| abstract |
A method of coating polymeric substrates, especially contact lenses, by reacting functional groups at the substrate polymer surface with complementary functional groups on a hydrophilic coating polymer in an aqueous medium to form covalent linkages between the two polymers. Both polymers are preferably hydrogels. Suitable functional groups include hydroxyl, carboxyl, amino and sulphonate groups. The coating enhances the hydrophilic character of the lens for a longer time relative to an untreated surface, and reduces the tendency for tear proteins to adhere to the lens surface. The coating polymers especially include, among others, polyethylene oxide and polypropylene oxide polymers with pendant functionalities, polydimethylsiloxane graft copolymers with polyethylene oxide, polypropylene oxide, glycidyl acrylate, glycidyl methacylate, epoxypropyl acrylate, or epoxypropyl methacrylate copolymer moieties, and graft copolymers of chitin and chitosan with polyethylene and polypropylene oxide polymers. |