Adjustable Intermolecular Interactions Allowing 2D Transition Metal Dichalcogenides with Prolonged Scavenging Activity for Reactive Oxygen Species

Abstract

There is an increasing demand for control over the dimensions and functions of transition metal dichalcogenides (TMDs) in aqueous solution toward biological and medical applications. Herein, an approach for the exfoliation and functionalization of TMDs in water via modulation of the hydrophobic interaction between poly(ε-caprolactone)-b-poly(ethylene glycol) (PCL-b-PEG) and the basal planes of TMDs is reported. Decreasing the hydrophobic PCL length of PCL-b-PEG from 5000 g mol (PCL ) to 460 g mol (PCL ) significantly increases the exfoliation efficiency of TMD nanosheets because the polymer-TMD hydrophobic interaction becomes dominant over the polymer-polymer interaction. The TMD nanosheets exfoliated by PCL -b-PEG (460-WS , 460-WSe , 460-MoS , and 460-MoSe ) show excellent and prolonged scavenging activity for reactive oxygen species (ROS), but each type of TMD displays a different scavenging tendency against hydroxyl, superoxide, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. A mechanistic study based on electron paramagnetic resonance spectroscopy and density functional theory simulations suggests that radical-mediated oxidation of TMDs and hydrogen transfer from the oxidized TMDs to radicals are crucial steps for ROS scavenging by TMD nanosheets. As-prepared 460-TMDs are able to effectively scavenge ROS in HaCaT human keratinocytes, and also exhibit excellent biocompatibility.

Design of therapeutic biomaterials to control inflammation

“…2D transition-metal dichalcogenides, which are graphene analogues with a flexible sheet-like structure, high surface-to-volume ratio and low toxicity in vivo, have also been explored as ROS scavengers 107 . For example, MoS 2 nanosheets can scavenge ROS and have been investigated for treating oxidative-stress-related diseases 108 , 109 . Similarly, Mo-based polyoxometalate nanoclusters can eliminate detrimental ROS in the treatment of acute kidney injury in mice 110 , 111 .…”

A Review of Transition Metal Dichalcogenides-Based Biosensors

“…The common methods for obtaining two-dimensional TMDCs (2D-TMDCs) monolayers films include mechanical exfoliation, chemical vapor deposition (CVD), and liquid exfoliation approach. Of these methods, 2D-TMDCs nanosheets can be scaled up for production under mild conditions by liquid exfoliation while achieving modification ( Yim et al, 2018 ). For example, the addition of surfactants ( Li et al, 2022b ) in aqueous solution can not only reduce the surface energy of exfoliated 2D-TMDCs nanosheets through intermolecular interactions to achieve effective exfoliation and dispersion of 2D-TMDCs, but also functionalize the surface of 2D-TMDCs nanosheets ( Yim et al, 2018 ).…”

“…Of these methods, 2D-TMDCs nanosheets can be scaled up for production under mild conditions by liquid exfoliation while achieving modification ( Yim et al, 2018 ). For example, the addition of surfactants ( Li et al, 2022b ) in aqueous solution can not only reduce the surface energy of exfoliated 2D-TMDCs nanosheets through intermolecular interactions to achieve effective exfoliation and dispersion of 2D-TMDCs, but also functionalize the surface of 2D-TMDCs nanosheets ( Yim et al, 2018 ). Therefore, this is an approach for the simultaneous exfoliation and functionalization of TMDCs in aqueous solution.…”

Two-dimensional quantum dots for biological applications

“…Li and colleagues [125] constructed the "therapeutic mesopores" on the surface of 2D niobium carbide (Nb 2 C) MXene with the versatile sol-gel chemistry method, which can solve surface engineering. Layered transition metal dichalcogenides are another important member of the 2D material family [17,222,223]. TMD is one of the most popular graphene analogs with excellent physicochemical properties such as large specific surface area [224], fascinating optical property [127], low toxicity [209], good chemical stability [225] as well as a simple synthesis process [226], which exhibit great advantages in tumor imaging and therapy.…”