Carbon quantum dots as drug carriers for tumor-associated macrophage repolarization following photothermal therapy

With the development of nanotechnology in the anticancer application, photothermal therapy (PTT) based on nanoparticles (NPs) could repolarize the tumor-associated macrophages (TAMs) from protumor (M2) phenotype to antitumor (M1) phenotype, thus regulating the tumor-suppressive immune environment. However, the inevitable local inflammation occurred in the residual tumor microenvironment after PTT recruited abundant abnormal TAMs to induce immune escape and survival of the remaining tumor cells. Here, TMP195 loaded carbon quantum dots (CQDs@TMP195) were developed as innovative nanoplatforms to achieve promising PTT and immune responses. In the nanoplatforms, CQDs with distinct antitumor performance were applied as an ideal drug-loading nanocarrier and initiated photothermal effects to generate heat under near-infrared (NIR) irradiation. The loaded TMP195 could repolarize the M2 phenotype TAMs into the M1 phenotype TAMs. Based on our work, the in vitro antitumor effects implied that CQDs@TMP195 could significantly kill cancer cells with minimal toxicity to normal cells. This study proposes a feasible therapeutic strategy for polarizing TAMs to the immunocompetent M1 phenotype after PTT.