Synergistic effect of carbon microstructure and topography of TiO2 nanorod arrays on hemocompatibility of carbon/TiO2 nanorod arrays composites

This study systematically investigated the synergistic effect of material’s surface topography and electronic structure on fibrinogen adsorption and platelet activation. Three kinds of oriented TiO2 nanorod arrays (TNA) were synthesized by the hydrothermal method by changing the growth parameters in order to adjust the surface topography and roughness. The carbon thin films with various sp3 C contents were deposited onto the top of TNA with the DC magnetic-filtered cathodic vacuum arc deposition. The structure, the surface topography, and the roughness of TNA were characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy, respectively. The sp3 C content in carbon films was estimated using Raman spectroscopy. The results demonstrated that the amount of fibrinogen adsorbed on surface was influenced merely by surface topography and roughness of TNA, but independent of surface carbon coating. In addition, the platelet adhesion decreased significantly with the increase of the sp3 C content in carbon coating at the same degree of roughness or adsorbed fibrinogen. The lowest platelet adhesion and activation was observed on the specific surface topography associated with the highest sp3 C content in carbon coating.