Monitoring proliferation and neurogenic differentiation of rADSCs on graphene-derivative substrates

Graphene and its derivatives, along with adipose-derived stem cells (ADSCs), have demonstrated great potential to be used in neuron tissue engineering. ADSCs from rats (rADSCs) were first isolated and the surface markers were evaluated using flow cytometry. The rADSCs were fibroblast-like, positively expressed CD90 and CD105, lacked surface markers CD31, CD34 and CD45, and also showed adipogenic and osteogenic differentiation potentials. Graphene oxide (GO) and reduced graphene oxide (rGO) substrates were successfully fabricated. Based on X-ray photoelectron spectroscopy spectra, it was found that GO had more oxygen containing groups than rGO. On these substrates, rADSCs were spread; they proliferated very well and no cytotoxicity was observed. For GO, better organized actin in rADSCs was observed than that on rGO, which was probably due to the higher amount of oxygen in GO. After neurogenic induction, it was found that rADSCs transformed from a fibroblast-like to a spindle-like morphology when observed under a light microscope and scanning electron microscopy, and still no cytotoxic effect was found. Furthermore, immunofluorescence staining showed that neural-specific markers MAP2 and NeuN were detected in cells on these substrates. Both GO and rGO substrates were cytocompatible for rADSCs and rGO was probably more prominent in enhancing neurogenic differentiation.