Low Cytotoxicity and Genotoxicity of Two-Dimensional MoS₂ and WS₂

Abstract

Atomically thin transition-metal dichalcogenides (TMDs) have attracted considerable interest because of their unique combination of properties, including photoluminescence, high lubricity, flexibility, and catalytic activity. These unique properties suggest future uses for TMDs in medical applications such as orthodontics, endoscopy, and optogenetics. However, few studies thus far have investigated the biocompatibility of mechanically exfoliated and chemical vapor deposition (CVD)grown pristine two-dimensional TMDs. Here, we evaluate pristine molybdenum disulfide (MoS 2 ) and tungsten disulfide (WS 2 ) in a series of biocompatibility tests, including live−dead cell assays, reactive oxygen species (ROS) generation assays, and direct assessment of cellular morphology of TMD-exposed human epithelial kidney cells (HEK293f). Genotoxicity and genetic mutagenesis were also evaluated for these materials via the Ames Fluctuation test with the bacterial strain S. typhimurium TA100. Scanning electron microscopy of cultured HEK293f cells in direct contact with MoS 2 and WS 2 showed no impact on cell morphology. HEK293f cell viability, evaluated by both live−dead fluorescence labeling to detect acute toxicity and ROS to monitor for apoptosis, was unaffected by these materials. Exposure of bacterial cells to these TMDs failed to generate genetic mutation. Together, these findings demonstrate that neither mechanically exfoliated nor CVD-grown TMDs are deleterious to cellular viability or induce genetic defects. Thus, these TMDs appear biocompatible for future application in medical devices.

Membrane destruction-mediated antibacterial activity of tungsten disulfide (WS2)

“…41 However, our present study demonstrates a clear antibacterial activity of WS 2 to both E. coli and S. aureus. This apparent discrepancy was rst from the fact that Chae and coworkers used human epithelial kidney cells (HEK293f), 41 i.e. one type of eukaryotic cells, which we also found limited cytotoxicity (more below).…”

Degradation behaviors and mechanisms of MoS2 crystals relevant to bioabsorbable electronics

“…In general, LAGBs have a misorientation angle <~15°, whereas HAGBs have an angle >~15°3 5 . Because of the hexagonal atomic structure of semiconducting MoS 2 in the 2H phase, the misorientation angle ranges from 0°to 60°3 3,36 . The atomic defect structures in MoS 2 grains and GBs greatly affect the mechanical, electrical, and optoelectronic properties of MoS 2 -based devices 35,[37][38][39][40][41][42][43] .…”

Biocompatibility and Nanotoxicity of Layered Two‐Dimensional Nanomaterials

“…In addition to those of exfoliated 2D TMD nanomaterials, the biocompatibility of chemical vapor deposition‐grown pristine TMDs have been increasingly investigated as the physicochemical properties of these two forms of 2D TMDs are fundamentally different, with the exfoliated form being more metallic, instead of semiconducting, as compared to the pristine nanomaterials . As a result, this raises the possibility that different biological effects will be triggered.…”

“…As a result, this raises the possibility that different biological effects will be triggered. In one such report, the nanotoxicity of pristine 2D MoS 2 and WS 2 towards human epithelial kidney cells (HEK293f) and Salmonella typhimurium TA100 bacteria were assessed through a series of examinations, such as fluorescence‐based live‐dead cell, ROS generation, and mutagenic assays . It was discovered that pristine 2D TMDs did not promote high level of ROS generation and were highly biocompatible towards HEK293f cells.…”