The uptake mechanism and biocompatibility of graphene quantum dots with human neural stem cells

Abstract

Cellular imaging after transplantation may provide important information to determine the efficacy of stem cell therapy. We have reported that graphene quantum dots (GQDs) are a type of robust biological labeling agent for stem cells that demonstrate little cytotoxicity. In this study, we examined the interactions of GQDs on human neural stem cells (hNSCs) with the aim to investigate the uptake and biocompatibility of GQDs. We examined the mechanism of GQD uptake by hNSCs and investigated the effects of GQDs on the proliferation, metabolic activity, and differentiation potential of hNSCs. This information is critical to assess the suitability of GQDs for stem cell tracking. Our results indicated that GQDs were taken up into hNSCs in a concentration- and time-dependent manner via the endocytosis mechanism. Furthermore, no significant change was found in the viability, proliferation, metabolic activity, and differentiation potential of hNSCs after treatment with GQDs. Thus, these data open a promising avenue for labeling stem cells with GQDs and also offer a potential opportunity to develop GQDs for biomedical applications.

pH-Responsive fluorescent graphene quantum dots for fluorescence-guided cancer surgery and diagnosis

“…24–33 We recently showed that GQDs did not affect stem cells viability, proliferation, metabolism and differentiation. 34,35 GQDs have been previously engineered to respond to pH change by us and others. 36,37 Unfortunately, most of these GQDs are responsive to only highly acidic or alkaline conditions at a slow rate and thus not suitable for bioimaging.…”

Glowing Graphene Quantum Dots and Carbon Dots: Properties, Syntheses, and Biological Applications

“…Another study by Yang et al showed that GQDs can penetrate into stem cells without affecting the cellular viability and proliferation capability. A more detailed investigation by Shang et al demonstrated that no significant change in the viability, proliferation, metabolic activity, self‐renewal ability and differentiation potential of human neural stem cells after treatment with GQDs (250 μg/ml) …”

Toxicity of graphene-family nanoparticles: a general review of the origins and mechanisms

“…GQDs entered cells and induced DNA damage by the increased expression of p53, Rad 51, and OGG1 proteins in NIH-3 T3 cells [87]. However, GQDs did not pose significant toxicity to human breast cancer cell lines (at a dose of 50 μg/mL) or human neural stem cells (at a dose of 250 μg/mL) [114, 115]. GO derivatives dramatically decreased the expression of differential genes that are responsible for the structure and function of the cell membrane, such as regulation of the actin cytoskeleton, focal adhesion and endocytosis [89].…”