Chrono-controlled hydrogel platform orchestrates metabolic reprogramming and cuproptosis-driven immune activation...

Triple-negative breast cancer (TNBC) poses significant therapeutic challenges due to its metabolic plasticity and immunosuppressive microenvironment. In this study, we present a sequential drug release hydrogel system (SeqGel) that reprograms tumor metabolism and modulates the immune landscape to suppress TNBC growth and metastasis. The poly(ethylene glycol)-based injectable hydrogel system could enable tunable biodegradation within 48 h to ensure repeated peritumoral administration and localized controlled drug release. Specifically, water-soluble small molecular dichloroacetate is rapidly released to redirect tumor cell metabolism from glycolysis to oxidative phosphorylation, thereby reducing lactic acid accumulation, restricting glucose uptake, and enhancing the susceptibility of cancer cells to mitochondrial damage. This is followed by the sustained release of pH-sensitive, copper complex-loaded polymeric nanoparticles PED@tCu, which facilitates efficient intracellular delivery and targeted mitochondrial localization, specifically impairing the function of complex II. Mechanistically, the ordered metabolic intervention enhances antitumor immunity by activating the AMPK pathway, promoting PD-L1 degradation, and upregulating MHC I to improve antigen presentation. In 4T1 subcutaneous tumor models, SeqGel effectively suppressed tumor growth and markedly reduced lung and lymph node metastases by promoting CD8⁺ T cell infiltration and depleting regulatory T cells. This study establishes a paradigm for metabolic-immune synergy, offering a promising strategy for targeting aggressive cancers through chrono-metabolic immunotherapy.