摘要 |
Non-cross-linked hydrogel, method for making it, and its uses in medicine and/or surgery, such as tubes, filaments, films, rings, implants and the like, especially in ophthalmolgy. The non-cross-linked hydrogel having a relatively high water content is made from a starting liquid composition (D) which comprises from 2 to 50 % of an acrylonitrile copolymer and of an olefinically unsaturated comonomer carrying anionic groups, optionally in salt form, the molar ratio of acrylonitrile to comonomer being between 90:10 and 100:0, a suitable solvent and a suitable non-solvent of the said copolymer, the solvent/non-solvent ratio being between 500:1 and 0.5:1 by weight, the said hydrogel having a microporous structure, an ionic capacity of between 0 and 500 mEq/kg of gel, a water content of between 50 and 98 %, and having a capacity for permanent deformation under stress, even at a temperature below 40 DEG C. |