Light-assisted therapy for biofilm infected micro-arc oxidation TiO₂ coating on bone implants

Implant-associated infections is a main factor leading to the failure of titanium (Ti) implants. Micro-arc oxidation is a convenient and effective technique to form a biocompatible metal (Ag⁺, Cu²⁺ and Zn²⁺) ions-doped TiO₂ coatings to combat bacterial infections. However, compared with the sterilization by metal ions, light-triggered antibacterial therapies have accepted more attention due to its higher antibacterial efficiency and security. Although TiO₂ is an excellent photocatalyst, it can be triggered by ultraviolet light due to the wide band gap. Herein, molybdenum disulfide (MoS₂) modified TiO₂ coating was fabricated on Ti by a hybrid process of micro-arc oxidation and hydrothermal treatment. The hybrid coating exhibits excellent antibacterial activity under the irradiation of 808 nm near-infrared light because of the synergistic antibacterial effects of reactive oxygen species and hyperthermia, and Staphylococcus aureus (S. aureus) biofilm can be eradicated within 15 min both in vivo and in vitro. Furthermore, collagen decorated on the surface of the hybrid coating can improve the proliferation, adhesion and spreading of MC3T3-E1 osteoblasts.