Metabolic regulating enhanced immunological activating nanocomposites for tumor microenvironment normalization and immunotherapy

The mitochondrial energy metabolic reprogramming of tumors leads to the hypoxic, acidic, and immunosuppressive microenvironment. To regulate the reprogrammed mitochondrial energy metabolism and the abnormal tumor microenvironment (TME) intracellularly and extracellularly, herein, we purposely constructed the metabolic regulating and immunological activating nanocomposites (NCs) formed by the manganese dioxide (MnO₂) nanoparticles loaded with lactate oxidase (LOX), dichloroacetic acid (DCA) and SR-717, camouflaged by the cell membrane of tumors. After the NCs targeting to the tumors, the loaded DCA inhibited the glycolysis and triggered the produced pyruvate into mitochondria for further degradation. DCA also reduced the amount of CD39 and CD73, thereby promoting the accumulation of ATP intracellularly. The cascade of MnO₂ and LOX catalyzed the lactate to pyruvate together with oxygen for the relief of the hypoxic and immunosuppressive TME. The regulation of the mitochondrial metabolism together with the degradation of lactate contributed to activating the immune cells. Meanwhile, the loaded SR-717 together with the release of Mn²⁺ activated the cyclic guanosine monophosphate adenosine monophosphate synthase/interferon gene stimulator signaling pathway for efficient antitumor effects and immunotherapy. Taken together, the designed multifunctional nanocomposites realized an effective tumor immunotherapy by regulating the reprogrammed mitochondrial energy metabolism intracellularly, relieving the abnormal TME and activating the innate antitumor immunological effects extracellularly. Our work established an approach to the enhanced immunotherapy by regulating the reprogrammed metabolism for efficient cancer treatment.