Influence of polar functional groups introduced by COOH+ implantation on cell growth and anticoagulation of MWCNTs

Abstract

Though multiwalled carbon nanotubes (MWCNTs) have shown great promise in biomedical applications, our understanding about their biocompatibility is limited. Here, COOH⁺ implantation was performed for MWCNTs in order to gain insight into how COOH⁺ implantation affected the cell growth and blood adsorption of MWCNTs. The extensive measurements demonstrated that carboxyl groups were successfully introduced onto the surface of MWCNTs, inducing more hydrophilicity compared with pristine MWCNTs. Two kinds of cells, mouse fibroblast cells (L929) and human endothelial cells (EAhy926), were used to assess the cell growth of MWCNTs before and after COOH⁺ implantation. COOH⁺ implantation led to a significant improvement in cell proliferation and adhesion, indicating superior cell adhesion over pristine MWCNTs. As the ion dose increased, the platelet adhesion assays of COOH⁺ implantation-MWCNTs (COOH/MWCNTs) displayed a significant enhancement, which implied COOH/MWCNTs could be used as anticoagulant and nonhemolytic material. The results were helpful to design modified surfaces of nanomaterials for improving their biocompatibility.