Papers by Keyword: Osteoblast

Abstract: In this paper, we study the effect of repairing the dog's femoral defects with the artificial bone integrating the nano-calcium phosphates/zirconia porous artificial bone scaffold with the autologous osteoblasts. We transplanted the artificial bone to the femoral defect of the dog, and at the same time, simple scaffold and the autologous cancellous bone were implanted as the control group. 3 months after the transplantation, the specimen was taken out with complete integration with the bone in these 3 groups and the bone defect got the complete bone union. The mechanics strength test showed that the group of the artificial bone was the strongest, followed by the cancellous bone group, and the simple material group was lower, but the strength was stronger than that before the transplantation. In the sixth month, the complete femoral defect repair was found in each group and the complete formation of the Haversian canal can be found on the histology examination. According to the mechanics strength test, there was no significant difference (P<0.05).

Abstract: Gene expression profile of osteoblast-like cells cultured on dense disk materials and porous materials of calcium phosphate ceramics was constructed from DNA microarray analyses. The profile revealed that gene expression patterns of porous materials were significantly different from those of dense disk materials. The porous materials had a capacity to induce expressions of genes involved in osteoblast differentiation, while dense disk materials regulated gene expressions related to osteoclastogenesis.

Abstract: This study is to investigate the effect of PAM on protein adsorption and osteoblastic cells adhesion to HA bioceramics. PAM was immobilized on the surface of HA bioceramics for bone scaffold by chelating. The outermost layer of the specimens was analyzed by XPS and FT-IR. The protein adsorption test was performed using the 10% bovine calf serum absorbed on the specimens in vitro. The osteoblastic cells were inoculated and cultured on the scaffolds. SEM, MTT test and ALP activity test evaluated the cell attachment, proliferation and activity on the scaffolds. Characteristic peaks in XPS and FT-IR spectra indicated PAM being immobilized on the surface of the bioceramics. PAGE and 2-D DIGE results indicated that HA absorbed more acidic proteins, while PAM-HA absorbed more basic and neutral proteins.The cell culture test indicated that the cells actively proliferated on the scaffolds. There was no significant difference between the ALP activity of the cells cultured for 1d, 3d, 5d and 7d on PAM-HA and that of the controls. PAM had no obvious effect on the cytocompatibility of HA, and PAM-HA bioceramics could be used as bone scaffold with potential ability to improve osteogenesis.

Abstract: Crystalline hydroxyapatite (HA) and 0.8 wt.% silicon-substituted HA (SiHA) thin films were produced using magnetron co-sputtering. These films were subjected to contact angle measurements and in vitro cell culture study using human osteoblast-like (HOB) cells. A wettability study showed that SiHA has a lower contact angle, and thus is more hydrophilic in nature, as compared to HA. Consequently, enhanced cell growth was observed on SiHA at all time-points. Furthermore, distinct and well-developed actin filaments could be seen within HOB cells on SiHA. Thus, this work demonstrated that the surface properties of the coating may be modified by the substitution of Si into the HA structure.

Abstract: Phosphorylated chitosan (PCS) was used as the template to control hydroxyapatite(HAp) growth, a novel nanocomposite composed of PCS and HAp was synthesized by biomimetic method. Calcium phosphate (Ca 2+= 60mM, Ca/P = 1.67) solution in HCl was added dropwise into PCS solution in NaOH. The precipitate was lyophilized to obtain the composite. The biocompatibility of the PCS-HAp nanocomopite was evaluated by osteoblast culture in vitro. The results showed that low crystallized HAp nanocrystals was formed on the PCS fibers and its crystallographic c-axis were aligned preferentially parallel to the long axis direction of PCS; the composite have good biocompatibility in vitro. It is expected that the novel composite to be a potential material for bone repair.

Abstract: In the present in vitro study, osteoblasts proliferation, vitality and ultrastructure were investigated when cultured in the presence of silver-hydroxyapatite/titania nanoparticles (nAg_HA/TiO2) compared to HA nanoparticles (nHA) at various concentrations and cell culture without nanoparticles for up to 120 hours. Results confirmed the detrimental influences of both nAg_HA/TiO2 and nHA on osteoblast growth.Cell vitality was slightly higher during the earlier 24h, but after that was inhibited. Both cell proliferation and vitality by addition of nanoparticles were restricted with concentrations of nanoparticles increasing. However, the respiration rates by addition of nanoparticles were showed higher than that of the cell culture without nanoparticles. No remarkable ultrastructure changes were showed in the osteoblasts exposed nanoparticles. The difference in cell proliferation, vitality and ultrastructure between nAg_HA/TiO2 and nHA were insignificant. It was demonstrated that biocompatibility of nAg_HA/TiO2 is almost the same as nHA.

Abstract: Novel poly(ε-caprolactone)-organosiloxane hybrid containing amine group was synthesized through sol-gel method. Triethoxysilane end-capped poly(ε-caprolactone) was prepared by reaction with α,ω-hydroxyl poly(ε-caprolactone) and 3-isocyanatopropyl triethoxysilane. It was then hydrolyzed and co-condensed with aminopropyl triethoxysilane through sol-gel method. The success of hybridization was evaluated by FT-IR by new formation of siloxane group. Osteoblast-like cell responses were assessed on this new hybrid material for the potential application as a bone tissue engineering scaffold. The cell responses were compatible with those on pure poly(ε-caprolactone) used as a control.

Abstract: The effect of anodic oxide films produced by β-glycerophosphate (β-GP) and calcium acetate (CA) anodizing on osteoblast-like cell attachment and spreading were evaluated in this study. Anodic oxide films were produced in different conditions: Group 1, 0.02 M β-GP and 0.2 M CA; Group 2, 0.03 M β-GP and 0.2 M CA; Group 3, 0.03 M β-GP and 0.2 M CA. Anodic oxide surface was significantly rougher in comparison to the control untreated titanium surfaces, and the surface roughness and composition of phosphate and oxide increased as the concentration of β-GP was increased. There was no significant difference in the cell viability when cells were cultured on the control or anodized surface using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Scanning electron micrographs revealed more spread cells on the anodized surface than on the smooth control surface. In conclusion, we suggested that the positive effects of anodized surfaces produced by β-GP and CA on spreading of osteoblast-like cells may be the result of the difference of surface roughness and amount of Ca and P in the oxide layer.

Abstract: The response of osteoblast-like cells cultured on blasted and/or acid etching surfaces and the influence of surface texture or microtopography on cell attachment, cell proliferation, and the gene expression of the osteoblastic phenotype using ROS 17/2.8 cell lines were evaluated. The blasted and/or acid etching surfaces were significantly rougher in comparison to machined and etched surfaces (p < 0.05). On X-ray diffraction analysis, titanium hydride (TiH2) was observed on the surface etched with a mixture of HCl-H2SO4 solution, whereas TiH2 was not observed on machined and blasted surfaces. After 24 h incubation, most of the cells of all the groups had a flattened, polygonal shape and were fully spread, exhibiting the onset of proliferation. The MTT assay showed a significant decrease on the blasted surface compared to the machined surface at 7 day culture (p < 0.05). The expression of osteopontin mRNA, α1 (I) collagen mRNA, and alkaline phosphatase mRNA on rough surfaces was higher than on the machined surfaces, and was highest on the blasted surface at day 7.

Abstract: Cranial sutures produce new bone at the sutural edges of the bone fronts in response to external stimuli. Little is known regarding the mechanism of osteogenesis in cranial sutures. Ets1 and Cbfa1 are two important osteogenic transcription factors regulating the differentiation and maturation of osteoblasts. But their function in cranial sutures is not still elucidated. We have investigated the gene expression of Ets1 and Cbfa1 in rat’s calvarial sutural osteoblast-like cells under a single period of mechanical strain. The cells were isolated from the cranial suture of SD rats and cultured in vitro, and subjected to a single 40 minutes mechanical strain using a four-point bending apparatus. The gene expression patterns of Ets1 and Cbfa1 were examined by RT-PCR. Both mRNA levels of Ets1 and Cbfa1 have increased significantly within 6 and 12 hours respectively after mechanical strain were applied, and the increase returned to control level thereafter. However, Ets1 and Cbfa1 exhibited different temporal expression patterns: Ets1 expressed immediately after the mechanical loading and reached the maximum transcription at 0.5h; whereas Cbfa1 experienced a latency period first, then increased slowly within 2 hours, and reached the maximum transcription at 6 h. The maximum transcription of Cbfa1 was about 2.58 fold of that of Ets1. Ets1and Cbfa1 may play different roles in regulating bone matrix protein expressions in osteoblast-like cells during suture distraction and their function is time-dependent. High frequency distraction (>2times/24h) is favourable to the maximal expression of the two genes.