Kong Young-Min, Kim Hyoun-Ee, Kim Hae-Won
Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea.
J Biomed Mater Res B Appl Biomater. 2008 Feb;84(2):334-9. doi: 10.1002/jbm.b.30876.
In this study, we report a new observation on the phase conversion that occurs during the sintering of hydroxyapatite (HA)-tricalcium phosphate (TCP) biphasic ceramics. During the sintering of the HA-TCP mixture powders, a large amount of TCP was converted into HA, as detected by X-ray diffraction. The amount of TCP transformed into HA was approximately 10-90% of that initially added. From the electron probe microscopy analysis, the HA transformed from TCP was found to be Ca-deficient with Ca/P ratios of 1.62-1.64. The dissolution behavior and osteoblastic responses in a series of HA-TCP biphasic ceramics (10-90% TCP) were assessed. The solubility of the HA-TCP biphasic ceramics was intermediate between that of the HA and TCP pure ceramics. However, in the case of the HA-90% TCP biphasic ceramic, the solubility was even higher than that of pure TCP. The cell proliferation and alkaline phosphatase activity of the cells on the biphasic ceramics were lower than those on pure HA, but higher than those on pure TCP. However, particularly in the HA-50% TCP biphasic composition, the cellular responses were significantly higher than those on pure HA. It is considered that the Ca-deficient apatite newly formed from the TCP may affect in some way the solubility and biological properties of the HA-TCP biphasic ceramics.
在本研究中，我们报告了关于羟基磷灰石（HA）-磷酸三钙（TCP）双相陶瓷烧结过程中发生的相转变的一项新观察结果。在HA-TCP混合粉末烧结过程中，通过X射线衍射检测发现大量TCP转变为HA。转变为HA的TCP量约为最初添加量的10%-90%。通过电子探针显微镜分析发现，由TCP转变而来的HA缺钙，钙磷比为1.62-1.64。评估了一系列HA-TCP双相陶瓷（10%-90% TCP）的溶解行为和成骨细胞反应。HA-TCP双相陶瓷的溶解度介于HA和TCP纯陶瓷之间。然而，对于HA-90% TCP双相陶瓷，其溶解度甚至高于纯TCP。双相陶瓷上细胞的增殖和碱性磷酸酶活性低于纯HA上的细胞，但高于纯TCP上的细胞。然而，特别是在HA-50% TCP双相组成中，细胞反应明显高于纯HA上的细胞。据认为，由TCP新形成的缺钙磷灰石可能在某种程度上影响HA-TCP双相陶瓷的溶解度和生物学特性。
