Characterization of Ca-phosphate biological materials by scanning transmission X-ray microscopy (STXM) at the Ca L2,3-, P L2,3- and C K-edges
Characterization of Ca-phosphate biological materials by scanning transmission X-ray microscopy (STXM) at the Ca L2,3-, P L2,3- and C K-edges
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DOI：
10.1016/j.actbio.2014.10.003
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发表时间：
2015-01-15
影响因子：
9.7
通讯作者：
Bourdelle, Franck
中科院分区：
文献类型：
--
作者：
Cosmidis, Julie;Benzerara, Karim;Bourdelle, Franck
几种自然产生的生物材料，包括骨骼和牙齿、病理性钙化、海洋磷化区域形成的微生物矿物沉积，以及用于骨和牙齿修复的受BIN启发的水泥，都是由钙磷酸盐组成的。通常使用X射线衍射、傅里叶变换红外光谱或核磁共振等大规模分析工具对这些材料进行鉴定和表征。然而，需要成像技术在微米和纳米尺度上提供关于钙磷酸盐相的空间分布和化学成分的信息。这种分析为材料可能是如何形成的提供了有洞察力的指示，例如通过最终在空间上与成熟相保持分离的瞬时前体相。在这里，我们提出了扫描透射式X射线显微镜(STXM)的分析，以钙磷酸盐为基准化合物，显示了指纹技术的可行性。我们用C K-，Ca L-2，L-3-和P L-2，L-3边的X射线吸收近边谱校正了测定钙磷酸盐相重要参数的方法，如钙磷比和碳酸盐含量，在类似于25 nm的尺度上。作为一个说明性的案例研究，我们还对在致密的纤维状胶原基质中形成的羟基磷灰石沉淀物进行了STXM分析。这项研究为未来几十纳米级的钙磷生物矿化过程的研究铺平了道路。(C)2014 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Several naturally occurring biological materials, including bones and teeth, pathological calcifications, microbial mineral deposits formed in marine phosphogenesis areas, as well as bin-inspired cements used for bone and tooth repair are composed of Ca-phosphates. These materials are usually identified and characterized using bulk-scale analytical tools such as X-ray diffraction, Fourier transform infrared spectroscopy or nuclear magnetic resonance. However, there is a need for imaging techniques that provide information on the spatial distribution and chemical composition of the Ca-phosphate phases at the micrometer- and nanometer scales. Such analyses provide insightful indications on how the materials may have formed, e.g. through transient precursor phases that eventually remain spatially separated from the mature phase. Here, we present scanning transmission X-ray microscopy (STXM) analyses of Ca-phosphate reference compounds, showing the feasibility of fingerprinting Ca-phosphate-based materials. We calibrate methods to determine important parameters of Ca-phosphate phases, such as their Ca/P ratio and carbonate content at the similar to 25 nm scale, using X-ray absorption near-edge spectra at the C K-, Ca L-2,L-3- and P L-2,L-3-edges. As an illustrative case study, we also perform STXM analyses on hydroxyapatite precipitates formed in a dense fibrillar collagen matrix. This study paves the way for future research on Ca-phosphate biomineralization processes down to the scale of a few tens of nanometers. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.