Osteoinduction in Novel Micropores of Partially Dissolved and Precipitated Hydroxyapatite Block in Scalp of Young Rats

Osteoinduction in muscles by porous ceramics has been reported to be a real phenomenon. In this study, osteoinduction in connective tissues was found in highly porous hydroxyapatite (HAp) ceramics with large specific surface areas. We have developed the combination method of the partial dissolution-precipitation (PDP) technique involving the stirring-supersonic treatment in 1.7 × 10−2 N HNO3 solution containing Ca2+ and PO43− to improve the surface and the bulk of commercially available synthetic HAp block (82.5% in porosity, 50–300 µm in pore size). The modified HAp was named as a partially dissolved and precipitated HAp (PDP-HAp). The PDP-HAp exhibited the porosities of 85–90%, the macropore sizes of 50–200 µm, and the specific surface areas of 1.0–2.0 m2/g, with microcracks. The aim of this study was to observe bone induction by the PDP-HAp with or without BMP-2 in scalp tissues of four-week-old rats. Young rats were divided into the PDP-HAp alone group and the PDP-HAp/BMP-2 group for a long-term observation. In the PDP-HAp group, bone induction occurred inside the many pores at nine months, and the ratio of induced bone was 12.0%. In the PDP-HAp/BMP-2 group, bone induction occurred in almost all pores at three months, and compact bone was found at nine months. The ratios of induced bone were 77.0% at three months and 86.0% at nine months. We believe that osteoinduction by the PDP-HAp might be different from the process of BMP-loaded HAp-induced bone formation, because the PDP-HAp has osteogenic microporous compartments with partially absorbable HAp crystals. The PDP technique may contribute to create bioceramics with osteoinductive property for bone regenerative medicine.

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Bone Induction in Porous HAp Block Modified by Partial Dissolution-Precipitation Technique with Supersonic Treatment in Rat Scalp

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.631.430 ◽

2014 ◽

Vol 631 ◽

pp. 430-434 ◽

Cited By ~ 1

Author(s):

Masaru Murata ◽

Toshiyuki Akazawa ◽

Y. Minamida ◽

Md. Arafat Kabir ◽

J. Hino ◽

...

Keyword(s):

Bone Formation ◽

Combination Method ◽

Bone Induction ◽

Partial Dissolution ◽

Surface Areas ◽

Micro Cracks ◽

Specific Surface Areas ◽

The Many ◽

Biomimetic Hydroxyapatite ◽

And Cartilage

Microcracks and trabecular fractures can be observed in physiological bone. Biomimetic hydroxyapatite (HAp) scaffolds have been strongly needed in bone regenerative medicine. We have been developing the combination method of the partial dissolution-precipitation techniques involving the stirring-supersonic treatment in 1.7×10-2 N HNO3 solution containing Ca2＋and PO43- ions to improve the surface and the bulk of commercially available synthetic HAp block (82.5% in porosity, 50-300µm in macropore). The modified HAp was named as a partially dissolved and precipitated HAp (PDP-HAp). The aims of this study are to characterize the PDP-HAp and to observe cell response for the ceramics in rat scalp tissue. The PDP-HAp exhibited the macropore sizes of 50-200µm, the porosities of 85-90%, and the specific surface areas of 1.0-2.0 m2･g-1, with many micro-cracks. Twenty rats were divided into 2 groups. At 9 months, bone induction occurred inside the many pores in the PDP-HAp group, while bone and cartilage were not found in the HAp group. We believe that osteoinduction by the PDP-HAp is different from the process of BMP-loaded HAp-induced bone formation. The PDP-HAp might be applied as potential ceramics with osteoinductive properity and excellent biocompatibility in difficult bone regenerative cases.

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Electrospun structures with controlled specific surface areas and pores

57th International Astronautical Congress ◽

10.2514/6.iac-06-c2.4.07 ◽

2006 ◽

Author(s):

Vasana Maneeratana ◽

Wolfgang M. Sigmund

Keyword(s):

Specific Surface ◽

Surface Areas ◽

Specific Surface Areas

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Ultrafine porous boron nitride nanofibers synthesized via a freeze-drying and pyrolysis process and their adsorption properties

RSC Advances ◽

10.1039/c5ra23426c ◽

2016 ◽

Vol 6 (2) ◽

pp. 1253-1259 ◽

Cited By ~ 42

Author(s):

Jing Lin ◽

Lulu Xu ◽

Yang Huang ◽

Jie Li ◽

Weijia Wang ◽

...

Keyword(s):

Boron Nitride ◽

Specific Surface ◽

Freeze Drying ◽

Adsorption Properties ◽

Pyrolysis Process ◽

Surface Areas ◽

Aspect Ratios ◽

Large Pore ◽

Specific Surface Areas

Ultrafine porous boron nitride nanofibers with high aspect ratios, high specific surface areas and large pore volumes has been synthesized in large quantity via a freeze-drying and post pyrolysis process.

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Experimental Investigation of Coal Dust Wettability Based on Surface Contact Angle

Journal of Chemistry ◽

10.1155/2016/9452303 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 15

Author(s):

Gang Zhou ◽

Han Qiu ◽

Qi Zhang ◽

Mao Xu ◽

Jiayuan Wang ◽

...

Keyword(s):

Surface Tension ◽

Contact Angle ◽

Specific Surface ◽

Coal Dust ◽

Single Point ◽

Contact Angles ◽

Critical Surface ◽

Volume Percentage ◽

Surface Areas ◽

Specific Surface Areas

Wettability is one of the key chemical properties of coal dust, which is very important to dedusting. In this paper, the theory of liquid wetting solid was presented firstly; then, taking the gas coal of Xinglongzhuang coal mine in China as an example, by determination of critical surface tension of coal piece, it can be concluded that only when the surface tension of surfactant solution is less than 45 mN/m can the coal sample be fully wetted. Due to the effect of particle dispersity, compared with the contact angle of milled coal particle, not all the contact angles of screened coal powder with different sizes have a tendency to increase. Furthermore, by the experiments of coal samples’ specific surface areas and porosities, it can be achieved that the volume of single-point total pore decreases with the gradual decreasing of coal’s porosity, while the ultramicropores’ dispersities and multipoint BET specific surface areas increase. Besides, by a series of contact angle experiments with different surfactants, it can be found that with the increasing of porosity and the decreasing of volume percentage of ultramicropore, the contact angle tends to reduce gradually and the coal dust is much easier to get wetted.

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Facile Method To Synthesize Mesoporous Multimetal Oxides (ATiO3, A = Sr, Ba) with Large Specific Surface Areas and Crystalline Pore walls

Chemistry of Materials ◽

10.1021/cm903303v ◽

2010 ◽

Vol 22 (4) ◽

pp. 1276-1278 ◽

Cited By ~ 39

Author(s):

Xiaoxing Fan ◽

Ying Wang ◽

Xinyi Chen ◽

Ling Gao ◽

Wenjun Luo ◽

...

Keyword(s):

Specific Surface ◽

Surface Areas ◽

Specific Surface Areas

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Carbon Microspheres Prepared by High Internal Phase Emulsion Polymerization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.3105 ◽

2011 ◽

Vol 239-242 ◽

pp. 3105-3108

Author(s):

Ming Xian Liu ◽

Li Hua Gan ◽

Jun Hu ◽

Hong Lai Liu ◽

Long Wu Chen

Keyword(s):

Electron Microscopy ◽

Specific Surface ◽

Aqueous Phase ◽

Apparent Density ◽

Tween 80 ◽

Carbon Microspheres ◽

High Internal Phase Emulsion ◽

Surface Areas ◽

Internal Phase ◽

Specific Surface Areas

In this paper, we present a novel approach for the synthesis of carbon microspheres via the polymerization of a high internal phase emulsion (HIPE). By using Span 80 and Tween 80 as emulsifiers, 1iquid paraffin as oil phase, and the mixture of resorcinol/formaldehyde (R/F) solution as aqueous phase, an O/W emulsion was obtained. This emulsion phase inverted to a W/O HIPE induced by ammonia which served as the polymerization catalyst. Carbon microspheres (CMs) were prepared by polymerization of the HIPE, followed by drying and carbonization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analyzer were used to characterize as-prepared CMs. The results indicate that, in case of 0.25 wt% ammonia of the HIPE, the diameters of CMs decreased from about 2 to 1 μm when the mass fraction of aqueous R/F decreased from 0.714 to 0.357; the apparent density and the specific surface areas of the CMs, however, did not change obviously, which are about 0.6 g/cm3and 200 m2/g, respectively. The dosage of ammonia has a significant influence on the morphology and properties of CMs. With increasing of the ammonia mass to 1 wt% of the HIPE, the resultant carbon materials comprise not only CMs, but also some carbon sheets; the apparent density of which increased to 0.9 g/cm3and the specific surface areas of which decreased to below 100 m2/g. In addition, the other parameters for CMs preparation were also investigated. It was found that the proper conditions were controlling the temperature of 303-333 K and the oil/aqueous phase mass ratio of 2.5:7.

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The Experimental Study on Grinding Properties of Gas Quenching Steel Slag

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.612 ◽

2011 ◽

Vol 189-193 ◽

pp. 612-617

Author(s):

Hong Wei Xing ◽

Yue Long ◽

Xiu Li ◽

Gao Liang Li ◽

Yu Zhu Zhang ◽

...

Keyword(s):

Specific Surface ◽

New Technology ◽

Steel Slag ◽

Economic Benefits ◽

Surface Areas ◽

Mineral Phases ◽

Quenching Process ◽

Gas Quenching ◽

Specific Surface Areas ◽

Better Than

A gas quenching process to deal with steel slag and its characteristics of the new technology was briefly introduced. The grinding characteristics, mineral phases of gas quenching steel slag and the potential economic benefits of using it as cement mixing material was studied by compared to heat-stew steel slag. The results indicated that the specific surface areas (S) and grinding times (t) of the gas quenching steel slag showed a first order exponential decay relationship. With the extension of time, the specific surface areas of heat-stew steel slag was tending to balance earlier than that of gas quenching steel slag; The energy consumption of gas quenching steel slag was much lower than that of heat-stew steel slag. Gas quenching steel slag was comprised of C2S, C3S, a certain amount of (Ca2(Al, Fe)2O5）and RO phase, but the content of RO phase was relatively low, which increased the grindability of the quenching steel slag, so that the grindability of gas quenching steel slag was much better than that of heat-stew steel slag. Gas quenching steel slag prepared for cement addictives would bring great economic benefits.

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Photocatalytic activity of CaTaO2N nanocrystals obtained from a hydrothermally synthesized oxide precursor

10.31219/osf.io/qdgam ◽

2019 ◽

Author(s):

Roberto Köferstein

Keyword(s):

Photocatalytic Activity ◽

Methyl Orange ◽

Specific Surface ◽

Morphological Properties ◽

Soft Chemistry ◽

Co Catalyst ◽

Surface Areas ◽

Oxide Precursor ◽

Photocatalytic Activities ◽

Specific Surface Areas

Highly crystalline CaTaO2N nanoparticles possessing large specific surface areas were investigated as photocatalysts for the decomposition of methyl orange. Two different Ca2Ta2O7 precursors were synthesized by classical solid state synthesis and a hydrothermal soft-chemistry approach, respectively. In both cases, nitridation was carried out by thermal ammonolysis. The obtained CaTaO2N samples were compared with respect to their optical, thermal and morphological properties as well as their photocatalytic activities. In particular, the influence of ammonolysis temperature on the photocatalytic properties was studied. Using hydrothermally synthesized Ca2Ta2O7, phase pure CaTaO2N was obtained already at a relatively low ammonolysis temperature of 860 °C. Morphological investigations show that the CaTaO2N samples from the hydrothermally synthesized precursor consist of single-crystalline particles of 45 to 70 nm diameter with high specific surface areas between 12 and 19 m2 g-1, depending on ammonolysis temperature. A considerable photocatalytic activity for methyl orange degredation was found for the nanoscaled CaTaO2N particles prepared at lower ammonolysis temperatures. Using CoOx as co-catalyst, a further strong enhancement of the methyl orange decomposition by a factor 5-10 was achieved.

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