levels of cell agglomeration / confluency, while the GAI + G2 Sample (e) showed small amounts of confluency, and the GA2.5 Sample (c) showed minimal confluency. Results are shown in FIG. 13.Example 12: Cell Density Studies

[0360] Studies were completed to evaluate cell localization and viability of retinal pigment epithelial cells (RPE) at various cell densities.

[0361] Samples of G5(90 / 60) gel precursor formulations were prepared. The G5(90 / 60) samples were then seeded with one of the following RPE cell concentrations: 5 million cells / mL, 10 million cells / mL, 15 million cells / mL, 20 million cells / mL, or 30 million cells / mL, PBS samples were prepared with the same cell concentrations. Samples were extruded / injected though subretinal cannula onto plates and allowed to grow for up to 8 weeks. Results are shown in FIG. 14A to FIG. 14E.

[0362] FIG. 14A shows cell growth results for a 5 million (M) cells / mL concentration. After 8 weeks of growth, the 5 M / mL cell density with hydrogel formulation resulted in poor surface area coverage and epithelial to mesenchymal transition (EMT), leaving notable gapsin the cell layer. The corresponding PBS injected cells at 5 M / mL was able to form monolayers over time.

[0363] FIG. 14B shows cell growth results for a 30 million (M) cells / mL concentration for 8 weeks. After 8 weeks of growth, both the hydrogel formulation and PBS control at 30 M / mL cell density showed notable gaps in the cell layer. The tight cell packing likely resulted in high stress conditions that bulged cells groups and created the noted gaps in the mature cell monolayer.

[0364] FIG. 14C shows cell growth results for a 20 million (M) cells / mL concentration at 3 days, 7 days, and 12 days. After 3 days, the 20 M / mL cell density showed notable cell clumps in the monolayer, and a high dead cell count after 7 days due to high number of cells that are unable to attach to surface of plate. After 12 days, a cell monolayer had formed from the remaining cells. Though the 20 M / mL cell density did form a monolayer after 12 days of growth, the high dead cell count at day 7 would not be ideal for in vivo injections.

[0365] FIG. 14D shows cell growth results for a 10 million (M) cells / mL concentration at 3 days, 7 days, 12 days, and 8 weeks (56 days). Cell adhesion and growth was shown to be healthy at 3 days, 7 days, and 12 days. After 8 weeks, a healthy cell monolayer remained.

[0366] FIG. 14E shows cell growth results for a 15 million (M) cells / mL concentration at 3 days, 7 days, 12 days, and 8 weeks (56 days). Cell adhesion and growth was shown to be healthy at 3 days, 7 days, and 12 days. After 8 weeks, a healthy cell monolayer remained.

[0367] FIG. 15 shows imaging of cell flow through glass needle for PBS and G5(90 / 60) samples. While cells in the PBS sample showed clear clumping and sticking during the injection (resulting from shear stress across the cannula), cells in the G5(90 / 60) samples flowed effectively through the needle (resulting from shear stress concentrated at the canular wall) without clumping for absorption to the needle inner surface.Example 13: Functional in vivo study(a) Overview of Induced Retinal Degeneration study

[0368] Dutch belted rabbits were induced to have rapid retinal pigment epithelial (RPE) degeneration mimicking geographic atrophy using an IV injection of sodium iodate (NalOs).

[0369] One week prior to the IV injection, the animals began immunosuppression using methylprednisolone steroid. One day post-sodium iodate administration, the test article (saline, RPE cells in saline suspension, or RPE cells in the GelMA polymer composition) was injected subretinally utilizing a 38 G polytip cannula. A standard pars-planar 3-portvitrectomy system was used. The polymer composition test article was crosslinked via 60s of light exposure from the light pipe at 80-100% intensity.

[0370] A baseline and weekly dark-adapted full field electroretinography (ffERG) were performed to assess electrical activity within the retina. The dark-adapted (scotopic) waveform from 3 cd s m’2light exposure was analyzed for the B wave amplitude, representing photoreceptor activity. Measuring the decrease from baseline levels demonstrated rapid loss of vision followed by stable vision in treated animals and continued decline in the control group.

[0371] Baseline and weekly optical coherence tomography (OCT) measurements were taken, focusing on the thickness of the outer nuclear layer (ONL), which represents the photoreceptors. Animals treated with polymer cell compositions showed thicker layers, implying a better-preserved retina.

[0372] Upon euthanasia of the animal at day 5 or 38, eyes were stained to investigate the retinal structure. At day 5, RPE monolayers (confirmed to be human) were observed in animals treated with the polymer composition, and cell clumps were observed in the suspension groups. Similarly, on day 38, clear RPE monolayers were observed in polymer composition groups. Furthermore, the transplanted RPE were functional in that they preserved photoreceptor structure through their supportive role. Animals treated with polymer composition and cells had more densely packed photoreceptors (as seen with a nearest neighbor calculation) in a linear pattern with preserved rhodopsin for light processing. tb) Test Formulations and Dosing

[0373] Induced pluripotent stem cell (iPSC)-derived retinal pigment epithelial (RPE) cells were harvested and mixed with the GelMA polymer composition using aseptic technique and sterile reagents.

[0374] The hydrogel formulation was a methacrylate functionalized gelatin polymer that upon light activation crosslinks, encapsulates and localizes the cells to the target tissue. The following groups were tested:1. Saline (no cells)2. Saline + 375k cell dose3. 1% GelMA (160 / 10) + 2.5% GelMA (90 / 60) + 375 k cell dose

[0375] On the day of surgery, polymers were reconstituted in the initiator solution prepared in N-2 -hydroxy ethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffered saline (HBS) for Group 3, or saline for Group 2. The hydrogel precursor solution was mixed withthe pelleted RPE cells to achieve the desired cell dose for injection, and the time at mixing was recorded. The prepared test article was stored at 37 °C.(c) Immunosuppression

[0376] Starting seven days prior to test article administration (Day -6), and continuing through the study duration, Dutch Belted Rabbits received a twice weekly injection of methylprednisolone (0.8 mg / kg) SQ. Immediately following surgery, all dosed animals received neomycin and polymyxin b sulfates and dexamethasone ophthalmic solution applied topically to both eyes (OU) three times daily for three days, and then received prednisolone acetate ophthalmic suspension topically OU (i.e., both eyes) three times daily for the remainder of the study.(d) NalCh Induction of Retinal Degeneration via Intravenous Injection (All Groups, Day I

[0377] A 30 mg / mL solution of NalOs in sterile 0.9% NaCl was prepared within 24 hours of administration to degenerate the RPE of the animal. At time of administration, animals were manually restrained and a thin layer of 5% lidocaine ointment was applied topically to the skin overlying the marginal ear vein prior to needle insertion. Wintergreen oil was also applied to facilitate vasodilation as needed. 1 mL / kg of the NalCE solution was slowly delivered intravenously. 50 mL of lactated Ringer’s solution was also administered subcutaneously (SQ) to reduce the risk of adverse renal effects. Animals were returned to their cage and monitored briefly.(e) Subretinal (SR) Dosing Procedure

[0378] The afternoon prior to surgery, animals received extended-release buprenorphine (0.1-0.15 mg / kg, SQ), or alternatively, standard buprenorphine HC1 (0.01-0.05 mg / kg, SQ) prior to dosing. Prior to surgery, eyes were dilated with 1% tropicamide HC1 and animals were sedated with a ketamine / dexmedetomidine cocktail (10-15 / 0.1-0.2 mg / kg IM). If additional sedation was needed, then acepromazine (0.25-1.0 mg / kg, SQ) was administered. Following induction of anesthesia, eyelashes were trimmed, and approximately 5% betadine solution on autoclaved sterile gauze was used to clean the periocular (eyelids) area of each eye, as well as used to irrigate the ocular surface and conjunctival cul-de-sacs (1 minute application time), followed by rinsing with sterile eyewash. 10% phenylephrine HC1 and 0.5% proparacaine HC1 was applied to the corneal surface of each eye, at least 2 minutes apart. Each animal was positioned beneath the surgical microscope with the first eye upwards. A surgical drape and eyelid speculum was then placed. If needed at any time duringthe procedures in order to maintain an adequate plane of anesthesia, isoflurane (0.5-3% in oxygen) was delivered via facemask.

[0379] 300 pL of test article (either the RPE cells in suspension or in polymer composition) were gently mixed, loaded into a 1 mL syringe or MicroDoseTM Injection Kit and connected to an extendible PolyTip® subretinal injection cannula (25G x 28 mm cannula with 38G (5 mm length) tip) or extendible Poly Vent® subretinal injection cannula (25G x 32 mm cannula with 38G (5 mm length) tip). The MedOne polymeric tip was extended, and the needle primed with approximately 240 pL (PolyTip) or 100 pL (Poly Vent) of test material. The needle and syringe pair were allowed to rest on an even surface for one minute as the pressure throughout the system equilibrated. Thereafter, the polymeric tip was wiped for excess solution utilizing sterile gauze followed by an additional 30 seconds of dwell time. The polymeric tip was then retracted, and the needle and syringe pair moved to the surgical field. The needle and syringe pair remained horizontal and in the same plane prior to injection. The MicroDose Injector was attached to a Viscous Fluid Control Pak (when available) to allow foot pedal-actuated injections at a controlled rate via the Constellation system. Care was taken to avoid excessively kinking or twisting the extension tubing to avoid creating pressure and cause material to drool from the tip. If solution was observed at the needle tip prior to injection, it was carefully wiped with sterile gauze.

[0380] Two 25G non-valved ports were placed at the pars plana to facilitate needle and light source entry into the vitreous. Wet field cautery was used to prepare the sites intended for the insertion of 25G ports. A small incision in the clear cornea was made using a 1.2 mm keratome to release pressure in the eye. The RESIGHT 700 fundus viewing system was used to visualize the posterior segment. Alternatively, a lens was placed on the cornea to facilitate visualization of the posterior segment of the eye. A local retinal detachment was created in the retina of the eye and the test article was administered inferior to the optic disc / medullary array via subretinal injection using the primed MedOne injector. If performing the controlled injections via foot pedal-actuation with the Constellation, the PSI was set to 9-30 (lower end for saline, higher end for polymer). 30 pL of the prepared test article was injected subretinally at a rate of approximately 30 pL / 15-20 seconds, and time at injection was recorded. After injection, the needle was held in place for at least 5 seconds, followed by the immediate application of high intensity light utilizing the vitrectomy setup light pipe (set to maximum intensity and focused in close proximity to the bleb) for at least 1 minute. This crosslinked the test articles containing hydrogel. The needle was then retracted, excess material in the tubing was collected, and the needle / tubing was discarded. The conjunctiva was closed withsuture. Neomycin and polymyxin b sulfates and dexamethasone topical solution was topically applied to the eye, then the procedures was repeated on the contralateral eye. A new needle / tubing and syringe was utilized for each eye injection. OCT confirmatory images were taken following dosing of both eyes.

[0381] Dexmedetomidine was reversed with atipamezole (1-2 mg / kg, intramuscular (IM)) and animals were returned to their cage and monitored for recovery. In the late morning through evening of surgery, animals received two additional doses of topical neomycin and polymyxin b sulfates and dexamethasone OU, and then three times daily for two additional days prior to transitioning to receiving topical prednisolone acetate suspension OU three times daily for the study duration. If standard buprenorphine HC1 was utilized for surgery rather than buprenorphine ER, an additional dose (0.01-0.05 mg / kg, SQ) was administered in the afternoon or evening of surgery, and additional dose(s) were administered the following day if needed based on assessment by veterinary staff.(f) Parameters MeasuredFull-Field Electroretinography (ffERG)

[0382] Sedation and Preparation'. Animals were dark adapted for at least twelve (12) hours prior to ERG. Animals were sedated with ketamine / dexmedetomidine (10-15 / 0.1-0.2 mg / kg, IM), and eyes were dilated with 1% tropicamide HC1.

[0383] Procedure: All activities and recording for the ERG procedure were performed under dim red lighting. Before ERGs were recorded, pupils were checked to ensure adequate dilation. Diagnosys ERG systems was utilized for measurements. Animals were positioned on the first ERG machine atop a warm pad, then 0.5% proparacaine and eye lubricant were applied to the eyes, followed by the electrode contact and reference leads. A reference subcutaneous lead was placed in the head and a ground lead placed near the tail of the animal. ERG parameters were as follows:

[0384] Dark-adapted ERG: Step 1-9: Each step advanced half log units in light intensity, from 0.001-10 cd s m'2scotopic ERG. Both ERG traces and oscillatory potentials were collected (where applicable: a-wave, b-wave, c-wave). Step 10: Dark-adapted 150 cd s m'2scotopic traces and oscillatory potentials were collected (where applicable: a-wave, b-wave, c-wave).

[0385] Post-Procedural Care: Following the procedure, animals either proceeded to OCT / fundus imaging, received atipamezole (1-2 mg / kg, IM) to reverse the effects of dexmedetomidine and were returned to their cages for recovery, or were euthanized at thefinal timepoint. If needed to aid in recovery, animals also received 40-60 mL warmed lactated Ringer’s solution SQ, when necessary.

[0386] Data Analytics: Dark-adapted responses for a-wave and b-wave were averaged and graphed for each group as light intensity vs. amplitude for dark-adapted responses. Results from the study described in Example 13(a) are shown in FIG. 16A. The vehicle (saline with no cells) demonstrates sustained vision loss. The GelMA formulation (1% GelMA (160 / 10) + 2.5% GelMA (90 / 60) + 375 k cell dose) demonstrated improved signaling and vision-loss superiority over the suspension (saline + 375k cell dose) after 30 days.

[0387] Sedation & Preparation: If not already sedated, animals were sedated prior to the procedure with ketamine / dexmedetomidine (10-15 / 0.1-0.2 mg / kg, IM), and eyes were dilated with 1% tropicamide HC1.

[0388] Procedure: Animals underwent OCT imaging procedures of the posterior section of the eye. If needed, a wire eyelid speculum was placed and 0.5% proparacaine HC1 was applied topically to the eye. Using the Heidelberg Spectralis OCT, a series of b-scans was acquired inferior (corresponding to the test article injection location), superior, temporal, and nasal to the optic nerve head. Following b-scan acquisition, en face BAF images was collected.

[0389] Post-Procedural Care: Following the procedure, animals either proceeded to fundus imaging, received atipamezole (1-2 mg / kg, IM) to reverse the effects of dexmedetomidine and were returned to their cages for recovery, or were euthanized at the final timepoint. If needed to aid in recovery, animals also received 40-60 mL warmed lactated Ringer’s solution SQ.

[0390] Data Analytics: Measurements of the outer nuclear layer (ONL) and total retinal thickness (TRT) in treated and untreated regions was performed. Results from the study described in Example 13(a) showing the changes in ONL thickness are shown in FIG. 16B. Results showed that the GelMA formulation provided a reduction in ONL thinning compared to the vehicle after 30 days, and a reduction in ONL thinning compared to the suspension formulation after 40 days.(g) Euthanasia / Tissue Collections:

[0391] At the final timepoint, animals were sedated with ketamine / dexmedetomidine (10- 15 / 0.1-0.2 mg / kg, IM), or remained sedated following final imaging collection, and euthanasia was performed with an overdose of sodium pentobarbital administered IC or IV, followed by auscultation or palpation to ensure death. Table 5 presents conditions the eyecups collected from designated animals subjected in preparation for RPE / Choroid flatmounting and imaging.Table 5 - RPE / Choroid Flatmountingbuffer. Using a #11 scalpel, 4-5 incisions were made around the RPE / choroid for flatmounting. An imaging spacer or vacuum grease was used to create a chamber on the slide. Mounting media (90% glycerol, 0.5% N-propyl gallate, 20 mM Tris pH 8; 3-4 drops) was applied within the spacer / chamber using a 2 mL transfer pipette. The slide was then coverslipped and stored at 4°C until shipment for analysis. Results from the study described in Example 13(a) are shown in FIG. 16C, showing a dense monolayer formation with GelMA formulation (top), whereas the suspension formulation showed little monolayer formation (bottom).Eyes Designated for Histopathology

[0393] Following euthanasia and confirmation of death, eyes designated for histopathology were enucleated, along with approximately 1-cm of attached optic nerve, marked with ink superiorly at the 12 o’clock position, and fixed in Davidson’s solution for approximately 24 hours at room temperature, followed by washes and storage in 70% ethanol at room temperature. Eyes were trimmed sagittally, trimmings discarded, and remaining globes processed to paraffin.

[0394] Using the Day 1 post-dose OCT images to guide trimming, eyes were embedded such that the surface closest to the bleb (either nasal or temporal) was sectioned first. All sections were collected on TOMO Adhesive Microscope Slides. Thirty (30) central sections containing the transplanted cells of each globe at 5 pm thickness were collected for each eye (1 section / slide). The 30 slides consisted of five (5) slides / level at 6 levels (450 pm between levels) within the bleb region (from nasal to optic nerve head or from temporal to optic nerve head depending on bleb location). The distance between levels was recorded. Additionally,five (5) slides on each side of the bleb (nasal and temporal) were collected for a total of ten (10) slides in the periphery. Slides were stained. The remaining paraffin blocks were reserved for further sectioning as needed. Results from the study described in Example 13(a) are shown in FIG. 16D. The cell suspension formulation showed disorganized photoreceptors and loss of axons and out segments, with the GelMA formulation showed a preserved three- layer construct of photoreceptor structure. The ONL thickness in the GelMA formulation was also about 10 pm greater than the suspension formulation.Eyes Designated for Cryosectioning for Immunohistochemistry (IHC)

[0395] Following euthanasia and confirmation of death, eyes designated for cryosectioning were enucleated and marked with a metallic sharpie superiorly at the 12 o’clock position. An approximately 3 mm incision was made at the limbus and the eye was placed in 4% paraformaldehyde (PF A) in phosphate-buffered saline (PBS) for 24 hours at room temperature or 48 hours at 4 °C. The anterior segment and lens were dissected away, and vitreous humor was gently removed. Eyes were cryoprotected in a gradient of sucrose (5- 30%) and embedded in OCT such that the optic nerve was facing down / anterior segment opening was up; nasal and temporal orientation were tracked.

[0396] Using the Day 1 post-dose OCT scans, the surface closest to the bleb (either nasal or temporal) was sectioned through first. With this approach, all sections had superior and inferior surfaces represented. All sections were collected on TOMO Adhesive Microscope Slides.

[0397] To survey the dosed region of the animal eye, sets of contiguous ribbons of 14 pm sections (n=3-4 sections / slide) were captured onto two slides every 100-200 pm at the following levels, using Day 1 post-dose OCT and bleb relation to the optic nerve head to guide: just temporal to the bleb (~5 slides), within the bleb (~5 slides / level at 6 levels for a total of ~30 slides), and just nasal to the bleb (~5 slides). Slides were scanned during collection for the cell depot and slides containing gel were documented. Slides were stored at room temperature. Results from the study described in Example 13(a) are shown in FIG. 16E and FIG. 16F. Use of the GelMA hydrogel-encapsulated RPE resulted in a denser photoreceptor layer and preserved photoreceptor RPE structure when compared to the suspension formulation.Example 14: In Vitro Effects of Injection Shear Stress

[0398] Retinal pigment epithelial (RPE) cells at a concentration of IxlO6were suspended in either 1% GelMA (160 / 10) + 2.5% GelMA (90 / 60) (GelMEDIX), saline (Suspension),gelatin + hyaluronic acid (Gelatin + HA), or hyaluronic acid (Polysaccharide). Thereafter, all solutions were injected through a MedOne PolyTip Cannula (27G x 32mm cannula with 38G (0.12mm) x 5mm tip (41G inner diameter)) at a controlled flow rate of 100 L / min.Immediately after injecting the RPE cell solutions, calcein AM (live cell marker) and propidium iodide (dead cell marker) were added to quantify total cell count, live cell count, and dead cell count. Cells positive for both calcein AM and propidium iodide were classified as dead.

[0399] Results of the test are shown in FIG. 17A. Results were as follows: (i) GelMA Formulation — about 75-80% living cells, about 20-25% dead cells, about 0% cells absorbed to needle; (ii) Suspension Formulation - about 30-35% living cells, about 15-20% dead cells, about 45-50% cells absorbed to needle; (iii) Gelatin + HA Formulation — about 55-60% dead cells, about 35-40% cells absorbed to needle; and (iv) HA Polysacharide Formulation — about 30-35% living cells, about 5-10% dead cells, about 55-60% cells absorbed to needle.

[0400] Chemical and mechanical properties of 1% GelMA (160 / 10) + 2.5% GelMA (90 / 60) prepared with 0.5% NVP (GMIX) vs. 1.05% GelMA (160 / 40) + 2.45% GelMA (90 / 40) prepared with 0.25% MBA (GMPMIX) are shown in FIG. 17B.

[0401] The RPE cells encapsulated in GMPMIX can degrade the hydrogel and form a monolayer, as shown in FIG. 17C.

Claims

CLAIMSWe claim:

1. A polymer composition, comprising:(i) from about 0.5% to about 15.0% w / v of at least one chemically modified gelatin;(ii) at least one polymer crosslinking initiator; and(iii) a population of cells, wherein the polymer composition comprises from about 5 million cells / mL to about 20 million cells / mL of the cells.

2. The polymer composition of claim 1, wherein the polymer composition comprises about from about 10 million cells / mL to about 15 million cells / mL of the cells; optionally about 10 million cells / mL of the cells or about 15 million cells / mL of the cells.

3. The polymer composition of any one of claim 1-2, wherein the polymer crosslinking initiator comprises one or more light-activated photo-initiators; optionally one or more photo-initiators activated by visible light.

4. The polymer composition of claim 3, wherein the polymer crosslinking initiator comprises: (i) eosin Y, N-vinylcaprolactam (NVC), triethanolamine, or any combination thereof; (ii) eosin Y disodium salt (EYDS), N-vinylcaprolactam (NVC), triethanolamine, or any combination thereof; (iii) eosin Y disodium salt (EYDS), N- Vinylpyrrolidone (NVP), triethanolamine, or any combination thereof; or (iv) eosin Y disodium salt (EYDS), methylene bisacrylamide (MBA), triethanolamine, or any combination thereof.

5. The polymer composition of claim 3, wherein the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y or eosin Y disodium salt (EYDS); (ii) from about 0.2% to about 0.3% methylene bisacrylamide (MBA); and (iii) triethanolamine.

6. The polymer composition of claim 3, wherein the polymer crosslinking initiator comprises: (i) about 50 pM eosin Y disodium salt (EYDS); (ii) about 0.25% methylene bisacrylamide (MBA); and (iii) about 1.5% v / v of triethanolamine.

7. The polymer composition of any one of claims 1-6, wherein the polymer composition comprises from about 0.5% to about 15.0% w / v of at least one acrylated gelatin; optionally from about 1.0% to about 10.0% w / v of at least one acrylated gelatin; optionally from about 1.0% to about 5.0% w / v of at least one acrylated gelatin.

8. The polymer composition of claim 7 , wherein the acrylated gelatin has a degree of functionalization from about 10-80%; optionally from 30-60%; optionally about 30%, about 45%, or about 60%.

9. The polymer composition of any one of claims 1-8, wherein the at least one acrylated gelatin comprises gelatin methacryloyl (GelMA).

10. The polymer composition of claim 9, wherein the polymer composition comprises from about 0.5% to about 15.0% w / v of GelMA; optionally from about 2.0% to about 5.0% w / v of GelMA; optionally about 1.0%, about 1.5%, about 2.0%, about 2.5%, about 3.0%, about 3.5%, about 4.0%, about 4.5%, or about 5.0% w / v of GelMA.

11. The polymer composition of any one of claims 9-10, wherein at least a portion of the GelMA has a degree of methacrylation (DoM) from about 10-80%; optionally from 40-60% DoM; optionally about 40% or about 60% DoM; optionally about 40% DoM.

12. The polymer composition of any one of claims 9-10, wherein the GelMA has a degree of methacrylation (DoM) from about 10-80%; optionally from 40-60% DoM; optionally about 40% or about 60% DoM.

13. The polymer composition of any one of claims 9-12, wherein at least a portion of the GelMA in the polymer composition has an average molecular weight from about 90 kDa to about 160 kDa; optionally wherein at least a portion of the GelMA in the polymer composition has an average molecular weight of about 90 kDa, about 138 kDa, or about 160 kDa; optionally wherein a portion of the GelMA in the polymer composition has an average molecular weight of about 90 kDa or about 160 kDa.

14. The polymer composition of any one of claims 9-12, wherein the GelMA in the polymer composition has an average molecular weight from about 90 kDa to about160 kDa; optionally wherein the GelMA in the polymer composition has an average molecular weight of about 90 kDa, about 138 kDa, or about 160 kDa.

15. The polymer composition of 14, wherein at least a portion of the GelMA in the polymer composition has an average molecular weight of about 90 kDa, and wherein at least a portion of the GelMA in the polymer composition has an average molecular weight of about 160 kDa.

16. The polymer composition of any one of claims 9-14, wherein at least a portion of the GelMA in the polymer composition has about 60% DoM and an average molecular weight from about 90-160 kDa; optionally about 60% DoM and an average molecular weight of about 90 kDa or about 160 kDa.

17. The polymer composition of any one of claims 9-14, wherein at least a portion of the GelMA in the polymer composition has about 40% DoM and an average molecular weight from about 90-160 kDa; optionally about 40% DoM and an average molecular weight of about 90 kDa or about 160 kDa.

18. The polymer composition of any one of claims 9-14, wherein at least a portion of the GelMA in the polymer composition has about 10% DoM and an average molecular weight from about 90-160 kDa; optionally about 10% DoM and an average molecular weight of about 90 kDa or about 160 kDa.

19. The polymer composition of any one of claims 9-14, wherein the polymer composition comprises: (a) about 2.5% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (b) about 2.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (c) about 5.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa; (d) about 5.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; (e) about 1.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa; (f) about 2.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa; (g) about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; (h) about 2.5% of GelMA, having about 40% DoM and an averagemolecular weight of about 90 kDa; (i) about 1.0% of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; (j) about 2.0% of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa; or (k) any combination of (a)-(j).

20. The polymer composition of any one of claims 9-14, wherein the polymer composition comprises: (a) GelMA which has about 60% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 10% DoM and an average molecular weight of about 160 kDa; optionally wherein the polymer composition comprises: (a) about 2.5% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa.

21. The polymer composition of any one of claims 9-14, wherein the polymer composition comprises: (a) GelMA which has about 40% DoM and an average molecular weight of about 90 kDa, and (b) GelMA which has about 40% DoM and an average molecular weight of about 160 kDa; optionally wherein the polymer composition comprises: (a) about 2.0-3.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) about 0.5-1.5% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

22. The polymer composition of claim 21, wherein the polymer composition comprises: (a) about 2.5% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; optionally wherein the polymer composition comprises: (a) 2.45% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) 1.05% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

23. The polymer composition of claim 21, wherein the polymer composition comprises: (a) about 2.0% w / v of GelMA, having about 40% DoM and an average molecularweight of about 90 kDa, and (b) about 1.0% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa; optionally wherein the polymer composition comprises: (a) 2.1% w / v of GelMA, having about 40% DoM and an average molecular weight of about 90 kDa, and (b) 0.9% w / v of GelMA, having about 40% DoM and an average molecular weight of about 160 kDa.

24. The polymer composition of any one of claims 1-23, wherein the at least one acrylated gelatin comprises gelatin acryloyl (GelAC).

25. The polymer composition of any one of claims 9-24, wherein the GelMA is functionalized with at least one acrylate-PEG-arginine-glycine-aspartic acid-serine (aery 1 ate-PEG-RGD S) .

26. The polymer composition of claim 25, wherein the polymer composition comprises about 5.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa, and the GelMA is functionalized with at least one acrylate-PEG- arginine-glycine-aspartic acid-serine (acrylate-PEG -RGDS).

27. The polymer composition of any one of claims 1-26, wherein the at least one acrylated gelatin comprises gelatin glycidyl acrylate (GelGA).

28. The polymer composition of claim 27, wherein the polymer composition comprises from about 0.5% to about 5.0% w / v of GelGA; optionally from about 1% to about 3.5% w / v of GelGA; optionally about 1.0% w / v of GelGA, about 2.5% w / v of GelGA, or about 3.5% w / v of GelGA.

29. The polymer composition of any one of claims 27-28, wherein the GelGA has a degree of functionalization (DoF) from about 45-60%; optionally about 45% or about 60% DoF.

30. The polymer composition of any one of claims 27-29, wherein the GelGA in the polymer composition has an average molecular weight of about 7 kDa, about 11.5 kDa, about 48 kDa, or about 50 kDa or more.

31. The polymer composition of any one of claims 27-30, wherein the Gel GA in the polymer composition comprises: (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; or (iv) any combination of (i)-(iii); optionally wherein the GelGA in the polymer composition comprises (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more.

32. The polymer composition of any one of claims 27-30, wherein the polymer composition comprises:(a) about 2.5% w / v of GelGA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGA has about 45% DoF; or(b) about 1.0% w / v of GelGA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGA has about 45% DoF.

33. The polymer composition of any one of claims 27-30, wherein the GelGA in the polymer composition comprises:(a) about 90% of GelGA with an average molecular weight of about 11.5 kDa; and(b) about 10% of GelGA with an average molecular weight of more than 11.5 kDa.

34. The polymer composition of any one of claims 27-30, wherein the polymer composition comprises:(a) about 2.5% w / v of GelGA which has a DoF of about 60%, and (i) about 90% of the GelGA has an average molecular weight of about 11.5 kDa; and (ii) about 10% of the GelGA has an average molecular weight of more than 11.5 kDa; or(b) about 3.5% w / v of Gel GA which has a DoF of about 60%, and (i) about 90% of the Gel GA has an average molecular weight of about 11.5 kDa; and (ii) about 10% of the Gel GA has an average molecular weight of more than 11.5 kDa.

35. The polymer composition of claim 27, wherein the polymer composition comprises:(a) about 2.5% w / v of Gel GA which has a DoF of about 60%, and (i) about 90% of the Gel GA has an average molecular weight of about 11.5 kDa and (ii) about 10% of the Gel GA has an average molecular weight of more than 11.5 kDa; and(b) about 2.0% w / v of GelMA, having about 10% DoM and an average molecular weight of about 160 kDa.

36. The polymer composition of claim 27, wherein the polymer composition comprises:(a) about 1.0% w / v of Gel GA which has a DoF of about 45%, and (i) about 70% of GelGA with an average molecular weight of about 7 kDa; (ii) about 20% of Gel GA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGA with an average molecular weight of about 50 kDa or more; and(b) about 2.0% w / v of GelMA, having about 60% DoM and an average molecular weight of about 90 kDa.

37. The polymer composition of any one of claims 1-36, wherein the at least one acrylated gelatin comprises gelatin glycidyl methacrylate (GelGMA); optionally wherein the polymer composition comprises about 10% w / v of GelGMA.

38. The polymer composition of claim 37, wherein the GelGMA has a degree of functionalization (DoF) of about 30% DoF.

39. The polymer composition of any one of claims 37-38, wherein the GelGMA in the polymer composition has an average molecular weight of about 7 kDa, about 48 kDa, or about 50 kDa or more.

40. The polymer composition of any one of claims 37-39, wherein the GelGMA in the polymer composition comprises: (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an averagemolecular weight of about 48 kDa; (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more; or (iv) any combination of (i)-(iii); optionally wherein the GelGMA in the polymer composition comprises (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more.

41. The polymer composition of any one of claims 37-38, wherein the polymer composition comprises: about 10% w / v of GelGMA which has a DoF of about 30%, and (i) about 70% of GelGMA with an average molecular weight of about 7 kDa; (ii) about 20% of GelGMA with an average molecular weight of about 48 kDa; and (iii) about 10% of GelGMA with an average molecular weight of about 50 kDa or more; optionally wherein the GelGMA has about 45% DoF.

42. The polymer composition of any one of claims 1-41, wherein the population of cells comprises an endothelial cell; optionally a human umbilical vein endothelial cell (HUVEC).

43. The polymer composition of any one of claims 1-41, wherein the population of cells comprises an epithelial cell; optionally a human retinal pigment epithelium cell (HRPEC); optionally HRPEC derived from embryonic stem cells or induced pluripotent stem cells (iPSC).

44. The polymer composition of any one of claims 1-41, wherein the population of cells comprises an ocular cell; optionally an ocular cell derived from a pluripotent stem cell or an embryonic stem cell.

45. The polymer composition of any one of claims 1-44, further comprising at least 0.1% (w / v) of a hydrophilic non-ionic surfactant; optionally wherein the hydrophilic nonionic surfactant comprises at least one poloxamer surfactant such as Poloxamer 407; optionally where in the composition comprises about 0.2% (w / v) of a poloxamer surfactant such as Poloxamer 407.

46. The polymer composition of any one of claims 1-37, further comprising one or more non-cell therapeutic agents; optionally wherein the one or more non-cell therapeutic agents comprises a small molecule, a gene therapy, or a protein therapy.

47. A precursor polymer composition, comprising the polymer composition of any one of claims 1-46.

48. A gel polymer composition, wherein the gel polymer composition is formed by photocrosslinking a precursor polymer composition of claim 47; optionally wherein the gel polymer composition is a hydrogel.

49. A gel polymer composition, comprising the polymer composition of any one of claims 1-46.

50. A method for treating and / or repairing a defect, injury, and / or disease in a target soft tissue of a subject, said method comprising: providing a precursor polymer composition of claim 47; administering the precursor polymer composition onto or under a surface of the target soft tissue of the subject, optionally the location of the soft tissue defect, injury, and / or disease; and crosslinking the precursor polymer composition by exposing the polymer crosslinking initiator in the polymer composition to crosslinking conditions, wherein the crosslinking of the precursor polymer composition produces a gel polymer composition.

51. A method for treating and / or repairing a defect, injury, and / or disease in a target soft tissue of a subject, said method comprising: providing a gel polymer composition of claim 48 or claim 49; and administering the gel polymer composition onto, under, or near a surface of the target soft tissue of the subject; optionally at the location of the soft tissue defect, injury, and / or disease.

52. The method of any one of claims 50-51, wherein target soft tissue is ocular tissue; optionally subconjunctival ocular tissue or retinal ocular tissue.

53. The method of claim 52, wherein the polymer composition is applied onto or under the surface of the ocular tissue by subconjunctival injection, subretinal injection, or suprachoroidal injection.

54. The method of any one of claims 50-53, wherein the defect, injury, and / or disease of the target soft tissue comprises an ocular defect, injury and / or disease; optionally an ocular ulcer; optionally a corneal ulcer from infections, injuries, perforations, or other defects.

55. The method of any one of claims 50-53, wherein the ocular defect, injury and / or disease comprises a retinal degeneration disease; optionally age-related macular degeneration (AMD) or retinitis pigmentosa.

56. Use of a polymer composition of any one of claims 47-49, for improving the cell viability of cells injected into a target tissue, wherein the polymer composition provides shear thinning properties which improve the cell viability of the cells as they are injected into the target tissue.

57. A method of treating and / or repairing injuries, defects, or diseases in a target soft tissue comprising a polymer composition of any one of claims 47-49, wherein the polymer composition provides a scaffold for cells after being injected into the target soft tissue, wherein the method: a. improves structure of restored tissue to recapitulate naturally occurring structures; and b. improves function of the transplanted cells to treat injuries, defects, or diseases through: i. direct action of the cells or, ii. supporting a secondary cell type to treat injuries, defects, or diseases.

58. The method of claim 57, wherein the cells are RPE cells.

59. The method of claim 58, wherein the RPE cells are administered subretinally.

60. The method of claim 58 or claim 59, wherein the RPE cells improve, treat and / or repair retinal degeneration, optionally age-related macular degeneration or geographic atrophy.

61. The method of any one of claim 58-60, wherein the polymer composition improves: a. RPE monolayer formation; and b. RPE function through preservation of photoreceptor structure and function; optionally wherein vision is restored or maintained.- I l l -

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