Encapsulation of apatite particles for improvement in bone regeneration
Encapsulation of apatite particles for improvement in bone regeneration
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DOI：
10.1023/a:1026342414262
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发表时间：
2003-11
期刊：
影响因子：
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通讯作者：
L. Rodríguez-Lorenzo;K. Gross
中科院分区：
文献类型：
--
作者：
L. Rodríguez-Lorenzo;K. Gross
The layering of fluorapatite on hydroxyapatite bodies provides a means of decreasing the solubility of hydroxyapatite, providing fluoride for possible stimulation of bone formation and delaying the release of calcium and phosphate from the more soluble hydroxyapatite. The purpose of this work was to encapsulate hydroxyapatite particles with fluorapatite spanning a thickness more than several crystallites deep. A three-step procedure was employed. Hydroxyapatite powder was immersed in an electrolyte solution until an equilibrium was established between the solid and the dissolved calcium at pH 4.67 and 37 °C. Equilibrium was determined by measurement of dissolved calcium with a calcium-specific ion-specific electrode. A 5×10−2M ammonium fluoride added to the suspension resulted in a rapid decrease of both calcium and fluoride in the solution. Analysis with X-ray diffraction indicated that a fluoride rich layer containing calcium fluoride deposited onto the particle surface. Scanning electron microscopy revealed submicron spherical precipitate clusters on the hydroxyapatite particles. These clusters transformed to fluorapatite by soaking in a 0.1 M K2HPO4solution at pH 8 and 70 °C. A total time of 10 h was necessary for complete transformation of CaF_2into fluorapatite.
