Effects of bone morphogenetic proteins on osteoblast cells: vascular endothelial growth factor, calcium, inorganic phosphate, and nitric oxide levels.

PURPOSE: Bone morphogenetic proteins (BMPs) play an important role in the initiation of bone formation by affecting cell growth and differentiation in a variety of cell types including osteoblasts. Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis and vasculogenesis, and also, VEGF signaling is important for skeletal development. Nitric oxide (NO), calcium (Ca), and inorganic Phosphate (Pi) are important molecules for cell functions. In this study, the effects of BMP on VEGF, Ca, NO, and Pi levels were investigated in an osteoblast cell culture. MATERIALS: Fifty thousand cells per milliliter were seeded and cultured on graft materials for 24 and 48 hours. Different concentrations of BMPs (combination of BMPs numbered from 1 to 14) were supplemented to the medium. RESULTS: BMP was found to increase VEGF (P = 0.00), Ca (P = 0.02), and Pi (P = 0.00) especially in the first 24 hours. The increase in the NO in the experimental groups were found to be statistically insignificant (P = 0.12). CONCLUSION: Our data state that further investigation should be performed on the effects of BMPs on osteoblast cell membranes and membrane receptors and cell signaling, together with their known effects on early phases of bone and vascular epithelial tissue formation.

The influence of titanium surfaces in cultures of neonatal rat calvarial osteoblast-like cells: an immunohistochemical study.

BACKGROUND: The goal of this present study was to evaluate the behavior of neonatal rat calvarial osteoblast-like cells cultured on different implant surfaces. MATERIALS: Sandblasted acid-etched (SLA) surfaces of 2 different companies with different alloy properties were used. These were named as SLA-1 and SLA-2. The osteoblasts behavior were analyzed on sand blasted-acid etched (SLA-1) surface (Straumann, Basel, Switzerland), sand blasted-acid etched (SLA-2) surface (Alpha bio, Petach-tikva, Israel), acid-etched surface (Alpha bio), machined surface (Alpha bio). To analyze the effect of titanium surfaces on cell proliferation, cell numbers, and cell viability cells were cultured on titanium discs for 7 days and measurements were held out at 24 hours and on day 7. Cell proliferation rate was assessed by bromodeoxyuridine (BrdU) immunohistochemical technique. Cell morphologies were evaluated by scanning electron microscopy. RESULTS: The highest number of BrdU labeled cells were seen on SLA-1 group at the end of 24 hours. The number of cells was found to be the highest in the acid-etched group on the 7th day, even though there were no significant differences between the groups at the end of 24 hours. Scanning electron microscopy views showed the morphological differences between the groups. Osteoblasts were able to proliferate on all of the tested surfaces, with differences in cell count and DNA synthesis values between the groups. CONCLUSION: Implant surface characteristics may modulate the biological response of osteoblast-like cells depending on the manufacturing techniques and cell culturing procedures.

Effects of bone morphogenetic protein on neonatal rat calvarial osteoblast-like cells: an in vitro study.

Bone morphogenetic proteins (BMPs) are factors that promote osteoblastic differentiation and osteogenesis. The aim of this study was to examine the behavior of neonatal rat calvarial osteoblast cells cultured on different concentrations of BMP graft materials. Fifty thousand cells per milliliter were seeded and cultured on graft materials for 24 and 48 h. Different concentrations of BMPs (combination of BMPs numbered from 1 to 14) were supplemented to the medium. To evaluate cellular proliferation and differentiation, specimens were examined for DNA synthesis, alkaline phosphatase (ALP) activity, cell numbers, and viability of the cells. Further, transforming growth factor-beta(1) (TGF-beta(1)) and lactate dehydrogenase (LDH) levels were investigated. Morphological appearance of the specimens at 24 and 48 h of incubation was evaluated using scanning electron microcopy. Evaluations of DNA synthesis, cell count, and cell viability data revealed that a significant difference existed at 24 and 48 h (p < 0.05). The TGF-beta(1) and ALP analysis showed only a significant difference between the groups at the end of 24 h (p < 0.05). Regarding the lactate dehydrogenase activity there was not any significant difference at 24 and 48 h (p > 0.05). No morphological differences were observed in cell morphology on BMP graft material and the control group. These results indicate that BMPs have an inductive effect on osteoblast differentiation and a possible inhibitory effect in the early phases of cell proliferation.