Initial formation kinetics of calcium phosphate on titanium in Hanks' solution characterized using XPS
Initial formation kinetics of calcium phosphate on titanium in Hanks' solution characterized using XPS
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DOI：
10.1002/sia.6900
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发表时间：
2020-10-22
影响因子：
1.7
通讯作者：
Ishikawa, Kunio
中科院分区：
文献类型：
--
作者：
Hiji, Akari;Hanawa, Takao;Ishikawa, Kunio
与其他金属相比，钛和钛合金具有优异的硬组织相容性的一个原因是它们在生物环境中形成磷酸钙的能力。许多研究证实了这一点，但其形成机制尚未完全阐明。在本研究中，为了阐明人体中钛上磷酸钙的初始形成动力学，将钛浸入模拟体液Hanks溶液中10（0）-10（6）s，然后使用XPS进行精确表征。浸泡在稀释的汉克斯溶液中的钛试样也进行了表征。结果表明，磷酸根离子优先被吸附并在10（0）-10（2）s内结合到钛表面。该反应是缓慢的，并且直到10（2）s，表面层的表观厚度几乎恒定为5.2nm。然而，钙离子和磷酸根离子迅速结合，10（3）s后形成磷酸钙。钙和磷酸盐的量随着时间的对数增加，因为钙和磷酸盐离子直接与钛表面反应，直到10（5）s。汉克斯溶液中所含的其他元素不被结合，优先形成磷酸钙。钙的掺入比磷酸盐快，10（3）s后[Ca]/[P]比值随时间的对数增加。然而，表面氧化膜本身的化学状态不改变浸泡在汉克斯溶液。本研究清楚地揭示了模拟体液中磷酸钙在钛上的形成动力学。
One cause of the excellent hard-tissue compatibility of Ti and Ti alloys compared with other metals is their ability to form calcium phosphate in biological environments. This is confirmed by many studies, although the formation mechanism has not been completely elucidated. In this study, to elucidate the initial formation kinetics of calcium phosphate on Ti in the human body, Ti was immersed in a simulated body fluid, Hanks' solution, for 10(0)-10(6) s, followed by precise characterization using XPS. Ti specimens immersed in diluted Hanks' solutions were also characterized. The results reveal that phosphate ions are preferentially adsorbed and are incorporated onto the Ti surface in 10(0)-10(2) s. This reaction is slow, and the apparent thickness of the surface layer is almost constant as 5.2 nm until 10(2) s. However, both calcium and phosphate ions are then rapidly incorporated, and calcium phosphate is formed after 10(3) s. The amounts of both calcium and phosphate increase with the logarithm of time because calcium and phosphate ions react directly with the Ti surface until 10(5) s. Other elements contained in Hanks' solution are not incorporated, calcium phosphate being formed preferentially. The incorporation of calcium is faster than that of phosphate, and the [Ca]/[P] ratio increases with the logarithm of time after 10(3) s. However, the chemical state of surface oxide film itself on Ti does not changed by immersion in Hanks' solution. The formation kinetics of calcium phosphate on Ti in a simulated body fluid are clearly revealed by this study.