Henss Anja, Rohnke Marcus, Knaack Sven, Kleine-Boymann Matthias, Leichtweiss Thomas, Schmitz Peter, El Khassawna Thaqif, Gelinsky Michael, Heiss Christian, Janek Jürgen
Institute of Physical Chemistry, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 58, 35392, Giessen, Germany,
Biointerphases. 2013 Dec;8(1):31. doi: 10.1186/1559-4106-8-31. Epub 2013 Nov 14.
The determination of the spatially resolved calcium distribution and concentration in bone is essential for the assessment of bone quality. It enables the diagnosis and elucidation of bone diseases, the course of bone remodelling and the assessment of bone quality at interfaces to implants. With time-of-flight secondary ion mass spectrometry (ToF-SIMS) the calcium distribution in bone cross sections is mapped semi-quantitatively with a lateral resolution of up to 1 μm. As standards for the calibration of the ToF-SIMS data calcium hydroxyapatite collagen scaffolds with different compositions were synthesized. The standards were characterised by loss of ignition, x-ray diffractometry (XRD) and x-ray photoelectron spectroscopy (XPS). The secondary ion count rate for calcium and the calcium content of the standards show a linear dependence. The obtained calibration curve is used for the quantification of the calcium content in the bone of rats. The calcium concentration within an animal model for osteoporosis induction is monitored. Exemplarily the calcium content of the bones was quantified by XPS for validation of the results. Furthermore a calcium mass image is compared with an XPS image to demonstrate the better lateral resolution of ToF-SIMS which advances the locally resolved quantification of the calcium content.
确定骨骼中空间分辨的钙分布和浓度对于评估骨质量至关重要。它有助于诊断和阐明骨疾病、骨重塑过程以及评估植入物界面处的骨质量。利用飞行时间二次离子质谱（ToF-SIMS），可对骨横截面中的钙分布进行半定量映射，横向分辨率高达1μm。为校准ToF-SIMS数据，合成了具有不同组成的羟基磷灰石-胶原蛋白支架作为标准品。通过灼烧失重、X射线衍射（XRD）和X射线光电子能谱（XPS）对标准品进行了表征。钙的二次离子计数率与标准品的钙含量呈线性关系。所得校准曲线用于定量大鼠骨骼中的钙含量。监测骨质疏松诱导动物模型中的钙浓度。作为示例，通过XPS对骨骼的钙含量进行定量以验证结果。此外，将钙质量图像与XPS图像进行比较，以证明ToF-SIMS具有更好的横向分辨率，这有助于对钙含量进行局部分辨定量。
