Immobilization of Albumin and Heparin on the Surface of Ti-O Films for Improving Blood Compatibility

Aminopropyltriethoxysilane (APTE) was covalently interacted with hydroxyl on the surface of Ti-O films prepared by magnetron sputtering, and albumin and heparin were immobilized on the APTE-coated surface with addition of 1-ethyl-3- (3-dimethyl aminopropyl) carbodiimide (EDC) as cross-link agent. X-ray photoelectron spectroscopy (XPS) was used to investigate the modified surface. Contact angle results indicate that there was an increase in the contact angle to the surface of APTE-coated Ti-O films, and a decrease in the contact angle to the surface of albuminand heparin-immobilized surfaces. Blood platelet adhesion in vitro was improved significantly after immobilization of albumin and heparin on Ti-O films. Endothelial cell (EC) culture tests showed that EC could grow on the surface of Ti-O films immobilized with albumin and heparin, but the growth and proliferation behavior of endothelial cells was not as good as on naked Ti-O films. This investigation showed that the surface of bio-inert inorganic materials immobilized with biological molecules is feasible and effective for improving the blood compatibility.