Preparation of superparamagnetic iron oxide nanoparticles conjugated hollow gold nanospheres for MR/CT dual-mode imaging and synergistic photothermal-chemotherapy of cancer

The development of multifunctional nanotheranostics that are safe, stimuli responsive for controlled drug release and possess the capability of precise imaging guided multi-modal synergistic therapy is of great significance for anti-cancer treatment. In this study, a multifunctional DOX-HSP nanocomposite was prepared by conjugating superparamagnetic iron oxide (SPIO) nanoparticles on the surface of DOX loaded hollow gold nanospheres (HGNs) and PEG modification for computed tomography (CT)/magnetic resonance (MR) dual-mode imaging and synergistic photothermal-chemotherapy. The prepared DOX-HSP demonstrated favorable biocompatibility, high drug loading capacity and considerable MR/CT image contrast agent capability. Moreover, on-demand controlled drug release could be achieved by well preventing the premature drug release with the blocking effect of conjugated SPIO nanoparticles in normal physiological environment and triggering drug release with NIR exposure in acidic environment. Furthermore, the in vitro cell experiment revealed that the anti-tumor effect could be significantly enhanced via synergistic photothermal-chemotherapy. Therefore, we believe that the prepared DOX-HSP nanocomposite could provide great potential values for biomedical area, including MR/CT imaging and synergistic cancer photothermal-chemotherapy. • A biosafe and multifunctional DOX-HSP nanocomposite was developed. • The high surface area and negative surface charge of HGNs permitted the remarkable DOX loading capacity. • On-demand controlled drug release could be achieved by the blocking effect of conjugated SPIO nanoparticles and NIR laser irradiation. • Excellent CT/MRI contrast agent capability could be achieved for precise diagnosis and monitoring the treatment efficiency during and after therapy. • The tumor therapeutic efficacy was significantly improved by synergistic photothermal-chemotherapy.