ABSTRACT
AIM: To evaluate the effect of MTA and Biodentine on viability, osteogenic differentiation and BMP-2 expression in osteogenic cells. METHODOLOGY: Saos-2 cells were used as a model of osteoblastic cells. Overexpression of BMP-2 was induced by transfection of a CMV-driven plasmid construct including the human BMP-2 coding sequence, and stably transfected cells were selected. Cell viability was assessed by the mitochondrial dehydrogenase enzymatic (MTT) assay. The bioactivity of the materials was evaluated by the alkaline phosphatase (ALP) assay and detection of calcium deposits with alizarin red staining (ARS). The gene expression of BMP-2 and ALP was quantified with real-time PCR. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: Viability tests revealed that MTA and Biodentine were not cytotoxic at the higher dilution (1 : 8) to BMP-2-transfected cells. MTA and Biodentine exhibited the highest ALP activity when compared to the Saos-BMP-2-unexposed control group (P < 0.05). Cell exposure to Biodentine and MTA had a significant stimulatory effect on the formation of mineralized nodules (P < 0.05). The highest increase in BMP-2 gene expression was observed after 3 days of BMP-2-transfected cells exposure to MTA and Biodentine in non-osteogenic medium in relation to Saos-BMP-2-unexposed control cells (P < 0.05). Exposure of cells to MTA in osteogenic medium for 1 day increased ALP gene expression by approximately 1.3-fold in relation to Saos-BMP-2-unexposed control cells (P < 0.05). CONCLUSIONS: Both MTA and Biodentine showed biocompatibility and bioactivity in Saos-BMP-2 overexpressing cells. Biodentine had a significantly greater effect on mineralization than MTA. Both MTA and Biodentine enhanced BMP-2 mRNA expression in the transfected system. Both MTA and Biodentine are suitable materials to improve osteoblastic cell mineralization.
Subject(s)
Aluminum Compounds/pharmacology , Bone Morphogenetic Protein 2/metabolism , Calcium Compounds/pharmacology , Osteoblasts/metabolism , Oxides/pharmacology , Silicates/pharmacology , Alkaline Phosphatase/metabolism , Blotting, Western , Cell Differentiation/drug effects , Cell Survival/drug effects , Cells, Cultured , Drug Combinations , Humans , Materials Testing , Real-Time Polymerase Chain Reaction , TransfectionABSTRACT
The fractionation and speciation of As in a contaminated soil were investigated, and a remediation strategy was tested. Regarding speciation, we found that As(V) prevails over As(III) whereas more than 40% of total arsenic is in organic form. The fractionation of As was investigated with two sequential extraction methods: a low mobility was found. Then we tested the possibility of using phosphoric acid to extract As from the soil and cleaning the washing effluents by sorption onto montmorillonite. The efficiency of the extraction and of the adsorption onto the clay were also investigated for Cr, Cu, Fe, Mn, Ni, Pb and Zn, whose total concentrations and fractionation in the soil are reported here. The extraction percentages for As and metals ranged from 30 to 65%; the residual proportions in the soil are presumably in very unreactive forms. Montmorillonite showed a good uptake capacity towards the investigated pollutants.
Subject(s)
Arsenic/chemistry , Environmental Restoration and Remediation/methods , Metals, Heavy/chemistry , Soil Pollutants/analysis , Adsorption , Bentonite , Chemical Fractionation , Italy , Phosphoric Acids , Spectrophotometry, AtomicABSTRACT
A novel electron paramagnetic resonance (EPR)-based oxygen mapping procedure (EPROM) is applied to cartilage grown in a single-, hollow-fiber bioreactor (HFBR) system. Chondrocytes harvested from the sterna of 17-day-old chick embryos were inoculated into an HFBR and produced hyaline cartilage over a period of 4 weeks. Tissue oxygen maps were generated according to the EPROM technique (Velan et al., Magn Reson Med 2000;43:804-809) by making use of the line-broadening effects of oxygen on the signal generated from nitroxide spin probes. In addition, the effect on oxygen consumption of the addition of cyanide to the tissue was investigated. Cyanide is a potent inhibitor of oxidative phosphorylation, and accordingly, given the constant provision of oxygen to the tissue, it would be expected to increase oxygen levels within the HFBR. The EPROM measurements showed a significant increase in oxygen concentration in the cartilage after the addition of cyanide. In contrast to other methods for studying oxygen in cartilage, EPROM can provide direct, noninvasive visualization of local concentrations in three dimensions.
