Immobilization of human thrombomodulin onto PTFE.

Human thrombomodulin (hTM) is an endothelial cell-surface glycoprotein and has effective anticoagulant properties. This protein was immobilized onto polytetrafluorethylene (PTFE) surfaces to create biomaterials with enhanced haemocompatibility. The PTFE surface was functionalized by CO2 plasma activation and subsequent vapour-phase graft polymerization of acrylic acid. Surface characterization after plasma treatment, grafting and hTM immobilization was achieved by attenuated total reflection-Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential and wetting measurements. The activity of immobilized hTM was estimated using the protein C activation test.