Oxygen-Independent Sulfate Radical and Fe2+-Modified Implants for Fast Sterilization and Osseointegration of Infectious Bone Defects

Currently, emerging dynamic therapy has gradually become a frequently used strategy for treating infectious bone defects via a rise in reactive oxygen species (ROS) levels, which can bring about oxidative harm to bacteria. However, ROS can be generated only under conditions of exogenous energy, limited by energy penetration or dependence on the existence of internal O₂/H₂O₂. Thus, we designed Na₂S₂O₈-decorated polyetheretherketone implants activated by Fe²⁺ for infected bone defects. In vitro experiments show that they generate sulfate radical (·SO₄^-) and hydroxyl radical (·OH) without O₂/H₂O₂ existence, effectively killing bacteria. Additionally, the released Fe²⁺ enters bacteria and triggers ferroptosis-like death via lipid peroxidation. In vivo experiments show implants achieve an ideal effect of bone integration through a high-efficiency bactericidal effect and enhanced osteogenic activity. As envisioned, our proposed strategy offers a promising approach to halt refractory infection of bone tissue by autonomously catalyzing ROS storms and ferroptosis-like death, facilitating bone-defect recovery.