Structural analysis of Si-substituted hydroxyapatite: zeta potential and X-ray photoelectron spectroscopy
Structural analysis of Si-substituted hydroxyapatite: zeta potential and X-ray photoelectron spectroscopy
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DOI：
10.1023/a:1021177601899
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发表时间：
2002-12-01
影响因子：
3.7
通讯作者：
Santos, JD
中科院分区：
文献类型：
--
作者：
Botelho, CM;Lopes, MA;Santos, JD
本研究的目的是确定硅的掺入对羟基磷灰石 (HA) 表面电荷的影响，并评估静态和动态系统中溶解引起的 HA 和 Si-HA 的表面结构变化。 X射线光电子能谱（XPS）分析表明，根据先前提出的取代机制，SiO4-基团取代了硅羟基磷灰石（Si-HA）晶格中的PO43-基团，而没有形成其他晶相，例如磷酸三钙或氧化钙。通过 Zeta 电位 (ZP) 测量确定，取代的硅导致 HA 的净表面电荷和等电点降低。在生理 pH = 7.4 时，与未修饰的 HA 相比，Si-HA 的表面电荷显着降低，即 - 50 +/- 5 至 - 71 +/- 5 eV，这是由于 HA 晶格中存在硅酸盐基团所致，这可能是使用 SBF 测试时体外磷灰石形成更快的原因。 XPS 结果表明，使用动态系统在 tris 缓冲液中进行溶解研究后，与其他离子物质相比，硅似乎优先从 Si-HA 表面浸出。 (C) 2002 年 Kluwer 学术出版社。
The aim of this study was to determine the effect of the incorporation of silicon on the surface charge of hydroxyapatite (HA) and to assess surface structural changes of HA and Si-HA induced by dissolution in both static and dynamic systems. X-ray photoelectron spectroscopy (XPS) analysis showed that SiO4- groups were substituted for PO43- groups in the silicon-hydroxyapatite (Si-HA) lattice according to a previously proposed substitution mechanism without the formation of other crystalline phases, such as tricalcium phosphate or calcium oxide. The substituted silicon induced a decrease in the net surface charge and the isoelectric point of HA as determined by zeta potential (ZP) measurements. At physiological pH = 7.4 the surface charge of Si-HA was significantly lowered compared to unmodified HA, i.e. - 50 +/- 5 to - 71 +/- 5 eV, caused by the presence of silicate groups in the HA lattice, which may account for a faster in vitro apatite formation using SBF testing. XPS results indicated that silicon seems to be preferentially leached out from Si-HA surface compared to other ionic species after dissolution studies in tris-buffer using a dynamic system. (C) 2002 Kluwer Academic Publishers.