Matrix and cell injury due to sub-impact loading of adult bovine articular cartilage explants: effects of strain rate and peak stress
Matrix and cell injury due to sub-impact loading of adult bovine articular cartilage explants: effects of strain rate and peak stress
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DOI：
10.1016/s0736-0266(00)00025-5
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发表时间：
2001-03-01
影响因子：
2.8
通讯作者：
Hunziker, EB
中科院分区：
文献类型：
--
作者：
Quinn, TM;Allen, RG;Hunziker, EB
软骨的机械过载与骨关节病的发生和发展有关。我们的目标是确定阈值水平的应变率和峰值应力，在亚冲击负荷可以诱导软骨基质损伤和软骨细胞损伤的牛骨软骨外植体和探索基质损伤，细胞损伤的空间模式，和施加的负载之间的关系。施加单次亚冲击载荷，其特征在于恒定应变速率在3 x 10（-5）和0.7 s（-1）之间，峰值应力在3.5和14 MPa之间，之后将外植体在培养物中保持4天。在较高的应变率，基质机械故障（组织裂纹）和细胞失活是最严重的软骨浅表区附近，并与持续增加的蛋白多糖从外植体的释放。相比之下，低应变率加载与细胞失活的情况下，risible基质损伤。此外，细胞活性和蛋白多糖的合成抑制整个软骨深度，但在径向依赖的方式与最严重的影响在圆柱形外植体的中心。结果突出的空间格局的基质损伤和细胞损伤，这取决于施加的有害负荷的性质。这些损伤模式也可能在其对降解性疾病进展的长期影响和软骨修复的可能性方面有所不同。(C)2001骨科研究学会。由Elsevier Science Ltd.出版，版权所有。
Mechanical overloading of cartilage has been implicated in the initiation and progression of osteoarthrosis. Our objectives were to identify threshold levels of strain rate and peak stress at which sub-impact loads could induce cartilage matrix damage and chondrocyte injury in bovine osteochondral explants and to explore relationships between matrix damage, spatial patterns of cell injury, and applied loads. Single sub-impact loads characterized by a constant strain rate between 3 x 10(-5) and 0.7 s(-1) to a peak stress between 3.5 and 14 MPa were applied, after which explants were maintained in culture for four days. At the higher strain rates, matrix mechanical failure (tissue cracks) and cell deactivation were most severe near the cartilage superficial zone and were associated with sustained increased release of proteoglycan from explants. In contrast, low strain rate loading was associated with cell deactivation in the absence of risible matrix damage. Furthermore, cell activity and proteoglycan synthesis were suppressed throughout the cartilage depth, but in a radially dependent manner with the most severe effects at the center of cylindrical explants. Results highlight spatial patterns of matrix damage and cell injury which depend upon the nature of injurious loading applied. These patterns of injury may also differ in terms of their long-term implications for progression of degradative disease and possibilities for cartilage repair. (C) 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.