Effect of Graphene on Differentiation and Mineralization of Dental Pulp Stem Cells in Poly(4-vinylpyridine) Matrix in Vitro

Abstract

We have investigated the influence of graphene nanoplatelet scaffolds for dental pulp cells (DPSCs) made from poly­(4-vinylpyridine) (P4VP) either via spin-casting flat films or electrospinning nano- and microscale fibers. We found that graphene predominated over other factors in promoting differentiation of DPSCs. In the absence of graphene, real-time-polymerase chain reaction (RT-PCR) and energy dispersive X-ray (EDX) analyses indicated that the DPSCs differentiated along odontogenic lineages only on the nano- and microelectrospun scaffolds. Closer scanning electron microscopy (SEM) imaging revealed formation of banded collagen structures, which nucleated on the electrospun fibers in the absence of graphene. Biomineral deposition was templated on these fibers, with mineral to protein ratios similar to dentin. In the microfibers, the graphene was completely encapsulated and appeared to hinder biomineralization. Previously minimal biomineralization and banded collagen were observed on flat spun cast substrates. Addition of graphene appeared to induce nucleation of banded collagen fibers and template biomineral deposition. Addition of graphene did not affect the outcome of the DPSCs cultured on the nanofibers, which biomineralized regardless of graphene inclusion. Based on these results, we hypothesize that direct contact with graphene is the primary factor determining differentiation of the DPSCs. On the flat surface and nanoscale electrospun fibers, the graphene protrudes from the sample enabling direct contact with the extracellular matrix (ECM) and cells, while on the microfibers, the graphene is fully encapsulated within the matrix. TUNA imaging with scanning force microscopy showed enhanced conductivity on fibers with encapsulated graphene, which we hypothesize may change the conformation of adsorbed ECM proteins, affecting DPSCs differentiation.

Hierarchical Therapeutic Ion‐Based Microspheres with Precise Ratio‐Controlled Delivery as Microscaffolds for In Situ Vascularized Bone Regeneration

“…For the quantitative reverse transcription polymerase chain reaction (qPCR) assay, [ 49 ] at predetermined day 3, 7, and 14, 250 µL RNA‐Quick Purification kit (Esunbio, China) was added into each well to extract the total RNA. Six genes (RUNX2, BMP2, OPN, ALP, OCN, and COL‐I) in relation to osteogenesis and two genes (VEGF and Ang‐1) in relation to angiogenesis were evaluated, and their specific primers were designed as listed in Table S4, Supporting Information.…”

Combination of 3D Printing and ALD for Dentin Fabrication from Dental Pulp Stem Cell Culture

“…DPSCs were isolated at the Stony Brook School of Dental Medicine from discarded third molar teeth under IRB exemption for de-identified surgical waste (CORIHS Project ID: 20076778, approval #00000125). − For all experiments, passage 5 cells were used, and cultures were grown in MEM Alpha (GIBCO, Invitrogen) with 10% FBS (HyClone), 200 μM l -ascorbic acid 2-phosphate, 10 mM β-glycerophosphate, 100 units/ml penicillin, and 100 μg/mL streptomycin, where the supplements were obtained from Sigma-Aldrich. The 3D printed and molded samples were placed in 12-well tissue culture plates, where they were plated with the DPSCs at a density of 9000 cells/cm 2 and incubated for 28 days at 37 °C under 5% CO 2 in a humidified environment.…”

“…It has been shown that Raman spectroscopy can characterize the biomolecules effectively. ,, Therefore, we obtained Raman spectroscopy to study the structure of the mineralized matrix. Gentleman et al showed that different structures in the teeth could be identified by the mineral-to-matrix ratio. , Mandair et al showed that the peak position could determine that the bone structure is mature or immature by the peak around 960 nm .…”

Nanomaterials Modulating the Fate of Dental-Derived Mesenchymal Stem Cells Involved in Oral Tissue Reconstruction: A Systematic Review

“…Its π-bonding allows growth factors released by DPSCs to be better absorbed by the surface, thus accelerating biomineralization on the scaffolds. 165 Graphene oxide is a highly oxidized form of graphene. Still, in contrast to graphene's low solubility, GO is highly soluble in water and easily binds to other biomolecules due to the presence of functional groups such as carbonyl, carboxyl, and epoxy groups because of its surface functionalization.…”