In situ forming hydrogels

Abstract

The invention features materials and methods for the liquid to solid transition of an injectable pre-hydrogel composition to a hydrogel. These methods can be carried out in situ.

1 . A hydrogel precursor composition comprising: 
 (a) a polymer, said polymer comprising a water soluble polymer domain with at least two hydrophobic interacting groups attached thereto, said polymer capable of assembling into a hydrogel under physiological conditions; and    (b) a physical chemical protecting group, said physical chemical protecting group preventing gelation of said hydrogel precursor composition.    
   
   
       2 . A hydrogel or hydrogel precursor composition comprising: 
 (a) a polymer, said polymer comprising a water soluble polymer domain with at least two hydrophobic interacting groups attached thereto, said polymer capable of assembling into a hydrogel under physiological conditions;    (b) a physical chemical protecting group, said physical chemical protecting group preventing gelation of said hydrogel precursor composition or hydrogel; and    (c) a molecule that disrupts an interaction between said physical chemical protecting group and said hydrophobic interacting groups.    
   
   
       3 . The hydrogel or hydrogel precursor composition of  claim 1 , wherein said polymer domain comprises poly(ethylene glycol), poly(vinyl alcohol), poly(vinyl pyrrolidone), poly(ethyl oxazoline), poly(acrylic acid), poly(acrylamide), poly(styrene sulfonate), poly(amino acids), polysaccharides, or copolymers thereof.  
   
   
       4 . The hydrogel or hydrogel precursor composition of  claim 1 , wherein said chemical protecting group is β-cyclodextrin.  
   
   
       5 . The hydrogel precursor composition of  claim 1 , wherein said hydrophobic interacting groups are positioned at the termini of said polymer domain.  
   
   
       6 . The hydrogel precursor composition of  claim 1 , wherein said hydrophobic interacting groups are positioned within said polymer domain.  
   
   
       7 . The hydrogel precursor composition of  claim 1 , wherein said hydrophobic interacting groups are hydrocarbons.  
   
   
       8 . The hydrogel precursor composition of  claim 5 , wherein said hydrocarbons are perfluorinated hydrocarbons.  
   
   
       9 . The hydrogel precursor composition of  claim 1 , wherein said physical chemical protecting group is a cyclodextrin.  
   
   
       10 . The hydrogel precursor composition of  claim 1 , wherein said physical chemical protecting group is a molecule that covalently binds to said hydrophobic interacting groups.  
   
   
       11 . The hydrogel or hydrogel precursor composition of  claim 9 , wherein said molecule that covalently binds to said hydrophobic interacting groups is hydrophilic.  
   
   
       12 . The hydrogel or hydrogel precursor composition of  claim 1 , wherein said polymer domain comprises poly(ethylene glycol) and said hydrophobic interacting groups are perfluorinated hydrocarbons.  
   
   
       13 . The hydrogel or hydrogel precursor composition of  claim 2 , wherein said molecule that disrupts an interaction between said physical chemical protecting group and said hydrophobic interacting groups is a molecule that binds to said physical chemical protecting group better than said hydrophobic interacting groups binds to said physical chemical protecting group.  
   
   
       14 . A method for forming a hydrogel in contact with a tissue, said method comprising the steps of: 
 (a) providing a solution, said solution comprising a polymer, said polymer comprising a water soluble polymer domain having at least two hydrophobic interacting groups attached thereto, said polymer capable of assembling into a hydrogel under physiological conditions, and a physical chemical protecting group, said physical chemical protecting group preventing gelation of said polymer;    (b) providing a molecule that disrupts an interaction between said physical chemical protecting group and said hydrophobic interacting groups;    (c) combining said solution with said molecule that disrupts an interaction between said physical chemical protecting group and said hydrophobic interacting groups to form a mixture, wherein prior to, during, or after said combining, said solution and said molecule that disrupts an interaction between said physical chemical protecting group and said hydrophobic interacting groups are contacted with a tissue; and    (d) allowing gelation of the solution of the mixture of step (c) in contact with said tissue.    
   
   
       15 - 18 . (canceled)