Bismuth oxybromide nanosheets accelerating healing of infected wounds at movable part through self-motion promoted piezo- and near infrared light activated photo-performance

The healing of wounds at movable part remains a significant challenge due to bacterial infections and mechanical external forces induced by unavoidable movements. Herein, bismuth oxybromide nanosheets (BiOBr NSs) with piezoelectric properties were developed to promote wound healing in such regions by converting repetitive mechanical motion into a driving force that activates BiOBr generating an electric field at the wound site. Additionally, oxygen vacancies were also introduced into BiOBr NSs to impart near infrared (NIR)-triggered photothermal and photodynamic antibacterial activity. Two types of BiOBr NSs were synthesized, differing in oxygen vacancy density: BiOBr-L with a lower density and BiOBr–H with a higher density. BiOBr–H NSs exhibited enhanced electron-hole separation ability, resulting in superior antibacterial efficacy with NIR irradiation compared to BiOBr-L NSs. Furthermore, both BiOBr NSs promoted cell migration and proliferation due to their piezoelectric properties. In vivo assessments demonstrated that BiOBr NSs significantly accelerated the healing of neck wounds. This study not only presents an effective strategy for designing wound dressings for wounds at movable parts but also broadens the biomedical applications of nanomaterials with piezoelectric and photoelectric properties.