Pulsed anodization of NiTi alloy to form a biofunctional Ni-free oxide layer for corrosion protection and hydrophilicity

Abstract This study introduced an electrochemical process for the formation of a biofunctional oxide layer on almost equiatomic NiTi alloy surface. The core technology used in proposed was anodization HNO3 electrolyte under pulsed voltage, which allowed poreless Ni-free TiO2 with thickness ~50 nm that exhibited hydrophilicity and corrosion protection. acquired led to enhanced endothelial cell activity, thereby beneficially promoting spreading organization actin stress fibers. protection significantly minimized Ni ion release from surface, further enhancing proliferation. proliferation ratio within cultivation period 168 h ~1.5 times higher than untreated Pulsed-anodization is one-step does not require heating alloy, minimizing risk superelasticity or shape memory deterioration alloy. These remarkable advantages demonstrated innovative surface modification overcomes critical drawbacks typically associated alloys.