Infection Microenvironment-Mediated Nanoplatform for In Vivo Persistent Luminescence Imaging and Chemodynamic Antibacterial Therapy

Infection microenvironment-mediated chemodynamic therapy (CDT) is an attractive way for the therapy of bacterial infection. However, therapeutic agents which can obtain real-time and in situ pathological information imaging signals during CDT are rare. Thus, it is an urgent need to explore antibacterial agents with both bacterial elimination and treatment process monitoring ability. Herein, we report an activatable antimicrobial nanoplatform with both ultralow-background persistent luminescent (PL) ''turn-on" imaging and therapeutic capability. Chitosan (CS) is used as a linker to immobilize copper ions on the surface of persistent luminescent nanoparticles (PLNPs) to fabricate PLNPs–CS–Cu2+. The PL emission of PLNPs is quenched by Cu2+ under physiological conditions but recovered due to the conversion of Cu2+ into Cu+ by high glutathione (GSH) levels at the infection site. The produced Cu+ catalyzes H2O2 to generate hydroxyl radicals (•OH) for bacterial killing through oxidative stress. Also, the depletion of GSH amplifies the oxidative stress and enhances the therapy efficacy. The as-prepared antibacterial nanoplatform is promising for highly sensitive persistent luminescent imaging and simultaneous treatment of bacterial infection.