Process and kinetics of bonelike apatite formation on sintered hydroxyapatite in a simulated body fluid
Process and kinetics of bonelike apatite formation on sintered hydroxyapatite in a simulated body fluid
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DOI：
10.1016/j.biomaterials.2004.11.022
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发表时间：
2005-07-01
期刊：
影响因子：
14
通讯作者：
Nakamura, T
中科院分区：
文献类型：
--
作者：
Kim, HM;Himeno, T;Nakamura, T
采用透射电子显微镜结合能谱(EDX)和激光电泳法研究了在800℃和1200℃不同温度下烧结的两种羟基磷灰石(HA)在模拟体液(SBF)中浸泡时间的变化。TEM-EDX分析表明，在SBF中浸泡后，两者都经历了相同的表面结构变化，形成了类骨磷灰石，即形成了富钙的无定形或纳米晶的磷酸钙(ACP)和贫钙的ACP，并最终结晶成类骨磷灰石。电泳法表征的Zeta电位表明，在SBF作用下，HA表面出现负电荷，从而与流体中的正钙离子相互作用形成富钙ACP，从而获得表面正电荷。然后，HAS上的富钙ACP与流体中的负磷酸盐离子相互作用形成贫钙ACP，该ACP通过结晶形成在SBF中溶解度低的骨状磷灰石而稳定下来。然而，与在800℃烧结的HA相比，在1200℃烧结的HA上，这些相的形成时间都晚于在1200℃烧结的HA，这是由于在800℃烧结的HA的初始表面负电荷低于在1200℃烧结的HA的初始表面电荷，这是由于表面羟基和磷酸盐基团的贫化导致了HA的表面负性。这些结果表明，羟基磷灰石的烧结温度可能不是影响其与活骨结合的过程，而是影响其表面生物活性类骨磷灰石的形成速度。(C)2004爱思唯尔有限公司。保留所有权利。
The surfaces of two hydroxyapatites (HA), which have been sintered at different temperatures of 800 and 1200 degrees C, was investigated as a function of soaking time in simulated body fluid (SBF) using transmission electron microscopy (TEM) attached with energy-dispersive spectrometry (EDX) and laser electrophoresis spectroscopy. The TEM-EDX indicated that after soaking in SBF, both the HAs form bonelike apatite by undergoing the same surface structural change, i.e., formations of a Ca-rich amorphous or nano-crystalline calcium phosphate (ACP) and a Ca-poor ACP, which eventually crystallized into bonelike apatite. Zeta potential characterized by the electrophoresis indicated that during exposure to SBF, the HA surfaces reveal negative surface charge, thereby interacting with the positive calcium ions in the fluid to form the Ca-rich ACP, which gains positive surface charge. The Ca-rich ACP on the HAs then interacts with the negative phosphate ions in the fluid to form the Ca-poor ACP, which stabilizes by being crystallized into bonelike apatite with a low solubility in the SBF. The exposure times for formations of these phases of the Ca-rich ACP, the Ca-poor ACP as well as the apatite were, however, all late on HA sintered at 1200 degrees C, compared with the HA sintered at 800 degrees C. This phenomenon was attributed to a lower initial negative surface charge of the HA sintered at 800 degrees C than of that one sintered at 1200 degrees C, owing to poverty in surface hydroxyl and phosphate groups which are responsible for the surface negativity of the HA. These indicate that sintered temperature of HA might influence not in terms of the process but in terms of the rate of formation of biologically active bonelike apatite on its surface, through which the HA integrates with living bone. (c) 2004 Elsevier Ltd. All rights reserved.