Kumar M, Dasarathy H, Riley C
Department of Chemistry, University of Alabama in Huntsville 35899, USA.
J Biomed Mater Res. 1999 Jun 15;45(4):302-10. doi: 10.1002/(sici)1097-4636(19990615)45:4<302::aid-jbm4>3.0.co;2-a.
In this study we examine the potential for using brushite (dicalcium phosphate dihydrate) as a coating for orthopedic implants. It was found that brushite is transformed into a more stable calcium phosphate (hydroxyapatite), regardless of the aqueous transforming media utilized. The transformation was carried out at room temperature in deionized water, deionized water with added calcium ions, and modified Hank's type solution without calcium and magnesium ions, modified Hank's type solution with calcium and magnesium ions, and modified Hank's type solution with added calcium ions. In several of the transformation systems it was noted that brushite provided an increased amount of calcium ions to the transforming media through solubility. The process was monitored using X-ray diffraction, X-ray photoelectron spectroscopy, and dissolution studies. Scanning electron microscopy and energy dispersive spectroscopy were also utilized for characterization. The brushite coatings can be easily achieved electrolytically on conducting substrates. The process is non line of sight, simple, and inexpensive; and when using an electrolyte that can sustain currents of approximately 100 mA/cm2, the necessary coating can be completed in about 3 min.
在本研究中，我们考察了使用透钙磷石（二水磷酸二钙）作为骨科植入物涂层的可能性。结果发现，无论使用何种水性转化介质，透钙磷石都会转化为更稳定的磷酸钙（羟基磷灰石）。转化在室温下于去离子水、添加了钙离子的去离子水、不含钙和镁离子的改良汉克氏溶液、含钙和镁离子的改良汉克氏溶液以及添加了钙离子的改良汉克氏溶液中进行。在几个转化体系中，注意到透钙磷石通过溶解度向转化介质提供了更多的钙离子。使用X射线衍射、X射线光电子能谱和溶解研究对该过程进行了监测。扫描电子显微镜和能量色散光谱也用于表征。透钙磷石涂层可以很容易地通过电解在导电基底上实现。该过程是非视线型的，简单且成本低廉；并且当使用能够维持约100 mA/cm2电流的电解质时，所需涂层可在约3分钟内完成。
