Polydopamine-Functionalized Graphene Oxide Loaded with Gold Nanostars and Doxorubicin for Combined Photothermal and Chemotherapy of Metastatic Breast Cancer

Breast cancer is the leading cancer type diagnosed in the female population, and cancer metastasis is the main reason for cancer-caused mortality. A novel nanoplatform is herein presented integrating polydopamine-functionalized nanosized reduced graphene oxide (NRGO), gold nanostars (GNS), and doxorubicin (DOX) (denoted as NRGO-GNS@DOX) for combinational treatment of metastatic breast cancer. Upon localized near infrared (NIR) laser irradiation, the NRGO-GNS@DOX nanocomposites induce significant cytotoxicity in 4T1 breast cancer cells due to a cumulative therapy effect of NRGO-GNS-elicited hyperthermia and DOX-induced cytotoxicity. Antitumor studies in orthotopic 4T1 breast tumor-bearing nude mice demonstrate that NRGO-GNS@DOX in combination with NIR laser irradiation inhibit the tumor growth and suppress the lung metastasis. Contribution of DOX-caused apoptosis of the cancer cells and hyperthermia-induced deconstruction of the tumor-associated blood vessels may account for the superior antitumor performance of the NRGO-GNS@DOX nanocomposites. These results imply a good potential of NRGO-GNS@DOX for combined photothermal and chemotherapy of the metastatic cancer.