Patent ID: 7364879

Claim:
A method for the production of a biodegradable, water absorbable γ-polyglutamic acid (γ-PGA) hydrogel comprising directly cross-linking (A) a mixture of γ-polyglutamic acid (γ-PGA) and a γ-polyglutamate and optionally a polysaccharide containing a carboxylic acid and/or carboxylate group, an amino acid, or a mixture thereof; and/or (B) a microbial culture broth containing a mixture of a γ-polyglutamic acid (γ-PGA) and a γ-polyglutamate and optionally a polysaccharide containing a carboxylic acid and/or carboxylate group, an amino acid, or a mixture thereof; and a cross-linker comprising a polyglycidyl ether having three or more functional groups, wherein each of 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; wherein said polyglycidyl ether is glycerol triglycidyl ether, di- or polyglycerol polyglycidyl ether, polyoxyethylene sorbitol polyglycidyl ether, or a mixture thereof.