Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstrasse 16-18, Leipzig, Germany.
Biopolymers. 2010 Jun;93(6):520-32. doi: 10.1002/bip.21386.
We have studied the molecular dynamics of one of the major macromolecules in articular cartilage, chondroitin sulfate. Applying (13)C high-resolution magic-angle spinning NMR techniques, the NMR signals of all rigid macromolecules in cartilage can be suppressed, allowing the exclusive detection of the highly mobile chondroitin sulfate. The technique is also used to detect the chondroitin sulfate in artificial tissue-engineered cartilage. The tissue-engineered material that is based on matrix producing chondrocytes cultured in a collagen gel should provide properties as close as possible to those of the natural cartilage. Nuclear relaxation times of the chondroitin sulfate were determined for both tissues. Although T(1) relaxation times are rather similar, the T(2) relaxation in tissue-engineered cartilage is significantly shorter. This suggests that the motions of chondroitin sulfate in natural and artificial cartilage are different. The nuclear relaxation times of chondroitin sulfate in natural and tissue-engineered cartilage were modeled using a broad distribution function for the motional correlation times. Although the description of the microscopic molecular dynamics of the chondroitin sulfate in natural and artificial cartilage required the identical broad distribution functions for the correlation times of motion, significant differences in the correlation times of motion that are extracted from the model indicate that the artificial tissue does not fully meet the standards of the natural ideal. This could also be confirmed by macroscopic biomechanical elasticity measurements. Nevertheless, these results suggest that NMR is a useful tool for the investigation of the quality of artificially engineered tissue.
我们研究了关节软骨中主要的大分子之一——硫酸软骨素的分子动力学。应用 (13)C 高分辨率魔角旋转 NMR 技术，可以抑制软骨中所有刚性大分子的 NMR 信号，从而可以专门检测高度移动的硫酸软骨素。该技术还可用于检测人工组织工程软骨中的硫酸软骨素。基于在胶原凝胶中培养的产生基质的软骨细胞的组织工程材料，应该提供尽可能接近天然软骨的特性。我们确定了这两种组织中硫酸软骨素的核弛豫时间。尽管 T(1)弛豫时间相当相似，但组织工程软骨中的 T(2)弛豫时间明显更短。这表明硫酸软骨素在天然和人工软骨中的运动方式不同。使用运动相关时间的宽分布函数对天然和组织工程软骨中硫酸软骨素的核弛豫时间进行了建模。尽管天然和人工软骨中硫酸软骨素的微观分子动力学描述需要相同的运动相关时间的宽分布函数，但从模型中提取的运动相关时间存在显著差异，这表明人工组织并不能完全满足天然理想的标准。这也可以通过宏观生物力学弹性测量来证实。然而，这些结果表明，NMR 是研究人工工程组织质量的有用工具。
