Coating of two polyether-polyurethanes and polyethylene with a heparin-poly-(vinyl alcohol) hydrogel.

Two polyether-polyurethane elastomers (Pellethane and Biomer) and polyethylene were coated with a heparin-poly(vinyl alcohol) hydrogel. The requisite surface modification in preparation for coating consisted of glow discharge cleaning and acid treatment for the polyether-polyurethanes and glow discharge cleaning and chromic acid oxidation for polyethylene. The chemical modifications increased surface wettability. Surface analysis by attenuated total reflectance Fourier transform infrared spectroscopy indicated that the acid treatment caused hydrolysis of the polyether segments of Pellethane and Biomer. Prolonged partial thromboplastin times were observed on the coated films. The results of toluidine blue assay of heparin in the solution in which the coated films were immersed for a long time suggested that heparin was covalently bound in the coating. Such coating techniques extend the usefulness of the heparin-poly(vinyl alcohol) hydrogel to a number of medically important substrate materials.