Tungsten Sulfide Quantum Dots as Multifunctional Nanotheranostics for in Vivo Dual-Modal Image-Guided Photothermal/Radiotherapy Synergistic Therapy

Designing a multifunctional nanomedicine for integration of precise diagnosis and effective treatment of tumors is desirable but remains a great challenge. Here, we report a multifunctional nanomedicine based on WS₂ quantum dots (QDs), which was prepared by a facile and "green" method through physical grinding and ultrasonication. The as-obtained WS₂ QDs with small size (3 nm) possess not only significant X-ray computed tomography (CT)/photoaccoustic (PA) imaging signal enhancement but also remarkable photothermal therapy (PTT)/radiotherapy (RT) synergistic effect for tumor treatment. With CT/PA imaging and the synergistic effect between PTT and RT, the tumor could be accurately positioned and thoroughly eradicated in vivo after intravenous injection of WS₂ QDs. Moreover, hematoxylin and eosin staining, blood hematology, and biochemistry analysis revealed no noticeable toxicity of WS₂ QDs in vitro and in vivo, which confirmed that WS₂ QDs possess good biocompatibility. This multifunctional nanoparticle could play an important role in facilitating simultaneously multimodal imaging and synergistic therapy between PTT and RT to achieve better therapeutic efficacy.