“Triple-Hop” nano-bomb combining CDT, PDT and immunetherapy for NIR-triggered cancer therapy

The development of non-interventional combination therapy with immune activation property provides a potential direction for solving the diversity, complexity and heterogeneity of malignant tumors. However, how to induce satisfactory immune activation by non-interventional treatment remains a great challenge. Herein, a "Triple-Hop" nano-bomb UCNPs@SiO2-psoralen-K2FeO4@lauric acid-RGD (USPFLR), was prepared and "detonated" after three steps. For step one, with NIR light as the "ignition" signal, USPFLR promoted the tumor to reach 40℃ and the phase transition of Lauric acid (LA) induced the release of K2FeO4 and psoralen, triggering H2O2/GSH depletion and ·OH /O2 production through multi-step cascade reactions of K2FeO4 and psoralen-involved photodynamic therapy (PDT). For step two, high ROS release and direct DNA damage caused by psoralen further significantly triggered ferroptosis pathway and cGAS-STING pathway, which promoted the maturation of dendritic cells (DCs) and induced immune activation and immune memory in the third step. Therefore, through the first step of O2 supply, GSH consumption and ROS generation, the second step of the activation of the ferroptosis pathway and cGAS-STING pathway and the third step of immune activation and immune memory, USPFLR nano-bombs successfully realized the "Triple-Hop" anti-tumor strategy, providing a referential application paradigm for tumor eradication and prevention of tumor recurrence.