Fe2O3@Au core@shell nanoparticle–graphene nanocomposites as theranostic agents for bioimaging and chemo-photothermal synergistic therapy

Herein, we present the synthesis and application of a new type of graphene-based magnetic and plasmonic nanocomposite for magnetic-field-assisted drug delivery and chemo-photothermal synergistic therapy. The nanocomposites were prepared via conjugation of the PEGylated Fe2O3@Au core/shell nanoparticles (Fe2O3@Au NPs) with reduced graphene oxide (rGO). The hybrid nanostructures (rGO–Fe2O3@Au NPs) are superparamagnetic and show great photothermal conversion efficiency under 808 nm near-infrared (NIR) laser irradiation and high drug loading ability (1.0 mg mg−1). MTT cell viability assay demonstrates that the chemotherapeutic drug, doxorubicin loaded rGO–Fe2O3@Au NPs (DOX–rGO–Fe2O3@Au NPs) have synergistic interaction between photothermal therapy (PTT) and chemotherapy. Furthermore, in vitro studies using HeLa cells show that the chemo-photothermal therapeutic efficacy of DOX–rGO–Fe2O3@Au NPs can be dramatically improved by the assistance of magnetic-field-guided drug delivery.