EFFECTS OF SOLUTE SIZE AND TISSUE COMPOSITION ON MOLECULAR AND MACROMOLECULAR DIFFUSIVITY IN HUMAN KNEE CARTILAGE.
EFFECTS OF SOLUTE SIZE AND TISSUE COMPOSITION ON MOLECULAR AND MACROMOLECULAR DIFFUSIVITY IN HUMAN KNEE CARTILAGE.
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DOI：
10.1016/j.ocarto.2020.100087
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发表时间：
2020-12-01
期刊：
影响因子：
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通讯作者：
Jackson, Alicia R
中科院分区：
文献类型：
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作者：
Travascio, Francesco;Valladares-Prieto, Sabrina;Jackson, Alicia R
目的：关节软骨是一种无血管组织。因此，扩散系数代表了营养物质和其他分子信号的基本运输机制，这些分子信号调节其细胞代谢和维持细胞外基质。了解溶质如何扩散到关节软骨中，对于阐明其病理机制以及设计修复和恢复其细胞外基质的治疗方法至关重要。就像在其他结缔组织中一样，关节软骨的扩散率可能会随其成分和特定的扩散溶质而变化。因此，本研究探讨了溶质大小和组织组成对膝关节软骨分子扩散的影响。设计：FRAP试验测量了5种分子探针在人膝关节软骨中的扩散系数，这些分子探针的大小从~332到70,000 Da不等。结果：扩散系数受分子尺寸的影响，扩散系数的大小随探针斯托克斯半径的增大而减小。尽管胫骨样品的水分含量明显高于股骨样品，而股骨样品的GAG含量较低，但胫骨样品和股骨样品的扩散系数值彼此之间没有显著差异。水分含量不影响扩散系数。相反，大分子的扩散系数对GAG含量敏感。结论：本研究为关节软骨中扩散的机制提供了新的认识。我们的发现可用于进一步研究骨关节炎和设计软骨修复或置换的治疗方法。
OBJECTIVE: Articular cartilage is an avascular tissue. Accordingly, diffusivity represents a fundamental transport mechanism for nutrients and other molecular signals regulating its cell metabolism and maintenance of the extracellular matrix. Understanding how solutes spread into articular cartilage is crucial to elucidating its pathologies, and to designing treatments for repair and restoration of its extracellular matrix. As in other connective tissues, diffusivity in articular cartilage may vary depending both its composition and the specific diffusing solute. Hence, this study investigated the roles of solute size and tissue composition on molecular diffusion in knee articular cartilage.DESIGN: FRAP tests were conducted to measure diffusivity of five molecular probes, with size ranging from ~332Da to 70,000Da, in human knee articular cartilage. The measured diffusion coefficients were related to molecular size, as well as water and glycosaminoglycan (GAG) content of femoral and tibial condyle cartilage.RESULTS: Diffusivity was affected by molecular size, with the magnitude of the diffusion coefficients decreasing as the Stokes radius of the probe increased. The values of diffusion coefficients in tibial and femoral samples were not significantly different from one another, despite the fact that tibial samples exhibited significantly higher water content and lower GAG content of the femoral specimens. Water content did not affect diffusivity. In contrast, diffusivities of large molecules were sensitive to GAG content.CONCLUSIONS: This study provides new knowledge on the mechanisms of diffusion in articular cartilage. Our findings can be leveraged to further investigate osteoarthritis and to design treatments for cartilage restoration or replacement.