Effect of graphene-based nanomaterials on corneal wound healing in vitro

Graphene-based nanomaterials (GBNs) are widely used due to their chemical and physical properties for multiple commercial and environmental applications. From an occupational health perspective, there is concern regarding the effects of inhalation on the respiratory system, and many studies have been conducted to study inhalation impacts on lung. Similar to the respiratory system, the eyes may also be exposed to GBNs and thus impacted. In this study, immortalized human corneal epithelial (hTCEpi) cells and rabbit corneal fibroblasts (RCFs) were used to investigate the toxicity of eight types of GBN: graphene oxide (GO; 400nm), GO (1μm), partially reduced graphene oxide (PRGO; 400nm), reduced graphene oxide (RGO; 400nm), RGO (2μm), graphene (110nm), graphene (140nm), and graphene (1μm). We next examined the effects of these GBNs on hTCEpi cell migration. We also determined whether the expression of α-smooth muscle actin (αSMA), a myofibroblast marker, is altered by the GBNs using RCFs. We found that RGO (400nm) and RGO (2μm) were highly toxic to hTCEPi cells and RCFs meanwhile, PRGO (400nm) was toxic only to hTCEpi cells. In addition, PRGO (400nm), RGO (400nm), and RGO (2μm) inhibited hTCEpi cell migration and significantly increased αSMA mRNA expression. Further study in vivo is required to determine if RGO nanomaterials delay corneal epithelial healing and induce scar formation.