Characterization of Different Nanostructured Bone Substitute Biomaterials

2014 ◽  
Vol 936 ◽  
pp. 695-700 ◽  
Author(s):  
Nelson Levandowski ◽  
Nelson H.A. Camargo ◽  
Daiara F. Silva ◽  
Gisele M.L. Dalmônico ◽  
Priscila F. Franczak
Keyword(s):  
Tricalcium Phosphate ◽  
Physicochemical Characterization ◽  
Bone Substitutes ◽  
Second Phase ◽  
State University ◽  
Transformation Kinetics ◽  
Beta Tricalcium Phosphate ◽  
Molecular Events ◽  
Kinetics Of

The present research paper centers on physicochemical characterization of six nanostructured alloplastic bone substitutes developed at Santa Catarina State University (UDESC Brazil). In addition to identifying the main phases, the focus was to measure the morphological and microstructural features, which are believed to be crucial for controlling and guiding biological and molecular events. The studied samples exhibited rounded granules measuring 200μm 10(PO4)6(OH)2] was found as main phase for HAp, BCP and HAp/Al2O3 biomaterials. For HAp/TiO2n, HAp/SiO2n and β-TCP, the major phase was beta tricalcium phosphate [Ca3(PO4)2-β]. The results demonstrate that the presence of a second phase of nanometer order, at a hydroxyapatite bioceramic matrix, may modify the surface diffusion of the grains and the phase transformation kinetics of hydroxyapatite and beta tricalcium phosphate at temperatures up to 1100°C.

scholarly journals Comparison of hydroxyapatite and beta tricalcium phosphate as bone substitutes after excision of bone tumors

2004 ◽  
Vol 72B (1) ◽  
pp. 94-101 ◽  
Author(s):  
Akira Ogose ◽  
Tetsuo Hotta ◽  
Hiroyuki Kawashima ◽  
Naoki Kondo ◽  
Wenguang Gu ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Bone Tumors ◽  
Bone Substitutes ◽  
Beta Tricalcium Phosphate

Characterization of Kinetics of Deformation-Enhanced Transformation in a Low Carbon Steel

2005 ◽  
Vol 475-479 ◽  
pp. 73-76
Author(s):  
Jun Jie Qi ◽  
Wang Yue Yang ◽  
Zu Qing Sun ◽  
X. Zhang
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Microstructural Development ◽  
Low Carbon ◽  
Transformation Kinetics ◽  
Nucleation Sites ◽  
Ferrite Nucleation ◽  
Kinetics Of ◽  
Kinetics Parameter

Quantitative characterization of microstructural development during deformation enhanced transformation in a low carbon steel was investigated on a Gleeble 1500 machine. General conclusions of the features of austenite transformation kinetics during deformation-enhanced transformation were formulated. It was shown that the process of deformation-enhanced transformation can be divided into three stages according to the characteristics of transformation kinetics: The kinetics equations of two early stages fitted well in J-M-A equation. The kinetics of the first stage obeys Cahn’s site saturation mechanism, with the value of kinetics parameter n of 4. Ferrite nucleates at austenite grain boundaries and triple points during the first stage. Kinetics of the second stage doesn’t obey Cahn’s theory, with the value of kinetics parameter n of 1-1.5, corresponding to ferrite nucleation repeatedly at areas with high stored energy in front of the ferrite/austenite interface. The kinetics doesn’t obey the law of J-M-A equation any more in the final stage, and only few nucleation sites left at this moment.

scholarly journals Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dajiang Du ◽  
Teruo Asaoka ◽  
Makoto Shinohara ◽  
Tomonori Kageyama ◽  
Takashi Ushida ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Porous Ceramic ◽  
Vital Staining ◽  
Bone Substitutes ◽  
Computer Assisted ◽  
Beta Tricalcium Phosphate ◽  
Ceramic Slurry ◽  
Internal Network ◽  
Rabbit Bone ◽  
Rabbit Femur

Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (β-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects.

scholarly journals Preparation and characterization of LA/PCL composite fibers containing beta tricalcium phosphate (β-TCP) particles

2014 ◽  
Vol 40 (3) ◽  
pp. 5049-5054 ◽  
Author(s):  
Chan-Hee Park ◽  
Eun Kyo Kim ◽  
Leonard D. Tijing ◽  
Altangerel Amarjargal ◽  
Hem Raj Pant ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Composite Fibers ◽  
Beta Tricalcium Phosphate

scholarly journals FABRICATION AND CHARACTERIZATION OF β-TRICALCIUM PHOSPHATE COMPOSITE WITH ALGINATE

2005 ◽  
Vol 19 (0) ◽  
pp. 136-141
Author(s):  
Hiroshi ENDO ◽  
Kiyoshi ITATANI ◽  
Tomohiro UMEDA ◽  
Seiichiro KODA
Keyword(s):  
Tricalcium Phosphate ◽  
Beta Tricalcium Phosphate ◽  
Fabrication And Characterization

Synthesis and Characterization of Beta Tricalcium Phosphate

2003 ◽  
Vol 240-242 ◽  
pp. 489-492 ◽  
Author(s):  
A. Destainville ◽  
A. Rolo ◽  
Eric Champion ◽  
Didier Bernache-Assollant
Keyword(s):  
Tricalcium Phosphate ◽  
Synthesis And Characterization ◽  
Beta Tricalcium Phosphate

scholarly journals Molecular Mediators for Raft-dependent Endocytosis of Syndecan-1, a Highly Conserved, Multifunctional Receptor

2013 ◽  
Vol 288 (20) ◽  
pp. 13988-13999 ◽  
Author(s):  
Keyang Chen ◽  
Kevin Jon Williams
Keyword(s):  
Src Family Kinases ◽  
Second Phase ◽  
Alanine Scanning Mutagenesis ◽  
Detailed Characterization ◽  
Recent Interest ◽  
Molecular Events ◽  
Remnant Lipoproteins ◽  
Two Phases ◽  
Hiv 1

Endocytosis via rafts has attracted considerable recent interest, but the molecular mediators remain incompletely characterized. Here, we focused on the syndecan-1 heparan sulfate proteoglycan, a highly conserved, multifunctional receptor that we previously showed to undergo raft-dependent endocytosis upon clustering. Alanine scanning mutagenesis of three to five consecutive cytoplasmic residues at a time revealed that a conserved juxtamembrane motif, MKKK, was the only region required for efficient endocytosis after clustering. Endocytosis of clustered syndecan-1 occurs in two phases, each requiring a kinase and a corresponding cytoskeletal partner. In the initial phase, ligands trigger rapid MKKK-dependent activation of ERK and the localization of syndecan-1 into rafts. Activation of ERK drives the dissociation of syndecan-1 from α-tubulin, a molecule that may act as an anchor for syndecan-1 at the plasma membrane in the basal state. In the second phase, Src family kinases phosphorylate tyrosyl residues within the transmembrane and cytoplasmic regions of syndecan-1, a process that also requires MKKK. Tyrosine phosphorylation of syndecan-1 triggers the robust recruitment of cortactin, which we found to be an essential mediator of efficient actin-dependent endocytosis. These findings represent the first detailed characterization of the molecular events that drive endocytosis of a raft-dependent receptor and identify a novel endocytic motif, MKKK. Moreover, the results provide new tools to study syndecan function and regulation during uptake of its biologically and medically important ligands, such as HIV-1, atherogenic postprandial remnant lipoproteins, and molecules implicated in Alzheimer disease.

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