Homologous Tumor Targeting Molybdenum‐Doped Prussian Blue for Enhancing Immunotherapy via PTT/CDT and Remodeled Tumor Immune Microenvironment

Abstract Immunotherapy offers a promising avenue for reducing tumor metastasis and recurrence but faces challenges from the tumor immunosuppressive microenvironment (TIME) and restricted antigen presentation. To address these challenges, this study have developed an innovative approach utilizing molybdenum (Mo)‐doped Prussian blue nanoparticles coated with a cancer cell membrane (CCM), referred to as PMo@CCM. This novel nanoplatform excels in performing photothermal therapy (PTT), while the Mo and Fe components effectively deplete glutathione (GSH) and generate reactive oxygen species (ROS), thereby significantly enhancing chemodynamic therapy (CDT) and remodeling the TIME. The synergistic PTT/CDT approach not only induces tumor immunogenic cell death (ICD) but also facilitates antigen presentation. The CCM coating further supplies antigens and prompts dendritic cell (DC) maturation. This comprehensive strategy markedly enhances the effectiveness of immunotherapy, as evidenced by a significant increase in T cell activation. Moreover, the use of programmed cell death protein 1 antibodies (anti PD‐1) effectively blocks the PD‐1 immune checkpoint pathway. RNA sequencing analysis has identified genes associated with the observed substantial reduction in tumor growth. In conclusion, the PMo@CCM nanoplatform enables homologously targeted tumor synergistic therapy, guided by photothermal and magnetic resonance imaging (PTI&MRI), significantly impeding the progression of both primary and metastatic tumors.