An anisotropic photocatalytic agent elicits robust photoimmunotherapy through plasmonic catalysis-mediated tumor microenvironment modulation

Photoimmunotherapy, which not only directly kills tumor cells but also elicits antitumor immune responses by inducing immunogenic cell death (ICD), has emerged as a promising approach for cancer treatment. However, the hypoxic immunosuppressive tumor microenvironment (TME) with limited immune response immensely compromises the therapeutic outcomes. Herein, an end-deposited plasmonic catalyst (GCNRs) is developed by selectively depositing semiconducting ceria nanosheets onto the two ends of gold nanorods for plasmonic catalysis-mediated TME modulation. Specially, an efficient low-power near-infrared-triggered electron-hole spatial separation along the longitudinal axis of GCNRs occurs due to the end-deposition morphology. The generated hot electrons and hot holes separately participate in the reactive oxygen species (ROS) generation and oxygen-evolution half-reaction, thereby modulating the immunosuppressive TME via concurrent ROS-mediated ICD-induction and H2O2-independent hypoxia relief. Unprecedentedly, mere injection of GCNRs can induce significant infiltration of cytotoxic T cells into tumor tissues, significantly inhibiting the growth and metastasis of tumors. Our study represents a promising plasmonic catalysis-mediated TME modulation strategy in phototherapy-based immuno-oncology.