Patent ID: 7790194

Claim:
A method of filling soft tissue comprising administering a hydrogel as an endoprosthesis to an area in need thereof, said hydrogel comprising about 0.5 to less than 3.5% by weight polyacrylamide, based on the total weight of the hydrogel; wherein the polyacrylamide is crosslinked polyacrylamide; said hydrogel consisting essentially of a polymer of said crosslinked polyacrylamide, and at least 95% by weight pyrogen-free water or saline solution, and less than 50 ppm of acrylamide and methylene-bis-acrylamide monomers, and wherein the hydrogel has an elasticity module from about 10 to 700 Pa and a complex viscosity from about 2 to 100 Pas, and wherein said endoprosthesis consists essentially of said hydrogel.