α-Fe ₂O ₃ Based Nanotherapeutics for Nir/Dihydroartemisinin Dual-Augmented Chemodynamic Antibacterial Therapy

Due to the negligible bacterial resistance, chemodynamic therapy (CDT) is a promising treatment for bacterial infection. However, it is severely impeded by the constant body temperature, shortage of Fe(Ⅱ) ions and insufficient H2O2 level in infected tissue. To enhance the therapeutic efficiency of CDT, novel strategies are urgently needed to tackle these problems. Herein, we exploited an infection microenvironment-responsive nanotherapeutics for near-infrared (NIR)/dihydroartemisinin (DHA) dual-augmented antibacterial CDT. The convenient encapsulation of DHA-loaded α-Fe2O3 nanorods with metal-polyphenol networks (MPN) led to the generation of an antibacterial nanoagent Fe2O3@DHA@MPN (FDM). Afterwards, its photothermal and peroxidase-like activities were intensively studied. Furthermore, the bactericidal efficacy of FDM was evaluated through both in vitro and in vivo antibacterial assays. Firstly, FDM showed both excellent photothermal and NIR/DHA dual-augmented peroxidase-like activities. Besides, it exhibited a pH-responsive release behavior of Fe(Ⅲ) ions. Moreover, it presented tannic acid-mediated bacterial adhesion effect. In vitro experiments demonstrated that FDM could achieve a satisfactory efficiency against both planktonic bacteria and biofilms. In vivo assays illustrated both the extraordinary synergistic antibacterial effect and efficient anti-inflammatory ability of FDM. The outcomes indicated that the exploited antibacterial agent could offer new insight on developing novel intelligent nanotherapeutics for clinical use in the future.