Synthesis And Photothermal Therapy Application Of Transition Metal Disulfides （MoS₂, WS₂） Nanomaterials

Photothermal therapy, a new therapeutic method emerged for the past decades, have aroused mounting attention in the field of cancer treatment due to its numerous advantages such as high accuracy and noninvasion. In order to achieve high efficient photothermal therapy, various photothermal agents were developed based on nanomaterial which can transform laser energy into heat. Transition metal disulfide (TMD), a branch of semiconductor materials with broad near-infrared (NIR) absorbance and low cytotoxicity, are getting extensive attention as potential photothermal agents. Herein, this thesis concentrate on fabrication of TMDs materials with preeminent properties, and apply them to photothermal therapy. The main content is summarized as follow:1. MoS2 nanoparticles with radar-like shape were synthesized through a facile and surfactant-free hydrothermal method using sodium molybdate and thioacetamide as material. The as-synthesized MoS2 nanoparticles exhibit good hydrophilicity and NIR absorbance, and the size is around 150 nm. This radar-like shape is influenced by material, reaction time and solvent according to our study. On the other hand, sub-3 nm-size WS2 quantum dots (QDs) were demonstrated using solvent exfoliation, and then modified by cysteine for further biological functionalization. The CT vaule of the as synthesized WS2 material indicated its possible application in theranostics.2.MoS2 radar-like nanoparticles (RNPs) were demonstrated as an 808 nm laser induced photothermal agent with outstanding photothermal performance. The radar-like morphology endowed MoS2 nanoparticles with higher photothermal conversion efficiency (53.3%) than other morpologies according to our calculation. Cytotoxicity assay indicated that the radar-like nanoparticles were biocompatible. Results of photothermal therapy in vitro and apoptosis assay indicated that tumor cells treated with MoS2 RNPs can be seriously damaged. Photothermal therapy on tumor-bearing mice was carried out to further verify the anti-cancer properties of MoS2 RNPs. All the aforementioned studies suggested that the MoS2 RNPs exhibit enormous potential in cancer photothermal therapy.