Targeted photothermal therapy of melanoma in C57bl/6 mice using Fe₃ O₄ @Au core-shell nanoparticles and near-infrared laser

Background: Gold nanoshells can be tuned to absorb a particular wavelength of light. As a result, these tunable nanoparticles (NPs) can efficiently absorb light and convert it to heat. This phenomenon can be used for cancer treatment known as photothermal therapy. In this study, we synthesized Fe₃ O₄ @Au core-shell NPs, magnetically targeted them towards tumor, and used them for photothermal therapy of cancer. Objective: The main purpose of this research was to synthesize Fe₃ O₄ @Au coreshell NPs, magnetically target them towards tumor, and use them for photothermal therapy of cancer. Material and Methods: In this experimental study, twenty mice received 2 × 10⁶ B16-F10 melanoma cells subcutaneously. After tumors volume reached 100 mm³,the mice were divided into five groups including a control group, NPs group, laser irradiation group, NPs + laser group and NPs + magnet + laser group. NPs were injected intravenously. After 6 hours, the tumor region was irradiated by laser (808 nm, 2.5 W/cm², 6 minutes). The tumor volumes were measured every other day. Results: The effective diameter of Fe₃ O₄ @Au NPs was approximately 37.8 nm. The average tumor volume in control group, NPs group, laser irradiation group, NPs + laser irradiation group and NPs + magnet + laser irradiation group increased to 47.3, 45.3, 32.8, 19.9 and 7.7 times, respectively in 2 weeks. No obvious change in the average body weight for different groups occurred. Conclusion: Results demonstrated that magnetically targeted nano-photothermal therapy of cancer described in this paper holds great promise for the selective destruction of tumors.