Phototherapeutic nanoagents for cancer immunotherapy

Phototherapy, referring to photodynamic/photothermal therapy, has been extensively validated to promote enhanced immunotherapeutic effects by stimulating tumor cell immunogenic death. Photoimmunotherapy has been persistently investigated to establish potent antitumor effects against primary and distant tumors, synchronously eliciting powerful immunological memory effects, thus ultimately preventing and eradicating rechallenged tumors. Phototherapeutic nanoagents play essential roles in ensuring the sufficient efficacy of photoimmunotherapy, which provides a flexible platform to integrate multifunctional types of phototherapy into a single platform. In particular, tailored nanoparticles are available to amplify tumor immunogenicity and to modulate the immunosuppressive tumor microenvironment simultaneously and spatiotemporally for the treatment of cancers. In this review, we summarized commonly adopted strategies to achieve enhanced cancer immunotherapies induced by conventionally designed phototherapeutic nanoagents. We also analyzed the immunotherapeutic performance and characteristics of phototherapy in detail. The manuscript implies our thoughts on the following aspects: directional design of photosensitizing agents, functional construction of nanomedicines, rational modulation of immunotherapy, and augmented phototherapeutic effects.