Antibacterial ability and cytocompatibility of Cu-incorporated Ni–Ti–O nanopores on NiTi alloy

Abstract

Nearly equiatomic nickel–titanium (NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable properties. However, it is prone to infection because of its poor antibacterial ability. The present work incorporated Cu into Ni–Ti–O nanopores (NP–Cu) anodically grown on the NiTi alloy to enhance its antibacterial ability, which was realized through electrodeposition. Our results show that incorporation of Cu (0.78 at%–2.37 at%) has little influence on the NP diameter, length and morphology. The release level of Cu ions is in line with loadage which may be responsible for the improved antibacterial ability of the NiTi alloy to combat possible bacterial infection in vivo. Meanwhile, the NP–Cu shows better cytocompatibility and even can promote proliferation of bone marrow mesenchymal stem cells (BMSCs), up-regulate collagen secretion and extracellular matrix mineralization when compared with Cu-free sample. Better antibacterial ability and cytocompatibility of the NP–Cu render them to be promising when serving as NiTi implant coatings.