Influence of silicon concentration on the haemocompatibility of amorphous carbon

Amorphous carbon (a-C) has good blood compatibility and has been proposed as a coating material for blood contacting devices such as heart pumps and stents. In this study, unhydrogenated a-C films with different silicon concentrations were synthesized by magnetron sputtering, and the corresponding evolution of the surface energy and compatibility with blood were analysed. The incorporation of silicon not only decreased the sp2-hybridized carbon bonding configurations, but the static evaluation of the films incubated in human platelet-rich plasma also showed a decrease in platelet adhesion. Bonding structure and surface energy were determined to be factors contributing to the improved haemocompatibility.