In vitro evaluation of the effect of the electronic cigarette aerosol, Cannabis smoke, and conventional cigarette smoke on the properties of gingival fibroblasts/gingival mesenchymal stem cells.

OBJECTIVE: The current study aimed to evaluate the effect of electronic cigarette (EC) aerosol, Cannabis, and conventional cigarettes smoke on gingival fibroblast/gingival mesenchymal stem cells' (GF/G-MSCs) of never smokers. MATERIAL AND METHODS: Human GF/G-MSCs (n = 32) were isolated and characterized using light microscopy, flow cytometry, and multilineage differentiation ability. Following the application of aerosol/smoke extracts, GF/G-MSCs were evaluated for cellular proliferation; colony-forming units (CFU-F) ability; cellular viability (using the MTT assay); mitochondrial depolarization using JC-1 dye; and genes' expression of ATM, p21, Oct4, and Nanog. RESULTS: Colony-forming units and viability (OD 450 nm) were significantly reduced upon exposure to Cannabis (mean ± SD; 5.5 ± 1.5; p < .00001, 0.47 ± 0.21; p < .05) and cigarettes smoke (2.3 ± 1.2 p < .00001, 0.59 ± 0.13, p < .05), while EC aerosol showed no significant reduction (10.8 ± 2.5; p = .05, 1.27 ± 0.47; p > .05) compared to the control group (14.3 ± 3, 1.33 ± 0.12). Significantly upregulated expression of ATM, Oct4, and Nanog (gene copies/GADPH) was noticed with Cannabis (1.5 ± 0.42, 0.82 ± 0.44, and 1.54 ± 0.52, respectively) and cigarettes smoke (1.52 ± 0.75, 0.7 ± 0.14, and 1.48 ± 0.79, respectively; p < .05), whereas EC aerosol caused no statistically significant upregulation of these genes compared to the control group (0.63 ± 0.1, 0.31 ± 0.12, and 0.64 ± 0.46, respectively; p > .05). The p21 gene was not significantly downregulated in EC aerosol (1.22 ± 0.46), Cannabis (0.71 ± 0.24), and cigarettes smokes (0.83 ± 0.54) compared to the control group (p = .053, analysis of variance). CONCLUSION: Cannabis and cigarettes smoke induce DNA damage and cellular dedifferentiation and negatively affect the cellular proliferation and viability of GF/G-MSCs of never smokers, whereas EC aerosol showed a significantly lower impact on these properties.

Characteristics of Human Natal Stem Cells Cultured in Allogeneic Medium.

Recently, human natal dental pulp stem cells (hNDP-SCs) have been characterized in vitro and it has been shown that they satisfy criteria defining human mesenchymal stromal cells (MSCs), as proposed by the International Society for Cellular Therapy. However, these results were reached in the presence of xenogeneic expansion medium, which has the potential to alter the cells' functional capacity. To determine the validity of the previously reported hNDP-SCs characteristics for human cell therapy, we have cultured hNDP-SCs in allogeneic expansion medium. Two hNDP-SC lineages were isolated from vital natal teeth, donated by a healthy newborn female and cultured in 2% platelet rich plasma (PRP). Analysis of the phenotypic expressions, proliferation rates, viability, telomerase length and in vitro adipogenic, osteogenic and chondrogenic differentiation potentials of two hNDP-SCs lineages (Zn001 and Zn002) were performed. Both lineages displayed similar morphology, proliferation rates, adipogenic, chondrogenic and osteogenic differentiation potential. Telomere shortening by 41.0% and 13.49% occurred from 3rd till 14th passage for lineages Zn001 and Zn002 respectively. Viability of both lineages was higher than 90%. Flow cytometry demonstrated that both lineages were positive to the majority of tested markers, including markers, which were negatively, expressed when hNDP-SCs were cultured previously in xenogeneic medium. Using immune-cytochemistry the cells were shown to express beta III-tubulin, nestin, neurofilaments and Nanog. PRP used as allogeneic medium is suitable for cultivation of hNDP-SCs.

The Effect of Strontium Ranelate Gel on Bone Formation in Calvarial Critical Size Defects.

AIM: The current study was designed to investigate the effectiveness of locally applied Strontium ranelate to induce bone formation. MATERIALS AND METHODS: Forty-eight female rats were divided into six groups (eight rats in each group): The three test groups included Strontium (SR) 2.5 mg, 5 mg and 10 mg that was dissolved in methylcellulose gel. The control groups included methylcellulose, simvastatin 5 mg and a negative control where the defect was left to heal without any intervention. At 44 days the groups were sacrificed, and the bone defects were assessed histomorphometically to assess bone formation. The data was statistically analysed. RESULTS: There was a statistically significant difference in the amount of new bone formation between all groups, where the 2.5 mg SR group showed the highest median bone percentage, is 41.95 %, followed by the 5, and 10 mg SR demonstrating a median bone are a percentage of 39.89%, and 30.19% respectively. Simvastatin showed a median bone percentage of 36.07 %, while the methylcellulose and the negative control groups demonstrated the lowest median area percentage of 23.12 and 20.70 % respectively. CONCLUSIONS: The study showed that the local application of an SR could up-regulate the bone formation and may prove to be a cost-effective method of bone regeneration.

Characteristics of human natal stem cells cultured in allogeneic medium

Abstract Recently, human natal dental pulp stem cells (hNDP-SCs) have been characterized in vitro and it has been shown that they satisfy criteria defining human mesenchymal stromal cells (MSCs), as proposed by the International Society for Cellular Therapy. However, these results were reached in the presence of xenogeneic expansion medium, which has the potential to alter the cells' functional capacity. To determine the validity of the previously reported hNDP-SCs characteristics for human cell therapy, we have cultured hNDP-SCs in allogeneic expansion medium. Two hNDP-SC lineages were isolated from vital natal teeth, donated by a healthy newborn female and cultured in 2% platelet rich plasma (PRP). Analysis of the phenotypic expressions, proliferation rates, viability, telomerase length and in vitro adipogenic, osteogenic and chondrogenic differentiation potentials of two hNDP-SCs lineages (Zn001 and Zn002) were performed. Both lineages displayed similar morphology, proliferation rates, adipogenic, chondrogenic and osteogenic differentiation potential. Telomere shortening by 41.0% and 13.49% occurred from 3rd till 14th passage for lineages Zn001 and Zn002 respectively. Viability of both lineages was higher than 90%. Flow cytometry demonstrated that both lineages were positive to the majority of tested markers, including markers, which were negatively, expressed when hNDP-SCs were cultured previously in xenogeneic medium. Using immune-cytochemistry the cells were shown to express beta III-tubulin, nestin, neurofilaments and Nanog. PRP used as allogeneic medium is suitable for cultivation of hNDP-SCs.

Resumo Recentemente, células-tronco da polpa dental humana (hNDP-SCs) foram caracterizadas in vitro e foi demonstrado que elas satisfazem critérios que definem células mesenquimais do estroma humana (MSCs), tal como proposto pela Sociedade Internacional para Terapia Celular. No entanto, esses resultados foram alcançados na presença de meio de expansão xenogênico, que tem o potencial de alterar a capacidade funcional das células. Para determinar a validade das características das hNDP-SCs anteriormente relatadas para a terapia celular humana, cultivamos hNDP-SCs em meio de expansão alogênico. Duas linhagens hNDP-SC foram isoladas de dentes natais vitais, doadas por uma recém-nascida saudável, e cultivadas em plasma rico em plaquetas a 2% (PRP). Análises das expressões fenotípicas, taxas de proliferação, viabilidade, comprimento de telomerase e potenciais de diferenciação adipogênica, osteogênica e condrogênica in vitro das duas linhagens hNDP-SC (Zn001 e Zn002) foram realizadas. Ambas as linhagens apresentaram morfologia, taxas de proliferação, potencial de diferenciação adipogênico, condrogênico e osteogênico semelhantes. O encurtamento dos telômeros em 41,0% e 13,49% ocorreu da 3ª até a 14ª passagem para as linhagens Zn001 e Zn002, respectivamente. A viabilidade de ambas as linhagens foi superior a 90%. A citometria de fluxo demonstrou que ambas as linhagens foram positivas para a maioria dos marcadores testados, incluindo marcadores, que foram negativamente expressados quando hNDP-SCs foram previamente cultivadas em meio xenogênico. Usando análise imunocitoquímica, as células mostraram expressar a beta III-tubulina, nestina, neurofilamentos e Nanog. O PRP usado como meio alogênico mostrou-se adequado para o cultivo de hNDP-SCs.