Proliferation Of Periodontal Stem Cells Research Articles

PHOTOBIOMODULATION INCREASES THE VIABILITY AND PROLIFERATION OF HUMAN PERIODONTAL LIGAMENT STEM CELLS CULTURED ON THE SURFACE OF POLYLATIC ACID FILMS

<h3>Backgorund</h3> Polylactic acid (PLA) is a biomaterial with diverse biomedical applications and has been a promising scaffold in tissue engineering mainly due to its biocompatibility, easy manipulation and low cost. Photobiomodulation using low-level laser irradiation has been shown to be a powerful tool to promote in vitro biostimulation in several cell types. The aim of this study was to evaluate the effectiveness of photobiomodulation on the viability and proliferation of human periodontal ligament stem cells (hPDLSC) cultured on PLA scaffolds. <h3>Methods</h3> PLA films were produced by solvent casting method and the surface topography was evaluated by scanning electronic microscopy (SEM) and atomic force microscopy (AFM). hPDLSC were isolated, characterized and cultured on the PLA films. Two groups were evaluated: Control - non irradiated; and Laser - irradiated with diode laser (InGaAIP) with wavelength of 660 nm, power of 30 mW, and a single dose of 1 J/cm² with radiation emitted continuously. Cell viability analyzes were performed 24 and 48 hours after irradiation using the the Alamar Blue biochemical assay and Live/Dead assay. Cell cycle events were assessed by flow cytometry and cell-biomaterial morphological interaction was evaluated by SEM. <h3>Results</h3> The films produced showed a flat and regular surface, with the occasional presence of small pores and an average roughness of 59.381 nm. The results of Alamar Blue assay showed a greater cell metabolic activity in irradiated group compared to control at 24 (<i>p</i><0.05) and 48 h (<i>p</i><0.001), which was confirmed in the Live/Dead assay by a higher density of viable cells in the Laser group. In the analysis of the cell cycle, the Laser group showed an increase of cells in the G2/M phase compared to the Control group (<i>p</i> <0.001). SEM images showed a higher cell density in the irradiated group, with maintenance of cell morphology and projections. <h3>Conclusion</h3> Taken together, the findings of this study demonstrated that photobiomodulation has the ability to increase the viability and proliferation of periodontal stem cells cultured on PLA scaffolds, which may contribute to the development of new studies using this protocol in periodontal tissue engineering.

Rutin promotes osteogenic differentiation of periodontal ligament stem cells under inflammatory microenvironment

To explore the effect of rutin on osteogenic differentiation of periodontal ligament stem cells under inflammatory microenvironment. Periodontal ligament stem cells (PDLSCs) were obtained by limited dilution method in vitro. PDLSCs were identified by flow cytometery. Lipopolysaccharide(LPS) was used to stimulate human periodontal ligament stem cells to establish an inflammation model in vitro. The experiment was divided into 4 groups: in group 1, only α-MEM was used to culture PDLSCs; in group 2, α-MEM medium containing LPS was used to culture PDLSCs, in group 3, rutin was added to α-MEM medium containing LPS to PDLSCs; and in group 4, α-MEM medium containing rutin was used to culture PDLSCs. Cell counting kit-8 was used to detect cell proliferation activity. Alkaline phosphatase(ALP) staining, ALP activity test, alizarin red staining, RT-PCR, and Western blot were used to detect the changes of osteogenic differentiation ability. The data were analyzed by SPSS 17.0 software package. The results of CCK-8 and ALP activity analysis showed that rutin at 10 μmol/L could significantly promote the proliferation and differentiation of periodontal stem cells under inflammatory state. ALP staining and alizarin red staining proved that (10 μmol/L) rutin could improve osteogenic differentiation of periodontal ligament stem cells under inflammatory microenvironment. RT-PCR and Western blot results showed that rutin could enhance the expression of osteogenic genes and proteins such as COL1, ALP, and RUNX2 under inflammatory state. Rutin can promote osteogenic differentiation of periodontal ligament stem cells under inflammatory microenvironment.

The Influence of Malassez Epithelial Residue in Inflammatory Periodontal Tissues on the Number of Periodontal Stem Cells and Their Differentiation Ability

To investigate the effect of Malassez epithelial surplus in inflammatory periodontal tissues on the number and differentiation ability of periodontal stem cells. 30 patients with periodontitis admitted to the hospital from November 2014 to April 2017 were selected as the observation group. A total of 30 healthy oral examination patients were selected as control group. Periodontal tissue in the 2 groups were taken and the periodontal ligament cells, the complete inflammatory periodontal ligament stem cells by using the low density screening, purification, and periodontal tissue were obtained by using differential digestion method of Malassez epithelial remaining, were observed under inverted microscope in the periodontal tissue Malassez epithelial residual form, will be in the periodontal tissue Malassez epithelial surplus together with inflammatory periodontal ligament stem cells, RT-PCR technique has been applied to the determination of ALP and Runx-2 mRNA expression level to observe the differentiation ability. Flow cytometry showed that the cell markers CD29 and CD90 in the cultured periodontal stem cells were positive (88.9% and 99.7%, respectively). A hematopoietic stem cell marker CD45 was negative (0.3%). The inverted microscope results showed that the residual epithelial cells of Malassez, isolated and cultured, had a large nuclear to cytoplasmic ratio, and the different cells were arranged relatively closely, with the overall cell structure of paving stone. The expression levels of ALP and runx-2 mRNA in the observation group were higher than those in the control group (P<0.05). Malassez epithelial surplus in inflammatory periodontal tissues can promote the proliferation of periodontal stem cells and improve the ability of osteogenic differentiation.