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| Titel: |
Effect of particle size on zinc release from zinc containing tricalcium phosphate (ZnTCP) in Zn-deficient osteoporosis rats |
| Auteur: |
Otsuka, Makoto Marunaka, Sunao Matsuda, Yoshihia Ito, Atsuo Naito, Hiroshi Ichinose, Noboru Kokubo, Tadashi Nakamura, Takashi Higuchi, William I. |
| Verschenen in: |
Bio-medical materials and engineering |
| Paginering: | Jaargang 13 (2003) nr. 2 pagina's 103-113 |
| Jaar: |
2003-06-03 |
| Inhoud: |
The effect of particle size on in vivo and in vitro Zn release of ZnTCP was investigated for the purpose of understanding Zn release behavior from a sustained-release device. The tricalcium phosphate powders (Ca2.7Zn0.3(PO4)2), with particle size of 7.5 and 553 μm (S-ZnTCP and L-ZnTCP), including a 10 mol% of Zn (6.17 w/w%), as new sustained-release preparations, were synthesized by heating, after then ground and sieved using 38 and 300 μm screens. The different powder samples were characterized by the X-ray powder diffractometry and scanning electron microscopy. The release rates from Zn-TCP powders (10 mg) were measured in 10 ml of simulated body fluid (SBF) containing 10 mg/100 ml Ca2+(SBF/H), SBF containing 5 mg/100 ml Ca2+ (SBF/L) or SBF without Ca2+ (SBF/-) at 37.0°C. The in vitro Zn release profiles for the smallest and the largest particles size of ZnTCP powders (L-ZnTCP and S-ZnTCP) at various Ca concentrations in SBF were significantly higher in SBF/- and SBF/L than in SBF/H. The Zn release rate from ZnTCP with different particle sizes were found to be inversely proportional to the concentration of calcium in SBF. After injection of a ZnTCP suspension containing 30 mg of S-ZnTCP powder on the backs of the rats, the plasma Zn level increased rapidly, reaching a concentration range of around 2 μg/ml. The area under the curve values of the plasma Zn concentration (Zn-AUC) over 6 days post injection of S-ZnTCP and L-ZnTCP were significantly higher than that of the control experiment. After the injection of S-ZnTCP and L-ZnTCP suspension, the plasma alkaline phosphatase activity (AIP) levels increased to more than 300 IU/l. In contrast, the AIP for the control decreased after 2 days. The area under the curve of the AIP (AIP-AUC) for 6 days of S-ZnTCP was significantly higher than that of other groups. |
| Uitgever: |
IOS Press |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
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