Aqueous phase preparation of ultrasmall MoSe₂ nanodots for efficient photothermal therapy of cancer cells

Abstract

Photothermal therapy (PTT) is a promising cancer treatment with both high effectiveness and fewer side effects. However, an ideal PTT agent not only needs strong absorption of near-infrared (NIR) light and high photothermal conversion efficiency, but also needs good biocompatibility, stability, and small size, which makes the design and preparation of a novel PTT agent a great challenge. In this work, we developed an ultrasonication-assisted liquid exfoliation method for the direct preparation of ultrasmall (2-3 nm) MoSe2 nanodots (NDs) in aqueous solution and demonstrated their superior properties as a PTT agent. The as-prepared MoSe2 NDs have strong absorption of NIR light and high photothermal conversion efficiency of about 46.5%. In vitro cellular experiments demonstrate that MoSe2 NDs have negligible cytotoxicity and can efficiently kill HeLa cells (human cervical cell line) under NIR laser (785 nm) irradiation.

Liquid Exfoliation of Colloidal Rhenium Disulfide Nanosheets as a Multifunctional Theranostic Agent for In Vivo Photoacoustic/CT Imaging and Photothermal Therapy

“…In the absence of PVP or utilizing the water as an alternative to NMP, only very light brown dispersions were obtained, suggesting ultralow exfoliation efficiency. Hence, compared with previous liquid exfoliation methods for TMDs the exfoliation method adopted in this work has several obvious merits: (1) the introduction of PVP can both improve the biocompatibility and the stability in physiological environment and enhance the exfoliation efficiency to obtain high‐yield production of ReS 2 dispersions; (2) the concept of “continual” exfoliation is realized, thus not only making full use of raw materials but also greatly reducing the exfoliation time from 7 to 2 h, (3) medium‐speed rather than relatively low‐speed centrifugation (usually <3000 rpm) was adopted for the remove of unexfoliated TMDs flakes, ensuring the obtained ReS 2 nanosheets are highly well‐dispersed. This simple and efficient liquid exfoliation method may facilitate the application of PVP‐capped ReS 2 nanosheets in biomedical fields.…”

Advanced Near‐Infrared Light‐Responsive Nanomaterials as Therapeutic Platforms for Cancer Therapy

“…PTT using small TMDC nanodots from MoSe 2 was demonstrated by Yuwen et al [202] MoSe 2 nanodots with an average particle size of 2.3 nm were produced via ultrasonication of bulk MoSe 2 with Pluronic F127 as the surfactant. These MoSe 2 nanodots possessed direct bandgap absorption peak around 800 nm, with an extinction coefficient of 17.4 L g −1 cm −1 at 808 nm and a photothermal conversion efficiency of 46.5%.…”

Design, Synthesis, and Surface Modification of Materials Based on Transition‐Metal Dichalcogenides for Biomedical Applications

“…The liquid‐based intercalation and exfoliation method (the top‐down approach) includes solution‐based exfoliation and chemical (ion) intercalation–exfoliation. Sonication‐assisted exfoliation in a liquid phase is the most widely used technique for preparation of 0D TMDCs . For example, highly catalytic MoS 2 nanodots were synthesized in N , N ‐dimethylformamide solution with the assistance of ultrasonication from bulk MoS 2 powders .…”