NIR responsive composite nanomaterials with in-situ deposition of cascaded nanozymes for multiple synergistic therapy of bacterial infection in diabetic mice

The bacterial infection of chronic wounds caused by diabetes has imposed a significant burden on society and families. Therefore, the collaborative and emerging antibacterial strategies are urgently designed and invented to reduce the burden of bacteria on wounds. Herein, an aptamer functionalized and near-infrared light responsive nano-antibacterial material (CuS@Pt-Au/Apt NPs) based on cascaded nanozymes is successfully constructed for the synergistic therapy of wound infection in diabetic mice. In vitro performance assays verify that CuS@Pt-Au/Apt NPs exhibit the sustained release of hydroxyl radical (·OH) and excellent photothermal properties. Varies in vitro antibacterial experiments demonstrate that the minimum inhibitory concentrations (MICs) of CuS@Pt-Au/Apt against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) are both 128 μg·mL−1 under NIR irradiation and glucose catalysis, while validate the efficient in vitro bactericidal activity, significant glutathione consumption and its antibacterial mechanism. In vivo anti-infection assays prove that CuS@Pt-Au/Apt NPs perform the best cutaneous wound healing capability with a remaining infected area of <2% for bacterial infection of diabetes, and significantly reduce the occurrence of inflammation at the infected wounds. This antibacterial strategy integrating targeting, chemodynamic therapy (CDT) and photothermal therapy (PTT) not only achieves synergistic and enhanced antimicrobial effects, but also addresses the limitations of nanozymes and promotes their biomedical applications.