▎ 摘　　要

An important clinical challenge is the development of implant surfaces which have good integration with the surrounding tissues and simultaneously inhibit bacterial colonization thus preventing infection. Recently, graphene oxide (GO) a derivative of graphene, has gained considerable attention in the biomedical field owing to its biocompatibility, surface functionalizability and promising antimicrobial activity. In this study gelatin-functionalized graphene oxide (GOGel) was synthesized by a simple one step modification where GO and GOGel were used to develop surface coatings on nitinol substrates. Mouse osteoblastic cell (MC3T3-E1) functions including cell attachment, proliferation and differentiation were investigated on GO-based coatings. The results indicated that MC3T3-E1 cell functions were significantly enhanced on both GO coated nitinol (GO@NiTi) and GOGel coated nitinol (GOGel@NiTi) compared with the control nitinol without coating (NiTi). Especially, the GOGel@NiTi surface exhibited the best performance for cell adhesion, proliferation and differentiation. Additionally the antimicrobial property of GO-based coatings against E. coli was studied with the evaluation of colony forming units (CFU) counting, live/dead fluorescent staining and scanning electron microscope (SEM). We found that the growth of E. coli was inhibited on GOGel@NiTi and particularly on GO@NiTi. SEM images revealed that the cell membrane of bacteria lost their integrity and live/dead fluorescent images confirmed the low live/dead ratio of E. coli after incubation on GOGel@NiTi and GO@NiTi. We conclude that GO-based coatings on NiTi combine the antimicrobial activity and improved biocompatibility and therefore present a remarkable potential in biomedical implant applications.