Recent Advances in Engineering Nanomedicines for Second Near-Infrared Photothermal-Combinational Immunotherapy

Immunotherapy has emerged as one of the major strategies for cancer treatment. Unlike conventional therapeutic methods, immunotherapy can treat both primary and distant metastatic tumors through triggering systematic antitumor immune responses and can even prevent tumor recurrence after causing the formation of immune memory. However, immunotherapy still has the issues of low patient response rates and severe immune-related adverse events in clinical practices. In this regard, the combination of nanomedicine-mediated therapy with immunotherapy can modulate a tumor immunosuppressive microenvironment and thus amplify antitumor immunity. In particular, second near-infrared (NIR-II) photothermal therapy (PTT), which utilizes light conversions to generate heat for killing cancer cells, has shown unique advantages in combining with immunotherapy. In this review, the recent progress of engineering nanomedicines for NIR-II PTT combinational immunotherapy is summarized. The role of nanomedicine-mediated NIR-II PTT in inducing immunogenic cell death and reprogramming the tumor immunosuppressive microenvironment for facilitating immunotherapy are highlighted. The development of NIR-II-absorbing organic and inorganic nonmetal and inorganic metal nanomedicines for the NIR-II PTT combinational immunotherapy of cancer is also introduced in detail. Lastly, the current challenges and future perspectives of these nanomedicines for combinational immunotherapy are proposed.