Patent ID: 7790417

Claim:
A biodegradable, water absorbable γ-polyglutamic acid hydrogel which is prepared by directly cross-linking (A) a γ-polyglutamic acid (γ-PGA), a γ-polyglutamate, or a mixture thereof, and optionally a polysaccharide containing a carboxylic group and/or carboxylate group, an amino acid, or a mixture thereof; or (B) a microbial culture broth containing a γ-polyglutamic acid (γ-PGA), a γ-polyglutamate, or a mixture thereof, and optionally a polysaccharide containing a carboxylic group and/or carboxylate group, an amino acid, or a mixture thereof; a cross-linker comprising a polyglycidyl ether having three or more functional groups, wherein the functional groups thereon can react with a carboxylic group (—COOH), carboxylate group (—COO − ), aldehyde group (—CHO), hydroxyl (—OH), carbonyl group (—CO), sulfone group (—SO 2 ), amino group (—NH 2 ) or nitro group (—NO 2 ), or a mixture thereof; and wherein said polyglycidyl ether is glycerol triglycidyl ether, di- or polyglycerol polyglycidyl ether and polyoxyethylene sorbitol polyglycidyl ether, or a mixture thereof.