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Biomedical Engineering and Bioengineering Commons™
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Articles 1 - 6 of 6
Full-Text Articles in Biomedical Engineering and Bioengineering
The Effect Of Peo Ratio On Degradation, Calcification And Bone Bonding Of Peo/Pbt Copolymer (Polyactive), C. A. Van Blitterswijk, J. V.D. Brink, H. Leenders, D. Baaker
The Effect Of Peo Ratio On Degradation, Calcification And Bone Bonding Of Peo/Pbt Copolymer (Polyactive), C. A. Van Blitterswijk, J. V.D. Brink, H. Leenders, D. Baaker
Cells and Materials
In this study, we evaluated the effect of PEO/ PBT proportion on the behavior of a range of PEO/ PBT segmented copolymers (Polyactive) during subcutaneous and intrabony implantation in the rat. It was demonstrated that varying the PEO proportion affected degradation, calcification and bone-bonding. The PEO/PBT 70/30 and 60/40 showed extensive degradation after 1 year, PEO/PBT 55145 an intermediate degradation, and the 40/60 and 30170 copolymers showed little and hardly any degradation respectively. PEO content also affected the degree of calcification . PEO/PBT 70/30 showed extensive and early calcification whereas almost no calcification was seen with PEO/PBT 30170. Since calcified …
Scanning Electron Microscopy Of The Osteoclast-Bone Interface In Vivo, H. Zhou, R. Chernecky, J. E. Davies
Scanning Electron Microscopy Of The Osteoclast-Bone Interface In Vivo, H. Zhou, R. Chernecky, J. E. Davies
Cells and Materials
Rat femoral bones were studied by scanning electron microscopy to demonstrate the morphology of osteoclast- bone matrix interfacial relationships. Two general morphological types of actively resorbing osteoclasts were observed . One cell type was approximately ovoid with highly fimbriated borders, fully attached and closely adapted to the resorption surface. The ruffled border of such cells was composed of a number of individual filopodia which were of uniform , regular shape and approximately 2-3 μm in length and 150 nm in diameter. They were found to penetrate the bone matrix to a depth of 1 μm and interdigitated with the surrounding …
Ultrastructural, Cytochemical, And Immunocytochemical Studies On Bone And Its Interfaces, M. D. Mckee, A. Nanci
Ultrastructural, Cytochemical, And Immunocytochemical Studies On Bone And Its Interfaces, M. D. Mckee, A. Nanci
Cells and Materials
Bone cells possess the ability to synthesize, secrete and direct the assembly and maintenance of extracellular matrix to form a functionally rigid and/or weight-bearing mineralized tissue complex, the skeleton. The skeleton not only supports and protects the organs and tissues of the body, but also acts as a mineral ion reservoir for maintaining systemic calcium balance (calcium homeostasis). The remarkable biological precision necessary for the formation, turnover and constant adaptation of bone to external mechanical forces is a dynamic process requiring a coordinated cellular effort relying on a variety of cell-cell and cell-matrix/mineral interactions. Indeed, cell-matrix interfaces found in a …
A Comparative Study Of The Interactions Of Two Calcium Phosphates, Peo/Pbt Copolymer (Polyactive) And A Silicone Rubber With Bone And Fibrous Tissue, C. A. Van Blitterswijk, J. R. De Wijn, H. Leenders, J. V.D. Brink, S. C. Hesseling, D. Bakker
A Comparative Study Of The Interactions Of Two Calcium Phosphates, Peo/Pbt Copolymer (Polyactive) And A Silicone Rubber With Bone And Fibrous Tissue, C. A. Van Blitterswijk, J. R. De Wijn, H. Leenders, J. V.D. Brink, S. C. Hesseling, D. Bakker
Cells and Materials
In this study, hydroxyapatite, tetracalcium phosphate, HPEO/PBT 55145 copolymer, PEO/PBT 55!45 copolymer (Polyactive) and silicone rubber were implanted as dense blocks, subcutaneously and. into the tibia of rats. Biocompatibility and degradation were investigated but most attention was directed to .the bone/biomaterial interactions. None of the materials showed any significant adverse tissue reactions. With exception of the silicone rubber, all materials sho~ed bone bonding phenomena based on both morphological and mechanical evaluations. (H)PEO/PBT 55145 copolymer is the first polymer reported to be bonded by bone and thus widens the spectrum of bone bonding materials with a low modulus, degradable, elastomer in …
Immunocytochemical And Lectin-Gold Characterization Of The Interface Between Alveolar Bone And Implanted Hydroxyapatite In The Rat, H. Kawaguchi, M. D. Mckee, H. Okamoto, A. Nanci
Immunocytochemical And Lectin-Gold Characterization Of The Interface Between Alveolar Bone And Implanted Hydroxyapatite In The Rat, H. Kawaguchi, M. D. Mckee, H. Okamoto, A. Nanci
Cells and Materials
The tissue response to implanted hydroxyapatite (HAP) in rat alveolar bone was investigated using morphological and cytochemical approaches. High-resolution immunogold labeling was used to examine the distribution of two non-collagenous bone proteins, osteopontin and osteocalcin, and two plasma proteins, a2HSglycoprotein (fetuin) and albumin. Glycoconjugates were characterized by lectin-gold cytochemistry using Ricinus communis I agglutinin and Wheat germ agglutinin. Transmission electron microscopy demonstrated the presence of an electron-dense, lamina limitans-like layer at the HAP particle-bone interface and organic material within the micropores of the particles. Mineral was observed in relation to both these sites. The HAP particle-bone interface was strongly …
Bone Growth On Sol-Gel Calcium Phosphate Thin Films In Vitro, Q. Qiu, P. Vincent, B. Lowenberg, M. Sayer, J. E. Davies
Bone Growth On Sol-Gel Calcium Phosphate Thin Films In Vitro, Q. Qiu, P. Vincent, B. Lowenberg, M. Sayer, J. E. Davies
Cells and Materials
Thin, sub-micron, films of calcium phosphate were fabricated on either glass or quartz supports by a colloidal suspension sol-gel method. These films, which varied in both surface chemistry and topography were then employed as culture substrata for osteogenic rat bone marrow cells. During an 18 day culture period, the cells elaborated a morphologically distinguishable bone matrix on all substrata which was similar to that reported earlier on tissue culture polystyrene. Selected samples of the culture substrata were fractured, critical point dried, and observed by scanning electron microscopy. Particular attention was paid to the morphologies of the interface between the so1-gellayer …