Interpenetrating networks with covalent and ionic crosslinks

Abstract

The invention features a composition comprising a self-healing interpenetrating network hydrogel comprising a first network and a second network. The first network comprises covalent crosslinks and the second network comprises ionic or physical crosslinks. For example, the first network comprises a polyacrylamide polymer and second network comprises an alginate polymer.

1 - 36 . (canceled) 
     
     
         37 . A tough interpenetrating networks hydrogel comprising a first network and a second network, wherein:
 the first network comprises a covalently crosslinked polymer selected from the group consisting of polyacrylamide, poly(vinyl alcohol), poly(ethylene oxide) and its copolymers, polyethylene glycol (PEG), methacrylated PEG, and polyphosphazene; and   the second network comprises an ionically crosslinked polymer selected from the group consisting of alginate, chitosan, and agarose;   wherein the first network and the second network are covalently coupled.   
     
     
         38 . The hydrogel of  claim 37 , wherein the first network comprises polyacrylamide or polyethylene glycol (PEG) and wherein the second network comprises alginate. 
     
     
         39 . The hydrogel of  claim 37 , wherein the first network comprises a covalent crosslinking agent selected from the group consisting of N,N-methylenebisacrylamide (MBAA), a methacrylate crosslinker, N,N′-dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (ECC), N-hydroxysuccinimide, N-hydroxysulfosuccinimide, glutaraldehyde, and a transglutaminase. 
     
     
         40 . The hydrogel of  claim 37 , wherein the hydrogel comprises at least 30 wt % water. 
     
     
         41 . The hydrogel of  claim 37 , wherein the hydrogel comprises between 30-98 wt % water. 
     
     
         42 . The hydrogel of  claim 37 , wherein the hydrogel has a fracture toughness value of at least 10 J/m 2 . 
     
     
         43 . The hydrogel of  claim 37 , wherein the hydrogel has a fracture toughness value from 10 J/m 2  to 9000 J/m 2 . 
     
     
         44 . The hydrogel of  claim 37 , wherein the hydrogel has a Young's modulus value of at least 10.0 kPa. 
     
     
         45 . The hydrogel of  claim 37 , wherein the hydrogel has a Young's modulus value of 10.0 kPa to 300 kPa. 
     
     
         46 . The hydrogel of  claim 37 , wherein the hydrogel has a stretch value (λ) of from 2 to 25. 
     
     
         47 . The hydrogel of  claim 37 , wherein the hydrogel has a stretch value (λ) of 21. 
     
     
         48 . The hydrogel of  claim 37 , wherein the second network comprises an ionic crosslinking agent selected from the group consisting of CaCl 2 , CaSO 4 , CaCO 3 , hyaluronic acid, and polylysine. 
     
     
         49 . A tough interpenetrating networks hydrogel comprising a first network and a second network, wherein:
 the first network comprises a covalently crosslinked polymer selected from the group consisting of polyacrylamide, poly(vinyl alcohol), poly(ethylene oxide) and its copolymers, polyethylene glycol (PEG), methacrylated PEG, and polyphosphazene; and   the second network comprises an ionically crosslinked polymer selected from the group consisting of alginate, chitosan, and agarose;   the hydrogel has a covalently crosslinked polymer/(covalently crosslinked polymer and ionically crosslinked polymer) ratio of between about 66.67 wt. % and 94.12 wt. % based on monomer weights; and   wherein the first network and the second network are covalently coupled.   
     
     
         50 . The hydrogel of  claim 49 , wherein the first network comprises polyacrylamide or polyethylene glycol (PEG) and wherein the second network comprises alginate. 
     
     
         51 . The hydrogel of  claim 49 , wherein the first network comprises a covalent crosslinking agent selected from the group consisting of N,N-methylenebisacrylamide (MBAA), a methacrylate crosslinker, N,N′-dicyclohexylcarbodiimide (DCC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (ECC), N-hydroxysuccinimide, N-hydroxysulfosuccinimide, glutaraldehyde, and a transglutaminase. 
     
     
         52 . The hydrogel of  claim 49 , wherein the second network comprises an ionic crosslinking agent selected from the group consisting of CaCl 2 , CaSO 4 , CaCO 3 , hyaluronic acid, and polylysine. 
     
     
         53 . The hydrogel of  claim 49 , wherein the first network comprises a covalent crosslinking agent that is N,N-methylenebisacrylamide (MBAA) and the second network comprises an ionic crosslinking agent that is CaSO 4 . 
     
     
         54 . The hydrogel of  claim 49 , wherein the hydrogel has a covalently crosslinked polymer/(covalently crosslinked polymer and ionically crosslinked polymer) ratio of between about 80 wt. % and 92.31 wt. % based on monomer weights. 
     
     
         55 . The hydrogel of  claim 49 , wherein the hydrogel has a Young's modulus value of at least 10.0 kPa. 
     
     
         56 . The hydrogel of  claim 49 , wherein the hydrogel has a stretch value (λ) of from 2 to 25.