BiVO4/Fe3O4@polydopamine superparticles for tumor multimodal imaging and synergistic therapy.

Background: Despite tremendous progress has been achieved in tumor theranostic over the past decade, accurate identification and complete eradication of tumor cells remain a great challenge owing to the limitation of single imaging modality and therapeutic strategy.

Results: Herein, we successfully design and construct BiVO4/Fe3O4@polydopamine (PDA) superparticles (SPs) for computed tomography (CT)/photoacoustic (PA)/magnetic resonance (MR) multimodal imaging and radiotherapy (RT)/photothermal therapy (PTT) synergistic therapy toward oral epithelial carcinoma. On the one hand, BiVO4 NPs endow BiVO4/Fe3O4@PDA SPs with impressive X-ray absorption capability due to the high X-ray attenuation coefficient of Bi, which is beneficial for their utilization as radiosensitizers for CT imaging and RT. On the other hand, Fe3O4 NPs impart BiVO4/Fe3O4@PDA SPs with the superparamagnetic property as a T2-weighted contrast agent for MR imaging. Importantly, the aggregation of Fe3O4 NPs in SPs and the presence of PDA shell greatly improve the photothermal conversion capability of SPs, making BiVO4/Fe3O4@PDA SPs as an ideal photothermal transducer for PA imaging and PTT. By integrating advantages of various imaging modalities (CT/PA/MR) and therapeutic strategies (RT/PTT), our BiVO4/Fe3O4@PDA SPs exhibit the sensitive multimodal imaging feature and superior synergistic therapeutic efficacy on tumors.

Conclusions: Since there are many kinds of building blocks with unique properties appropriating for self-assembly, our work may largely enrich the library of nanomateirals for tumor diagnosis and treatment.