Topol Heiko, Demirkoparan Hasan, Pence Thomas J
Carnegie Mellon University in Qatar, P.O. Box 24866, Doha, Qatar.
Carnegie Mellon University in Qatar, P.O. Box 24866, Doha, Qatar.
J Mech Behav Biomed Mater. 2021 Jan;113:104154. doi: 10.1016/j.jmbbm.2020.104154. Epub 2020 Oct 28.
A variety of biochemical and physical processes participate in the creation and maintenance of collagen in biological tissue. Under mechanical stimuli these collagen fibers undergo continuous processes of morphoelastic change. The model presented here is motivated by experimental reports of stretch-stabilization of the collagen fibers to enzymatic degradation. The fiber structure is modeled in terms of a fiber density evolution that is regulated by means of a fixed creation rate and a mechano-sensitive dissolution rate. The theory accounts for the possibly different natural configurations of the fiber unit constituents and the ground substance matrix. It also generalizes previous theoretical descriptions so as to account for finite survival times of the individual fiber units. Special consideration is given to steady state fiber-remodeling processes in which fiber creation and dissolution are in balance. Fiber assembly processes that involve prestretching the fiber constituents yield a homeostatic stress response with a characteristic fiber tone. Fiber density returns to homeostasis after mechanical disruption when sufficient time has passed.
多种生化和物理过程参与生物组织中胶原蛋白的生成和维持。在机械刺激下，这些胶原纤维会经历持续的形态弹性变化过程。此处提出的模型是受胶原纤维拉伸稳定以抵抗酶降解的实验报告所启发。纤维结构是根据纤维密度演化来建模的，该演化通过固定的生成速率和机械敏感的溶解速率来调节。该理论考虑了纤维单元成分和基质可能不同的自然构型。它还对先前的理论描述进行了推广，以考虑单个纤维单元的有限存活时间。特别关注了纤维生成和溶解处于平衡状态的稳态纤维重塑过程。涉及对纤维成分进行预拉伸的纤维组装过程会产生具有特征性纤维张力的稳态应力响应。当经过足够长的时间后，纤维密度在机械破坏后会恢复到稳态。
