Patent ID: 8795727

Claim:
A method of making a fragmented hydrogel composition, comprising: combining in an alkaline solution of at least 30 mM chitosan, carboxymethylcellulose, carboxymethylchitosan, or a derivative thereof with a molecular weight of less than or equal to 5000 Dalton, a degree of deacetylation of 30% to 100%, a degree of deacetylation greater than or equal to 70%, and a multi-armed polyethylene glycol with a molecular weight of 10,000 Dalton to 30,000 Dalton and at least two nucleophilic groups; combining a multi-armed polyethylene glycol with a molecular weight of 10,000 Dalton to 30,000 Dalton and at least two eletrophilic groups with an aqueous solution; combining the alkaline and aqueous solution; allowing the hydrogel composition to substantially cure; drying the substantially cured hydrogel composition under elevated temperature and reduced pressure; and fragmenting the dry hydrogel composition by cryogenic grinding or cryogenic milling.