Zinc-Containing Calcium Phosphate Ceramics with a (Ca+Zn)/P Molar Ratio of 1.67

Zinc-containing calcium phosphate ceramics with a (Ca+Zn)/P molar ratio of 1.67 (ZnHAP ceramics) were synthesized to clarify the main phase for zinc release. ZnHAP ceramics with a zinc content at or more than 0.20 wt% contained zinc-containing tricalcium phosphate. The ion activity product of monophasic ZnHAP ceramic containing at or less than 0.13 wt% of zinc corresponded to that of pure HAP ceramic. The presence of tricalcium phosphate (TCP) phases was necessary condition for ZnHAP ceramics to release zinc. The coexistence of TCP phases in the ZnHAP ceramics meant that a phase with a (Ca+Zn)/P molar ratio higher than 1.67 also coexisted. Although the phase was assumed to be zinc oxide, zinc was not concentrated anywhere in the ZnHAP ceramics including grain boundaries.

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Studies on micellar calcium phosphate: composition and apparent solubility product in milk over a wide pH range

Journal of Dairy Research ◽

10.1017/s0022029900023517 ◽

1984 ◽

Vol 51 (2) ◽

pp. 251-257 ◽

Cited By ~ 44

Author(s):

Lesley C. Chaplin

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Calcium Phosphates ◽

Activity Product ◽

Apparent Solubility ◽

Ion Activity ◽

Phosphate Phase ◽

Wide Ph Range ◽

Solubility Products ◽

Ph Range

SummaryCalcium and phosphate concentrations in milk ultrafiltrate prepared at 37 °C over the pH range 4.0–8.0 have been measured and used to calculate the apparent solubility products for various calcium phosphates in milk. Micellar calcium phosphate had a constant Ca/Pi = 1·58·10·03 at all pH values and a near-invariant ion activity product for CaHP04. Apparent solubility products have also been obtained for brushite, hydroxyapatite and amorphous tricalcium phosphate in milk salt solution over a similar pH range. No evidence was found for a hydroxyapatite or amorphous tricalcium phosphate phase in milk.

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Enhanced effect of β-tricalcium phosphate phase on neovascularization of porous calcium phosphate ceramics: In vitro and in vivo evidence

Acta Biomaterialia ◽

10.1016/j.actbio.2014.09.028 ◽

2015 ◽

Vol 11 ◽

pp. 435-448 ◽

Cited By ~ 60

Author(s):

Y. Chen ◽

J. Wang ◽

X.D. Zhu ◽

Z.R. Tang ◽

X. Yang ◽

...

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Calcium Phosphate Ceramics ◽

Phosphate Phase

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Bimodal Porous Bi-Phasic Calcium Phosphate Ceramics and Its Dissolution in SBF Solution

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.330-332.91 ◽

2007 ◽

Vol 330-332 ◽

pp. 91-94 ◽

Cited By ~ 2

Author(s):

Y. Zhang ◽

Yoshiyuki Yokogawa ◽

Tetsuya Kameyama

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Biphasic Calcium Phosphate ◽

Reaction Rate ◽

Ceramic Materials ◽

Calcium Phosphate Ceramics ◽

Fine Powders ◽

Beta Tricalcium Phosphate ◽

Sbf Solution ◽

New Phase

Biphasic calcium phosphate (BCP) ceramics, a mixture of hydroxyapatite (HAp) and beta-tricalcium phosphate (β-TCP), of varying HAp/β-TCP ratios were prepared from fine powders. Porous BCP ceramic materials with HAp/β-TCP weight rations of 20/80, 40/60, and 80/20 were prepared. In this study, the bioactivity is reduced at a larger HAp content rate, which is likely related to the high driving pore for the formation of a new phase, and the reaction rate was proportional to the β-TCP. The porous BCP ceramics having a bigger porosity rate can easily under up dissolution. The powder having a larger β-TCP content rate can easily generate a new phase. The dissolution results confirmed that the biodegradation of calcium phosphate ceramics could be controlled by simply adjusting the amount of HAp or β-TCP in the ceramics and porosity rate.

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Effect of Macrophage on Degradation of β-TCP Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.288-289.549 ◽

2005 ◽

Vol 288-289 ◽

pp. 549-552

Author(s):

Shi Pu Li ◽

Hong Lian Dai ◽

Yu Hua Yan ◽

Xian Ying Cao ◽

Qi Xin Zheng

Keyword(s):

Calcium Phosphate ◽

Carbonic Anhydrase ◽

Tricalcium Phosphate ◽

Culture Medium ◽

Calcium Phosphate Ceramics ◽

Sem Observation ◽

Ph Values ◽

Calcium And Phosphorus

Mice macrophages which were mixed with β-tricalcium phosphate (β-TCP) ceramics powder were cultured, both calcium and phosphorus concentrations in the culture medium were evidently higher than that of β-TCP ceramics powder without cells. The microscope and SEM observation showed that macrophages wrapped β-TCP particles, and then phagocytized them into cytoplasm. The pH values inside and outside macrophage in β-TCP-bearing were tested. The histochemistry observation showed that there were many carbonic anhydrase positive grains in the cytochylema of macroghage after β-TCP ceramics powder being implanted. TEM investigation indicated that many β-TCP particles were phagocytized into the cytochylema of macroghage, and then vacuole was found after particles had degraded. The results showed that macrophages could take part in the degradation of calcium phosphate ceramics in two different ways.

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Fabrication of Biphasic Calcium Phosphate Bioceramics from the Recycling of Bone Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.2328 ◽

2012 ◽

Vol 610-613 ◽

pp. 2328-2331 ◽

Cited By ~ 1

Author(s):

Nan Hee Lee ◽

Kyu Hong Hwang ◽

Jong Kook Lee

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Biphasic Calcium Phosphate ◽

Raw Materials ◽

Liquid Environment ◽

Bone China ◽

Calcium Phosphate Ceramics ◽

Bone Ash ◽

Naoh Solution ◽

Moisture Protection

Biphasic calcium phosphate bioceramics were fabricated from the recycling of bone ash which is mostly used as raw materials of bone china. Precursor calcium phosphate powders were prepared by soaking the commercial bone ash in 0.1 M of NaOH solution at 80°C for 4 h. Calcium phosphate powders was obtained by calcination at 800°C for 1 h to completely remove residual organics. Biphasic calcium phosphate bioceramics which is composed of hydroxyapatite and tricalcium phosphate was fabricated by the sintering of pressed compacts at 1200°C for 1 h under moisture protection. The bone ash derived-biphasic calcium phosphate ceramics consists of mostly HA and small amounts of α-tricalcium phosphate, magnesium oxide and calcium oxide. After polishing the HA ceramics, they were immersed in buffered water at 37°C for 3 and 7 days. The bone ash derived- biphasic calcium phosphate ceramics show high biostability in liquid environment with immersion time compared with commercial calcium phosphate ceramics.

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Osteoclastic resorption of calcium phosphate ceramics with different hydroxyapatite/β-tricalcium phosphate ratios

Biomaterials ◽

10.1016/s0142-9612(97)00036-7 ◽

1997 ◽

Vol 18 (15) ◽

pp. 1037-1041 ◽

Cited By ~ 295

Author(s):

S Yamada

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Calcium Phosphate Ceramics ◽

Osteoclastic Resorption

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Effect of Sintering Temperature on Biphasic Calcium Phosphate (BCP) Biocomposite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1087.475 ◽

2015 ◽

Vol 1087 ◽

pp. 475-478 ◽

Cited By ~ 1

Author(s):

Shah Rizal Kasim ◽

Nor Firdaus Muhamad ◽

Sivakumar Ramakrishan

Keyword(s):

Calcium Phosphate ◽

Mathematical Models ◽

Design Of Experiment ◽

Tricalcium Phosphate ◽

Biphasic Calcium Phosphate ◽

Sintering Temperature ◽

Present Report ◽

Tcp Phases ◽

Different Temperatures ◽

Formation Porosity

The present report aims to fabricate biphasic calcium phosphate (BCP) biocomposite in order to study the effects of sintering temperature on the sintered BCP biocomposite characteristics (phase’s formation, porosity and hardness properties). These effects were quantified using design of experiment (DOE) to develop mathematical models. BCP biocomposite pellets (60 wt% HA) were fabricated using mixing, pressing and sintered at two different temperatures (1100°C and 1250°C). The experiment was run by following the run order suggested by DOE software (Minitab 16) through randomization stage. Results show that sintering temperature will affect the formation of α-tricalcium phosphate (α-TCP) and the porosity of the samples. The formation of α-TCP phases will reduce the hardness value of BCP biocomposite.

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