Patent ID: 7160931

Claim:
A method of forming a removable implant in an animal comprising inserting a thermally reversible gel into said animal, said gel having a semi-solid form at body temperature and a liquid form upon cooling to a temperature below a threshold temperature, said threshold temperature being at least 5° C. below body temperature, wherein said gel comprises a star copolymer and a solvent, the copolymer having the star-shaped structure A(B)n with n>2, wherein A is soluble in the solvent, and is selected from the group consisting of polyethylene glycol (PEG), polyvinyl pyrrolidone, polyvinyl alcohol, polyhydroxyethylmethacrylate, and hyaluronic acid; and B is convertible between soluble and insoluble in the solvent when heated to a temperature between ambient temperature and body temperature, and comprises poly-N-isopropyl acrylamide (PNIPAAm), hydroxypropylmethyl cellulose and other methyl celluloses, poly(ethylene glycol vinyl ether-co-butyl vinyl ether), polymers of N-alkyl acrylamides, poly(amino acid)s, peptide sequences, poly(methacryloyl-L-alanine methyl ester), poly(methacryloyl-L-alanine ethyl ester) or nitrocellulose; and wherein said gel is reversibly convertible between said semi-solid and said liquid form as a function of temperature.