Computed tomography detects changes in contrast agent diffusion after collagen cross-linking typical to natural aging of articular cartilage
Computed tomography detects changes in contrast agent diffusion after collagen cross-linking typical to natural aging of articular cartilage
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DOI：
10.1016/j.joca.2011.07.008
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发表时间：
2011-10-01
影响因子：
7
通讯作者：
Toyras, J.
中科院分区：
文献类型：
--
作者：
Kokkonen, H. T.;Makela, J.;Toyras, J.
目的：研究蔗糖诱导的胶原交联对软骨力学性能和扩散性能的影响。特别是，我们研究了对比增强计算机断层扫描（CECT）检测胶原交联增加后关节软骨变化的潜力，这是一种与年龄相关的现象。方法：以牛完整髌骨（n = 7）为材料制备骨软骨塞（φ = 6.0 mm, n = 28）。从每个髌骨制备的四个相邻样品中的两个用蔗糖处理以增加胶原交联，而另外两个样品作为配对对照。对一对样品进行机械测试，然后使用材料测试装置进行机械损伤。对比剂[ioxaglate (Hexabrix (TM))]扩散在另一对标本中使用CECT成像25小时。测定了样品的水分含量、胶原蛋白和蛋白聚糖含量、胶原网络结构和交联量(1 -羟基赖基吡啶啉（HP）、赖基吡啶啉（LP）和戊苷（Pent）]。结果：经丝糖处理后，Pent和LP的软骨胶原交联明显增加（P < 0.001）。CECT可以检测到交联增加，处理后的蔗糖中造影剂的渗透和扩散通量显著低于未处理的样品（P < 0.05）。蔗糖处理后的样品的平衡模量（+164%,P < 0.05）和应变相关动态模量（+47%,P < 0.05）均显著高于对照样品，但初始动态模量与蔗糖处理之间没有相关性。丝糖处理对水分、蛋白聚糖和胶原含量以及胶原结构没有显著影响。结论：综上所述，CECT技术在检测胶原交联增加引起的软骨组织变化方面非常敏感。这一点很重要，因为交联的增加被认为与组织损伤易感性的增加有关。(C) 2011国际骨关节炎研究学会。Elsevier Ltd.出版。版权所有。
Objective: The effect of threose-induced collagen cross-linking on the mechanical and diffusive properties of cartilage was investigated in vitro. In particular, we investigated the potential of Contrast Enhanced Computed Tomography (CECT) to detect changes in articular cartilage after increased collagen cross-linking, which is an age-related phenomenon.Methods: Osteochondral plugs (phi = 6.0 mm, n = 28) were prepared from intact bovine patellae (n = 7). Two of the four adjacent samples, prepared from each patella, were treated with threose to increase the collagen cross-linking, while the other two specimen served as paired controls. One sample pair was mechanically tested and then mechanically injured using a material testing device. Contrast agent [ioxaglate (Hexabrix (TM))] diffusion was imaged in the other specimen pair for 25 h using CECT. Water fraction, collagen and proteoglycan content, collagen network architecture and the amount of cross-links 1 hydroxylysyl pyridinoline (HP), lysyl pyridinoline (LP) and pentosidine (Pent)] of the samples were also determined.Results: Cartilage collagen cross-linking, both Pent and LP, were significantly (P < 0.001) increased due to threose treatment. CECT could detect the increased cross-links as the contrast agent penetration and the diffusion flux were significantly (P < 0.05) lower in the threose treated than in untreated samples. The equilibrium modulus (+164%, P < 0.05) and strain dependent dynamic modulus (+47%, P < 0.05) were both significantly greater in the threose treated samples than in reference samples, but there was no association between the initial dynamic modulus and the threose treatment. The water fraction, proteoglycan and collagen contents, as well as collagen architecture, were not significantly altered by the threose treatment.Conclusions: To conclude, the CECT technique was found to be sensitive at detecting changes in cartilage tissue due to increased collagen cross-linking. This is important since increased cross-linking has been proposed to be related to the increased injury susceptibility of tissue. (C) 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.