scholarly journals Preparation, Physical-Chemical Characterization, and Cytocompatibility of Polymeric Calcium Phosphate Cements

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Rania M. Khashaba ◽  
Mervet Moussa ◽  
Christopher Koch ◽  
Arthur R. Jurgensen ◽  
David M. Missimer ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Setting Time ◽  
Chemical Characterization ◽  
Biological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Iii ◽  
Calcium Phosphate Cements ◽  
And Control

Aim. Physicochemical mechanical andin vitrobiological properties of novel formulations of polymeric calcium phosphate cements (CPCs) were investigated.Methods. Monocalcium phosphate, calcium oxide, and synthetic hydroxyapatite were combined with either modified polyacrylic acid, light activated polyalkenoic acid, or polymethyl vinyl ether maleic acid to obtain Types I, II, and III CPCs. Setting time, compressive and diametral strength of CPCs was compared with zinc polycarboxylate cement (control). Specimens were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy.In vitrocytotoxicity of CPCs and control was assessed.Results. X-ray diffraction analysis showed hydroxyapatite, monetite, and brushite. Acid-base reaction was confirmed by the appearance of stretching peaks in IR spectra of set cements. SEM revealed rod-like crystals and platy crystals. Setting time of cements was 5–12 min. Type III showed significantly higher strength values compared to control. Type III yielded high biocompatibility.Conclusions. Type III CPCs show promise for dental applications.

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

2007 ◽  
Vol 221 (8) ◽  
pp. 951-958 ◽  
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.

Synthesis of Alpha-Tricalcium Phosphate by Wet Reaction and Evaluation of Mechanical Properties

2012 ◽  
Vol 727-728 ◽  
pp. 1164-1169 ◽  
Author(s):  
Mônica Beatriz Thürmer ◽  
Rafaela Silveira Vieira ◽  
Juliana Machado Fernandes ◽  
Wilbur Trajano Guerin Coelho ◽  
Luis Alberto Santos
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Phosphate Cements

Calcium phosphate cements have bioactivity and osteoconductivity and can be molded and replace portions of bone tissue. The aim of this work was to study the obtainment of α-tricalcium phosphate, the main phase of calcium phosphate cement, by wet reaction from calcium nitrate and phosphoric acid. There are no reports about α-tricalcium phosphate obtained by this method. Two routes of chemical precipitation were evaluated and the use of two calcinations temperatures to obtain the phase of cement. The influence of calcination temperature on the mechanical properties of cement was evaluated. Cement samples were characterized by particle size analysis, X-ray diffraction, mechanical strength and scanning electron microscopy. The results demonstrate the strong influence of synthesis route on the crystalline phases of cement and the influence of concentration of reactants on the product of the reaction, as well as, on the mechanical properties of cement.

Improvement of Anti-Washout Performance of Calcium Phosphate Cement Using Modified Starch

2007 ◽  
Vol 336-338 ◽  
pp. 1628-1631 ◽  
Author(s):  
Ling Chen ◽  
Hong Xiang ◽  
Xiao Xi Li ◽  
Jian Dong Ye ◽  
Xiu Peng Wang ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Body Fluid ◽  
Clinical Applications ◽  
Modified Starch ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Phosphate Cements ◽  
Modified Starches ◽  
Gelatinized Starch ◽  
Bone Repairing

Calcium phosphate cements (CPCs) are well-known orthopedic materials for filling bone. However, CPC pastes tend to disintegrate immediately when contacting with blood or other aqueous (body) fluids, which is a main limitation of its clinical applications in bone repairing, reconstruction and augmentation. To improve the anti-washout performance of CPC, modified starches such as pre-gelatinized starch, etherified starch, and esterified starch were added to the liquid phase of CPC in this work. CPC with good anti-washout performance was prepared and the effects of the modified starches on the properties of CPC were investigated. The results showed that the CPC with the modified starches were more stable in simulated body fluid than that without modified starch, especially the CPC with the etherified starch (II). X-ray diffraction analysis revealed that the modified starches did not inhibit CPC components from converting to hydroxyapatite. Furthermore, the anti-washout mechanism of the modified starches in CPC was discussed. It is concluded that the addition of the modified starches such as pre-gelatinized starch, etherified starch, and esterified starch to CPC can improve its anti-washout performance and should be of value in clinical surgery where the cement is exposed to blood.

scholarly journals Bactericidal and Bioresorbable Calcium Phosphate Cements Fabricated by Silver-Containing Tricalcium Phosphate Microspheres

2020 ◽  
Vol 21 (11) ◽  
pp. 3745
Author(s):  
Michiyo Honda ◽  
Yusuke Kawanobe ◽  
Kohei Nagata ◽  
Ken Ishii ◽  
Morio Matsumoto ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Bacterial Adhesion ◽  
Inflammatory Responses ◽  
Spray Pyrolysis Technique ◽  
Biological Properties ◽  
Histological Evaluation ◽  
Bone Apposition ◽  
Calcium Phosphate Cements

Bacterial adhesion to the calcium phosphate surface is a serious problem in surgery. To prevent bacterial infection, the development of calcium-phosphate cements (CPCs) with bactericidal properties is indispensable. The aim of this study was to fabricate antibacterial CPCs and evaluate their biological properties. Silver-containing tricalcium phosphate (Ag-TCP) microspheres consisting of α/β-TCP phases were synthesized by an ultrasonic spray-pyrolysis technique. The powders prepared were mixed with the setting liquid to fabricate the CPCs. The resulting cements consisting of β-TCP and hydroxyapatite had a porous structure and wash-out resistance. Additionally, silver and calcium ions could be released into the culture medium from Ag-TCP cements for a long time accompanied by the dissolution of TCP. These data showed the bioresorbability of the Ag-TCP cement. In vitro antibacterial evaluation demonstrated that both released and immobilized silver suppressed the growth of bacteria and prevented bacterial adhesion to the surface of CPCs. Furthermore, histological evaluation by implantation of Ag-TCP cements into rabbit tibiae exhibited abundant bone apposition on the cement without inflammatory responses. These results showed that Ag-TCP cement has a good antibacterial property and good biocompatibility. The present Ag-TCP cements are promising for bone tissue engineering and may be used as antibacterial biomaterials.

Fabrication and in Vitro Evaluation of Calcium Phosphate Combined with Chitosan Fibers for Scaffold Structures

2009 ◽  
Vol 24 (1_suppl) ◽  
pp. 113-124 ◽  
Author(s):  
Qin Lian ◽  
Dichen Li ◽  
Zhongmin Jin ◽  
Jue Wang ◽  
Aimin Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Calcium Phosphate ◽  
In Vitro Study ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chitosan Fiber ◽  
In Vitro Performance ◽  
Rapid Tool

A rapid prototyping and rapid tool technique-based method was developed to fabricate chitosan fiber calcium phosphate cement composites (CF/CPC) for bone tissue engineering scaffold applications. The products were characterized and the in vitro performance with canine bone marrow stem cells (BMCs) on CF/CPC scaffold with controlled fiber structures evaluated. The X-ray diffraction analysis showed that about 91% of the inorganic part of the CF/CPC scaffold was hydroxyapatite (HA) and the variation in CF had little effect on the percentage of HA content. The results from in vitro study demonstrated that the interconnected macropores rapidly formed inside the CF/CPC scaffolds and that the patterns were related to the fiber structures used. The differences in the fiber structures altered the morphology of the BMCs without affecting the proliferation of the BMCs.

Evaluation of α-Tricalcium Phosphate Cement Obtained at Different Temperatures

2012 ◽  
Vol 727-728 ◽  
pp. 1187-1192 ◽  
Author(s):  
Rafaela Silveira Vieira ◽  
Wilbur Trajano Guerin Coelho ◽  
Mônica Beatriz Thürmer ◽  
Juliana Machado Fernandes ◽  
Luis Alberto Santos
Keyword(s):  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Setting Time ◽  
Calcium Pyrophosphate ◽  
In Vitro Test ◽  
Calcium Phosphate Cements ◽  
Similar Chemical ◽  
Different Temperatures ◽  
Vitro Test

The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.

Characterization of α/β-TCP Based Injectable Calcium Phosphate Cement as a Potential Bone Substitute

2012 ◽  
Vol 529-530 ◽  
pp. 157-160 ◽  
Author(s):  
Kemal Sariibrahimoglu ◽  
Joop G.C. Wolke ◽  
Sander C.G. Leeuwenburgh ◽  
John A. Jansen
Keyword(s):  
Compressive Strength ◽  
Calcium Phosphate ◽  
Setting Time ◽  
Surrounding Tissue ◽  
Calcium Phosphate Cements ◽  
Apatite Cement ◽  
Tcp Phase

Calcium phosphate cements (CPCs) can be a suitable scaffold material for bone tissue engineering because of their osteoconductivity and perfect fit with the surrounding tissue when injected in situ. However, the main disadvantage of hydroxyapatite (HA) forming CPC is its slow degradation rate, which hinders complete bone regeneration. A new approach is to use hydraulic apatite cement with mainly α/β-tricalciumphosphate (TCP) instead of α-TCP. After hydrolysis the α/β-TCP transforms in a partially non-absorbable HA and a completely resorbable β-TCP phase. Therefore, α-TCP material was thermally treated at several temperatures and times resulting in different α/β-TCP ratios. In this experiment, we developed and evaluated injectable biphasic calcium phosphate cements (BCPC) in vitro. Biphasic α/β-TCP powder was produced by heating α-TCP ranging from 1000-11250°C. Setting time and compressive strength of the CPCs were analyzed after soaking in PBS for 6 weeks. Results demonstrated that the phase composition can be controlled by the sintering temperature. Heat treatment of α-TCP, resulted in 100%, 75% and 25% of α-to β-TCP transformation, respectively. Incorporation of these sintered BCP powder into the cement formulation increased the setting time of the CPC paste. Compressive strength decreased with increasing β-TCP content. In this study, biphasic CPCs were produced and characterized in vitro. This injectable biphasic CPC presented comparable properties to an apatitic CPC.

Spectroscopic and Structural Studies of Some Precursors for the Deposition of PZT and Related Materials by MOCVD

1997 ◽  
Vol 495 ◽  
Author(s):  
Kirsty A. Fleeting ◽  
Tony C. Jones ◽  
Tim Leedham ◽  
M. Azad Malik ◽  
Paul O'brien ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Lead Zirconium Titanate ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
Chemical Methods ◽  
X Ray ◽  
Mocvd Precursors ◽  
And Control ◽  
Substrate Temperatures

ABSTRACTMOCVD is a useful method for the deposition of thin films of lead zirconium titanate, PZT, because of its good step coverage and control of composition. Results are herein presented on a number of novel compounds which are potential MOCVD precursors. The compounds studied include Pb(tmhd)2, Zr(OBu')4 and Ti(OPr')4. Another commonly utilized precursor Zr(tmhd)4, is not ideal, in that it is a high melting point solid, and hence requires high substrate temperatures. We have sought to modify Zr precursors through chemical methods and have synthesized a number of novel, more volatile, and less intrinsically thermally stable MOCVD precursors. Full chemical characterization of the Zr precursors (NMR, IR, MS, CHN, TGA/DSC, Single Crystal X-ray diffraction) has been undertaken. We also present structural results on some related lead precursors.

Phyto-fabricated Cr2O3 nanoparticle for multifunctional biomedical applications

Nanomedicine ◽  
2020 ◽  
Vol 15 (17) ◽  
pp. 1653-1669
Author(s):  
Hamza Elsayed Ahmed Mohamed ◽  
Shakeeb Afridi ◽  
Ali Talha Khalil ◽  
Tanzeel Zohra ◽  
Muhammad Ali ◽  
...  
Keyword(s):  
Biological Properties ◽  
In Vitro Assays ◽  
X Ray Diffraction ◽  
Potential Measurement ◽  
Polio Virus ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy

Aim: The biosynthesis of chromium oxide nanoparticles (Cr2O3 NPs), using Hyphaene thebaica as a bioreductant, for assessment of their potential nanomedicinal applications. Materials & methods: Biosynthesized Cr2O3 NPs were characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, energy dispersive x-ray spectroscopy, scanning and transmission electron microscopy, selected area electron diffraction, UV–Vis spectroscopy and ζ-potential measurement. In vitro assays were used to assess the biological properties of Cr2O3 NPs. Results: Nanoparticles with size approximately 25–38 nm were obtained with a characteristic Cr–O vibration at 417 cm-1. A broad spectrum antimicrobial potential and antioxidant nature is reported. Slight inhibition of polio virus and biocompatibility at low doses was observed. Conclusion: We conclude a multifunctional nature of biogenic Cr2O3 NPs.

scholarly journals Changes in mandible due to osteoporosis

2007 ◽  
Vol 54 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Srdjan Postic
Keyword(s):  
Calcium Phosphate ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Mandibular Bone ◽  
X Ray ◽  
Noticeable Increase ◽  
Edentulous Mandible ◽  
Bone Structures ◽  
Inorganic Constituents ◽  
And Control

Introduction: Osteoporosis may occur in bone tissue as a result of ageing. Aim: The aim of this study was to investigate remodeling of old human edentulous mandibular bone due to osteoporosis. Materials and Methods: Osseous surfaces of one edentulous and one dentate mandible were extracted from a cadaver. This study included 5 methods of analysis of bone structures in experimental and control bony samples of human mandibular bones. Absolute densities of samples were determined. SEM analysis and X-ray diffraction analysis of spectra were used to assess bony layers. Results: Minimum density 1.9658 g/cm3 of edentulous ridge site was detected. SEM micrographs indicated reductions of trabecular and lamellar width. Significant differences (p<0.01) in cancellous site width were recorded in experimental basal specimens. Noticeable increase of porosity was observed in 6.35% of edentulous ridge site and 14.06% of experimental basal site. There was a significant correlation between oxygen presence (p=0.046) eroded and defect bone surfaces (p<0.001). Complexes of hydroxyapatite, calcium-phosphate, tetracalcium-pyrophosphate and amorphous calcium-phosphate were inorganic constituents considerable mineral modifications of edentulous ridge site. Conclusion. Based on the results of the present study, various levels of degradation of cortical matrix and cancellous layers of edentulous mandible may be observed as a result of osteoporosis. .

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