Patent ID: 7935361

Claim:
An endoprosthesis for soft tissue augmentation; said endoprosthesis being injectable into soft tissue as a polymer hydrogel and having a complex viscosity of about 2 to 100 Pas; said polymer hydrogel comprising less than 50 ppm of acrylamide and methylene-bis-acrylamide, at least 95% by weight pyrogen-free water or a saline solution, and at least 0.5% by weight polyacrylamide and less than 3.5% by weight polyacrylamide, based on the total weight of the polymer hydrogel, wherein said polyacrylamide consists essentially of a cross-linked polymerized acrylamide, wherein the cross-linking consists essentially of the use of N,′N′-methylene bis-acrylamide as a cross-linker; and wherein said endoprosthesis consists essentially of said polymer hydrogel.