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Full-Text Articles in Engineering
Primary Bone Formation In Porous Hydroxyapatite Ceramic: A Light And Scanning Electron Microscopic Study, M. Okumura, H. Ohgushi, S. Tamai, E. C. Shors
Primary Bone Formation In Porous Hydroxyapatite Ceramic: A Light And Scanning Electron Microscopic Study, M. Okumura, H. Ohgushi, S. Tamai, E. C. Shors
Cells and Materials
Porous hydroxyapatite ceramics combined with rat marrow cells were implanted subcutaneously in the back of syngeneic Fischer rats . Fluorochrome-labeling (calcein, tetracycline) was performed post-operatively and the ceramics were harvested 4 weeks after implantation. Undecalcified thin sections of the implants were observed under light microscopy or fluoromicroscopy and the corresponding areas were also analyzed in a scanning electron microscope connected to an electron probe microanalyzer (SEM-EPMA). Many pore areas of the ceramics showed bone and osteoid formation together with active osteoblasts. The bone formation began directly on the surface of the ceramic and proceeded in a centripetal direction towards the …
Ultrastructural Study Of Bone Formation On Synthetic Hydroxyapatite In Osteoblast Cultures, J. M. Sautier, J. R. Nefussi, N. Forest
Ultrastructural Study Of Bone Formation On Synthetic Hydroxyapatite In Osteoblast Cultures, J. M. Sautier, J. R. Nefussi, N. Forest
Cells and Materials
Collagenase isolated rat calvaria cells forming a mineralized matrix in vitro were cultured in the presence of synthetic hydroxyapatite. Interactions between bone cells and hydroxyapatite biomaterial were followed by transmission electron microscopy. The appearance of a granular, collagen free, electron-dense layer at the periphery of the material was noted initially. Progressively, an amorphous, granular material formed and extended between the hydroxyapatite aggregates. Osteoblastic cells then synthesized an osteoid matrix which mineralized on the first formed granular collagen free layer, following a classical pattern of calcification . Demineralization of ultrathin sections confirmed the presence of this interface between the material and …
A Comparative Study Of Bovine Pericardium Mineralization: A Basic And Practical Approach, Branko B. Tomazic, Chakwan Siew, Walter E. Brown
A Comparative Study Of Bovine Pericardium Mineralization: A Basic And Practical Approach, Branko B. Tomazic, Chakwan Siew, Walter E. Brown
Cells and Materials
The biomineralization of bovine pericardium (BP) heart valve bioprostheses was investigated by simulation of the process under in vitro and in vivo conditions. The nature and composition of calcific deposits that formed in human heart valve bioprostheses were compared with the mineral formed on BP discs immersed in a calcifying medium or subcutaneously implanted into Sprague-Dawley rats. The early stage of experimental biomineralization in vitro took place on the surface only, while in vivo deposition appeared to be intrinsic, as documented by histological cross sections. The chemical composition of the initial mineral phase formed under in vitro conditions had a …