The Effect of Liquid-Phase Exfoliated Graphene Film on Neurodifferentiation of Stem Cells from Apical Papilla

Background: Dental stem cells, which originate from the neural crest, due to their easy accessibility might be good candidates in neuro-regenerative procedures, along with graphene-based nanomaterials shown to promote neurogenesis in vitro. We aimed to explore the potential of liquid-phase exfoliated graphene (LPEG) film to stimulate the neuro-differentiation of stem cells from apical papilla (SCAP). Methods: The experimental procedure was structured as follows: (1) fabrication of graphene film; (2) isolation, cultivation and SCAP stemness characterization by flowcytometry, multilineage differentiation (osteo, chondro and adipo) and quantitative PCR (qPCR); (3) SCAP neuro-induction by cultivation on polyethylene terephthalate (PET) coated with graphene film; (4) evaluation of neural differentiation by means of several microscopy techniques (light, confocal, atomic force and scanning electron microscopy), followed by neural marker gene expression analysis using qPCR. Results: SCAP demonstrated exceptional stemness, as judged by mesenchymal markers’ expression (CD73, CD90 and CD105), and by multilineage differentiation capacity (osteo, chondro and adipo-differentiation). Neuro-induction of SCAP grown on PET coated with graphene film resulted in neuron-like cellular phenotype observed under different microscopes. This was corroborated by the high gene expression of all examined key neuronal markers (Ngn2, NF-M, Nestin, MAP2, MASH1). Conclusions: The ability of SCAPs to differentiate toward neural lineages was markedly enhanced by graphene film

Photosynthetic reaction center/graphene bio-hybrid for low-power optoelectronics

Photosynthetic reaction center (pRC) purified from Rhodobacter sphaeroides 2.4.1 purple bacteria was deposited on a graphene carrier exfoliated from the liquid phase and layered on the surface of SiO2/Si substrate for optoelectronic application. Light-induced changes in the drain-source current vs. gate voltage are demonstrated. Dried photosynthetic reaction centers/graphene composite on SiO2/Si shows a photochemical/-physical activity, as a result of interaction with the current flow in the graphene carrier matrix. The current changes are sensitive to light, due to the contribution from the charge separation in the pRC, and to the applied gate and drain-source voltages

Photosynthetic reaction center/graphene bio-hybrid for low-power optoelectronics

Photosynthetic reaction center (pRC) purified from Rhodobacter sphaeroides 2.4.1 purple bacteria was deposited on a graphene carrier exfoliated from the liquid phase and layered on the surface of SiO2/Si substrate for optoelectronic application. Light-induced changes in the drain-source current vs. gate voltage are demonstrated. Dried photosynthetic reaction centers/graphene composite on SiO2/Si shows a photochemical/-physical activity, as a result of interaction with the current flow in the graphene carrier matrix. The current changes are sensitive to light, due to the contribution from the charge separation in the pRC, and to the applied gate and drain-source voltages