Self-Healing Photothermal Nanotherapeutics for Enhanced Tumor Therapy through Triple Ferroptosis Amplification and Cascade Inflammation Inhibition.

The therapeutic effectiveness of photothermal therapy (PTT) is limited by heat tolerance and PTT-induced inflammation, which increases the risk of tumor metastasis and recurrence. Ferroptosis combined with PTT can achieve significant therapeutic effects. In this work, we designed self-healing photothermal nanotherapeutics to achieve effective PTT with triple-amplified ferroptosis and cascade inflammation inhibition after photothermal treatment. After the ferroptosis-inducing ability of mangiferin (MF) was first elucidated, the nanocomplex PFeM, coordinated by Fe and MF with polyvinylpyrrolidone (PVP) modification, was prepared by a one-pot self-assembly method. PFeM with laser irradiation could induce intensified ferroptosis by integrating the functions of MF to deactivate glutathione peroxidase 4, Fe/Fe to generate lethal reactive oxygen species via the Fenton reaction, and the photothermal effect to amplify ferroptosis. More importantly, the released MF could achieve cascade inflammation inhibition, thereby reversing the proinflammatory microenvironment caused by PTT. The in vivo antitumor and anti-inflammatory effects of PFeM were further confirmed in a 4T1 tumor-bearing mouse model. This study expounding the ferroptosis-inducing effects of MF and utilizing the strategy of chelating MF with iron ions can provide a new idea for developing photothermal nanoagents with clinically convertible safety ingredients and a green preparation process that improve efficacy and reduce adverse reactions during PTT.