GB1319007A - Nonthrombogenic plastics - Google Patents

Abstract

1319007 Heparin coated articles CORNING GLASS WORKS 3 Nov 1971 [4 Nov 1970] 51041/71 Heading B2E A method of bonding heparin to a thermoplastic material comprises impregnating the surface of the material with an amino coupling agent by subjecting the refluxing solution of aminosilane in a plastics swelling agent to swell the surface of the material and bond the aminosilane coupling agent to the material, drying to remove the plastics swelling agent, protonating by immersing the material in an aqueous acid saline solution and immersing the material in an aqueous acidic solution of a heparin salt for a time sufficient to bond the heparin to the protonated aminosilane coupling agent. Suitable thermoplastics materials are polyethylene, polypropylene, polystyrene, polyisobutylene, polyvinyl chloride, polyvinylidene fluoride, polyvinyl acetate, polyacrylonitrile, polyethyl acrylate, polymethyl methacrylate, polyethylene glycol terephthalate, polytetrafluoroethylene, polyhexamethylene diamine adipate, cellulose actate, ethyl cellulose, polyformaldhehyde and copolymers of these. Suitable swelling agents are toluene, benzene and hexane. Preferred aminosilane coupling agents have a chemical structure in which the central silicon atom has attached thereto at least one hydrolyzable alkyloxy group or halogen atom. Treatment with the plastics with the swelling agent may be effected for an extended period. Preferably coupling agent used in a 10% solution at a reflex time 16 to 64 hours. Protonating solution preferably contains at least 0.1 mol of an alkali metal or ammonium halide at a pH of 1-4. Protonation may be carried out by immersion for 5-20 hours. The heparin may be applied as the sodium, lithium, barium or ammonium salt. The heparin solution preferably contains at least 1 milligram of heparin per milligram of solution and should be at a pH of between 3 and 4. The method may be applied to prosthetic devices.