Complementary information on bone ultrastructure from scanning small angle X-ray scattering and Fourier-transform infrared microspectroscopy
Complementary information on bone ultrastructure from scanning small angle X-ray scattering and Fourier-transform infrared microspectroscopy
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DOI：
10.1016/s8756-3282(99)00165-9
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发表时间：
1999-09-01
期刊：
影响因子：
4.1
通讯作者：
Fratzl, P
中科院分区：
文献类型：
--
作者：
Camacho, NP;Rinnerthaler, S;Fratzl, P
扫描小角X射线散射（扫描SAXS）和傅里叶变换红外显微光谱（FT-FTIR）以前已被独立地用于表征骨的结构特性，在解剖位置分辨的方式。SAXS提供了磷灰石晶体物理特性的直接测量，FT-XRD在分子水平上评估矿物和有机基质的结构。在本研究中，这两种方法都适用于检查相同的发展中的骨组织从L-4椎骨的14个月大（意外死亡）。对200 μ m厚的切片进行处理，通过扫描电子显微镜和SAXS进行检查，在皮质骨和松质骨的特定位置以200 μ m的空间分辨率收集光谱。确定的参数包括总SAXS强度，晶体厚度（T），以及主要晶体取向的程度和方向。对于FT-FTIR分析，从样品顶部纵向切割4 μ m厚的切片，从与SAXS光谱相同的位置获得100 × 100 μ m（2）区域的光谱，计算磷酸盐nu（1，3）胶原酰胺I和碳酸盐nu（2）的积分面积，以获得矿物质：基质和碳酸盐：矿物质比率。还评估了A型、B型和不稳定碳酸盐（分别取代羟基磷灰石、磷酸盐和表面位置）的相对量。收集偏振FT-FTIR数据以确定磷灰石和胶原组分的分子取向。本研究结果表明，从两种技术获得的信息是互补的。SAXS和FT-FTIR数据均显示，松质骨区域中的晶体明显大于皮质骨区域，皮质骨中的矿化更大，松质骨中的晶体定向程度大于皮质骨。晶体厚度的扫描SAXS测量显着相关的结晶度，A型碳酸酯取代，和晶体取向的FT-FTIR测量。总之，发现SAXS和FT-FTIR的联合使用提供了在微观结构和超微结构水平上骨结构变化的有价值的、独特的信息。虽然每种方法都可以单独使用，但这些技术的组合为骨晶体成熟的机制提供了额外的见解。(C)1999年，Elsevier Science Inc. All rights reserved.
Scanning small angle X-ray scattering (scanning SAXS) and Fourier-transform infrared microspectroscopy (FT-IRM) have previously been utilized independently to characterize the structural properties of bone in an anatomical position-resolved fashion. Whereas SAXS provides a direct measure of the physical characteristics of apatitic crystals, FT-IRM assesses structure of both mineral and organic matrix at the molecular level. In the present study both methods were applied to examine the same developing bone tissue from the L-4 vertebra of a 14-month-old (accidental death). A 200-mu m-thick section was processed for examination by scanning electron microscopy and SAXS, Spectra were collected at 200 mu m spatial resolution at specific locations in cortical and cancellous bone. Parameters determined included total SAXS intensity, crystal thickness (T), and degree and direction of predominant crystal orientation. For FT-IRM analysis, a section 4 mu m thick was cut longitudinally from the top of the sample, Spectra of regions 100 x 100 mu m(2) were acquired from the same locations as the SAXS spectra, Integrated areas of the phosphate nu(1,3) collagen amide I, and carbonate nu(2), absorbances, were calculated to obtain mineral: matrix and carbonate:mineral ratios. The relative quantities of types A, B, and labile carbonate (substituted for apatite hydroxyl, phosphate, and surface positions, respectively) were also evaluated. Polarized FT-IRM data were collected to determine molecular orientation of the apatite and collagen components. The results of this study show that the information obtained from the two techniques is complementary. Both SAXS and FT-IRM data revealed that the crystals were significantly larger in the cancellous region compared with the cortical region, that mineralization was greater in the cortex, and that the crystals were oriented to a larger degree in the cancellous compared with the cortical bone. The scanning SAXS measure of crystal thickness was significantly correlated to the FT-IRM measures of crystallinity, type A carbonate substitution, and crystal orientation. In conclusion, it was found that the combined use of SAXS and FT-IRM provides valuable, unique information on structural changes in bone at both the microstructural and ultrastructural level. Although each method can be used individually, the combination of techniques provides additional insights into the mechanism of bone crystal maturation. (C) 1999 by Elsevier Science Inc. All rights reserved.