Morphological and structural modifications of octacalcium phosphate induced by poly-L-aspartate
Morphological and structural modifications of octacalcium phosphate induced by poly-L-aspartate
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DOI：
10.1021/cg034078d
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发表时间：
2004-01-01
影响因子：
3.8
通讯作者：
Cam, D
中科院分区：
文献类型：
--
作者：
Bigi, A;Bracci, B;Cam, D
结果表明，聚L天冬氨酸对水溶液中磷酸八钙的合成有强烈的抑制作用，并引起明显的形态和结构改变。在所用的实验条件下，在没有聚电解质的情况下，OCP以单个血小板的形式析出，沿c轴方向拉长，平均尺寸为22.0×1.3×0.2微米(3)。较低的PASP浓度(高达22微米)会导致血小板的平均尺寸减小和聚集物的形成，在TEM-ED图像中，聚集物主要由平行于其长度的纤维聚集组成，并在垂直于c轴的方向上表现出单向的无序。相对较高的PASP浓度(高达110微米)极大地减少了产物的总量，产物以近球形的聚集体形式沉淀，结构无序增加。X射线衍射谱随PASP浓度的增加而改变，表明OCP结构中磷灰石层的无序度增加，贡献增加，这可能与观察到的热稳定性降低有关，并表明PASP可能与OCP结构的水合层相互作用。
The results of this paper indicate that the presence Of poly-L-aspartic acid (PASP) strongly inhibits the synthesis of octacalcium phosphate (OCP) in aqueous solution and provokes remarkable morphological and structural modifications. Under the experimental conditions employed, in the absence of the polyelectrolyte, OCP precipitates as individual platelets, elongated along the c-axis direction, of mean dimensions 22.0 x 1.3 x 0.2 mum(3). Low PASP concentrations (up to 22 muM) induce a reduction of the mean dimensions of the platelets and the formation of aggregates, which in the TEM-ED images appear mostly constituted of fibers aggregated parallel to their length, and exhibit unidirectional disorder in the direction orthogonal to the c-axis. Relatively high PASP concentrations (up to 110 muM) greatly reduce the total amount of product, which precipitates as almost spherical aggregates with increasing structural disorder. The modification of the X-ray diffraction pattern on increasing PASP concentration indicates an increasing disorder and an increasing contribution of the apatitic layer of the OCP structure, which could be related to the observed reduction of thermal stability, and suggests a possible interaction of PASP with the hydrated layer of the OCP structure.