An inverse method for predicting tissue-level mechanics from cellular mechanical input.
An inverse method for predicting tissue-level mechanics from cellular mechanical input.
复制标题
一种根据细胞机械输入预测组织水平力学的逆方法。
DOI：
10.1016/j.jbiomech.2008.11.014
复制
发表时间：
2009
影响因子：
2.4
通讯作者：
Kohles,SeanS
中科院分区：
文献类型：
--
作者：
Kim,Wangdo;Tretheway,DerekC;Kohles,SeanS
细胞外基质（ECM）提供了一种动态的三维结构，将机械刺激转化为细胞。这种局部机械刺激可以指导生物功能，包括组织发育。描述机械调节器的作用的理论假设细胞对ECM上的外部机械力的变化的反应。产生特定的局部细胞位移模式所需的确切ECM机械刺激仍然未知。细胞组织逆问题提供了一种替代方法来澄清这种关系。为结构动力学而开发的逆动力学问题将局部状态变量的测量（在细胞水平）转化为未知或期望的强制函数（在组织或ECM水平）。本文介绍了使用本征值（谐振频率），本征向量（模式形状），和动态规划，以减少一个简化的细胞-组织系统的数学阶数，并估计ECM所需的机械刺激一个指定的细胞力学环境。有限元和逆数值分析进行了一个简单的二维模型，以确定加权参数的影响和减少的分析模式导致的解决方案。仿真结果表明，机械模式的数量减少（从30到14到7）可以充分再现未知的力的时间历程上的ECM边界。细胞到组织（逆）和组织到细胞（边界值）建模之间的代表性比较说明了逆模型的多尺度适用性。
Extracellular matrix (ECM) provides a dynamic three-dimensional structure which translates mechanical stimuli to cells. This local mechanical stimulation may direct biological function including tissue development. Theories describing the role of mechanical regulators hypothesize the cellular response to variations in the external mechanical forces on the ECM. The exact ECM mechanical stimulation required to generate a specific pattern of localized cellular displacement is still unknown. The cell to tissue inverse problem offers an alternative approach to clarify this relationship. Developed for structural dynamics, the inverse dynamics problem translates measurements of local state variables (at the cell level) into an unknown or desired forcing function (at the tissue or ECM level). This paper describes the use of eigenvalues (resonant frequencies), eigenvectors (mode shapes), and dynamic programming to reduce the mathematical order of a simplified cell–tissue system and estimate the ECM mechanical stimulation required for a specified cellular mechanical environment. Finite element and inverse numerical analyses were performed on a simple two-dimensional model to ascertain the effects of weighting parameters and a reduction of analytical modes leading toward a solution. Simulation results indicate that the reduced number of mechanical modes (from 30 to 14 to 7) can adequately reproduce an unknown force time history on an ECM boundary. A representative comparison between cell to tissue (inverse) and tissue to cell (boundary value) modeling illustrates the multiscale applicability of the inverse model.