Multi-Layer Graphene Oxide in Human Keratinocytes: Time-Dependent Cytotoxicity, Proliferation, and Gene Expression

Few-layer graphene oxide (GO) has shown no or very weak cytotoxicity and anti-proliferative effects in a wide range of cell lines, such as glioma cells and human skin HaCaT cells at concentrations up to 100 mu g/mL. However, as multi-layer GO has hardly been explored in the biomedical field, in this study, this other type of GO was examined in human keratinocyte HaCaT cells treated with different concentrations, ranging from 0.01 to 150 mu g/mL, for different periods of time (3, 12, and 24 h). The results revealed a time-concentration dependence with two non-cytotoxic concentrations (0.01 and 0.05 mu g/mL) and a median effective concentration value of 4.087 mu g/mL at 24 h GO exposure. Contrary to what has previously been reported for few-layer GO, cell proliferation of the HaCaT cells in contact with the multi-layer GO at 0.01 mu g/mL showed identical proliferative activity to an epidermal growth factor (1.6-fold greater than the control group) after 96 h. The effects of the multi-layer GO on the expression of 13 genes (SOD1, CAT, MMP1, TGFB1, GPX1, FN1, HAS2, LAMB1, LUM, CDH1, COL4A1, FBN, and VCAN) at non-cytotoxic concentrations of GO in the HaCaT cells were analyzed after 24 h. The lowest non-cytotoxic GO concentration was able to upregulate the CAT, TGFB1, FN1, and CDH1 genes, which confirms multi-layer GO's great potential in the biomedical field.

Automated summary

The study revealed that multi-layer graphene oxide shows time-concentration dependence and has potential biomedical applications in human keratinocyte cells. Compared to few-layer graphene oxide, multi-layer graphene oxide at non-cytotoxic concentrations had positive effects on gene expression in HaCaT cells.