Sivakumar M, Kumar T S, Shantha K L, Rao K P
Biomaterials Division, Central Leather Research Institute, Adyar, Madras, India.
Biomaterials. 1996 Sep;17(17):1709-14. doi: 10.1016/0142-9612(96)87651-4.
A simple method of converting the calcium carbonate skeleton of the corals available in the Indian coast into hydroxyapatite granules has been developed. By heating the coral to 900 degrees C, the organic materials were eliminated. Powder X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were employed to characterize the coral and to optimize the processing parameters as well as to confirm the hydroxyapatite formation. The coral used exhibits the presence of both aragonite and calcite phases (dimorphism). At a temperature of 900 degrees C the coral was found to decompose all the carbonate phases. The pre-heated coral is converted into hydroxyapatite by a chemical exchange reaction with di-ammonium phosphate under hydrothermal conditions. The hydroxyapatite obtained was in powder form and does not contain any impurities. The in vitro solubility test of the apatite granules performed in Gomoris, Michalelis, Sorensens, Ringer's and phosphate buffer of pH 7.2 and de-ionized water indicated the stability of the coralline hydroxyapatite.
一种将印度海岸可得的珊瑚碳酸钙骨架转化为羟基磷灰石颗粒的简单方法已被开发出来。通过将珊瑚加热到900摄氏度，有机物质被去除。采用粉末X射线衍射分析（XRD）、傅里叶变换红外光谱（FTIR）和热重分析（TGA）来表征珊瑚、优化工艺参数以及确认羟基磷灰石的形成。所使用的珊瑚呈现出文石和方解石相（双晶现象）。在900摄氏度的温度下，发现珊瑚分解了所有的碳酸盐相。在水热条件下，通过与磷酸二铵的化学交换反应，将预热的珊瑚转化为羟基磷灰石。所得到的羟基磷灰石为粉末形式，且不含任何杂质。在戈莫里氏、米凯利斯氏、索伦森氏、林格氏溶液以及pH值为7.2的磷酸盐缓冲液和去离子水中对磷灰石颗粒进行的体外溶解度测试表明了珊瑚羟基磷灰石的稳定性。
