School of Engineering, Brown University, Providence, Rhode Island, United States of America.
Department of Molecular Pharmacology, Physiology and Biotechnology, Center of Biomedical Engineering, Brown University, Providence, Rhode Island, United States of America.
PLoS One. 2014 Apr 16;9(4):e90976. doi: 10.1371/journal.pone.0090976. eCollection 2014.
Traction Force Microscopy (TFM) is a powerful approach for quantifying cell-material interactions that over the last two decades has contributed significantly to our understanding of cellular mechanosensing and mechanotransduction. In addition, recent advances in three-dimensional (3D) imaging and traction force analysis (3D TFM) have highlighted the significance of the third dimension in influencing various cellular processes. Yet irrespective of dimensionality, almost all TFM approaches have relied on a linear elastic theory framework to calculate cell surface tractions. Here we present a new high resolution 3D TFM algorithm which utilizes a large deformation formulation to quantify cellular displacement fields with unprecedented resolution. The results feature some of the first experimental evidence that cells are indeed capable of exerting large material deformations, which require the formulation of a new theoretical TFM framework to accurately calculate the traction forces. Based on our previous 3D TFM technique, we reformulate our approach to accurately account for large material deformation and quantitatively contrast and compare both linear and large deformation frameworks as a function of the applied cell deformation. Particular attention is paid in estimating the accuracy penalty associated with utilizing a traditional linear elastic approach in the presence of large deformation gradients.
牵引力显微镜（TFM）是一种强大的定量分析细胞-材料相互作用的方法，在过去的二十年中，它极大地促进了我们对细胞机械传感和机械转导的理解。此外，最近在三维（3D）成像和牵引力分析（3D TFM）方面的进展强调了第三维度在影响各种细胞过程中的重要性。然而，无论在哪个维度上，几乎所有的 TFM 方法都依赖于线性弹性理论框架来计算细胞表面的牵引力。在这里，我们提出了一种新的高分辨率 3D TFM 算法，该算法利用大变形公式以前所未有的分辨率来量化细胞的位移场。结果提供了一些第一个实验证据，表明细胞确实能够施加大的材料变形，这需要提出一个新的理论 TFM 框架来准确计算牵引力。基于我们之前的 3D TFM 技术，我们重新制定了我们的方法，以准确地考虑大的材料变形，并定量地对比和比较线性和大变形框架，作为施加的细胞变形的函数。特别注意估计在存在大变形梯度时使用传统线性弹性方法的准确性代价。
