Length-dependent corrosion behavior, Ni2+ release, cytocompatibility, and antibacterial ability of Ni-Ti-O nanopores anodically grown on biomedical NiTi alloy

摘要

In the present work, nickel-titanium-oxygen nanopores with different length (0.55-114 mu m) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, nickel ion (Ni2+) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni2+ release. In addition, the Ni2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is 11 mu m. Encouragingly, the length scale covers the one (1-11 mu m) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1-11 mu m are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications.