Comparative Effects of Graphene and Molybdenum Disulfide on Human Macrophage Toxicity

Graphene and other 2D materials, such as molybdenum disulfide, have been increasingly used in electronics, composites, and biomedicine. In particular, MoS(2)and graphene hybrids have attracted a great interest for applications in the biomedical research, therefore stimulating a pertinent investigation on their safety in immune cells like macrophages, which commonly engulf these materials. In this study, M1 and M2 macrophage viability and activation are mainly found to be unaffected by few-layer graphene (FLG) and MoS(2)at doses up to 50 mu g mL(-1). The uptake of both materials is confirmed by transmission electron microscopy, inductively coupled plasma mass spectrometry, and inductively coupled plasma atomic emission spectroscopy. Notably, both 2D materials increase the secretion of inflammatory cytokines in M1 macrophages. At the highest dose, FLG decreases CD206 expression while MoS(2)decreases CD80 expression.CathBandCathLgene expressions are dose-dependently increased by both materials. Despite a minimal impact on the autophagic pathway, FLG is found to increase the expression ofAtg5and autophagic flux, as observed by Western blotting of LC3-II, in M1 macrophages. Overall, FLG and MoS(2)are of little toxicity in human macrophages even though they are found to trigger cell stress and inflammatory responses.