Nitric Oxide‐Mediated Dual‐Functional Smart Titanium Implant Coating for Antibacterial and Osseointegration Promotion in Implant‐Associated Infections

Abstract The balance of antibacterial and osseointegration‐promoting properties on titanium (Ti) implants in a simple and efficient manner is crucial for the management of implant‐associated infections, a condition that has become a significant global health concern. Herein, a nitric oxide (NO)‐mediated dual‐function smart coating with antibacterial and osseointegration‐promoting properties is developed for Ti implants. The coating leverages the distinct properties of NO at high and low concentrations to enable an on‐demand functional switch. Specifically, antibacterial function is achieved through a rapid release of high‐dose NO in response to the infection microenvironment and near‐infrared stimulation. Once the infection is resolved and normal physiological conditions are restored, the coating gradually releases low‐dose NO to promote osseointegration. In vitro tests confirm that the coating exhibits antibacterial ratio of 97.84% and 97.18% against methicillin‐resistant Staphylococcus aureus and its biofilms, respectively, and demonstrates the ability to activate osteoblasts. The rat femoral implant‐associated infection model further certifies that the responsive NO release mechanism of the coating efficiently facilitates the on‐demand functional switch between antibacterial and osseointegration‐promoting properties. Notably, the use of the dual‐functional nonantibiotic agent, NO, significantly mitigates the risk of bacterial resistance.