Lactate metabolic reprogramming based on LOX/LDHi-Cu NP to enhance copper death in hepatocellular carcinoma cells.

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Background: Cuproptosis—copper-triggered mitochondrial proteotoxicity—has emerged as a promising anti-HCC modality, yet intratumoral lactate accumulation restrains TCA flux and suppresses this death pathway. We therefore engineered a lactate-oxidase/high-density-dopamine–copper nanoplatform (LOX/LDHi-Cu NP) that simultaneously depletes lactate and delivers Cu²⁺ to reprogram tumor metabolism and potentiate cuproptosis. Methods: LOX/LDHi-Cu NP was synthesized via one-step dopamine polymerization with Cu²⁺ chelation; size, zeta potential, and Cu-release kinetics were characterized. In vitro, HepG2 and Huh-7 cells were treated with NPs ± lactate supplementation; lactate, ATP, ROS, mitochondrial membrane potential, and copper-dependent protein aggregation were quantified. Cuproptosis was verified by propidium-iodide staining and rescue with TTM. In vivo, orthotopic HCC-bearing mice received intravenous NPs; tumor lactate, Cu accumulation, ICD markers, and growth inhibition were assessed. Results: LOX/LDHi-Cu NP exhibited uniform nanostructure and acid-responsive copper release; the platform efficiently scavenged lactate, reinstated oxidative phosphorylation, and enabled robust copper-dependent DLAT aggregation, ROS burst, and cuproptotic death in vitro. In orthotopic HCC mice, the nanoplatform selectively accumulated within tumors, markedly lowered intratumoral lactate, evoked immunogenic cell death, and achieved significant tumor suppression without systemic toxicity, collectively demonstrating that lactate-metabolic reprogramming sensitizes hepatocellular carcinoma to cuproptosis. Conclusions: Metabolic reprogramming via LOX/LDHi-Cu NP effectively overcomes lactate-mediated cuproptosis resistance, offering a translatable strategy for potentiating copper-based HCC therapy.