Hydrolytically degradable polysaccharide hydrogels

Abstract

Provided are polysaccharide compositions capable of controllable hydrolytic degradation and suitable for controlled release of therapeutic agents. Also provided are methods for synthesizing such compositions and a variety of applications in which the compositions may be used.

What is claimed: 
     
         1 . A composition, comprising:
 a polymer comprising a plurality of repeat units,   at least one repeat unit comprising
 a biocompatible backbone comprising a polysaccharide; 
 a hydrolytically degradable linker; and 
 a crosslinker, 
   the hydrolytically degradable linker being disposed between the biocompatible backbone and the crosslinker group,   the hydrolytically degradable linker degrading upon exposure to an aqueous medium, and   the crosslinker group covalently binding at least one repeat unit to a second repeat unit.   
     
     
         2 . The composition of  claim 1 , wherein the hydrolytically degradable linker comprises at least one ester. 
     
     
         3 . The composition of  claim 1 , wherein the hydrolytically degradable linker comprises lactic acid, caprolactone, or glycolic acid. 
     
     
         4 . The composition of  claim 3 , wherein the hydrolytically degradable linker comprises lactic acid. 
     
     
         5 . The composition of  claim 1 , wherein the crosslinker comprises a crosslinking product of an acryl or a methacryl moiety. 
     
     
         6 . The composition of  claim 1 , further comprising one or more cells disposed therein or thereon. 
     
     
         7 . The composition of  claim 6 , wherein a cell comprises a mammalian cell. 
     
     
         8 . The composition of  claim 6 , wherein a cell comprises a stem cell. 
     
     
         9 . The composition of  claim 1 , further comprising one or more agents disposed therein. 
     
     
         10 . The composition of  claim 9 , wherein an agent comprises a therapeutic agent, a marker, a label, a dye, or any combination thereof. 
     
     
         11 . The composition of  claim 1 , wherein the composition comprises two repeat units that differ in the composition of their hydrolytically degradable linkers. 
     
     
         12 . The composition of  claim 1 , wherein the composition comprises two repeat units that differ in the composition of their biocompatible backbones. 
     
     
         13 . The composition of  claim 1 , wherein the composition comprises two repeat units that differ in the composition of their crosslinkers. 
     
     
         14 . The composition of  claim 1 , wherein the polysaccharide comprises hyaluronic acid. 
     
     
         15 . A macromer, comprising
 a biocompatible backbone comprising a polysaccharide;   a hydrolytically degradable linker; and   a polymerizable crosslinker;   the hydrolytically degradable linker being disposed between the biocompatible backbone and the crosslinker group,   the hydrolytically degradable linker degrading upon exposure to an aqueous medium, and   the crosslinker comprising a carbon-carbon double bond.   
     
     
         16 . The macromer of  claim 14 , wherein the hydrolytically degradable linker comprises at least one ester. 
     
     
         17 . The macromer of  claim 14 , wherein the hydrolytically degradable linker comprises lactic acid, caprolactone, or glycolic acid. 
     
     
         18 . The macromer of  claim 14 , wherein the crosslinker comprises an acrylate or a methacrylate moiety. 
     
     
         19 . The macromer of  claim 14 , wherein a polysaccharide comprises hyaluronic acid. 
     
     
         20 . The macromer of  claim 14 , wherein the hydrolytically degradable linker and the crosslinker together define the following structure: