In Vitro Cell Adhesion and Hemocompatibility of Carbon Nanotubes with CNx Coating

Multi-walled carbon nanotubes (MWCNTs) prepared by chemical vapor deposition (CVD) were sprayed on C wafers. Then, an 8 nm-thick CNx coating was deposited on MWCNTs by ion beam deposition (IBAD). The cell adhesion and hemocompatibility of MWCNTs with and without CNx coating were investigated using contact-angle measurements, cell- and platelet-adhesion assays, and hemolytic-rate testing. The results showed that mouse fibroblast cells (L929) cultured on MWCNTs with CNx coating displayed a higher cell-adhesion strength, viability, proliferation, and spreading than those on MWCNTs without CNx coating, indicating that CNx coating induced MWCNTs showed an increase in cytocompatibility. Despite MWCNTs with CNx coating displayed higher hemolytic and platelet adsorption rates than those on MWCNTs without CNx coating, its hemolytic rate values below 5% were acceptable. And CNx coating inhibited red blood cell adhesion and deformation. Good cell growth and hemocompatibility on MWCNTs with CNx coating were probably related to the positive contribution of nitrogen functional groups to hydrophilicity and the three-dimensional network configuration.