Facile synthesis of multifunctional Fe3O4@SiO2@Au magneto-plasmonic nanoparticles for MR/CT dual imaging and photothermal therapy

Abstract

Magneto-plasmonic nanoparticles have exhibited great potential in cancer diagnosis and therapy because of their excellent magnetic and optically activable plasmonic properties. However, it is still a great challenge to combine these two components in one single-nanoparticle. In this work, we developed a facile method to synthesize monodispersed and uniform theranostic agents of Fe₃O₄@SiO₂@GNSs–PEG (PMGNSs) nanoparticles. The as-synthesized PMGNSs composed of a superparamagnetic Fe₃O₄ inner core, silica as the midlayer and coated with gold nanoshells at the outside, with uniform size distribution of less than 100 nm. It has been demonstrated to be with excellent magnetic resonance (MR) and computed tomography (CT) imaging contrast abilities at different concentrations. Meanwhile, the as-synthesized PMGNSs exhibited high stability with no significant change of photothermal performance after five laser ON/OFF cycles, and high photothermal conversion ability with temperature increase of 40 °C under 808 nm laser irradiation at 2 W cm⁻² for 10 min at the concentration of 160 μg ml⁻¹. Furthermore, in vitro photothermal therapy ability has also been demonstrated on HePG2 cancer cells.