Multifunctional inorganic nanomaterials for cancer photoimmunotherapy

Phototherapy and immunotherapy in combination is regarded as the ideal ther-apeutic modality to treat both primary and metastatic tumors.Immunother-apy uses different immunological approaches to stimulate the immune system to identify tumor cells for targeted elimination.Phototherapy destroys the pri-mary tumors by light irradiation,which induces a series of immune responses through triggering immunogenic cancer cell death.Therefore,when integrat-ing immunotherapy with phototherapy,a novel anti-cancer strategy called pho-toimmunotherapy(PIT)is emerging.This synergistic treatment modality can not only enhance the effectiveness of both therapies but also overcome their inherent limitations,opening a new era for the current anti-cancer therapy.Recently,the advancement of nanomaterials affords a platform for PIT.From all these nanomaterials,inorganic nanomaterials stand out as idealmediators in PIT due to their unique physiochemical properties.Inorganic nanomaterials can not only serve as carriers to transport immunomodulatory agents in immunotherapy owing to their excellent drug-loading capacity but also function as photother-mal agents or photosensitizers in phototherapy because of their great optical characteristics.In this review,the recent advances of multifunctional inorganic nanomaterial-mediated drug delivery and their contributions to cancer PIT will be highlighted.