Osteoblastic Lineage (osteoblastic + lineage)

Distribution by Scientific Domains


Selected Abstracts


Formation of three-dimensional cell/polymer constructs for bone tissue engineering in a spinner flask and a rotating wall vessel bioreactor

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2002
Vassilios I. Sikavitsas
Abstract The aim of this study is to investigate the effect of the cell culture conditions of three-dimensional polymer scaffolds seeded with rat marrow stromal cells (MSCs) cultured in different bioreactors concerning the ability of these cells to proliferate, differentiate towards the osteoblastic lineage, and generate mineralized extracellular matrix. MSCs harvested from male Sprague,Dawley rats were culture expanded, seeded on three-dimensional porous 75:25 poly(D,L -lactic- co -glycolic acid) biodegradable scaffolds, and cultured for 21 days under static conditions or in two model bioreactors (a spinner flask and a rotating wall vessel) that enhance mixing of the media and provide better nutrient transport to the seeded cells. The spinner flask culture demonstrated a 60% enhanced proliferation at the end of the first week when compared to static culture. On day 14, all cell/polymer constructs exhibited their maximum alkaline phosphatase activity (AP). Cell/polymer constructs cultured in the spinner flask had 2.4 times higher AP activity than constructs cultured under static conditions on day 14. The total osteocalcin (OC) secretion in the spinner flask culture was 3.5 times higher than the static culture, with a peak OC secretion occurring on day 18. No considerable AP activity and OC secretion were detected in the rotating wall vessel culture throughout the 21-day culture period. The spinner flask culture had the highest calcium content at day 14. On day 21, the calcium deposition in the spinner flask culture was 6.6 times higher than the static cultured constructs and over 30 times higher than the rotating wall vessel culture. Histological sections showed concentration of cells and mineralization at the exterior of the foams at day 21. This phenomenon may arise from the potential existence of nutrient concentration gradients at the interior of the scaffolds. The better mixing provided in the spinner flask, external to the outer surface of the scaffolds, may explain the accelerated proliferation and differentiation of marrow stromal osteoblasts, and the localization of the enhanced mineralization on the external surface of the scaffolds. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 136,148, 2002 [source]


Overexpression of Smurf2 Stimulates Endochondral Ossification Through Upregulation of ,-Catenin,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2008
Qiuqian Wu MD
Abstract Ectopic expression of Smurf2 in chondrocytes and perichondrial cells accelerated endochondral ossification by stimulating chondrocyte maturation and osteoblast development through upregulation of ,-catenin in Col2a1-Smurf2 embryos. The mechanism underlying Smurf2-mediated morphological changes during embryonic development may provide new mechanistic insights and potential targets for prevention and treatment of human osteoarthritis. Introduction: Our recent finding that adult Col2a1-Smurf2 mice have an osteoarthritis-like phenotype in knee joints prompted us to examine the role of Smurf2 in the regulation of chondrocyte maturation and osteoblast differentiation during embryonic endochondral ossification. Materials and Methods: We analyzed gene expression and morphological changes in developing limbs by immunofluorescence, immunohistochemistry, Western blot, skeletal preparation, and histology. A series of markers for chondrocyte maturation and osteoblast differentiation in developing limbs were examined by in situ hybridization. Results: Ectopic overexpression of Smurf2 driven by the Col2a1 promoter was detected in chondrocytes and in the perichondrium/periosteum of 16.5 dpc transgenic limbs. Ectopic Smurf2 expression in cells of the chondrogenic lineage inhibited chondrocyte differentiation and stimulated maturation; ectopic Smurf2 in cells of the osteoblastic lineage stimulated osteoblast differentiation. Mechanistically, this could be caused by a dramatic increase in the expression of ,-catenin protein levels in the chondrocytes and perichondrial/periosteal cells of the Col2a1-Smurf2 limbs. Conclusions: Ectopic expression of Smurf2 driven by the Col2a1 promoter accelerated the process of endochondral ossification including chondrocyte maturation and osteoblast differentiation through upregulation of ,-catenin, suggesting a possible mechanism for development of osteoarthritis seen in these mice. [source]


Titanium foam-bioactive nanofiber hybrids for bone regeneration

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 8 2008
Timothy D. Sargeant
Abstract We have reported previously a method to introduce bioactive nanofiber networks through self-assembly into the pores of titanium alloy foams for bone repair. In this study we evaluate the in vitro colonization by mouse pre-osteoblastic cells of these metal,peptide amphiphile hybrids containing phosphoserine residues and the RGDS epitope. The aim was to determine the effect of varying the RGDS epitope concentration within a given range, and confirm the ability for cells to infiltrate and survive within the nanofiber-filled interconnected porosity of the hybrid material. We performed proliferation (DNA content) and differentiation assays (alkaline phosphatase and osteopontin expression) as well as SEM and confocal microscopy to evaluate cell colonization of the hybrids. At the RGDS epitope concentrations used in the nanofiber networks, all samples demonstrated significant cell migration into the hybrids, proliferation, and differentiation into osteoblastic lineage. Copyright © 2008 John Wiley & Sons, Ltd. [source]


A Murine Osteosarcoma Cell Line with a Potential to Develop Ossification upon Transplantation

CANCER SCIENCE, Issue 6 2001
Tomomi Kusumi
An Osteosarcoma cell line has been established from a soft tissue tumor that occurred spontaneously in a BALB/c mouse. This cell line showed ossification when transplanted into syngeneic mice. To examine the mechanism of bone formation, the expression of mRNAs for osteoblastic and chon-droblastic markers and factors associated with ossification has been investigated. In culture, the cells exhibited a spindle shape in the growth phase, but had a polygonal shape in the stationary phase. Reverse transcription-polymerase chain reaction analysis showed that the cells expressed mRNAs for pro-,(I) chain of type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and core binding factor al, suggesting differentiation into the stage of osteoblasts during the stationary phase. After transplantation, histological examination revealed small foci of pale blue material and basophilic networks that were scattered in the tumor tissues at one week. The former stained positive with alcian blue, suggesting a chondroid matrix. Pro-,(II) chain of type II collagen mRNA was expressed at one week. A large part of tumors at two and three weeks consisted of basophilic networks, which stained positive via von Kossa's method, indicating a calcified woven bone. In situ hybridization analysis showed strong expression of osteopontin and osteocalcin mRNAs in tumor cells surrounding the bone matrix. Bone morphogenetic protein-6 and -7 mRNAs were detected in transplanted tumors, but not in cultured cells. These results suggest that the cell line has the properties of an osteoblastic lineage when cultured in vitro and has an ossifying ability through endochondral bone formation processes when transplanted in vivo. [source]


Adhesion pattern and growth of primary human osteoblastic cells on five commercially available titanium surfaces

CLINICAL ORAL IMPLANTS RESEARCH, Issue 7 2010
Giovanni Passeri
Abstract Objective: The aim of this study is to analyze the morphology and proliferation of human osteoblastic cells in vitro on five commercially available titanium surfaces. Materials and methods: Human primary cells of the osteoblastic lineage were obtained from bone explants. The cells were plated on polished (T1), machined (T2), sand-blasted/acid-etched (T3), sand-blasted/acid-etched, modified with hydrogen peroxide rinse (T4), and plasma-sprayed titanium (T5) disks. Cell morphology was studied after 6, 24, 72 h, 7 and 14 days of culture by scanning electron microscopy. The formation and distribution of focal adhesions was investigated by immunocytochemical staining at 3, 6 and 24 h. Cell growth was measured by an MTT assay after 3, 7 and 9 days of culture. Moreover, the production of osteocalcin and osteoprotegerin (OPG) was evaluated in the supernatants by ELISA. Results: Morphological analysis revealed that substrate topography profoundly affected cells' shape and their anchoring structures. Large lamellipodia were formed on polished and machined surfaces, while thin filopodia were more frequently observed on T3 and T4 samples. Moreover, cells formed stronger focal adhesions on T3 and T4 surfaces, and cell proliferation was higher on rough surfaces. Osteocalcin production was higher on the T4 surface, whereas OPG steadily increased on every surface. Conclusions: Taken together, these data show that all the surfaces allowed cell attachment, adhesion and proliferation, but T4 and T5 surfaces appeared to be a better substrate for the adhesion, proliferation and differentiation of cells of the osteoblastic lineage. To cite this article: Passeri G, Cacchioli A, Ravanetti F, Galli C, Elezi E, Macaluso GM. Adhesion pattern and growth of primary human osteoblastic cells on five commercially available titanium surfaces. Clin. Oral Impl. Res. 21, 2010; 756,765. doi: 10.1111/j.1600-0501.2009.01906.x [source]