Mesoporous manganese nanocarrier target delivery metformin for the co-activation STING pathway to overcome immunotherapy resistance.

Targeting the stimulator of interferon genes (STING) pathway is a promising strategy to overcome primary resistance to immune checkpoint inhibitors in non-small cell lung cancer with the STK11 mutation. We previously found metformin enhances the STING pathway and thus promotes immune response. However, its low concentration in tumors limits its clinical use. Here, we constructed high-mesoporous Mn-based nanocarrier loading metformin nanoparticles (Mn-MSN@Met-M NPs) that actively target tumors and respond to release higher concentration of Mn ions and metformin. The NPs significantly enhanced the T cells to kill lung cancer cells with the STK11 mutant. The mechanism shows that enhanced STING pathway activation promotes STING, TBKI, and IRF3 phosphorylation through Mn ions and metformin release from NPs, thus boosting type I interferon production. , NPs in combination with a PD-1 inhibitor effectively decreased tumor growth. Collectively, we developed a Mn-MSN@Met-M nanoactivator to intensify immune activation for potential cancer immunotherapy.