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

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 oxi-dation (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 effec-tively eliminate and inhibit the adhesion and proliferation of bacteria over a long period time while pro-moting 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.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Automated summary

This study developed a surface-modified titanium implant with osseointegration and antibacterial functions, which is of great significance for the repair of infectious bone defects.