Analysis of the Resorption of Calcium Phosphate Cement by Using High-Resolution X-Ray 3-D CT

High resolution X-ray CT is a powerful means for analyzing comprehensive ceramic biomaterials in a living body. The benefit of this method is that morphological and volume changes of implant materials can be evaluated without retrieve of the implant in an animal body, resulting in no killing of the animals and long term evaluation even more than one year. In this study, in situ techniques for observation of calcium phosphate cement is developed. Calcium phosphate cement (CPC) was implanted into a femur and under skin of a rat. The volume and morphology change of the CPC were repeatedly measured using the same rat for more than 12 months. The 3-dimentional (3-D) structures of the CPC were imaged and reconstructed from hundreds of 2-D cross sectional CT images, which were obtained at one time by a 360 degree rotation of the sample. The structure of the CPC was visualized with 3-D, and the volume were numerically analyzed by using a 3-D structure analyzing computer software, which enabled two-value processing and estimation of the quantities of the CPC. Moreover some of the CPC samples were retrieved and were observed by SEM. In the results, the surface of the calcium phosphate cement changed from smooth to jagged with increasing implanted period. The CPC volume implanted into bone was gradually decreased with increasing implanted period. The volume loss was 8 % after 12 months. The CPC volume under skin after 1 month increased by 7 %. After that the volume gradually decreased in next 3 months. Absorption process of CPC in a rat will be discussed.

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Fabrication and evaluation of calcium phosphate cement scaffold with controlled internal channel architecture and complex shape

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/09544119jeim302 ◽

2007 ◽

Vol 221 (8) ◽

pp. 951-958 ◽

Cited By ~ 8

Author(s):

X Li ◽

D Li ◽

B Lu ◽

L Wang ◽

Z Wang

Keyword(s):

Tissue Engineering ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Complex Shape ◽

X Ray Diffraction ◽

X Ray ◽

Precise Control ◽

Internal Channel ◽

Channel Architecture

The ability to have precise control over internal channel architecture, porosity, and external shape is essential for tissue engineering. The feasibility of using indirect stereo-lithography (SL) to produce scaffolds from calcium phosphate cement materials for bone tissue engineering has been investigated. The internal channel architecture of the scaffolds was created by removal of the negative resin moulds made with SL. Scanning electron microscopy (SEM) showed highly open, well-interconnected channel architecture. The X-ray diffraction examination revealed that the hydroxyapatite phase formed at room temperature in the cement was basically stable up to 850 °C. There was no phase decomposition of hydroxyapatite, although the crystallinity and grain size were different. The ability of resulting structure to support osteoblastic cells culture was tested in vitro. Cells were evenly distributed on exterior surfaces and grew into the internal channels of scaffolds. To exploit the ability of this technique, anatomically shaped femoral supracondylar scaffolds with 300-800 μm interconnected channels were produced and characterized.

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Evaluation of resistance to fragmentation of injectable calcium-phosphate cement paste using X-ray microcomputed tomography

Journal of the Ceramic Society of Japan ◽

10.2109/jcersj2.16199 ◽

2017 ◽

Vol 125 (1) ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Kohei NAGATA ◽

Kei FUJIOKA ◽

Toshiisa KONISHI ◽

Michiyo HONDA ◽

Masaki NAGAYA ◽

...

Keyword(s):

Calcium Phosphate ◽

Cement Paste ◽

Calcium Phosphate Cement ◽

Microcomputed Tomography ◽

X Ray

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Setting Characteristics and High Compressive Strength of an Anti-washout, Injectable Calcium Phosphate Cement Combined with Thermosensitive Hydrogel

Materials ◽

10.3390/ma13245779 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5779

Author(s):

Yao Xie ◽

Jia Liu ◽

Shu Cai ◽

Xiaogang Bao ◽

Qianqian Li ◽

...

Keyword(s):

Compressive Strength ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Photoelectron Spectroscopy ◽

Setting Time ◽

Volume Ratio ◽

Hydration Product ◽

Thermosensitive Hydrogel ◽

Early Hydration ◽

X Ray

In this work, a thermosensitive poly(D,L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D,L-lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel was introduced into calcium phosphate cement (CPC) to enhance the anti-washout property of CPC. The effects of the hydrogel on the setting time, injectability, anti-washout property and compressive strength of CPC were thoroughly investigated. The results showed that the hydrogel significantly increased the injectability and anti-washout property of CPC, meanwhile maintained the setting time with an acceptable range. Moreover, the hydrogel improved the initial compressive strength of CPC. The composite cement with 20% v/v hydrogel in the liquid phase showed fine crystals of hydration product, a more compact microstructure and lower porosity compared with control CPC. The analysis of X-ray diffraction (XRD), infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) indicated that suitable volume ratio of hydrogel (20% v/v) in the setting liquid of CPC could promote the formation of hydroxyapatite in the early hydration period. The degradation behavior of the cement was characterized by immersion tests in simulated body fluid. The hydrogel had no adverse effect on the degradation rate of CPC over the immersion period of 23 days. This study indicated that incorporating PLGA-PEG-PLGA hydrogel could be a promising strategy to reinforce the handing properties and initial compressive strength of calcium phosphate cement.

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Injectability of a Macroporous Calcium Phosphate Cement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.284-286.157 ◽

2005 ◽

Vol 284-286 ◽

pp. 157-160 ◽

Cited By ~ 7

Author(s):

J.A. Delgado ◽

I. Harr ◽

Amisel Almirall ◽

Sergio del Valle ◽

Josep A. Planell ◽

...

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Tricalcium Phosphate ◽

Extrusion Process ◽

X Ray Diffraction ◽

Foaming Agent ◽

X Ray ◽

Ir Analysis ◽

Hydrolysis Of

In this work an injectable and self setting calcium phosphate/albumen foam is developed. The effect of both the amount of albumen and the particle size of the starting a-tricalcium phosphate (a-TCP) powder on the injectability of the cement paste is studied. X-ray diffraction (XRD) and infrared (IR) analysis of the samples reveal that the hydrolysis of a-TCP to calcium deficient hydroxyapatite (CDHA) is not affected by the addition of albumen. A foamed structure formed by spherical pores with diameters between 100 and 500 µm is observed by SEM. This porous structure is maintained after injection of the paste, although some deformation of the pores is produced due to the extrusion process. The injectability of the cements is increased by the presence of albumen as compared with cements prepared in the same conditions but without foaming agent.

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Preparation and Properties of Calcium Phosphate Cement Containing ZnO Whisker

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.1044 ◽

2009 ◽

Vol 610-613 ◽

pp. 1044-1048

Author(s):

Ya Meng Guo ◽

Dong Xu Li ◽

Yan Bao Li

Keyword(s):

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

X Ray Diffraction ◽

Hardening Material ◽

X Ray ◽

Crystal Fiber ◽

Key Factor ◽

New Type ◽

Bone Repairing ◽

Scanning Electron

Calcium phosphate cement (CPC) is a self-hardening material for bone repairing. ZnO whisker is a new type reinforced materials lately, which is acerose single crystal fiber. In this study, ZnO whisker was added into the CPC with different ratios, and each specimen kept at 37 oC in 100% humidity for 24 hrs. The phase and microstructure of the calcium phosphate pastes were investigated using X-ray diffraction and scanning electron microscopy, respectively. It has been found that ZnO whisker could supply nucleating center, TTCP and DCPA could be much easier to form HA around the ZnO whisker. The adding amount of ZnO whisker is a key factor that determines the mechanical properties.

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Effect on Mechanical Strength of Tricalcium Phosphate Cement by Additions of Sodium Alginate

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1181 ◽

2012 ◽

Vol 727-728 ◽

pp. 1181-1186 ◽

Cited By ~ 2

Author(s):

W.T. Coelho ◽

Juliana Machado Fernandes ◽

Rafaela Silveira Vieira ◽

Mônica Beatriz Thürmer ◽

Luis Alberto Santos

Keyword(s):

Aqueous Solution ◽

Compressive Strength ◽

Calcium Phosphate ◽

Mechanical Strength ◽

Sodium Alginate ◽

Calcium Phosphate Cement ◽

Bone Substitutes ◽

Alpha Phase ◽

X Ray Diffraction ◽

X Ray

The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified.

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Electron microscopy of rabbit FC crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077220 ◽

1983 ◽

Vol 41 ◽

pp. 730-731

Author(s):

Robert A. Grant ◽

Laura L. Degn ◽

Wah Chiu ◽

John Robinson

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

High Resolution Electron Microscopy ◽

Molecular Replacement ◽

X Ray ◽

X Ray Crystallography ◽

Resolution Electron ◽

Replacement Technique ◽

Hydrated Crystal ◽

Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

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High Resolution Study of Polytypism: Application to SiC and Au3 Mn

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055540 ◽

1982 ◽

Vol 40 ◽

pp. 540-541

Author(s):

G. Van Tendeloo ◽

J. Van Landuyt ◽

S. Amelinckx

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Stacking Sequence ◽

X Ray ◽

Powerful Technique ◽

Resolution Study ◽

The Ideal

Polytypism has been studied for a number of years and a wide variety of stacking sequences has been detected and analysed. SiC is the prototype material in this respect; see e.g. Electron microscopy under high resolution conditions when combined with x-ray measurements is a very powerful technique to elucidate the correct stacking sequence or to study polytype transformations and deviations from the ideal stacking sequence.

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A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055904 ◽

1982 ◽

Vol 40 ◽

pp. 722-723 ◽

Cited By ~ 1

Author(s):

R. Gronsky

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

High Resolution ◽

Computer Simulations ◽

Structural Characteristics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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