RESUMO
PURPOSE: This study was performed to evaluate the osteogenic potential of 3mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) and niobium oxide containing Y-TZPs with specific ratios, new (Y,Nb)-TZPs, namely YN4533 and YN4533/Al20 discs. MATERIALS AND METHODS: 3Y-TZP, YN4533 and YN4533/Al20 discs (15 mm diameter and 1 mm thickness) were prepared and their average surface roughness (Ra) and surface topography were analyzed using 3-D confocal laser microscope (CLSM) and scanning electron microscope (SEM). Mouse pre-osteoblast MC3T3-E1 cells were seeded onto all zirconia discs and evaluated with regard to cell attachment and morphology by (CLSM), cell proliferation by PicoGreen assay, and cell differentiation by Reverse-Transcription PCR and Quantitative Real-Time PCR, and alkaline phosphatase (Alp) staining. RESULTS: The cellular morphology of MC3T3-E1 pre-osteoblasts was more stretched on a smooth surface than on a rough surface, regardless of the material. Cellular proliferation was higher on smooth surfaces, but there were no significant differences between 3Y-TZP, YN4533, and YN4533/Al20. Osteoblast differentiation patterns on YN4533 and YN4533/Al20 were similar to or slightly higher than seen in 3Y-TZP. Although there were no significant differences in bone marker gene expression (alkaline phosphatase and osteocalcin), Alp staining indicated better osteoblast differentiation on YN4533 and YN4533/Al20 compared to 3Y-TZP. CONCLUSION: Based on these results, niobium oxide containing Y-TZPs have comparable osteogenic potential to 3Y-TZP and are expected to be suitable alternative ceramics dental implant materials to titanium for aesthetically important areas.
Assuntos
Animais , Camundongos , Fosfatase Alcalina , Diferenciação Celular , Proliferação de Células , Cerâmica , Implantes Dentários , Expressão Gênica , Nióbio , Osteoblastos , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real , TitânioRESUMO
Objective: To explore the effect of low intensity pulsed ultrasound (LIPUS) on the osteogenesis of rabbit bone marrow stromal cells (BMSCs) in vitro. Methods: Rabbit bone marrow was drawn out and cultured with conditioned culture medium to harvest BMSCs; the third generation BMSCs were randomly assigned to the experimental group and the control group. The experimental group was exposed to LIPUS 20 min/day for 1, 2 or 3 weeks, and the control group received no treatment. The cell proliferation was observed under inverted microscope. Von Kossa staining and alkaline phosphatase (ALP) activity test were employed to assess the osteogenesis of the cells. Results: BMSCs became larger after being stimulated with LIPUS, with increased nuclei and decreased nuclear to cytoplasm ratio; BMSCs untreated with LIPUS was flat and had lower refractive index. ALP activities of LIPUS-treated (1, 2, and 3 weeks) BMSCs increased significantly compared with that of the control group(P<0.05); the pixel value of calcification nodule in experimental group(after 3 weeks) was also higher than that of the control group(P<0.05). Conclusion: LIPUS can accelerate the osteogenesis of rabbit BMSCs in conditioned culture medium.
RESUMO
STUDY DESIGN: Retrospective study. PURPOSE: This study was designed to determine the effectiveness of bone mineral density measurement as a supplementary tool for evaluation of osteogenic potential in patients with spinal fusion. To this end, we correlated bone mineral density (BMD) with osteogenic potential from cultured mesenchymal stem cells (MSCs). OVERVIEW OF LITERATURE: Many studies have correlated osteogenic potential of in vitro cultured MSCs with aging or osteoporosis. METHODS: We studied twenty-five individuals with harvested bone marrow from the ilium during lumbar spinal surgery. The BMD of the femoral neck was measured using dual energy X-ray absorptiometry prior to bone marrow aspiration, and the osteoporotic group was classified as those with T-scores below-2.5. After MSCs were isolated from bone marrow, in vitro induction of osteogenesis was performed. We analyzed the patient's osteogenic potential from cultured MSCs such as mineral deposition stain, bone alkaline phosphatase (ALP) activity and osteoblast-specific gene expression in RT-PCR. RESULTS: On mineral staining, the osteoporotic group had a scanty matrix mineral deposition in contrast to the non-osteoporotic group. The expression of osteocalcin in the osteoporotic group was 1.5 to 3 times less than in the non-osteoporotic group. At the 3rd week after the induction of osteogenesis, the activity of ALP of cultured MSCs in the osteoporotic group was lower than in the control group (mean, 45+/-19 u/L, in osteoporotic group vs 136+/-7 u/L in non-osteoporotic), and there was a statistically significant and positive correlation between BMD & ALP (r=0.487, p=0.013). CONCLUSIONS: There is a positive correlation between BMD and osteogenic potential derived from MSCs. The measurement of BMD can provide supplementary data for evaluating osteogenic potential clinically.