Papers by Keyword: Bone Marrow Cell

Abstract: The main purpose of this study is to synthesize nano-hydroxyapatite/cellulose (nHAP/Cel) and nano-hydroxyapatite/chitosan (nHAP/CS) scaffolds via co-precipitation method for bone tissue engineering due to their suitable biocompatibility, cytotoxicity and mechanical properties. The characterizations of these scaffolds were investigated by Infrared absorption spectra (FT-IR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The cytotoxicity of these nanoparticles was evaluated with bone marrow cell using the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazoliumbromide) (MTT) assay. The porosity of scaffolds was estimated 87%. The results indicate that the nano composite scaffolds have good morphology, tissue biocompatibility and biodegradability to be used for tissue engineering.

Abstract: The aim of this research work was to investigate in vitro effect of the carbonate apatite/poly (ε-caprolactone) (CO₃Ap/PCL) on α-tricalcium phosphate (α-TCP) foam was produced by sintering CaCO₃ and CaHPO₄2H₂O at 1500°C for 5 h. It was then coated with carbonate apatite (CO₃Ap)/Poly-ε-caprolactone (PCL) (wt/wt=1/3) to improve both mechanical and biological properties. The initial cell attachment and proliferation of the bone marrow cells were carried out on the α-TCP and CO₃Ap/PCL-coated α-TCP foams. The cell proliferation was calculated by AlamarBlue assay. The cells were able to migrate and proliferate well on both α-TCP and CO₃Ap/PCL-coated α-TCP foams indicating an excellent biocompatibility. The incorporation of CO₃Ap on the coating layer improved cellular attachment and accelerated proliferation. Thus, CO₃Ap/PCL-coated α-TCP foam might be a promising candidate as implant material.

Abstract: In recent years, it has been proposed that the new era of implants design should be focused on the use of the new generation of biocompatible materials or reengineers the currently available materials. The objective of this research was to study cell-metal interactions using highly porous TiO2 foam. To obtain the porous TiO2 foam, polymeric foam replication methods might be one of the most effective methods. Surface chemical composition, morphology and phase are investigated by field emission scanning electron microscope (FESEM) and X-Ray Diffraction (XRD). In vitro cellular response of cells has been studied on TiO2 foam. In the investigations of the cellular responses of cells, two aspects were considered: the number of growing cells and their morphological features. It was clear that rough surface morphology was important factor for better cell-metal interaction. Surface topography can affect the cell migratory significantly and adhesion behavior on implant surfaces.

Abstract: Appropriate culture conditions cause bone marrow stem cells to differentiate into multilineage cells such as adipocytes, chondrocytes, and osteoblasts. One key factor that regulates intercellular signaling and cell differentiation is the extracellular matrix microenvironment. The composition of the extracellular matrix influences cellular functions. In the present study, we investigated the effects of a microenvironment comprising a three-dimensional apatite-fiber scaffold (AFS) that has two kinds of pores (micro- and macro pores) on proliferation and subsequent differentiation of bone marrow stem cells. Morphologic observation revealed that osteoblastic cells in the AFS were distributed primarily in the same location on the fibrous scaffold and formed bridges within micro- and macro pores. We used molecular approaches to evaluate cell proliferation and differentiation in detail. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that culturing bone marrow cells on AFS increases expression of osteocalcin (OC) mRNA compared with culture in a dish. Furthermore, cells cultured in AFS expressed type X collagen (Col X), which is a marker of hypertrophic cartilage. These data suggest that the three-dimensional microenvironment of AFS facilitates cell proliferation and differentiation, and promotes endochondral ossification of bone marrow cells.

Abstract: Porous Titanium Scaffolds were produced by using a rapid prototyping technique. These scaffolds were either coated or not with a calcium phosphate coating via an eletrodeposition method. Rat bone marrow mesenchymal stem cells were cultured on the scaffolds at a density of 106 cells/scaffold for a period of 3 days. Cell proliferation was measured by using the Alamar Blue assay. The scaffolds were observed by SEM and polarized light microscopy. Constructs were then implanted subcutaneously for 4 weeks in syngenic rats. Cells proliferated well after seeding. After subcutaneous implantation, histology and SEM revealed the presence of uniform coatings as well as Ca and P deposits in the non-coated scaffolds suggesting mineralization.

Abstract: The purpose of this study was to estimate influence of lysine for osteogenesis in the porous hydroxyapatite (HA) scaffolds with bone marrow cells. The HA scaffolds were soaked in 100mM concentration of lysine solution. They were kept in bone marrow cell suspension at 1×106 cells/ml density. Another HA scaffolds without immersion in lysine solution were kept in the cell suspension at 1×106 or 1×107 cells/ml density. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. In several sections, total pores and ones with bone were counted. Many pores containing bone were found in1×107 cells/ml concentration group. The significant difference was between 1×107 cells/ml group, the lysine group, and 1×106 cells/ml group. Although more bone formation was seen in lysine group than in 1×106 cells/ml group. There was no significant difference between the groups. Concentration of lysine to add in culture medium or scaffold should be improved respectively.

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: The purpose of this study was to estimate hard tissue formation in two types of porous columnar hydroxyapatite (HA) in order to use as a scaffold for regeneration of dentine-pulp complex. Hard tissue formation in the columnar HA scaffold with a hollow center was compared to that in the columnar HA scaffold without a hollow center. The scaffolds were immersed in hyaluronic acid sodium salt solution and were soaked in bone marrow cell suspension. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. The scaffolds with a hollow center showed new hard tissue formation in many pores between the superficies and the wall of hollow. On the other hand, in the scaffolds without a hollow center, hard tissue formation was observed in only a few pores in the area near the external superficies. The results of this study suggested that the supply of nutrition and bioactive substance from the surrounding tissue were indispensable for differentiation of bone marrow cells and formation of new hard tissue in scaffold. A large contact area of a scaffold to the surrounding tissue may contribute to nutrition supply into the pores.

Abstract: Osseous tissue can be formed by culturing marrow cells with compounds such as dexamethasone and that a bone matrix cultured in this manner possesses BMP activity. We have reported that artificial bones with a high level of osteogenic potential can be prepared by culturing artificial bone materials with cultured osseous tissue. Here, in an attempt to develop activated cultured bone constructs with even greater osteogenic potential, the effects of the female hormone estriol on osteogenesis were investigated. Bone marrow cells were collected from the femur shafts of 7-week-old male Fischer rats, and subjected to primary and secondary cultures. During secondary culture with or without dexamethasone (Dx), 10-5, 10-6, 10-7, 10-8 or 10-9 M of estriol was added to a standard culture medium containing ascorbic acid and β-glycerophosphosphate. The alkaline phosphatase(ALP) activity and Ca levels were measured and statistically analyzed. There was a significant difference in ALP activity between the control group and the estriol groups, and ALP activity was the highest in the 10-7 and 10-8 M groups, being about 2.5 times higher than in the control group. Similar results were seen for Ca levels. Furthermore, in vivo study showed10-7M-estriol-treated-cultured bone/ceramic construct has significant high osteogenic potential when it is grafted into in vivo. Estriol has been reported to increase bone mass, and the results of the present study suggest that the osteogenic potential of cultured bone constructs can be more than doubled by adjusting the concentration of estriol in bone marrow cell culture. Therefore, the use of estriol may be able to facilitate osteogenesis in bone regeneration therapy.