Bottom-up synthesis of WS2 nanosheets with synchronous surface modification for imaging guided tumor regression

Publication date: Available online 10 June 2017
Source:Acta Biomaterialia
Author(s): Shige Wang, Jiulong Zhao, Hailun Yang, Chenyao Wu, Fei Hu, Haizhou Chang, Guixiang Li, Dan Ma, Duowu Zou, Mingxian Huang
Two-dimensional transition metal dichalcogenides (TMDs) have been receiving great attention as NIR photothermal transducing agent in tumor photothermal therapy. Keeping in mind the low efficiency of the conventional top-down exfoliation method to produce 2D TMDs and the complexity of their surface modifications, we herein proposed a bottom-up strategy for the one-pot and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS2 nanosheets, by hydrothermally treating the mixture solution of tetrathiotungstate and PVP. The material design was based on the chelating-coordinating effect between the lone pair electrons of oxygen belonging to the carbonyl group of PVP and the unoccupied orbital (5d orbitals) of tungsten. The WS2 nanosheets with synchronous surface PVP grafting showed an excellent photothermal conversion performance, while the surface anchored PVP guaranteed its colloidal stability. Moreover, the strong X-ray attenuation ability and near-infrared (NIR) absorbance of WS2-PVP360kDa enable the sensitive in vitro and in vivo computed tomography and photoacoustic imaging. The WS2-PVP360kDa nanosheets were biocompatible and exhibited promising in vitro and in vivo anti-cancer efficacy. Findings in this report may greatly promote the design of colloidal stable and biocompatible 2D TMDs and their future clinical translations.Statement of SignificanceA bottom-up strategy for the one-pot and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS2 nanosheets was proposed for the first time by hydrothermally treating the mixture solution of tetrathiotungstate and PVP. PVP was synchronously graphed on WS2 nanosheets surface owing to the chelating-coordinating effect between the lone pair electrons of oxygen belonging to the carbonyl group of PVP and the unoccupied orbital (5d orbitals) of tungsten. WS2-PVP nanosheets were biocompatible and showed excellent photothermal conversion performance and colloidal stability. WS2-PVP nanosheets exhibited promising computed tomography, photoacoustic imaging and anti-cancer efficacy both in vitro and in vivo.

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