The dynamic therapeutic effect of a targeted photothermal nanovaccine incorporating toll-like receptor 7 agonist enhanced cancer immunotherapy

Photothermal therapy (PTT) is a noninvasive and effective thermal therapeutic approach. Near-infrared (NIR) light responsive organic nanoparticles (NPs) have been shown to enhance the efficacy of cancer PTT. However, photothermal ablation induced NPs are currently more effective in treating primary and metastatic cancer. Herein, we designed a NIR light responsive theranostic nanosystem that combines PTT with immunotherapy. The caffeic acid doped polyaniline NPs (CA-PANi) were explored for their potential as PTT agents and their ability to mediate immunogenic cell death (ICD). The nano-theranostic agent of CA-PANi functionalized with the RGD (Arg-Gly-Asp) peptide plays a functional role in targeting integrin receptor overexpressed cancer cells. Furthermore, to enhance the immune response in the immune suppressive tumor microenvironment (iTME), imiquimod (R837) a Toll-like receptor 7 agonist that can promote dendritic cell (DC) maturation greatly inhibits tumor growth and tumor recurrence by initiating a strong antitumor immune response. Therefore, combination of PTT and immunotherapy involving CA-PANi-R837-RGD (denoted as CPRR) to improve the therapeutic effect will provide a nanovaccine strategy for targeted antitumor therapy.