In vitro Osteogenic impulse effect of Dexamethasone on periodontal ligament stem cells

Polycaprolactone-collagen nanofibers loaded with dexamethasone and simvastatin as an osteoinductive and immunocompatible scaffold for bone regeneration applications

Physiological inflammation has been shown to promote bone regeneration; however, prolonged inflammation impedes the osteogenesis and bone repair process. To overcome the latter we aimed to develop a dual drug delivering nanofibrous scaffold to promote osteogenic differentiation of mesenchymal stromal cells (MSCs) and modulate the pro-inflammatory response of macrophages. The polycaprolactone (PCL)-collagen nanofibrous delivery system incorporating dexamethasone and simvastatin was fabricated by electrospinning process. The morphological analysis and mRNA, as well as protein expression of proinflammatory and anti-inflammatory cytokines in human monocytes (U937 cells), demonstrated the immunocompatibility effect of dual drug-releasing nanofibrous scaffolds. Nitric oxide estimation also demonstrated the anti-inflammatory effect of dual drug releasing scaffolds. The scaffolds demonstrated the osteogenic differentiation of adipose-derived MSCs by enhancing the alkaline phosphatase (ALP) activity and mineral deposition after 17 days of cell culture. The increased expression of Runt-related transcription factor-2 (RUNX-2) and osteocalcin at mRNA and protein levels supported the osteogenic potential of dual drug-loaded fibrous scaffolds. Hence, the results indicate that our fabricated nanofibrous scaffolds exhibit immunomodulatory properties and could be employed for bone regeneration applications after further in-vivo validation.

Effect of puerarin on osteogenic differentiation of human periodontal ligament stem cells

Objective

To investigate the effects of the flavonoid, puerarin, on osteogenic differentiation of human periodontal ligament stem cells (PDLSCs).

Methods

Human PDLSCs were isolated from patients undergoing orthodontic treatment, and the cell surface markers CD146, CD34, CD45, and STRO-1 were identified by immunofluorescence. Cell proliferation was detected by MTT assay; alkaline phosphatase (ALP) activity was measured, and calcium deposition was detected by alizarin red staining. PCR was then used to detect the distributions of COL-I, OPN, Runx2, and OCN, genes related to osteogenic differentiation.

Results

Staining was positive for cytokines CD146, CD34, CD45, and STRO-1 in the experimental group; staining was also positive for silk protein, but negative for keratin. After 7 days of culture, exposure to puerarin significantly promoted the level of intracellular ALP; increased puerarin concentration led to increased intracellular ALP. Red mineralized nodules appeared upon exposure to puerarin and the number of nodules was concentration-dependent. PCR analysis revealed that COL-I, OPN, Runx2, and OCN expression levels increased as puerarin concentration increased.

Conclusions

Exposure to puerarin can promote proliferation and ALP activity in human PDLSCs, thus promoting both molecular and osteogenic differentiation; these findings may provide a theoretical basis for the clinical treatment of periodontal disease with puerarin.

Are We Economically Efficient Enough to Increase the Potential of in Vitro Proliferation of Osteoblasts by Means of Pharmacochemical Agents?

Background:

The aim of this study was to test the necessity of using expensive and unaccesible pharmacological-chemical agents in the proliferation of bone tissue cultures and in the induction of mineralized matrix formation to increase the osteogenic effect.

Methods:

For this purpose, human primary cell cultures were prepared and then divided into two groups. Whereas the cells in group I were fed with an osteoblast stimulator medium containing Dulbecco’s Modified Eagle Medium (DMEM) and β-glycerophosphate, the cells in group II were fed with DMEM containing dexamethasone and 2-phospho-L-ascorbic acid trisodium salt. Both groups were evaluated in terms of viability, toxicity, and proliferation and then compared in terms of cell surface morphology through inverted light and environmental scanning electron microscopy. In addition to immunoflow cytometric analyses, the effects of alkaline phosphatase activities were evaluated using the spectrophotometric method to examine the osteoblastic activities. Costs were calculated in the currency of the European Union (Euros). The Tukey Honestly Significant Difference test was used to reach the statistical evaluation of the data after the analysis of variance.

Results:

It was reported that the level of the alkaline phosphates was higher in group I compared to group II. It was observed that the surface morphology quality, the number of living cells, and proliferation were higher in group II and that the results were deemed statistically significant.

Conclusion:

It was found that the 2-phospho-L-ascorbic acid trisodium salt and dexamethasone mixture was as effective as the expensive commercial kits on the osteogenic effect on human primary bone tissue.