Targeted hot ion therapy of infected wound by glycol chitosan and polydopamine grafted Cu-SiO2 nanoparticles

Quick and effective elimination of drug-resistant bacteria and simultaneous repairing the infectious tissue remain challenging in clinics. In this study, multifunctional glycol chitosan and polydopamine coated copper-doped mesoporous silica ([email protected]@GCS) nanoparticles with near-infrared (NIR) photothermal conversion ability and bacteria-targeting property are prepared. When infection occurred, the environment becomes acidic, and [email protected]@GCS nanoparticles with pH-sensitive could be accumulated on the surface of the bacteria. The NIR light-induced heating and Cu ions released from [email protected]@GCS nanoparticles created a distinct “hot ions effect”, showing high-efficiency, quick and long-term inhibition of bacteria (methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli)) as well as biofilm. In addition, the [email protected]@GCS nanoparticles with “mild hot ions effect” could induce macrophages polarization into a pro-inflammatory M1 phenotype, resulting in the clearance of infection through the immune-antibacterial effect. Moreover, the “mild hot ions effect” endows [email protected]@GCS nanoparticles with remarkable bioactivity, which stimulates the migration and angiogenesis of endothelial cells. The in vivo results confirmed that [email protected]@GCS nanoparticles with laser irradiation could efficiently remove bacteria and significantly promote wounds closure, epithelization and angiogenesis during infectious wound healing process.