Bottom-Up Synthesis of Metal-Ion-Doped WS2 Nanoflakes for Cancer Theranostics

摘要

Recently, two-dimensional transition metal dichalcogenides (TMDCs) have received tremendous attention in many fields including biomedicine. Herein, we develop a general method to dope different types of metal ions into WS2 nanoflakes, a typical class of TMDCs, and choose Gd3+-doped WS2 (WS2:Gd3+) with polyethylene glycol (PEG) modification as a multifunctional agent for imaging-guided combination cancer treatment. While WS2 with strong near-infrared (NIR) absorbance and X-ray attenuation ability enables contrasts in photoacoustic (PA) imaging and computed tomography (Cr), Gd3+ doping offers the nanostructure a paramagnetic property for magnetic resonance (MR) imaging. As revealed by trimodal PA/CT/MR imaging, WS2:Gd3+-PEG nanofiakes showed efficient tumor homing after intravenous injection. in vivo cancer treatment study further uncovered that WS2:Gd3+-PEG could not only convert NIR light into heat for photothermal therapy (PTT) but also enhance the ionizing irradiation-induced tumor damage to boost radiation therapy (RI). Owing to the improved tumor oxygenation after the mild PTT, the combination of PTT and RI induced by WS2:Gd3+-PEG resulted in a remarkable synergistic effect to destroy cancer. Our work highlights the promise of utilizing inherent physical properties of TMDC-based nanostructures, whose functions could be further enriched by elementary doping, for applications in multimodal bioimaging and synergistic cancer therapy.