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Objective·To investigate the antibacterial effect of Nd:YAG laser on Fusobacterium nucleatum(F.nucleatum)in vitro. Methods·The laser effect on the biofilm formation ability of planktonic F.nucleatum were observed by crystal violet test;confocal laser scanning microscopy(CLSM) was used to detect the effect on the bacteria viability of mature biofilm; scanning electron microscopy (SEM) was performed to investigate the effect on the morphology of mature bioflm. Results·After 15 s radiation the biofilm formation ability of F.nucleatum went down.The viability of F.nucleatum in mature biofilm went down under 35 s iradiation. The deformation of mature biofilm and bacterium became distincted with the iradiation time raised. Conclusion·Nd:YAG laser shows the inhibition of biofilm formation ability on planktonic F.nucleatum.The vitality of F.nucleatum in mature biofilm is depressed after laser radiation. Laser can destroy the construction of the mature biofilm and bacteria.
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Objective·To investigate the effects of psoralen and angelicin on inflammation cytokine expression of human periodontal ligament cells (hPDLCs).Methods· hPDLCs were primarily cultured using tissue explant method.Effects ofpsoralen and angelicin on the cell viability were tested by CCK-8 assay,hPDLCs were stimulated by Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) after treatment with different concentrations of psoralen and angelicin for 2 h.mRNA expression of IL-1β and IL-8 were determined by real-time PCR.Enzyme-linked immunosorbent assay (ELISA) was used to measure the secretion of IL-1β and IL-8.Results · hPDLCs were cultured successfully by tissue explant method.Psoralen and angelicin (≤ 12.5 μg/mL) did not show significant effects on the cell viability of hPDLCs.Pg-LPS markedly elevated the mRNA expression of IL-1β and IL-8,which could be attenuated by psoralen and angelicin in a dose-dependent manner.Likewise,the up-regulated protein secretion of IL-1β and IL-8 could be significantly blocked by psoralen and angelicin.Conclusion · Psoralen and angelicin could attenuate the inflammatory response of hPDLCs induced by Pg-LPS,Therefore,psoralen and angelicin may act as natural agents to prevent and treat periodontitis.
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Objective To investigate the effect of enamel matrix proteins (EMPs) on gene expression in human bone marrow stromal cells (hBMSCs) by cDNA microarray. Methods hBMSCs were cultured in vitro by whole bone marrow technique. Those stimulated with EMPs at a concentration of 200 ?g/mL in vitro were classified as test group, and those normally cultured were served as control. Afer culturing for 5 days, a cDNA microarray containing 4 096 genes was used to detect and analyze the gene expression. Four differentially-expressed genes in cDNA microarray were determined by real-time PCR for validation of the microarray data. Results Twenty-seven genes of hBMSCs were differentially expressed in the presence of EMPs, among which 18 were up-regulated and 9 down-regulated. The result of real-time PCR was in accordance with that of the cDNA microarray. Conclusion cDNA microarray technique can screen the differentially-expressed genes in hBMSCs treated with EMPs, which lays a foundation for the research of molecular mechanism of EMPs in inducing the regeneration of periodontal tissue.
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Objective To evaluate the feasibility of reconstructing horizontal periodontal bone defects by tissue engineering based on bone marrow stromal cells(BMSCs)as seed cells and enamel matrix proteins(EMPs)as growth factors. Methods Two healthy rhesus monkeys were selected, and BMSCs were isolated from iliac marrow and serial subcultivation was conducted. The cells of induced BMSCs at passage 3 were harvested and mixed with Bio-oss collagen. The models of horizontal periodontal bone defects were established surgically in each buccal side of the posterior teeth, and were divided into four groups (blank control group, material group, cells/material group and cells/material/EMPs group). The histological and Micro-CT observation were carried out 8 weeks later. Results In the blank control group, the defects were filled with fibrous connective tissue. There was newly-formed alveolar bone in the material group. In the cells/material group, periodontal regeneration could be observed, while the newly-formed cementum was irregular and less in quantity. In the cells/material/EMPs group, the amount of newly-formed alveolar bone was larger, and the newly-formed cementum was continuous and regular. Conclusion The tissue engineering technique of BMSCs as seed cells in combination with EMPs induction can significantly promote the regeneration of periodontal tissue.