One-step fabrication of Ag@Polydopamine film modified NiTi alloy with strong antibacterial property and enhanced anticorrosion performance

Abstract

In this paper, silver nanoparticles (Ag NPs) containing polydopamine (Pdop) films (Ag@Pdop hybrid films) was designed to modify the surface of nickel-titanium (NiTi) alloys by taking a one-step immersing approach. The formation of the Ag@Pdop hybrid films could undergo a co-deposition of a fast formation of Ag NPs and a time-consuming formation of Pdop films on the NiTi surface. The loading content of Ag NPs could be controlled by making adjustment to the initial concentration of AgNO3 (CAgNO3). In such films, the endowed antibacterial and enhanced anticorrosion properties of the Ag@Pdop modified NiTi alloys are mainly attributed to Ag NPs and the Pdop film, respectively. Compared with the polished NiTi, the obtained 40Ag@Pdop hybrid film exhibits strong antibacterial performance (antibacterial ratio > 99%), improved corrosion resistance property, and desirable cytocompatibility. Additionally, the film can effectively inhibit the Ni ions leaching from the substrate and display a sustainable release of Ag ions. This work could provide an effective guidance on the design of Ag containing films to prevent the infection induced by implantation.