Enzymatic digestion of articular cartilage results in viscoelasticity changes that are consistent with polymer dynamics mechanisms.
Enzymatic digestion of articular cartilage results in viscoelasticity changes that are consistent with polymer dynamics mechanisms.
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DOI：
10.1186/1475-925x-8-32
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发表时间：
2009-11-04
影响因子：
3.9
通讯作者：
Fyhrie DP
中科院分区：
文献类型：
--
作者：
June RK;Fyhrie DP
骨关节炎引起的软骨退化影响着全世界数百万老年人，尽管经过30年的研究，但基质生物聚合物对软骨粘弹性的具体贡献仍然未知。聚合物动力学理论可以使这样的理解，并预测，软骨应力松弛将进行更快时，平均聚合物长度缩短。本研究测试了聚合物动力学的预测是否与特定软骨细胞外基质分子的酶消化引起的软骨力学变化一致。将小牛软骨外植体培养过夜，然后浸入IV型胶原酶、细菌透明质酸酶或对照溶液中。在孵育0、1和2天后进行应力松弛和循环载荷试验。孵育1天后，胶原酶和细菌透明质酸酶酶消化后，应力松弛进行得更快（均p ≤ 0.01）。胶原酶和细菌透明质酸酶消化1天后，1 Hz及以上频率下的储能模量和损耗模量较小（所有p ≤ 0.02）。这些结果表明，酶消化改变软骨粘弹性的方式与聚合物动力学机制一致。未来的研究可能会扩大使用聚合物动力学作为微观结构模型，了解特定的基质分子对组织水平的粘弹性能的贡献。
Cartilage degeneration via osteoarthritis affects millions of elderly people worldwide, yet the specific contributions of matrix biopolymers toward cartilage viscoelastic properties remain unknown despite 30 years of research. Polymer dynamics theory may enable such an understanding, and predicts that cartilage stress-relaxation will proceed faster when the average polymer length is shortened. This study tested whether the predictions of polymer dynamics were consistent with changes in cartilage mechanics caused by enzymatic digestion of specific cartilage extracellular matrix molecules. Bovine calf cartilage explants were cultured overnight before being immersed in type IV collagenase, bacterial hyaluronidase, or control solutions. Stress-relaxation and cyclical loading tests were performed after 0, 1, and 2 days of incubation. Stress-relaxation proceeded faster following enzymatic digestion by collagenase and bacterial hyaluronidase after 1 day of incubation (both p ≤ 0.01). The storage and loss moduli at frequencies of 1 Hz and above were smaller after 1 day of digestion by collagenase and bacterial hyaluronidase (all p ≤ 0.02). These results demonstrate that enzymatic digestion alters cartilage viscoelastic properties in a manner consistent with polymer dynamics mechanisms. Future studies may expand the use of polymer dynamics as a microstructural model for understanding the contributions of specific matrix molecules toward tissue-level viscoelastic properties.