A sequential targeting nanoplatform for anaplastic thyroid carcinoma theranostics.

Effective accumulation of nanoparticles (NPs) in tumor regions is one of the major motivations in nanotechnology research and that the establishment of an efficient targeting nanoplatform for the treatment of malignant tumors is urgently needed for theranostic applications. In this study, we engineered multifunctional sequential targeting NPs for achieving synergistic antiangiogenic photothermal therapy (PTT) and multimodal imaging-guided diagnosis for anaplastic thyroid carcinoma (ATC) theranostics. Antibody bevacizumab with an affinity towards vascular endothelial growth factor (VEGF) on the tumor cell surface was conjugated onto the surface of polymer NPs for VEGF targeting and antiangiogenic therapy. Encapsulated IR825 was employed as a photothermal agent (PTA) with a mitochondrial targeting capability, which further cascades NPs into mitochondria to enhance hyperthermic efficiency in the ablation of tumor cells. Importantly, the combination of bevacizumab and IR825 in a single nanosystem achieved desirable accumulations of NPs and that sequential targeted PTT combined with antiangiogenesis significantly promoted the therapeutic efficiency in eradicating tumors by near-infrared (NIR) laser irradiation. Furthermore, these NPs are extraordinary contrast agents for photoacoustic, ultrasound and fluorescence imaging applications, providing multimodal imaging capabilities for therapeutic monitoring and a precise diagnosis. Therefore, this multifunctional nanoplatform provides a promising theranostic strategy for extremely malignant ATC. STATEMENT OF SIGNIFICANCE: Anaplastic thyroid carcinoma (ATC), with extremely aggressive behavior, lacks a satisfactory therapeutic method and a comprehensive early diagnostic strategy. Herein, we successfully synthesized a sequential targeting nanoplatform (IR825@Bev-PLGA-PFP NPs) with theranostic function, which specifically binds to VEGF on the tumor cell surface and further cascades into mitochondria to achieve effective accumulation of NPs in the tumor regions. As a result, it solves the urgent demand for ATC detection and therapy. By breaking the limitation of traditional target, such as low efficacy and frequent recurrence as the results of low accumulation, sequential targeting combined with synergistic antiangiogenic PTT completely eradicates tumors without any residual tissue and side effect. Therefore, this strategy paves a solid way for further investigation in the theranostic progressing of ATC.