Oxygen vacancy-enhanced microwave catalysis of Zn-Fe spinel for implant-related infections

Implant-related infections (IRIs) pose a major challenge in orthopedic applications due to the persistence of biofilms, which are highly resistant to conventional antibiotics. This study introduces oxygen vacancy-engineered Zn-Fe spinel nanoparticles as microwave-responsive antibacterial agents. The oxygen vacancies in the spinel structure enhance reactive oxygen species (ROS) generation under microwave irradiation, providing a dual-mode antibacterial mechanism of thermal and oxidative stress. Zn-Fe spinel nanoparticles were synthesized using a sol-gel method and evaluated for their antibacterial efficacy against Staphylococcus aureus biofilms. Under microwave irradiation, the Zn-Fe spinel demonstrated significant biofilm disruption and bacterial eradication. Mechanistic studies revealed that oxygen vacancies promoted ROS generation, leading to bacterial membrane damage. In vivo experiments using a mouse infection model confirmed the material's antibacterial efficacy and biocompatibility, with no observed toxicity. This study highlights the potential of oxygen vacancy-enhanced Zn-Fe spinel as a microwave-assisted, antibiotic-free strategy for treating deep-seated infections associated with orthopedic implants.