Patent ID: 8329826

Claim:
A surface modification method for an interpenetrating polymer network hydrogel, wherein said surface modification is capable of providing a basis for cell or tissue attachment to said surface modified interpenetrating polymer network, comprising: a) activating functional groups on the surface of a PEG/PAA interpenetrating polymer network hydrogel, wherein said functional groups are the carboxylic groups as part of the PAA network of said PEG/PAA interpenetrating polymer network hydrogel; and b) reacting said activated functional groups with amine-containing molecules or hydroxyl-containing molecules, which once activated form ester groups and (i) subsequently form amide linkages when reacted with said amine containing molecules, or (ii) ester linkages when reacted with said hydroxyl-containing molecules, wherein steps 1(a) and 1(b) are performed in an aqueous environment and do not require UV treatment.