Evaluating the cytotoxicity of graphene oxide using embryonic stem cells-derived cells

Graphene oxide (GO) has several potential biomedical applications and therefore cytotoxic evaluation of GO is very important. However, the two most common in vitro models for testing cytotoxicity-primary human cells and immortalized cell lines-suffer serious limitations, namely limited supplies of cells and unrealistic cellular responses, respectively. Here, we demonstrate the use of embryonic stem cell (ESC)-derived cells to study GO cytotoxicity. We tested the use of retinal pigment epithelium (RPE) cells derived from three-dimensional human ESC cultures ("ESC-RPE" cells) as a model of GO cytotoxicity by exposing them to varying concentrations of GO nanosheets. For comparison, we also performed the same test with primary human retinal pigment epithelium cells ("hRPE"), and with cells derived from a human RPE cell line ("ARPE19" cells). We found that cytotoxicity metrics (viability, apoptosis, intracellular reactive oxygen species, and mitochondrial membrane potential) were very similar in ESC-RPE cells and hRPE cells, and those in ARPE19 cells were very different. We conclude that cell models of GO cytotoxicity derived from ESCs are an excellent alternative to primary human cells, without the limitations of tissue availability.