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

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.

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.

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.