title: Three-dimensional cultures of normal human osteoblasts: proliferation and differentiation potential in vitro and upon ectopic implantation in nude mice.
abstract: We report the establishment in vitro of three-dimensional (3D) cultures of human osteoblasts (hOB) derived from normal adults and supported uniquely by the extracellular matrix (ECM) they deposit. Osteoblasts were cultured in 3D cultures in vitro for up to 120 days. The 3D cultures, examined at 25, 31, and 48 days, expressed protein markers of osteoblastic cells, namely osteonectin, collagen type I, fibronectin, osteopontin, bone sialoprotein, biglycan, and decorin. Sequentially, alkaline phosphatase (AP) and then Ca incorporation, mineralization of matrix (monitored by histochemistry and transmission electron microscopy), and finally osteocalcin expression, were detected in the 3D cultures. Ultrastructurally, morphology progressed from early to mature osteoblast and to osteocyte-like. Cells were embedded in a matrix with organized collagen type I fibers containing, increasingly with time of culture, needle-shaped crystals, often associated with matrix vesicles, characteristic of those in bone. During the culture (up to 120 days) there was an outgrowth of proliferating osteogenic cells from the 3D structure. Subcutaneous implantation in nude mice for 20 days of osteoblasts cultured in 3D culture for different lengths of time in vitro, showed progression of mineralization from the inner region of the implant outward, with peripheral cells being embedded in nonmineralized, collagen-rich matrix. The 3D implants were invaded by vessels derived from the host.
authors: Dipartimento di Oncologia, Biologia e Genetica, Università di Genova, C. Europa 26, Genoa 16132, Italy.
authors: D
authors: D
authors: Ferrera
authors: S
authors: S
authors: Poggi
authors: C
authors: C
authors: Biassoni
authors: G R
authors: GR
authors: Dickson
authors: S
authors: S
authors: Astigiano
authors: O
authors: O
authors: Barbieri
authors: A
authors: A
authors: Favre
authors: A T
authors: AT
authors: Franzi
authors: A
authors: A
authors: Strangio
authors: A
authors: A
authors: Federici
authors: P
authors: P
authors: Manduca
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D002113:Calcification, Physiologic / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation; D002455:Cell Division; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008854:Microscopy, Electron; D008875:Middle Aged; D009368:Neoplasm Transplantation; D010006:Osteoblasts / Q000378:metabolism / Q000637:transplantation* / Q000648:ultrastructure*; D010012:Osteogenesis / Q000502:physiology
chemical_list: D015415:Biomarkers; D000469:Alkaline Phosphatase; D002118:Calcium