Raman microspectroscopic analysis of the tissue-specific composition of the human osteochondral junction in osteoarthritis: A pilot study
Raman microspectroscopic analysis of the tissue-specific composition of the human osteochondral junction in osteoarthritis: A pilot study
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DOI：
10.1016/j.actbio.2020.02.020
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发表时间：
2020-04-01
影响因子：
9.7
通讯作者：
Saarakkala, Simo
中科院分区：
文献类型：
--
作者：
Das Gupta, Shuvashis;Finnila, Mikko A. J.;Saarakkala, Simo
本研究利用拉曼光谱技术研究了骨关节炎(OA)疾病的严重程度对人类胫骨平台骨软骨交界处生物组成的影响。我们的目标是从未固定的水化标本中分析矿化骨软骨组织的空间组成，即钙化软骨(CC)和软骨下骨板(SBP)。我们推测晚期骨性关节炎时CC和SBP的矿化减少。从7具身体供体的胫骨平台采集28个直径为4 mm的圆柱形骨软骨标本，按组织病理学分级分为三组：健康组(n=5)、早期骨关节炎(n=8)和晚期骨关节炎(n=15)。拉曼光谱进行了多变量聚类分析，以识别不同的组织。最后，对组织特异性成分进行了分析，并用线性混合模型对OA的影响进行了统计评估。拉曼光谱的聚类分析成功地区分了CC和SBP以及潮标区和未钙化的软骨。与SBP相比，CC的矿化程度更高，矿物的结晶程度更高。两种组织都表现出相似的成分变化，作为组织病理学OA严重程度的函数。在OA早期，矿化倾向于增加，矿物含有较少的碳酸盐取代。与早期矿化相比，晚期矿化的矿物晶体富含碳酸盐，而矿化总体减弱。这项拉曼光谱研究为研究天然组织中复杂的骨软骨连接提供了新的方法。在这项研究中，拉曼显微光谱学被用来研究骨关节炎退行性变对人类骨软骨交界处组织特异性生化成分的影响。多变量聚类分析使我们能够表征钙化的软骨和软骨下骨板以及潮位区的微妙的成分变化。钙化软骨和软骨下骨板在有机相和矿物相的组成差异将成为设计骨软骨修复生物材料的关键基准参数。我们发现矿化和碳酸盐替代的组织特异性变化是作为组织病理学OA严重程度的函数。我们开发的方法可以用来研究与骨关节炎相关的骨软骨连接的代谢变化。(C)2020 Acta Materialia Inc.，由Elsevier Ltd.出版。
This study investigates the influence of osteoarthritis (OA) disease severity on the bio-composition of the osteochondral junction at the human tibial plateau using Raman microspectroscopy. We specifically aim to analyze the spatial composition of mineralized osteochondral tissues, i.e., calcified cartilage (CC) and subchondral bone plate (SBP) from unfixed, hydrated specimens. We hypothesize that the mineralization of CC and SBP decreases in advanced OA. Twenty-eight cylindrical osteochondral samples (d = 4 mm) from tibial plateaus of seven cadaveric donors were harvested and sorted into three groups following histopathological grading: healthy (n = 5), early OA (n = 8), and advanced OA (n = 15). Raman spectra were subjected to multivariate cluster analyses to identify different tissues. Finally, the tissue-specific composition was analyzed, and the impact of OA was statistically evaluated with linear mixed models. Cluster analyses of Raman spectra successfully distinguished CC and SBP as well as a tidemark region and uncalcified cartilage. CC was found to be more mineralized and the mineral was more crystalline compared with SBP. Both tissues exhibited similar compositional changes as a function of histopathological OA severity. In early OA, the mineralization tends to increase, and the mineral contains fewer carbonate substitutions. Compared with early OA, mineral crystals are rich in carbonate while the overall mineralization decreases in advanced OA. This Raman spectroscopic study advances the methodology for investigating the complex osteochondral junction from native tissue. The developed methodology can be used to elucidate detailed tissue-specific changes in the chemical composition with advancing OA.Statement of SignificanceIn this study, Raman microspectroscopy was utilized to investigate the influence of osteoarthritic degeneration on the tissue-specific biochemical composition of the human osteochondral junction. Multivariate cluster analyses allowed us to characterize subtle compositional changes in the calcified cartilage and subchondral bone plate as well as in the tidemark region. The compositional differences found between the calcified cartilage and subchondral bone plate in both organic and mineral phases will serve as critical benchmark parameters when designing biomaterials for osteochondral repair. We found tissue-specific changes in the mineralization and carbonate substitution as a function of histopathological OA severity. Our developed methodology can be used to investigate the metabolic changes in the osteochondral junction associated with osteoarthritis. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd.