AuPt-loaded Fe-N-C flower-like nanocascade reactor with self-supplied reaction substrates and multiple enzyme activities for the study of hypoxic tumors

When nano-enzymes are used in tumor therapy research, they usually exhibit only a single enzyme activity, which limits their therapeutic effect in hypoxic tumors. This paper designs a hyaluronic acid (HA)-modified Au-Pt-Fe trimetallic flower-like nanomaterial for tumor cascade catalysis integrated with low-temperature photothermal therapy. GOx activity exhibited by AuPt nanoparticles converts glucose in tumor cells into gluconic acid and H 2 O 2 . This process not only deprives tumor cells of their energy source but also produces H 2 O 2 . Iron single-atom nanomaterials can exhibit excellent CAT and POD activities, catalyzing H 2 O 2 reactions in tumor cells. Among them, a portion of H 2 O 2 is converted to O 2 by the activity of nanozyme CAT, which is used to alleviate tumor tissue hypoxia and serve as a substrate for the GOx-like activity reaction of AuPt NPs. The H 2 O 2 is continuously produced by the glucose catalytic reaction, and a portion of it can further decompose into toxic OH through POD activity, contributing to tumor cell destruction. The glucose-H 2 O 2 -O 2 cycle reaction is realized, that is, the self-supply of H 2 O 2 and O 2 in the catalytic process within tumor cells. The introduction of AuPt nanoparticles enhances the photothermal conversion ability of the material. By using near-infrared light irradiation, mild-temperature photothermal therapy (m-PTT) can be achieved, which further improves the treatment effect while protecting surrounding tissues. This work expands the application of multi-metal nanomaterials in cascade catalysis combined with low-temperature photothermal therapy, providing a novel strategy for integrated tumor treatment.