The different N concentrations induced cytocompatibility and hemocompatibility of MWCNTs with CNx coatings

Carbon nitride coatings were deposited on the multiwalled carbon nanotubes (MWCNTs) which were prepared by chemical vapor deposition (CVD) using ion beam assisted deposition (IBAD) system. The morphology of the MWCNTs as well as variation in composition and chemical bonds between atoms in the coatings were measured using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The relationship between N/C atomic composition ratio and chemical bonding states and cytocompatibility and hemocompatibility of the MWCNTs with CNx coatings was investigated using fibroblast cell (L929) adhesion and blood clotting assays. The results revealed that the higher N/C or sp2CN/sp3C/N ratio stimulated the cell growth, proliferation, and spreading and prolonged the kinetic blood-clotting time and recalcification time.

Highlight
► A 15 nm-thick CNx coating with different N/C ratios is deposited on MWCNTs.
► N-group leads MWCNTs to an improved viability and proliferation of fibroblast cells.
► N-group produces better condition for the cellular and pseudopod spreading.
► N-group also affects the blood-clotting and recalcification time of MWCNTs.
► N/C and sp2CN/sp3CN ratio are responsible for good cell and blood compatibility.