Patent ID: 7193007

Claim:
A gelable composition comprising a star copolymer and a solvent, the copolymer having the star-shaped structure A(B)n, wherein A is soluble in the solvent, wherein A is selected from the group consisting of polyethylene glycol (PEG), polyvinyl pyrrolidone, polyvinyl alcohol, polyhydroxyethylmethacrylate, and hyaluronic acid; B is convertible between soluble and insoluble in the solvent depending on an environmental condition, and wherein B is selected from the group consisting of poly-N-isopropyl acrylamide (PNIPAAm), hydroxypropylmethyl cellulose and other methyl celluloses, poly(ethylene glycol vinyl ether-co-butyl vinyl ether), polymers of N-alky acrylamides, poly(amino acid)s, peptide sequences, poly(methacryloyl-L-alanine methyl ester), poly(methacryloyl-L-alanine ethyl ester) and nitrocellulose; and n is greater than 2, the composition being reversibly convertible from liquid to gel as a function of the environmental condition.