Tumor Microenvironment-Responsive Hydrogen-Generating Zn-Doped ReZIF-8 Nanoplatform for Enhanced Tumor Suppression.

Hydrogen-based tumor therapy demonstrates therapeutic potential, while the efficacy remains limited by insufficient intracellular hydrogen generation, poorly controlled release kinetics, and inadequate immune response potentiation. To address these limitations, a partially reduced zinc-doped zeolitic imidazolate framework-8 (ReZIF-8) is developed, functioning as a dual-functional nanoplatform for both intracellular hydrogen generation and controlled Zn(II) ions (Zn²⁺) overload. The cationic surface charge of ReZIF-8 enhances cellular internalization, while its pH-responsive properties facilitate controlled intracellular hydrogen gas (H₂) release. The accumulated H₂ and Zn²⁺ overload act synergistically to disrupt redox homeostasis in tumor cells, inducing reactive oxygen species (ROS)-dependent immunogenic cell death (ICD). This ICD activation robustly stimulates innate immune responses and enhances antigen cross-presentation. Intratumoral administration of ReZIF-8 in a B16F10 melanoma mouse model elicits potent antitumor efficacy via intracellular H₂-triggered terminal differentiation and cell cycle arrest. The therapeutic effect is further enhanced in combination with αPD-1 immune checkpoint blockade, resulting in extended survival and significant suppression of metastatic progression, highlighting its translational potential. The ReZIF-8-mediated H₂-generating nanoplatform reprograms intratumoral redox balance to simultaneously induce ICD, amplify antitumor immunity, and drive terminal differentiation. This triple-pronged mechanism leverages synergistic modulation to achieve comprehensive tumor control.