Minimalist O₂ generator formed by in situ KMnO₄ oxidation for tumor cascade therapy

Diverse oxygen generation strategies have been developed to overcome hypoxia in tumors for enhancing the therapeutic efficacy, but inevitably suffering from tedious synthesis process of oxygen generators in vitro before in vivo administration. Herein, we show direct injection of commercially and clinically used KMnO₄ into solid tumors enables in situ formation of MnO₂ as an oxygen depot for cascade oxidation damage and enhanced photodynamic therapy. KMnO₄ can damage tumor tissues by oxidation and generate MnO₂, and subsequent intravenous injection of Ce6 allows MnO₂-triggered hypoxia-modulated photodynamic therapy of tumors. Excellent cascade tumor suppression effect is realized both in vitro and in vivo based on the KMnO₄-Ce6 system without the need of synthesis. The proposed strategy lays down a novel way with unprecedented superiors of no need of synthesis process and ultra-facile administration procedure for tumor hypoxia-modulated cascade therapy.