Integration of immunogenic activation and immunosuppressive reversion using mitochondrial-respiration-inhibited platelet-mimicking nanoparticles.

Here, we developed platelet membranes (PM) as nano-carriers to co-encapsulate metformin (Met) and IR780 (PM-IR780-Met NPs). The resulting nano-carrier ensured a longer circulation lifetime and facilitated the greater accumulation of IR780 and Met in tumors owing to the active adhesion between PM and tumor cells. As a photodynamic therapy (PDT) agent, IR780 could effectively kill the tumor by producing toxic reactive singlet oxygen species (ROS), while the introduction of Met inhibited mitochondrial respiration and reduced tumor oxygen consumption, thereby evoking an oxygen-boosted PDT and propelling the immunogenic cell death (ICD)-based immunogenic pathway. Meanwhile, the reversed tumor hypoxia also impeded the myeloid derived suppressor cell (MDSC)-regulated immunosuppressive pathway. Finally, tremendous T cells were recruited and activated, providing a promising platform to eliminate the primary tumors and synchronously opening a new avenue for the effective ablation of tumor metastasis.