Objective      To determine the effect of graphene oxide (GO) on the cell viability of human embryonic stem cells (hESCs)-derived retinal pigmental epithelial (RPE) cells.       Methods      RPE cells were derived from hESCs via natural differentiation. After identification by immunofluorescence assay and transmission electron microscope (TEM)

hESCs-derived RPE cells were co-cultured with 0

12.5

25

50 and 100 μg/mL GO for 24 h. Cell viability was tested by CCK-8 kit. Reactive oxygen species (ROS) was tested with DCFH-DA probe.       Results      hESCs-derived RPE cells showed a classical paving-stone shaped morphology with tight connections between the cells and abundant pigment particles in the cytoplasma. Immunofluorescence assay showed that RPE cells expressed the early- and late-stage markers as well as tight junction markers. Besides

RPE cells showed the ability to phagocytize the outer segment of photoreceptors. RPE cells were arranged in a single layer

and the microvilli were observed by TEM. CCK-8 assay showed no significant difference among different groups. ROS had no statistically significant difference among the treatment groups and the control group. With an atomic force microscope

GO solution was proved to be monolayer. The results of ultraviolet-visible spectrophotometry and Raman spectrometry showed that after strong oxidation of graphene

the original ordered structure had been broken

with production of large amount of defect and unordered structure.       Conclusion      GO has considerate biocompatibility with hESCs-derived RPE cells

which implies that GO is the potential nano-carrier for RPE cells.