Bimetallic nanozyme-mediated dual ferroptosis/cuproptosis synergy potentiates immunotherapy in bladder cancer.

Immunotherapy for bladder cancer remains limited by immunosuppressive tumor microenvironment (TME) and low immunogenicity. Here, we developed a TME-responsive bimetallic porous nanozyme, Fe/Cu-HPC@GOx/PEG, to synergistically induce dual ferroptosis/cuproptosis and amplify antitumor immunity. The nanozyme integrates Fe-Cu bimetal catalytic centers within a hierarchical porous carbon framework, enabling glucose oxidase (GOx)-triggered H₂O₂ generation and subsequent Fenton/Fenton-like reactions. In vitro studies demonstrated that the nanozyme effectively depleted glutathione, inactivated GPX4, and accumulated lipid peroxides to drive ferroptosis. Concurrently, hypoxia alleviation via O₂ generation suppressed HIF-1α-mediated glycolysis, blocked ATP7B-dependent Cu⁺ efflux, and triggered DLAT lipoylation, leading to cuproptosis. Mitochondrial dysfunction from dual cell death pathways synergistically enhanced oxidative stress and immunogenic cell death (ICD), evidenced by calreticulin exposure, HMGB1/ATP release, and dendritic cells maturation. In vivo, Fe/Cu-HPC@GOx/PEG significantly suppressed tumor growth and remodeled the TME, with increased CD8⁺ T cell infiltration and elevated pro-inflammatory cytokines. Systemic toxicity evaluation confirmed biocompatibility, showing no organ damage or biochemical abnormalities. This work presents a paradigm-shifting strategy that leverages metal ion-mediated dual death pathways to overcome immunotherapy resistance, offering a clinically translatable nanoplatform for precision oncology.