Abstract
Nickel-titanium (NiTi) alloys are widely employed as implantable devices, but their intrinsic poor antibacterial activity and Ni-ion release remain a major challenge. Leveraging copper's antibacterial efficacy, we developed a facile one-pot route to construct copper-loaded polydopamine films on NiTi alloy (Cu@PDA/NiTi). In a dopamine-CuSO(4) mixture, dopamine simultaneously polymerizes and reduces Cu(2+), the resulting Cu(2+) coordinates with PDA to form a metal-phenolic network (MPN), which incorporates both Cu(2+) and Cu nanoparticles (NPs). By tuning CuSO(4) concentration (C (CuSO(4)) ) from 1 to 30 mM, the Cu@PDA/NiTi possesses adjustable Cu content and antibacterial potency. Antibacterial ratios toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reach 46.3-99.4% and 47.5-97.3%, respectively, while Ni-ion release is markedly suppressed and corrosion resistance significantly enhanced. In vitro and in vivo assays confirm excellent biosafety. This scalable strategy offers a practical avenue for customizable antibacterial NiTi implants and inspires the design of next-generation functional biomaterials.