Self-powered electro-activated Mg_xFe_1-xS₂ scaffold for gas-ion therapy in osteosarcoma suppression and bone...

Postoperative treatment of osteosarcoma faces the dual challenges of tumor recurrence and extensive bone defect repair, necessitating the development of a synergistic strategy capable of simultaneously eliminating residual tumor cells and promoting bone regeneration. Existing prosthetic implants are often limited by their singular functionality, leading to issues such as high recurrence rates and non-union. This study innovatively constructs a functional titanium alloy scaffold system synergistically driven by a biodegradable "shell-like" triboelectric nanogenerator (BS-TENG). The BS-TENG efficiently converts natural joint movement into electricity. Within the acidic tumor microenvironment, this electrical output accelerates the breakdown of the scaffold's Mg_xFe_1-xS₂ coating, leading to the localized release of H₂S gas and Fe²⁺ ions. The H₂S upregulates HMOX1 protein expression, which synergizes with heightened Fe²⁺ levels to induce intense lipid peroxidation, thereby activating a selective ferroptosis cascade in osteosarcoma cells and drastically lowering their survival. In physiological conditions, the scaffold shows excellent biocompatibility. Concurrent electrical stimulation and controlled Mg²⁺ release significantly boost alkaline phosphatase activity and calcium nodule formation, effectively promoting bone regeneration. In vivo validation confirms a 90% tumor inhibition rate alongside robust biosafety, offering a novel self-powered paradigm for integrated therapy and repair post-osteosarcoma surgery.