The potential of nanotechnology for photothermal therapy-based synergistic immunotherapy: a review

With the continuous discovery of new materials and a deeper understanding of tumor diseases, more possibilities have been identified for the delivery of antitumor drugs and the treatment of tumors. Currently, the treatment of tumors is not limited to traditional chemotherapy and radiotherapy. Photothermal therapy (PTT) is a new type of noninvasive therapeutic strategy that has aroused widespread concern. PTT can generate a large amount of heat in a specific external environment to achieve the purpose of tumor ablation. Notably, PTT produces heat to kill tumors. In addition, tumor tissues produce many related molecules, which can submit antigens to stimulate T cells and cause antitumor immunity, a process known as the immunogenic cell death (ICD) effect of the tumor environment. However, relying solely on PTT to induce the ICD effect in tumor tissues is challenging, and the immunosuppressive character of the tumor microenvironment weakens the curative effect. Therefore, it is necessary to combine therapy with PTT to achieve the desired efficacy. Here, this review summarizes recent nanomaterial-based PTT and its concomitant ICD, discusses how to amplify the effect of ICD and combines immunotherapy with cotherapy to carry out antitumor research, and finally looks forward to the prospect of PTT combination therapy for tumor treatment.