Study on synergistic mechanism of Cu-TCPP@MnO2 composites for photothermal/photodynamic/chemodynamic treatment of infected wound healing

Abstract

Photodynamic antibacterial based on metal organic framework (MOF) structure shows broad application prospects. But it is limited by the problem of hypoxia in the bacterial microenvironment. The oxygen-producing nanozyme strategy is the key to solving the problem. In this work, MnO₂ oxygen-producing nanozyme was introduced on the basis of the metal organic framework Cu-TCPP to obtain Cu-TCPP@MnO₂, which can produce oxygen synchronously during PDT. Moreover, under the excitation of 660 + 808 nm dual laser irradiation, the synergistic treatment of PDT, CDT and PTT was achieved. In the in vitro antibacterial experiment, the inhibition rate of Cu-TCPP@MnO₂ against Staphylococcus aureus under dual laser excitation can reach 99.9 %, and the biofilm removal rate is close to 80 %. The inhibition rate of Escherichia coli is also as high as 99.5 %. In the in vivo treatment of mouse models, the wound area was only 2.39 % after 13 days, achieving efficient sterilization, controlling inflammation and promoting tissue repair. This synergistic antibacterial strategy has shown remarkable effects in wound healing giving the material great potential for medical applications.