From bio-inertness to osseointegration and antibacterial activity: A one-step micro-arc oxidation approach for multifunctional Ti implants fabricated by additive manufacturing

[Display omitted] •Bio-inertness of Ti has been a long-term shortcoming of the material.•A two-layer hierarchical structure was formed on the surface of 3D printed pure Ti using a one-step MAO approach.•The MTi/Ag/CaP implant showed an excellent long-term antibacterial property and biocompatibility in vitro.•The MTi/Ag/CaP implant showed good osteogenecity and osseointegration in vivo.•The one-step MAO shows potential as a promising approach for the prevention and treatment of IBDs. Infectious bone defects (IBD) remain a major problem in orthopedics in clinical settings. For IBD repair, implants possessing multiple functions such as osseointegration and antibacterial activity are in demand. This study aims to develop a surface-modified titanium (Ti) implant (MTi/Ag/CaP) with osseointegration and antibacterial functions for IBD repair. The pure Ti implant is printed using a selective laser melting technique, and a two-layer hierarchical structure is formed on its surface using a one-step micro-arc oxidation (MAO) approach. The outer layer is an apatite-like material decorated with Ag nanoparticles, whereas the inner layer is porous TiO2. In vitro experiments show that the MTi/Ag/CaP implant can effectively eliminate and inhibit the adhesion and proliferation of bacteria over a long period time while promoting MG-63 cell adhesion, proliferation, and osteogenic differentiation. In vivo experiments further reveal that the MTi/Ag/CaP implant produces more mineralized bone tissue than non-treated samples and interlocks closely with the bone tissue after 8 weeks. The one-step MAO modification developed in this study is simple, efficient, and environment-friendly, which demonstrates great potential as a promising approach for providing advanced biomedical materials in orthopedic applications, including for the prevention and treatment of IBDs.