Contribution of Proteoglycan Osmotic Swelling Pressure to the Compressive Properties of Articular Cartilage
Contribution of Proteoglycan Osmotic Swelling Pressure to the Compressive Properties of Articular Cartilage
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DOI：
10.1016/j.bpj.2011.07.006
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发表时间：
2011-08-17
影响因子：
3.4
通讯作者：
Sah, Robert L.
中科院分区：
文献类型：
--
作者：
Han, EunHee;Chen, Silvia S.;Sah, Robert L.
带负电荷的蛋白聚糖（PG）通过其固定电荷密度（FCD）和高渗透压（pi（PG））向关节软骨提供抗压性，并且胶原网络（CN）提供限制力以平衡pi（PG）。本研究的目的是：1）在将生物化学测量转换为FCD-PI（PG）关系时，考虑胶原纤维内水; 2）计算PI（PG）和ON对牛生长过程中全层软骨压缩行为的贡献（胎儿、小牛和成年人）和人类成年人老化（年轻人和老年人）;以及3）预测人类老化中距关节表面的深度对pi（PG）的影响。纤维外FCD（EF）和PI（PG）随着牛的生长而增加，由于CN浓度的增加，而PG浓度是稳定的。这种与成熟相关的增加被压缩放大。随着人的正常衰老，FCD（EF）和PI（PG）下降。在所有牛和年轻人软骨中，pi（PG）值接近平衡应力（σ（EQ）），但在老年人软骨中仅约为σ（EQ）的一半。深度相关的变化，应变，FCD（EF），PI（PG），CN应力曲线在人类软骨表明随着年龄的增长，浅层的功能恶化。这些结果表明FCD-PI（PG）关系的效用，用于阐明基质大分子对软骨生物力学特性的贡献。
The negatively charged proteoglycans (PG) provide compressive resistance to articular cartilage by means of their fixed charge density (FCD) and high osmotic pressure (pi(PG)), and the collagen network (CN) provides the restraining forces to counterbalance pi(PG). Our objectives in this work were to: 1), account for collagen intrafibrillar water when transforming biochemical measurements into a FCD-pi(PG) relationship; 2), compute pi(PG) and ON contributions to the compressive behavior of full-thickness cartilage during bovine growth (fetal, calf, and adult) and human adult aging (young and old); and 3), predict the effect of depth from the articular surface on pi(PG) in human aging. Extrafibrillar FCD (FCD(EF)) and pi(PG) increased with bovine growth due to an increase in CN concentration, whereas PG concentration was steady. This maturation-related increase was amplified by compression. With normal human aging, FCD(EF) and pi(PG) decreased. The pi(PG)-values were close to equilibrium stress (sigma(EQ)) in all bovine and young human cartilage, but were only approximately half of sigma(EQ) in old human cartilage. Depth-related variations in the strain, FCD(EF), pi(PG), and CN stress profiles in human cartilage suggested a functional deterioration of the superficial layer with aging. These results suggest the utility of the FCD-pi(PG) relationship for elucidating the contribution of matrix macromolecules to the biomechanical properties of cartilage.