Catalase-like metal–organic framework nanoparticles to enhance radiotherapy in hypoxic cancer and prevent cancer recurrence

Tumor hypoxia typically occurs inside a solid tumor with an inadequate oxygen supply, sharply reducing the therapeutic efficiency of radiotherapy and significantly increasing the risk of local tumor recurrence. Herein, we designed folic acid modified enzyme-like hafnium-based manganoporphyrin metal-organic framework nanoparticles (MnTCPP-Hf-FA MOF NPs) to overcome hypoxia-induced radioresistance and prevent postoperative recurrence. Hf, a high-Z element, can effectively absorb X-ray energy and convert O₂ and H₂O into reactive oxygen species to induce cell apoptosis. The MnTCPP ligand has an enzyme-like ability to catalytically decompose endogenous H₂O₂ into O₂ for enhancing RT in hypoxic tumors. <i>In vivo</i> experiments revealed that the MOF NPs could effectively inhibit melanoma growth and prevent tumor postoperative recurrence with only one X-ray irradiation after intravenous injection. We expect that the current study provides a versatile approach for solving the critical radioresistance issue of hypoxic tumors.