A Two-Pronged Nanostrategy of Iron Metabolism Disruption to Synergize Tumor Therapy by Triggering the Paraptosis-Apoptosis Hybrid Pathway.

Iron metabolism has emerged as a promising target for cancer therapy; however, the innate metabolic compensatory capacity of cancer cells significantly limits the effectiveness of iron metabolism therapy. Herein, bioactive gallium sulfide nanodots (GaS x ), with dual functions of "reprogramming" and "interfering" iron metabolic pathways, were successfully developed for tumor iron metabolism therapy. The constructed GaS x nanodots ingeniously harness hydrogen sulfide (H 2 S) gas, which is released in response to the tumor microenvironment, to reprogram the inherent transferrin receptor 1 (TfR1)-ferroportin 1 (FPN1) iron metabolism axis in cancer cells. Concurrently, the gallium ions (Ga 3+ ) derived from GaS x act as a biochemical "Trojan horse", mimicking the role of iron and displacing it from essential biomolecular binding sites, thereby influencing the fate of cancer cells. By leveraging the dual mechanisms of Ga 3+ -mediated iron disruption and H 2 S-facilitated reprogramming of iron metabolic pathways, GaS x prompted the initiation of a paraptosis-apoptosis hybrid pathway in cancer cells, leading to marked suppression of tumor proliferation. Importantly, the dysregulation of iron metabolism induced by GaS x notably increased tumor cell susceptibility to both chemotherapy and immune checkpoint blockade (ICB) therapy. This study underscores the therapeutic promise of gas-based interventions and metal ion interference strategies for the tumor metabolism treatment.