scholarly journals Smart Calcium Phosphate Bioceramic Scaffold for Bone Tissue Engineering

2012 ◽  
Vol 529-530 ◽  
pp. 19-23 ◽  
Author(s):  
G. Daculsi ◽  
Thomas Miramond ◽  
Pascal Borget ◽  
Serge Baroth
Keyword(s):  
Tissue Engineering ◽  
Stem Cell ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mechanical Test ◽  
The Body ◽  
Stable Phase ◽  
X Rays ◽  
Cell Colonization

The development of CaP ceramics involved a better control of the process of resorption and bone substitution. Micro Macroporous Biphasic CaP, (MBCP+) is a concept based on an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases Ca and P ions into the biological medium. The MBCP+ is selected for tissue engineering in a large European research program on osteoinduction and mesenchymal stem cell technology (REBORNE 7thEU frame work program, Regenerative Bone defects using New biomedical Engineering approaches,www.reborne.org). We have optimized the matrices in terms of their physical, chemical, and crystal properties, to improve cell colonization and to increase kinetic bone ingrowth. The fast cell colonization and resorption of the material are associated to the interconnected macropores structure which enhances the resorption bone substitution process. The micropore content involves biological fluid diffusion and suitable adsorption surfaces for circulating growth factors. The bioceramics developed for this project was fully characterized using X-Ray diffraction, FTIR, X-rays micro tomography, Hg porosimetry, BET specific surface area, compressive mechanical test, and SEM. Preclinical tests on the optimized scaffold were realized in critical size defects in several sites of implantation and animals (rats, rabbits, goats, dogs).The smart scaffold has a total porosity of 73%, constituted of macropores (>100µm), mesopores of 10 to 100µm and high micropores (<10µm) content of more or less 40%. The crystal size is <0.5 to 1 µm and the specific surface area was around 6m2/g. Thein vivoexperiment indicated higher colonization by osteogenic cells demonstrating suitable matrices for tissue engineering. The HA/TCP ratio of 20/80 was also more efficient for combination with total bone marrow or stem cell cultivation and expansion before to be implanted.

scholarly journals Synthesis of ZSM-23 Zeolite by Two-Stage Temperature-Varied Crystallization and Its Isomerization Performance

2020 ◽  
Vol 10 (21) ◽  
pp. 7546
Author(s):  
Xiaoyan Chen ◽  
Hongjuan Xi ◽  
Congbiao Chen ◽  
Zhongyi Ma ◽  
Bo Hou
Keyword(s):  
Hydrothermal Synthesis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Aluminum Sulfate ◽  
The Body ◽  
Aluminum Nitrate ◽  
Two Stage ◽  
Long Chain

Several ZSM-23 zeolites with different acid distributions are synthesized by two-stage temperature-varied crystallization and changing the species of aluminum source via conventional hydrothermal synthesis. The crystallinity, micropores, external specific surface area and the Si/Al ratios are measured by XRD, BET, ICP and XPS, indicating that both the body phase and the surface of the zeolite synthesized by two-stage temperature-varied crystallization have higher Si/Al ratio, and the zeolite synthesized with aluminum nitrate as the aluminum source exhibit the largest specific surface area. The properties of acidity and Pt obtained by NH3-TPD, TEM, Py-IR and H2-TPR show that the suitable B-acid distribution leads to high Pt dispersion over the zeolite. Applying these catalysts to the isomerization of n-dodecane, the zeolite synthesized with aluminum sulfate as aluminum source by two-step temperature-varied crystallization shows the best isomerization performance, that the selectivity of i-dodecane reaches 81.2% at 90.7% conversion. Therefore, the matching of acidity, external specific surface area and Pt dispersion of the zeolites is the key to improve the isomerization performance of long-chain alkanes.

Development and potential applications of gelatine, honey, and cellulose electrospun nanofibres as a green polymer

2021 ◽  
Vol 4 (2) ◽  
pp. 90
Author(s):  
Nurul Haiza Sapiee ◽  
Nurul Atiqah Izzati Zulkifly ◽  
Noor Fitrah Abu Bakar
Keyword(s):  
Tissue Engineering ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Small Pore ◽  
Potential Applications ◽  
Electrospun Nanofibres ◽  
Pharmaceutical Industries ◽  
Green Polymers ◽  
Green Polymer

Nanofibres have emerged as a brilliant technology to be applied in various areas due to their excellent properties that include having a great flexibility, prominent specific surface area and structural strength. Electrospinning is one of the most effective and favourable methods to fabricate nanofibres mainly because electrospun nanofibres have been demonstrated to possess small pore sizes, large specific surface area, and can be produced with different functions to fill the need of various applications in industries. Due to their remarkable properties, electrospun nanofibres have been proven to be suitable for applications in food packaging, medical, pharmaceutical and even in tissue engineering. Currently, there have been numerous research utilising both electrospun synthetic and natural polymers. Natural or green polymers are considered more favourable due to their biodegradable properties and potential biocompatibility. Therefore, there has been a shift to include more research regarding these green polymers. Green polymers can source from both plant polysaccharides and animal protein. Considering the different characteristics of synthetic polymers, the processing and fabrication methods may differ and must be adjusted accordingly. To well summarise the development of these green polymer nanofibres, we review fabrication methods of gelatine, honey and cellulose-based nanofibre and their potential applications in industries. There are indeed numerous promising areas for the usage of these green polymers which are based on their splendid individual properties especially when combined to form nanofibres via electrospinning. We hope this will promote continuous research and development for the applications in various industries including but not limited to tissue engineering, biomedical, food and pharmaceutical industries. 

Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Adsorption Process ◽  
Continuous System ◽  
Gas Oil ◽  
Average Pore ◽  
Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

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