The Fabricated Collagen-Based Nano-Hydroxyapatite/β-Tricalcium Phosphate Scaffolds

2012 ◽  
Vol 506 ◽  
pp. 57-60 ◽  
Author(s):  
M. Ebrahimi ◽  
Naruporn Monmaturapoj ◽  
S. Suttapreyasri ◽  
P. Pripatnanont
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Calcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Total Porosity ◽  
Xrd Pattern ◽  
Collagen Coating ◽  
Dimensional Shrinkage

The biphasic calcium phosphate (BCP) concept was introduced to overcome disadvantages of single phase biomaterials. In this study, we prepared BCP from nanoHA and β-TCP that were synthesized via a solid state reaction. Three different ratios of pure BCP and collagen-based BCP scaffolds (%HA/%β-TCP; 30/70, 40/60 and 50/50) were produced using a polymeric sponge method. Physical and mechanical properties of all materials and scaffolds were investigated. XRD pattern proved the purity of each HA, β-TCP and BCP. SEM showed overall distribution of macropores (80-200 µm) with appropriate interconnected porosities. Total porosity of pure BCP (93% ± 2) was found to be higher than collagen-based BCP (85%± 3). It was observed that dimensional shrinkage of larger scaffold (39% ± 4) is lower than smaller one (42% ± 5) and scaffolds with higher HA (50%) ratio experienced greater shrinkage than those with higher β-TCP (70%) ratio (45% ±3 and 36% ±1 respectively). Mechanical properties of both groups tend to be very low and collagen coating had no influence on mechanical behavior. Further studies may improve the physical properties of these composite BCP.

Magnesium-Silicon Substituted Carbonate Hydroxyapatite (Mg-Si CHA): Factors Affecting Sintering

2016 ◽  
Vol 694 ◽  
pp. 88-93
Author(s):  
Ahmad Fauzi Mohd Noor ◽  
Harmiza Zainudin
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Major Effect ◽  
Carbonate Content ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Complex Process ◽  
Powder Properties ◽  
Properties Of Materials

Sintering has major effect on the final properties of materials such as density, porosity and microstructure. Sintering of Mg-Si CHA in particular is a complex process since changes could occur during sintering, which include phase formation, grain size, pore size and carbonate content, and this in turn affects the mechanical properties. Improved mechanical properties of Mg-Si CHA is critical in load bearing implant applications. Poor control of thermal treatment of Mg-Si CHA during sintering would cause carbonate loss, leading to partial or total decomposition of Mg-Si CHA, subsequently would affect the physical and mechanical properties. The influence of powder properties (particle size, porosity, morphology) and sintering parameters (heating rate, firing atmosphere) on the sintered Mg-Si CHA microstructure was studied using scanning electron microscopy (SEM) characterization technique. The SEM results showed that we are able to produce sintered Mg-Si CHA without cracking of the compacted pellets, while keeping the carbonate level in the amount required (2 – 8%). X-Ray diffraction (XRD) was also performed on the sintered samples and the results indicated that a single phase Mg-Si-CHA was obtained, while Fourier transform infra-red (FTIR) spectroscopy result confirmed that as-synthesized Mg-Si CHA powder was a B-type.

Effect of self-assembled nanofibrous silk/polycaprolactone layer on the osteoconductivity and mechanical properties of biphasic calcium phosphate scaffolds

2012 ◽  
Vol 8 (1) ◽  
pp. 302-312 ◽  
Author(s):  
S.I. Roohani-Esfahani ◽  
Z.F. Lu ◽  
J.J. Li ◽  
R. Ellis-Behnke ◽  
D.L. Kaplan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Self Assembled

Evaluation of the Influence of Pre-Alloyed Powder Fe65Nb on the Production of Metal Matrices by Powder Metallurgy

2020 ◽  
Vol 1012 ◽  
pp. 3-8
Author(s):  
A.C.G. Silva ◽  
Hellen C.P. Oliveira ◽  
Thales Eduardo Leal ◽  
Paulo Santos Assis
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Solid State ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Toxic Element ◽  
Alloyed Powder ◽  
Eds Analysis ◽  
Porosity Measurements

The objective of this paper is to study Fe65Nb-Cu metal matrices, thus varying the content of the pre-alloyed Fe65Nb powder from 10% to 100%. Therefore, powders of Fe65Nb and Cu were used, innovating in the chemical composition of the commonly used matrices. The objective is to evaluate the substitution of Co (toxic element, commonly used) by Nb (98.2% of reserves are Brazilian). For the sintering of the samples it was used hot pressing technique. The parameters were set at: 850°C / 35MPa / 3min. The sintered bodies underwent SEM/EDS analysis and density and porosity measurements were performed. From the results it is possible to say that the compositions of (10% and 30% Fe65Nb) presented the best physical and mechanical properties. The relative density decreases for the compositions with 40%, 50% and 60% Fe65Nb is justified by the presence of fragile particles in metal matrices, since they require more energy in order to efficiently transport matter (diffusion) in a solid state.

scholarly journals Chitosan/ biphasic calcium phosphate nanofibrous scaffolds for bone tissue engineering

2020 ◽  
pp. 11-17
Author(s):  
Truong Le Bich Tram Truong
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Osteogenic Differentiation ◽  
Late Stage ◽  
Biphasic Calcium Phosphate ◽  
Cell Attachment ◽  
The Novel ◽  
Osteogenic Cells ◽  
Nanofibrous Scaffolds

In this article, chitosan/biphasic calcium phosphate (CS/BCP)nanofibers were prepared by electrospinning. From the culture of osteogenic cells, the biocompatibility of CS/BCP nanofibrous substrates was identified and increased by the photocrosslinking. The enhancement in cell attachment and proliferation was caused by the improvement in nanofibers’ mechanical properties. The biocompatibility to osteoblasts was also promoted with the content of BCP. The osteogenic differentiation in early, middle and late stage was encouraged by the addition of BCP on nanofibrous substrates. The CS/BCP nanofibers were highly specific to osteogenic cells, revealed by difficulties in the growth of non-osteogenic cells on this composite nanofibrous scaffold. The novel nanofibrous scaffolds showed great potential in the tissue engineering of bones.

scholarly journals Influence of surface porosity and pH on bacterial adherence to hydroxyapatite and biphasic calcium phosphate bioceramics

2009 ◽  
Vol 58 (1) ◽  
pp. 132-137 ◽  
Author(s):  
Teemu J. Kinnari ◽  
Jaime Esteban ◽  
Nieves Z. Martin-de-Hijas ◽  
Orlando Sánchez-Muñoz ◽  
Sandra Sánchez-Salcedo ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bacterial Infections ◽  
Biphasic Calcium Phosphate ◽  
Ph Value ◽  
Bacterial Species ◽  
Total Porosity ◽  
Ceramic Materials ◽  
Bone Substitutes ◽  
Surgical Trauma ◽  
Logarithmic Scale

Hydroxyapatite (HA) and biphasic calcium phosphate (BCP) ceramic materials are widely employed as bone substitutes due to their porous and osteoconductive structure. Their porosity and the lowering of surrounding pH as a result of surgical trauma may, however, predispose these materials to bacterial infections. For this reason, the influence of porosity and pH on the adherence of common Gram-positive bacteria to the surfaces of these materials requires investigation. Mercury intrusion porosimetry measurements revealed that the pore size distribution of both bioceramics had, on a logarithmic scale, a sinusoidal frequency distribution ranging from 50 to 300 nm, with a mean pore diameter of 200 nm. Moreover, total porosity was 20 % for HA and 50 % for BCP. Adherence of Staphylococcus aureus and Staphylococcus epidermidis was studied at a physiological pH of 7.4 and at a pH simulating bone infection of 6.8. Moreover, the effect of pH on the ζ potential of HA, BCP and of both staphylococci was evaluated. Results showed that when pH decreased from 7.4 to 6.8, the adherence of both staphylococci to HA and BCP surfaces decreased significantly, although at the same time the negative ζ-potential values of the ceramic surfaces and both bacteria diminished. At both pH values, the number of S. aureus adhered to the HA surface appeared to be lower than that for BCP. A decrease in pH to 6.8 reduced the adherence of both bacterial species (mean 57 %). This study provides evidence that HA and BCP ceramics do not have pores sufficiently large to allow the internalization of staphylococci. Their anti-adherent properties seemed to improve when pH value decreased, suggesting that HA and BCP bioceramics are not compromised upon orthopaedic use.

Characterization and Bioactivity of Hydroxyapatite-ZrO2 Composites with Commercial Inert Glass (CIG) Addition

2014 ◽  
Vol 631 ◽  
pp. 166-172
Author(s):  
B. Bulut ◽  
N. Demirkol ◽  
Ziya Engin Erkmen ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Calcium Phosphate ◽  
Dental Implant ◽  
Compression Strength ◽  
Vickers Microhardness ◽  
Physical And Mechanical Properties ◽  
Apatite Formation ◽  
Main Component

Hydroxyapatite is a kind of calcium phosphate that has generated great interest as an advanced orthopedic and dental implant candidate. Although HA has excellent biocompatibility, it’s poor mechanical properties limit its use as an implant material. Therefore HA is preferred as a main component in composite materials. The aim of this study is to determine the characterization and bioactivity of HA-ZrO2composites with the addition of 5 and 10 wt% commercial inert glass (CIG). The highest density and Vickers microhardness were obtained in HA-ZrO2-5 wt% CIG composite sintered at 1300 °C. The highest compression strength was measured in HA-ZrO2-5 wt% CIG composite sintered at 1200 °C. Thein vitrobioactivity tests were performed on the composites having the highest physical and mechanical properties. The apatite formation was observed on all samples subjected to bioactivity tests. As a result, the optimum mechanical properties and bioactivity were obtained on HA-ZrO2- 5 wt% CIG composite sintered at 1200 °C.

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