Photo/thermo-responsive and size-switchable nanoparticles for chemo-photothermal therapy against orthotopic breast cancer

Tumor penetration of nanocarriers is still an unresolved challenge for effective drug delivery. Herein, we described a size-switchable nanoplatform in response to an external near-infrared (NIR) laser for transcellular drug delivery. The nanoplatform was constructed with a poly(N-isopropylacrylamide) (PNIPAM)-based nanogel encapsulating chitosan-coated single-walled carbon nanotubes, followed by loading a chemotherapeutic drug, doxorubicin (DOX). In mice bearing orthotopic breast tumors, the photothermal effect from single-walled carbon nanotubes upon NIR irradiation potently inhibited tumor growth. The antitumor effect of the nanomedicine with NIR irradiation might be attributed to its capability of transcellular transport and tumor penetration in mice. In addition, the nanomedicine with NIR irradiation could elicit an antitumor response by increasing cytotoxic T cells and decreasing myeloid-derived suppressor cells. These results validated the application of photo/thermo-responsive nanomedicine in the orthotopic model of breast cancer.