Anti-thrombotic effect of amorphous hydrogenated carbon (a-C:H) films: influence of electron structure

Summary form only given. In this work, we focus on the relationship between the electron structure and wettability of amorphous hydrogenated carbon (a-C:H) and its blood compatibility. A series of films with different electron structure and wettability were fabricated using plasma immersion ion implantation-deposition (PIII-D), followed by annealing in vacuum between 200-600/spl deg/C. They were characterized by Raman, elastic recoil detection (ERD) and atomic force microscopy (AFM). The physical properties and surface characteristics of the films including the carrier concentration and mobility, resistivity and band gap were also examined. The thrombogenesis of the films was evaluated employing in vitro platelet adhesion tests. The results were correlated with the biological data to elucidate the blood compatibility mechanism of a-C:H films. The platelet adhesion and activation of a-C:H is affected by annealing. It is believed that the possible factors affecting blood compatibility are the adhesion energy of blood plasma, band gap, carrier type and concentration. Improving the electronic structure of a-C:H films is critical to the abatement of platelet activation.