Surface engineering of DLC thin films with controlled zeta potential using plasma processing and evaluation of cytocompatibility

Abstract

Coronary Stent is recently often used for the revascularization of occluded coronary artery, but bare metal stent often caused restenosis by thrombosis attached on stent. To decrease thrombosis on bare metal stent, the newly developed biomimetics Diamond-Like carbon (DLC) thin film is evaluated after providing high cytocompatibility on the surface of Stent by plasma treatment. To investlgate the affect of the bonded network into the DLC thin film on plasma treatment, two kinds of DLC thin film were deposited in CH4 and C2H2 gases by PECVD. As a result, the amount of sp2 C-H and sp3 C-H bonded networks in DLC thin films deposited with C2H2 gas (C2H2-DLC) decreased and those of sp2 C-C and sp3 C-C bonded networks increased compared with those ln the DLC thin films deposited with CH4 gas (CH4-DLC). NH3 and O2 plasma surface treatments were performed for two kinds of DLC thin film. As a result, many functlOnal groups were introduced into the C2H2-DLC thin films surface compared with into the CH4-DLC thin films surface. From these results, the surface of the DLC thin films deposited with C2H2 gaS Were treated with plasma, and their effects on endothelial and smooth muscle cells were studied. It was observed that the endothelial cell growth ratio in the case of the DLC thin films whose surface was treated With plasmas was higher than that in the case of the untreated DLC thin films. Therefore, this test results indicate the newly developed biomimetic DLC thin films coatlng will be one of the best coatlng for metalic medical devices. © 2009 CPST.