Photochemical grafting of alpha-propylsulphate-poly(ethylene oxide) on polyurethane surfaces and enhanced antithrombogenic potential.

The aim of this study is the grafting of photoreactive alpha-propylsulphate-poly(ethylene oxide) (PEO-SO3), one end of which is capped with an azidophenyl group, on polyurethane (PU) surfaces via a photochemical technique. The anti-Factor Xa activity and the platelet adhesion characteristics of the modified PU surface were evaluated by a chromogenic assay method and by a flow-controlled chamber method, respectively. X-ray photoelectron spectroscopy analysis showed that PEO-SO3 was covalently grafted on the PU surface. The grafted surface showed anti-Factor Xa activity in the presence of antithrombin III, and significantly reduced platelet adhesion characteristics as compared with those of the unmodified PU surface. These results suggest that the grafting of PEO-SO3 improves the antithrombogenicity of PU surfaces.