Rapid Biofilm Elimination on Bone Implants Using Near‐Infrared‐Activated Inorganic Semiconductor Heterostructures

Abstract Bacterial infections often cause orthopedic surgery failures. It is hard for the immune system and antibiotics to clear bacteria adhered to implants after they form a mature biofilm, and a secondary surgery is required to remove the infected implants. To avoid this, a hybrid coating of Bi 2 S 3 @Ag 3 PO 4 /Ti is prepared to eliminate biofilm using near‐infrared (NIR) light. Bi 2 S 3 nanorod (NR) arrays are prepared on titanium (Ti) implants through hydrothermal methods, and Ag 3 PO 4 nanoparticles (NPs) are loaded on Bi 2 S 3 NR arrays using a stepwise electrostatic adsorption strategy. The introduction of Ag 3 PO 4 NPs enhances the photocatalysis performances of Bi 2 S 3 , and the hybrid coating also exhibits good photothermal effects. After 808 nm light irradiation for 15 min, it shows superior bactericidal efficiency of 99.45% against Staphylococcus aureus , 99.74% against Escherichia coli in vitro, and 94.54% against S. aureus biofilm in vivo. Bi 2 S 3 @Ag 3 PO 4 /Ti also shows good cell viability compared to pure Ti. This NIR‐activated‐inorganic hybrid semiconductor heterojunction coating is biocompatible and could be employed to eliminate biofilm effectively, which makes it a very promising strategy for the surface modification of bone implant materials.