242 resultados para POLY(P-PHENYLENEVINYLENE) COPOLYMERS
Resumo:
Background: Fibroblasts are considered important cells in periodontitis. When challenged by different agents, they respond through the release of cytokines that participate in the inflammatory process. The aim of this study is to evaluate and compare the expression and production of macrophage inflammatory protein (MIP)-1 alpha, stromal-derived factor (SDF)-1, and interleukin (IL)-6 by human cultured periodontal ligament and gingival fibroblasts challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Methods: Fibroblasts were cultured from biopsies of gingival tissue and periodontal ligament of the same donors and used on the fourth passage. After confluence in 24-well plates, the culture medium alone (control) or with 0.1 to 10 mu g/ml of LPS from P. gingivalis was added to the wells, and after 1, 6, and 24 hours, the supernatant and the cells were collected and analyzed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively. Results: MIP-1 alpha, SDF-1, and IL-6 protein production was significantly greater in gingival fibroblasts compared to periodontal ligament fibroblasts. IL-6 was upregulated in a time-dependent manner, mainly in gingival fibroblasts (P<0.05), which secreted more MIP-1 alpha in the lowest concentration of LPS used (0.1 mu g/ml). In contrast, a basal production of SDF-1 that was inhibited with the increase of LPS concentration was detected, especially after 24 hours (P<0.05). Conclusion: The distinct ability of the gingival and periodontal ligament fibroblasts to secrete MIP-1 alpha, SDF-1, and IL-6 emphasizes that these cells may differently contribute to the balance of cytokines in the LPS-challenged periodontium. J Periodontol 2010;81:310-317.
Resumo:
The aim of the present study was to evaluate the in vitro osteogenic potential of subcultured human osteoblastic cells derived from alveolar bone on a titanium (Ti) surface produced by an anodized alkali treatment (BSP-AK). Primary osteoblastic cells were subcultured on BSP-AK and machined Ti discs (control) and grown for periods of up to 21 days under osteogenic conditions. Morphologic and biochemical methods were used to assess important parameters of in vitro bone-like tissue formation. Although no major differences were observed between the BSP-AK and the control Ti surface in terms of cell attachment and mineralized matrix formation, a significant increase in cell population, ALP activity, and collagen content was detected in cultures on BSP-AK surface. Our results demonstrate that human osteoblastic cells are sensitive to the BSP-AK-modified Ti surface during the transitional stage between the end of the proliferative phase and the onset of the differentiation /matrix maturation ones. Together with the good mechanical properties exhibited by the Ca- and P- coating, our findings suggest that BSP-AK treatment could be useful for the development of a new surface for dental and orthopedic implants. (c) 2008 Wiley Periodicals, Inc.J Biomed Mater Res 88A: 841-848, 2009