Investigation of oral toxicity of WS2 nanosheets to mouse intestine: Pathological injury, trace element balance, lipid profile changes, and autophagy.

The success of graphene oxides has gained extensive research interests in developing novel 2D nanomaterials (NMs). WS₂ nanosheets (NSs) are novel transition metal-based 2D NMs, but their toxicity is unclear. In this study, we investigated the oral toxicity of WS₂ NSs to mouse intestines. Male mice were administrated with vehicles, 1, 10, or 100 mg/kg NSs via intragastric route, once a day, for 5 days. The results indicate that the NSs did not induce pathological or ultrastructural changes in intestines. There were minimal changes of trace elements that the exposure did not induce W accumulation, and only Co levels were dose-dependently increased. Lipid droplets were observed in all groups of mice, but lipidomics data indicate that WS₂ NSs only significantly decreased four lipid species, all belonging to phosphatidylcholine (PC). The levels of proteins regulating autophagic lipolysis, namely, LC3, lysosomal associated membrane protein 2 (LAMP2) and perilipin 2 (PLIN2), were increased, but it was only statistically significantly different for LC3. The results of this study suggest that repeated intragastric exposure to WS₂ NSs only induced minimal influences on pathological injury, trace element balance, autophagy, and lipid profiles in mouse intestines, indicating relatively high biocompatibility of WS₂ NSs to mouse intestine via oral route.