Vascular homeostasis and the concept of mechanobiological stability
Vascular homeostasis and the concept of mechanobiological stability
复制标题
DOI：
10.1016/j.ijengsci.2014.08.003
复制
发表时间：
2014-12-01
影响因子：
6.6
通讯作者：
Humphrey, J. D.
中科院分区：
文献类型：
--
作者：
Cyron, C. J.;Humphrey, J. D.
血管力学自20世纪70年代初以来一直被深入研究，主要沿袭了连续介质力学的经典概念。然而，与典型的工程材料相比，血管的一个重要区别是材料在这些活组织中不断降解和沉积。在这篇文章中，我们研究了这种质量周转的力学后果。在Lyapunov稳定性理论的启发下，我们引入了力学生物平衡和稳定性的新概念，证明了只有在一定的预应力下沉积新的材料，并且血管在力学和机械生物学上都是稳定的，血管才能在生理条件下保持其结构和功能。此外，我们引入了机械生物学适应性的概念，作为在连续水平上理解血管行为的第三个基石。我们论证了适应性代表了机械生物系统和典型的人造系统稳定性之间的关键区别。基于这些想法，我们建议改变范式，可以通过考虑常见的动脉病理来说明这一点。我们认为，动脉瘤可以被解释为机械生物不稳定性，预测其破裂风险不仅应考虑最大直径或壁应力，还应考虑机械生物稳定性。对不同模型参数对所谓的机械生物稳定裕度的影响进行了数学分析，该稳定裕度是用来表征机械生物稳定性的单一标量，揭示了这种稳定性随着质量周转、材料硬度和大规模生产中应力依赖变化的能力的特征时间常数而增加。由于这些参数中的每一个都可以被适当的药物改变，本文发展的理论可以指导动脉病变(如动脉瘤)的预后和新疗法的发展。(C)2014爱思唯尔有限公司。保留所有权利。
Vascular mechanics has been studied in depth since the early 1970s mainly following classical concepts from continuum mechanics. Yet, an important distinction of blood vessels, in contrast to typical engineering materials, is the continuous degradation and deposition of material in these living tissues. In this paper we examine mechanical consequences of such mass turnover. Motivated by Lyapunov's stability theory, we introduce the new concepts of mechanobiological equilibrium and stability and demonstrate that blood vessels can maintain their structure and function under physiological conditions only if new material is deposited at a certain prestress and the vessels are both mechanically and mechanobiologically stable. Moreover, we introduce the concept of mechanobiological adaptivity as a third corner stone to understand vascular behavior on a continuum level. We demonstrate that adaptivity represents a key difference between the stability of mechanobiological and typical human-made systems. Based on these ideas, We suggest a change of paradigm that can be illustrated by considering a common arterial pathology. We suggest that aneurysms can be interpreted as mechanobiological instabilities and that predictions of their rupture risk should not only consider the maximal diameter or wall stress, but also the mechanobiological stability. A mathematical analysis of the impact of the different model parameters on the so-called mechanobiological stability margin, a single scalar used to characterize mechanobiological stability, reveals that this stability increases with the characteristic time constant of mass turnover, material stiffness, and capacity for stress-dependent changes in mass production. As each of these parameters may be modified by appropriate drugs, the theory developed in this paper may guide both prognosis and the development of new therapies for arterial pathologies such as aneurysms. (C) 2014 Elsevier Ltd. All rights reserved.