Abstract
Graphene oxide (GO) is a biocompatible material considered a favorable stem cell culture substrate. In this study, GO was modified with polydopamine (PDA) to facilitate depositing GO onto a tissue culture polystyrene (PT) surface, and the osteogenic performance of the PDA/GO composite in pluripotent embryonic stem cells (ESCs) was investigated. The surface chemistry of the PDA/GO-coated PT surface was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A high cell viability of ESCs cultured on the PDA/GO composite-coated surface was initially ensured. Then, the osteogenic differentiation of the ESCs in response to the PDA/GO substrate was assessed by alkaline phosphatase (ALP) activity, intracellular calcium levels, matrix mineralization assay, and evaluation of the mRNA and protein levels of osteogenic factors. The culture of ESCs on the PDA/GO substrate presented higher osteogenic potency than that on the uncoated control surface. ESCs cultured on the PDA/GO substrate expressed significantly higher levels of integrin α5 and β1, as well as bone morphogenetic protein receptor (BMPR) types I and II, compared with the control groups. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38, and c-Jun-N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) was observed in ESCs culture on the PDA/GO substrate. Moreover, BMP signal transduction by SMAD1/5/8 phosphorylation was increased more in cells on PDA/GO than in the control. The nuclear translocation of SMAD1/5/8 in cells was also processed in response to the PDA/GO substrate. Blocking activation of the integrin α5/β1, MAPK, or SMAD signaling pathways downregulated the PDA/GO-induced osteogenic differentiation of ESCs. These results suggest that the PDA/GO composite stimulates the osteogenic differentiation of ESCs via the integrin α5/β1, MAPK, and BMPR/SMAD signaling pathways.
Highlights
Macro, micro, and nanoscale extracellular matrix (ECM) organization provides a dynamic microenvironment to facilitate pivotal cell functions, including cell survival, migration, proliferation, and differentiation [1,2]
To understand the molecular mechanisms underlying the link between embryonic stem cells (ESCs) and the PDA/Graphene oxide (GO) substrate, we explored whether integrins, as an adhesion receptor, and bone morphogenetic protein receptors (BMPRs), as representative osteogenic-functioning receptors, are associated with PDA/GO substrate-derived ESC-osteolineage commitment
The present study showed that a PDA/GO composite-coated cell culture substrate
Summary
Macro-, micro-, and nanoscale extracellular matrix (ECM) organization provides a dynamic microenvironment to facilitate pivotal cell functions, including cell survival, migration, proliferation, and differentiation [1,2]. The biophysical roles of the ECM include being a critical regulator of stem cell behavior and function. A carbon-based nanomaterial with versatile physicochemical properties, has attracted increased research attention in various bio-engineering fields [7]. Graphene is a flat monolayer of carbon atoms patterned into a honeycomb, two-dimensional (2D) lattice, and it serves as a biocompatible and implantable platform for stem cell culture and artificial microenvironments [8,9,10]. Growing evidence has indicated that a graphene surface provides a biocompatible nanoscale to accelerate the differentiation of human mesenchymal stem cells (hMSCs) into a bone cell specification without cellular toxicity [8,16,17]. GO-incorporated poly (lactic-co-glycolic acid) (PLGA) nanofiber structures enhance the proliferation and osteogenic differentiation of hMSCs [18]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
