Functionalized Gold Nano-stars as Chemotherapeutic Drugs Vector for Chemo-and Photothermal Synergistic Therapy of Breast Cancer

Gold nano-stars with average size of 25 nm were prepared using a one-step method simply through mixing of HAuCl4 solution with HEPES buffer (pH 7. 4). UV. Vis spectroscopy measurement result showed that the absorption peak of the nano. stars was 750 nm. The 16. mercaptohexadecanoic acid (C(16)H(32)O(2)s) was conjugated to the gold nano. stars through Au. S bond, and then doxorubicin (DOX) was loaded onto C16H32O2S through hydrophobic interaction. The absorption peak of the nanomaterial was red shifted to 800 nm and a characteristic peak of DOX at 480 nm occurred. Next, bovine serum albumin (BSA) was coated onto the surface of the nanomaterials to increase their stability and biocompatibility. Accordingly, the absorption peak was red shifted to 806 nm with an increase of the particle size measured by DLS, which indicated that BSA was successfully wrapped onto the drug. loaded nano. stars. The as-synthesized nanocomposites were added into the breast cancer cells (MCF-7) to explore the effect of chemo. and photothermal synergistic therapy. The cell viability analysis results showed that pure laser irradiation had no significant effects on cell viability. Nanomaterials without loaded DOX only decreased the cell viability by 15%, which indicated the low cytotoxicity of the drug delivery vector. With the addition of above vector with DOX and laser irradiation, the cell survival rate decreased to 25% compared with the negative control, while the survival rate of the cells was kept 70% after being incubated with the same concentration of free DOX and irradiated with same power density of laser. The above results demonstrated that the as. prepared DOX. loaded nano-stars realized chemo-and photothermal synergistic therapy of breast cancer (MCF-7) with an enhanced therapeutic efficiency.