RESUMO
<p><b>OBJECTIVE</b>To investigate the effects of 20% fluor-hydroxyapatite (FHA) on proliferation and osteogenic differentiation of human MG63 osteosarcoma cells.</p><p><b>METHODS</b>FHA was prepared by chemical precipitation method, and its structure and surface features were tested by scanning microscope, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy. MG63 cells were cultured and divided into FHA, hydroxyapatite (HA) and control groups (n = 3). The proliferation of the cells was evaluated using methylthiazol tetrazolium (MTT) assay. ALP activity of the cells was assessed. Osteogenic differentiation was evaluated based on the reverse transcription PCR (RT-PCR) of differentiation-related genes, namely, collagen type I (Col I), alkaline phosphatase (ALP), osteocalcin (OCN) and core binding factor α1 (Cbfα1). The data were analyzed statistically by one-way analysis of variance using SPSS 13.0 software.</p><p><b>RESULTS</b>XRD test showed that the main crystalline phase of FHA was similar to that of HA. Absorptance value of cells exposed to FHA(1.87±0.06) measured by MTT was higher than that of the control(1.25±0.02) on the third day(P < 0.05), and there was no statistically significant difference between the cells exposed to FHA and HA(1.84±0.03) (P > 0.05). ALP activity of the cells exposed to FHA(4.62±0.09)was higher than that of the control (1.92 ± 0.05) (P < 0.05). RT-PCR tests showed that compared with the control, FHA up-regulated the expression of Col I, ALP and OCN mRNA, down-regulated the expression of Cbfα1 mRNA.</p><p><b>CONCLUSIONS</b>FHA enhances the proliferation and osteogenic differentiation-related gene expression, and has good biocompatibility.</p>
Assuntos
Humanos , Fosfatase Alcalina , Genética , Metabolismo , Análise de Variância , Materiais Biocompatíveis , Neoplasias Ósseas , Metabolismo , Patologia , Diferenciação Celular , Genética , Proliferação de Células , Fisiologia , Colágeno Tipo I , Genética , Metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core , Genética , Durapatita , Química , Farmacologia , Hidroxiapatitas , Osteocalcina , Genética , Metabolismo , Osteogênese , Osteossarcoma , Metabolismo , Patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
Objective: To compare the quantities of water-soluble, water-insoluble glucans synthesized by S. mutans in 3-4 years old children with high dmft and no caries. Methods: The quantities of water-soluble and water-insoluble glucans synthesized by S. mutans from dental plaques of children with high dmft (dmft≥5) and caries-free (dmft=0) were measured using the anthrone method. Results: S. mutans isolated from the children with high dmft had stronger ability in producing both water-soluble and water-insoluble glucans than those isolated from the caries-free children (0.0332 mg/ml v.s. 0.0192 mg/ml and 0.0357 mg/ml v.s. 0.0215 mg/ml respectively). Children with high dmft harbored more isolates with higher water-soluble or water-insoluble glucans producing ability than caries-free children. Water-insoluble glucans produced by all the clinical isolates is higher than water-soluble glucans (0.0301 mg/ml v.s. 0.0267 mg/ml) and the difference was statistically significant. Conclusion: There may be a correlation between the extracellular glucans producing ability of S. mutans and the caries susceptibility in deciduous teeth.
