Biomaterial-assisted photoimmunotherapy for cancer

With the development of phototherapy, which is a type of light-induced cancer treatment, various biomaterials have been well designed as photoabsorbing/sensitizing agents or effective carriers to enhance the therapeutic efficacy and evade the side effects of phototherapy. In recent years, the immunological responses induced by phototherapy have been widely explored, which are mainly triggered by the tumor associated antigens (TAAs) released from the dying cancer cells after phototherapy, together with the secretion of damage associated molecular patterns (DAMPs) and various pro-inflammatory cytokines/factors. To amplify these immunological responses induced by phototherapy, various adjuvant nano/micromaterials are introduced to boost the immune system to recognize and kill cancer cells. Moreover, such immune responses are further demonstrated to work in synergy with other immunotherapies such as immune checkpoint blockade (ICB), chimeric antigen receptor (CAR)-T cell and cytokine therapy, achieving significantly increased immune response rates and successful therapeutic outcomes. Here, this minireview will focus on the recent progress in engineering biomaterials for enhanced photoimmunotherapy and discuss the challenges, opportunities and future prospects in this field.