Differential cytotoxic effects of graphene and graphene oxide on skin keratinocytes

Abstract

Impressive properties make graphene-based materials (GBMs) promising tools for nanoelectronics and biomedicine. However, safety concerns need to be cleared before mass production of GBMs starts. As skin, together with lungs, displays the highest exposure to GBMs, it is of fundamental importance to understand what happens when GBMs get in contact with skin cells. The present study was carried out on HaCaT keratinocytes, an in vitro model of skin toxicity, on which the effects of four GBMs were evaluated: a few layer graphene, prepared by ball-milling treatment (FLG), and three samples of graphene oxide (GOs, a research-grade GO1, and two commercial GOs, GO2 and GO3). Even though no significant effects were observed after 24 h, after 72 h the less oxidized compound (FLG) was the less cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 62.8 μg/mL (WST-8 assay) and 45.5 μg/mL (propidium iodide uptake), respectively. By contrast, the largest and most oxidized compound, GO3, was the most cytotoxic, inducing mitochondrial and plasma-membrane damages with EC50s of 5.4 and 2.9 μg/mL, respectively. These results suggest that only high concentrations and long exposure times to FLG and GOs could impair mitochondrial activity associated with plasma membrane damage, suggesting low cytotoxic effects at the skin level.

An Increase in Membrane Cholesterol by Graphene Oxide Disrupts Calcium Homeostasis in Primary Astrocytes

“…The size of GO sheets determines the toxicity and the inflammatory response in primary macrophages . On the same line, studies conducted on fibroblasts revealed that the cytotoxic potential of GNMs is mainly dependent on the oxidative state, with FLG being significantly less cytotoxic than GO . In primary neurons, exposure to GO and FLG causes very different effects on synaptic plasticity .…”

Graphene oxide induces cytotoxicity and oxidative stress in bluegill sunfish cells

“…Human multiple myeloma cells (RPMI‐8226) treated with 50 μg ml –1 of GO for 24 hours caused minor variation in the morphology of the exposed cells (Wu et al, ). Similarly, the human skin keratinocyte cells (HaCaT) lost their morphology when exposed to GO at 50 μg ml –1 for 72 hours (Pelin et al, ). However, A549 cells exposed to GO at 200 μg ml –1 did not show any detectable changes in their morphology (Chang et al, ).…”

Skin irritation potential of graphene-based materials using a non-animal test

“…8 However, despite the importance of skin exposure and the dermotoxic potential of GBMs, very limited data on the cutaneous toxicity of these materials are currently available. Only few in vitro data regarding the effects on skin fibroblasts 9 and keratinocytes [10][11][12][13] are available, so far. In HaCaT skin keratinocytes, we previously demonstrated that FLG and GO reduced cell viability after interaction with plasma membrane.…”