Treatment of metastatic breast cancer by combination of chemotherapy and photothermal ablation using doxorubicin-loaded DNA wrapped gold nanorods.

Despite the exciting advances in cancer therapy over past decades, tumor metastasis remains the dominate reason for cancer-related mortality. In present work, DNA-wrapped gold nanorods with doxorubicin (DOX)-loading (GNR@DOX) were developed for treatment of metastatic breast cancer via a combination of chemotherapy and photothermal ablation. The GNR@DOX nanoparticles induced significant temperature elevation and DOX release upon irradiation with near infrared (NIR) light as shown in the test tube studies. It was found that GNR@DOX nanoparticles in combination with laser irradiation caused higher cytotoxicity than free DOX in 4T1 breast cancer cells. Animal experiment with an orthotropic 4T1 mammary tumor model demonstrated that GNR@DOX nanoplatform significantly reduced the growth of primary tumors and suppressed their lung metastasis. The Hematoxylin and Eosin (H&E) and immunohistochemistry (IHC) staining assays confirmed that the tumor growth inhibition and metastasis prevention of GNR@DOX nanoparticles were attributed to their abilities to induce cellular apoptosis/necrosis and ablate intratumoral blood vessels. All these results suggested a considerable potential of GNR@DOX nanoplatform for treatment of metastatic breast cancer.