Magnetic field-induced synergistic therapy of cancer using magnetoplasmonic nanoplatform

Combining photothermal and chemotherapy using single nanoplatform is an emerging direction in cancer nanomedicine. Herein, a magnetic field (MF) induced combination of chemo/photothermal therapy is demonstrated using Fe3O4@mSiO2@Au core@shell@satellites nanoparticles (NPs) loaded with chemotherapeutic drug doxorubicin (DOX), both in vitro and in vivo. An application of an external MF to the NPs dispersion causes magnetophoretic movement and aggregation of the NPs. While the synthesized NPs only slightly absorb light at similar to 800 nm, their aggregation results in a significant near infrared (NIR) absorption associated with plasmon resonance coupling between the Au satellites in the NPs aggregates. As a result, the aggregates revealed an enhanced photothermal conversion efficiency (similar to 67 % versus similar to 19 % for NPs in absence of MF) and an enhanced NIR photothermal effect was observed under 808 nm laser irradiation. A combination of the MF induced NIR photothermal therapy (PTT) with DOX chemotherapeutic action resulted in an efficient killing of NPs treated cancer cells in vitro and tumor growth restriction in 4T1-tumor-bearing mice in vivo. Histological studies showed striking differences in development and malignancy between tumors treated with the combination of NPs, MF and an 808 nm laser, and the control treatments, revealing a synergy of the MF-induced NIR PTT and chemotherapy and suggesting a promising strategy for cancer therapy.