Ferric Ion Driven Assembly of Catalase‐like Supramolecular Photosensitizing Nanozymes for Combating Hypoxic Tumors

A facile approach to assemble catalase‐like photosensitizing nanozymes with a self‐oxygen‐supplying ability was developed. The process involved Fe3+‐driven self‐assembly of fluorenylmethyloxycarbonyl (Fmoc)‐protected amino acids. By adding a zinc(II) phthalocyanine‐based photosensitizer (ZnPc) and the hypoxia‐inducible factor 1 (HIF‐1) inhibitor acriflavine (ACF) during the Fe3+‐promoted self‐assembly of Fmoc‐protected cysteine (Fmoc‐Cys), the nanovesicles Fmoc‐Cys/Fe@Pc and Fmoc‐Cys/Fe@Pc/ACF were prepared, which could be disassembled intracellularly. The released Fe3+ could catalyze the transformation of H2O2 enriched in cancer cells to oxygen efficiently, thereby ameliorating the hypoxic condition and promoting the photosensitizing activity of the released ZnPc. With an additional therapeutic component, Fmoc‐Cys/Fe@Pc/ACF exhibited higher in vitro and in vivo photodynamic activities than Fmoc‐Cys/Fe@Pc, demonstrating the synergistic effect of ZnPc and ACF. Fe3+ ions can promote the self‐assembly of Fmoc‐protected amino acids to form nanovesicles and catalyze the transformation of H2O2 enriched in cancer cells to oxygen, thereby ameliorating the hypoxic condition and promoting the photosensitizing activity of the encapsulated photosensitizer (ZnPc) in the nanovesicles. By entrapping an additional therapeutic agent (ACF), the nanovesicles can exhibit a synergistic effect for eradication of hypoxic cancer cells and tumors.