Method and material for enhanced tissue-biomaterial integration

Abstract

The present invention relates to the covalent binding of a hydrogel to an extracellular matrix (ECM). The integration of the hydrogel with the tissue is superior to that in previous techniques. Moreover, unlike previous techniques, the present invention does not require a photoinitiator. Potential therapeutic applications include tissue repair and delivery of drugs or cells. The ECM is first exposed, then treated with a priming agent. Then a polymerizable agent is added and crosslinked to the ECM. Two primary embodiments of methods are disclosed. In the first, the priming agent is an oxidizer which creates tyrosyl radicals in the ECM, which are then bound by acrylate groups in the polymerizable agent. In the second, the priming agent contains aldehydes which bind amino groups in the ECM.

1 . A method of integrating a hydrogel to an extracellular matrix, comprising the steps of:
 (a) providing an exposed extracellular matrix;   (b) priming the extracellular matrix by treating with a priming agent to create a primed extracellular matrix;   (c) adding to the primed extracellular matrix a solution of a polymerizable agent; and   (d) reacting the primed extracellular matrix and polymerizable agent to create a hydrogel covalently bound to the extracellular matrix.   
     
     
         2 . The method of  claim 1 , wherein:
 said extracellular matrix comprises a plurality of tyrosine residues,   said priming step comprises oxidizing said extracellular matrix,   said priming agent comprises an oxidizing agent,   said primed extracellular matrix comprises a plurality of tyrosyl radicals,   said polymerizable agent comprises an acrylate group reactable with said tyrosyl radicals, and   said reacting step comprises binding said polymerizable agent to the tyrosyl radicals and crosslinking said polymerizable agent.   
     
     
         3 . The method of  claim 2 , wherein said extracellular matrix is disposed in a living body. 
     
     
         4 . The method of  claim 3 , wherein said body is that of a mammal. 
     
     
         5 . The method of  claim 4 , wherein said body is that of a human. 
     
     
         6 . The method of  claim 3 , wherein said providing step comprises treating said extracellular matrix with chondroitinase ABC. 
     
     
         7 . The method of  claim 2 , wherein said extracellular matrix comprises a collagen. 
     
     
         8 . The method of  claim 7 , wherein said collagen is disposed in a cartilage. 
     
     
         9 . The method of  claim 2 , wherein said oxidizing agent comprises a hydrogen peroxide solution. 
     
     
         10 . The method of  claim 2 , wherein said priming step further includes exposing said extracellular matrix and said polymerizable agent to a source of electromagnetic radiation. 
     
     
         11 . The method of  claim 2 , wherein, said source of electromagnetic radiation is a source of ultraviolet light. 
     
     
         12 . The method of  claim 2 , wherein said polymerizable agent has at least one free radical polymerizable group selected from the group consisting of an of an acrylate, a diacrylate, oligoacrylate, dimethacrylate, and oligomethacrylate. 
     
     
         13 . The method of  claim 2 , wherein said reacting step comprises exposing said extracellular matrix and said polymerizable agent to a source of ultraviolet radiation. 
     
     
         14 . The method of  claim 2 , wherein said reacting step comprises using a redox initiator. 
     
     
         15 . The method of  claim 2 , wherein said reacting step comprises an ionic crosslinking reaction. 
     
     
         16 . The method of  claim 2 , wherein said reacting step comprises an enzymatic crosslinking reaction. 
     
     
         17 . The method of  claim 2 , wherein said method is carried out transdermally. 
     
     
         18 . The method of  claim 2 , wherein a diffusible drug substance is added with said polymerizable agent. 
     
     
         19 . The method of  claim 2 , wherein a plurality of living cells are added with said polymerizable agent. 
     
     
         20 . The method of  claim 2 , whereby a solid repair in a tissue is created. 
     
     
         21 . A hydrogel produced by the method comprising the following steps:
 (e) providing an exposed extracellular matrix;   (f) priming the extracellular matrix by treating with a priming agent to create a primed extracellular matrix;   (g) adding to the primed extracellular matrix a solution of a polymerizable agent; and   (h) reacting the primed extracellular matrix and polymerizable agent to create a hydrogel covalently bound to the extracellular matrix; wherein   said extracellular matrix comprises a plurality of tyrosine residues, said priming step comprises oxidizing said extracellular matrix, said priming agent comprises an oxidizing agent, said primed extracellular matrix comprises a plurality of tyrosyl radicals, said polymerizable agent comprises an acrylate group reactable with said tyrosyl radicals, and said reacting step comprises binding said polymerizable agent to the tyrosyl radicals and crosslinking said polymerizable agent.   
     
     
         22 . A hydrogel covalently bound to an extracellular matrix at a plurality of tyrosine residues of said matrix. 
     
     
         23 . A hydrogel in accordance with  claim 22 , wherein said extracellular matrix is composed of a plurality of collagen fibers in a cartilage matrix. 
     
     
         24 . A method of forming a hydrogel covalently bound to a cartilage tissue, comprising the steps of:
 (a) exposing a plurality of tyrosine residues disposed in a plurality of collagen fibers further disposed in a cartilage tissue by treating the tissue with a glycanase to remove a plurality of polysaccharides;   (b) oxidizing the tyrosine residues, by treating with a hydrogen peroxide solution and a source of ultraviolet light, to produce a plurality of tyrosyl groups in the collagen;   (c) adding a polymerizable agent comprising one or more acrylate groups; and   (d) reacting the tyrosyl groups and the polymerizable agent to create a hydrogel covalently bound to the collagen.   
     
     
         25 . The method of  claim 1 , wherein:
 said extracellular matrix comprises a plurality of amino groups,   said priming agent comprises a compound with an aldehyde group and a carrier compound with an amino group,   said priming step comprises reacting said priming agent with said extracellular matrix to covalently bind said extracellular matrix and said priming agent,   said primed extracellular matrix consists of said extracellular matrix covalently bound to said priming agent, and   said reacting step consists of covalently binding said polymerizable agent to said primed extracellular matrix and crosslinking said polymerizable agent.   
     
     
         26 . The method of  claim 25 , wherein said extracellular matrix is disposed in a living body. 
     
     
         27 . The method of  claim 26 , wherein said body is that of a mammal. 
     
     
         28 . The method of  claim 27 , wherein said body is that of a human. 
     
     
         29 . The method of  claim 25 , wherein said polymerizable agent has at least one free radical polymerizable group selected from the group consisting of an of an acrylate, a diacrylate, oligoacrylate, dimethacrylate, and oligomethacrylate. 
     
     
         30 . The method of  claim 25 , wherein said reacting step comprises exposing said extracellular matrix and said polymerizable agent to a source of ultraviolet radiation. 
     
     
         31 . The method of  claim 25 , wherein said reacting step comprises using a redox initiator. 
     
     
         32 . The method of  claim 25 , wherein said reacting step comprises an ionic crosslinking reaction. 
     
     
         33 . The method of  claim 25 , wherein said reacting step comprises an enzymatic crosslinking reaction. 
     
     
         34 . The method of  claim 25 , wherein said method is carried out transdermally. 
     
     
         35 . The method of  claim 25 , wherein a diffusible drug substance is added with said polymerizable agent. 
     
     
         36 . The method of  claim 25 , wherein a plurality of living cells are added with said polymerizable agent. 
     
     
         37 . The method of  claim 25 , whereby a solid repair in a tissue is created. 
     
     
         38 . A hydrogel produced by the method comprising the following steps:
 (e) providing an exposed extracellular matrix;   (f) priming the extracellular matrix by treating with a priming agent to create a primed extracellular matrix;   (g) adding to the primed extracellular matrix a solution of a polymerizable agent; and   (h) reacting the primed extracellular matrix and polymerizable agent to create a hydrogel covalently bound to the extracellular matrix;   wherein,   
       said extracellular matrix comprises a plurality of amino groups, said priming agent comprises a compound with an aldehyde group and a carrier compound with an amino group, said priming step comprises reacting said priming agent with said extracellular matrix to covalently bind said extracellular matrix and said priming agent, said primed extracellular matrix consists of said extracellular matrix covalently bound to said priming agent, and said reacting step consists of covalently binding said polymerizable agent to said primed extracellular matrix and crosslinking said polymerizable agent. 
     
     
         39 . A hydrogel covalently bound via a priming agent to an extracellular matrix at a plurality of amino groups in said extracellular matrix.