Self-enhanced photothermal-chemodynamic antibacterial agents for synergistic anti-infective therapy

Cu 2-x S nanostructures have been intensively studied as outstanding chemodynamic therapy (CDT) and good photothermal therapy (PTT) antibacterial agents due to their highly efficient Cu(Ⅰ)-initiated Fenton-like catalytic activity and good photothermal conversion property. However, they still suffer from shortage of Cu(Ⅰ) supply in the long-term and comparatively low inherent photothermal conversion efficiency. Herein, we constructed a self-enhanced synergistic PTT/CDT nanoplatform (Cu 1.94 S@MPN) by coating Cu 1.94 S nanoparticles with Fe(Ⅲ)/tannic acid based metal-polyphenol networks (MPN). Activated by the acidic bacterial infection microenvironment, Cu 1.94S @MPN could be decomposed to continuously release Cu(Ⅱ), Fe(Ⅲ) ions and tannic acid. As the result of tannic acid-involved Cu and Fe redox cycling, Cu(Ⅰ)/Fe(Ⅱ)-rich CDT could be achieved through the highly accelerated catalytic Fenton/Fenton-like reactions. More importantly, experimental results demonstrated that Cu 1.94 S@MPN exhibited both excellent photothermal antibacterial and photothermal-enhanced CDT properties to eradicate bacteria in vitro and in vivo . Overall, this novel nanotherapeutics has great potential to become a clinic candidate for anti-infective therapy in future. Through the coating of Cu 1.94 S nanoparticles with Fe(Ⅲ)/tannic acid complexes, a novel non-antibiotic nanotherapeutics was successfully constructed. This antibacterial agent exhibited excellent self-enhanced photothermal/chemodynamic synergistic therapeutic efficacy in vivo .