Haemocompatibility of tetrahedral amorphous carbon films

Tetrahedral amorphous carbon (ta-C) films have been prepared by filtered ar e deposition (FAD). The structure of the ta-C films was characterised by Ra man Spectroscopy. The haemocompatibility of the formed films was studied by measurement of haemolysis ratio and observation of platelet adhesion. Comp ared with low-temperature isotropic pyrolytic carbon (LTI-carbon), which is being used as the material for artificial heart valves in clinical use at present, the ta-C films showed improved anticoagulation property. In order to understand the observed haemocompatibility results, the surface energy o f the films was evaluated to analyse surface adsorption of human serum albu min (HSA) and human fibrinogen (HFG). However, it was found that the ta-C f ilms are identical to Ln-carbon with respect to protein adsorption. It is b elieved that effective work function could be a reason for the observed var iation in haemocompatibility between the ta-C films and LTI-carbon. (C) 200 0 Elsevier Science S.A. All rights reserved.