Bioactive VS4-based sonosensitizer for robust chemodynamic, sonodynamic and osteogenic therapy of infected bone defects

Most bone defects caused by bone disease or trauma are accompanied by infection, and there is a high risk of infection spreading and defect expansion. Clinical treatments include local debridement and systemic administration of antibiotics still have a high failure rate. Therefore, it is desired to develop a high efficiency strategy against these two possible consequences. In this study, an ultrasound responsive vanadium tetrasulfide-loaded MXene (VSM) Schottky junction is constructed for rapid methicillin-resistant staphylococcus aureus (MRSA) clearance and bone regeneration. Due to the peroxidase (POD)-like activity of VS 4 and the abundant Schottky junctions, VSM has high electron-hole separation efficiency and a decreased band gap, exhibiting a strong chemodynamic and sonodynamic antibacterial efficiency of 94.03%. Under the stimulation of medical dose ultrasound, the steady release of vanadium element promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The in vivo application of VSM in infected femoral plateau bone defects of rats also has a great therapeutic effect, eliminating MRSA infection, inhibiting inflammation and improving bone regeneration. The present work successfully develops an ultrasound responsive VS 4 -based versatile sonosensitizer for robust effective antibacterial and osteogenic therapy of infected bone defects.