Raman spectral classification of mineral- and collagen-bound water's associations to elastic and post-yield mechanical properties of cortical bone.
Raman spectral classification of mineral- and collagen-bound water's associations to elastic and post-yield mechanical properties of cortical bone.
复制标题
矿物质和胶原蛋白结合水与皮质骨弹性和屈服后机械性能关联的拉曼光谱分类。
DOI：
10.1016/j.bone.2015.07.024
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发表时间：
2015
期刊：
影响因子：
4.1
通讯作者：
Akkus,Ozan
中科院分区：
文献类型：
--
作者：
Unal,Mustafa;Akkus,Ozan
与骨基质结合的水被认为是抗骨折能力的预测因子。然而，结合水是一个难以进行无损测量的变量。迄今为止，用于研究骨水合状态的唯一非破坏性方法是磁共振变体（NMR 或 MRI）。首次通过短波红外 (SWIR) 拉曼光谱研究骨水合状态，以研究矿物质结合水和胶原结合水室与机械性能的关联。三十个皮质骨样品用于基于拉曼的定量水分析、重量分析、孔隙率测量和生物力学测试。开发了连续脱水方案来替代骨骼中未结合（加热干燥）和结合（乙醇处理）的水。连续收集拉曼光谱以追踪脱水过程中的 OH 伸缩带。研究了之前确定的四个峰：I3220/I2949、I3325/I2949 和 I3453/I2949 反映了有机基质相关水室（主要是胶原相关水）和骨胶原部分的状态，而 I3584/I2949 反映了矿物质相关水室和骨矿物质部分的状态。这些光谱生物标志物与骨的弹性和屈服后机械特性相关。胶原-水相关生物标志物（I3220/I2949 和 I3325/I2949）与韧性（R2= 0.81 和 R2= 0.79；p < 0.001）和屈服后韧性（R2= 0.65 和 R2= 0.73；p < 0.001）呈显着正相关。矿泉水相关生物标志物与弹性模量呈显着负相关（R2= 0.78；p < 0.001），与强度呈正相关（R2= 0.46；p < 0.001）。虽然基于磁共振的技术可用于测量非结合水和结合水，但这是第一项对结合水区室中胶原蛋白和矿物质结合水进行差异探测的研究。我们首次展示了不同结合水区室对湿骨机械性能的贡献的证据，以及报告的基于拉曼的水测量与机械性能的相关性，强调了有必要采用方法在体内无创地评估这些新的生物标志物，以改善对那些可能因衰老和疾病而面临骨折风险的人的当前诊断。
Water that is bound to bone's matrix is implied as a predictor of fracture resistance; however, bound water is an elusive variable to be measured nondestructively. To date, the only nondestructive method used for studying bone hydration status is magnetic resonance variants (NMR or MRI). For the first time, bone hydration status was studied by short-wave infrared (SWIR) Raman spectroscopy to investigate associations of mineral-bound and collagen-bound water compartments with mechanical properties. Thirty cortical bone samples were used for quantitative Raman-based water analysis, gravimetric analysis, porosity measurement, and biomechanical testing. A sequential dehydration protocol was developed to replace unbound (heat drying) and bound (ethanol treatment) water in bone. Raman spectra were collected serially to track the OH-stretch band during dehydration. Four previously identified peaks were investigated: I3220/I2949, I3325/I2949and I3453/I2949reflect status of organic-matrix related water (mostly collagen-related water) compartments and collagen portion of bone while I3584/I2949reflects status of mineral-related water compartments and mineral portion of bone. These spectroscopic biomarkers were correlated with elastic and post-yield mechanical properties of bone. Collagen–water related biomarkers (I3220/I2949and I3325/I2949) correlated significantly and positively with toughness (R2= 0.81 and R2= 0.79; p < 0.001) and post-yield toughness (R2= 0.65 and R2= 0.73; p < 0.001). Mineral-water related biomarker correlated significantly and negatively with elastic modulus (R2= 0.78; p < 0.001) and positively with strength (R2= 0.46; p < 0.001). While MR-based techniques have been useful in measuring unbound and bound water, this is the first study which probed bound-water compartments differentially for collagen and mineral-bound water. For the first time, we showed an evidence for contributions of different bound-water compartments to mechanical properties of wet bone and the reported correlations of Raman-based water measurements to mechanical properties underline the necessity for enabling approaches to assess these new biomarkers noninvasively in vivo to improve the current diagnosis of those who may be at risk of bone fracture due to aging and diseases.