How molybdenum disulfide (MoS₂) modulates actin assembly kinetics and NIH-3T3 fibroblast cell morphology and spreading

The actin cytoskeleton is active biological networks that change in response to the cell’s microenvironment allowing for vital functions such as cell motility, division, and maintaining cell morphology. Molybdenum disulfide (MoS₂) is a 2D transition metal dichalcogenide nanomaterial utilized in various biomedical applications due to its biocompatibility, electrochemical, and mechanical properties. The use of MoS₂ in these applications increases the need to determine how these specific nanomaterials influence biological molecule structure and functions. While previous studies have shown the effects of MoS₂ at the cellular level, it is not well established how MoS₂ directly influences the actin cytoskeleton. In this study, we investigate the effects of MoS₂ on actin cytoskeletal dynamics in the cell and determine how MoS₂ modulates actin filament assembly kinetics. Using total internal reflection fluorescence microscopy, we determined how varying concentrations of MoS₂ nanoflakes influence the elongation rate of individual actin filaments. We studied changes in NIH-3T3 mouse fibroblast viability, morphology, and spreading in response to MoS₂ nanomaterials. Our results showed an increase in cell spreading without a significant change in cell viability after MoS₂ treatment. These results indicate that the MoS₂ nanoflakes can modulate the actin cytoskeleton without inducing adverse effects on the cell depending on the concentration, leading to more safe uses of MoS₂ nanomaterials in biomedical applications.