GRAFTING OF PEO TO GLASS, NITINOL, AND PYROLYTIC CARBON SURFACES BY GAMMA-IRRADIATION

Glass, nitinol, and pyrolytic carbon surfaces were grafted with poly(e thylene oxide) (PEO) and PEO-containing Pluronic (R) surfactants by ga mma irradiation. These substrates were coated with a primer layer of t richlorovinylsilane (TCVS), which allows grafting of organic polymers. The TCVS-coated substrates were adsorbed with PEO or Pluronics (R) an d exposed to 0.3 Mrad of gamma radiation to graft the polymer to the s urface. PEO-grafted substrates were characterized by contact angle mea surement, X-ray photoelectron spectroscopy, fibrinogen adsorption, and platelet adhesion and activation. Surface modification with PEO reduc ed fibrinogen adsorption by as much as 99%. Platelet adhesion was sign ificantly reduced or prevented on the modified surfaces. Protein-and p latelet-resistance effects were independent of hydrophilicity of the P EO-grafted surfaces. Polymer grafting by gamma radiation to TCVS-coate d substrates provides a facile process to improve thromboresistance of inorganic biomaterials. (C) 1997 John Wiley & Sons, Inc.