Radiosensitive core/satellite ternary heteronanostructure for multimodal imaging-guided synergistic cancer radiotherapy.

Developing safe, effective and targeting radiosensitizers with clear action mechanisms to achieve synergistic localized cancer treatment is an important strategy for radiotherapy. Herein, we design and synthesize a ternary heteronanostructure radiosensitizer (SeAuFe-EpC) with core/satellite morphology by a simple method to realize multimodal imaging-guided cancer radiotherapy. The mechanistic studies reveal that Se incorporation could drastically improve the electrical conductivity and lower the energy barrier between the three components, resulting in more electrons transfer between Se-Au interface and migration over the heterogeneous junction of Au-Fe3O4 NPs interface. This synergistic interaction enhanced the energy transfer and facilitated more excited excitons generated by SeAuFe-EpC NPs, thus promoting the transformation of 3O2 to 1O2via resonance energy transfer, finally resulting in irreversible cancer cell apoptosis. Additionally, based on the X-ray attenuation ability and high NIR absorption of AuNPs and the superparamagnetism of Fe3O4, in vivo computer tomography, photoacoustic and magnetic resonance tri-modal imaging have been employed to visualize the tracking and targeting ability of the NPs. As expected, the NPs specifically accumulated in orthotopic breast tumor area and achieved synergistic anticancer efficacy, but showed no toxic side effects on main organs. Collectively, this study sheds light on the potential roles of core/satellite heteronanostructure in imaging-guided cancer radiotherapy.