Development of multifunctional cobalt ferrite/graphene oxide nanocomposites for magnetic resonance imaging and controlled drug delivery

Developing multifunctional theranostic platforms with complementary roles has drawn considerable attention in recent years. In this study, superparamagnetic cobalt ferrite/graphene oxide (CoFe2O4/GO) nanocomposites with integrated characteristics of magnetic resonance imaging and controlled drug delivery were prepared by sonochemical method. The morphology, microstructure and physical properties of as-prepared CoFe2O4/GO were investigated in detail by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectra, N-2 adsorption/desorption isotherm, thermogravimetric analysis (TGA), superconducting quantum interference device (SQUID) and zeta potential measurements. The obtained CoFe2O4/GO exhibited superparamagnetic property and dose-dependent T-2-weighted enhancement effect with relaxivity coefficient of 92.71 mM(-1) s(-1). Furthermore, the CoFe2O4/GO showed negligible cytotoxicity even at a high concentration after being treated for 96 h. Doxorubicin hydrochloride (DOX) as an anti-tumor model drug was loaded on CoFe2O4/GO. The nanocomposites were found to be able to efficiently transport DOX into the cancer cells and then cause cell death. The drug loading capacity of this nanocarrier was as high as 1.08 mg/mg and the drug release behavior demonstrated a sustained and pH-responsive way. The results suggested that the as-prepared CoFe2O4/GO showed great potential as an effective multifunctional nanoplatform for magnetic resonance imaging and controlled drug delivery for simultaneous cancer diagnosis and chemotherapy. (C) 2015 Elsevier B.V. All rights reserved.