Biophysical Society Thematic Meeting - June 28-July 1, 2015

New Biological Frontiers Illuminated by Molecular Sensors and Actuators

Poster Abstracts

51-POS Board 51 Three-Dimensional Cellular Traction Force Measurement and Simulation on a Flat and Compliant Substrate Hsuan Yang 1,2 , Hung-Hui Li 3 , Yu-Chi Ai 1,4 , Yi-Ting Chang 3 , Jia-Yang Juang 3 , Kdng-Hui Lin 1 . 1 Institute of Physics, Academia Sinica, Taipei, Taiwan, 2 Graduate Institute of Biophysics, National Central University, Taoyuan, Taiwan, 4 Department of Physics, National Taiwan University, Taipei, Taiwan. 3 Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan, Measuring cellular traction force is essential to understand how cells process mechanical cues from microenvironment and respond to it. Most traction force measurements focus on the shear stress on a two-dimensional flat and compliant substrate. Recently more and more studies investigate three-dimensional (3D) traction stress including the normal stress whose magnitude is not negligible and play a role for cell migration speed. We present a 3D traction force method based on finite element method to analyze the displacements of marker beads embedded in the substrate under cell traction. We found the downward normal stress is sometimes located near the nucleus and sometimes near the proximal of focal adhesions which both are reported in the literature. We also perform simulation which we impose upward normal traction stress at the distal site of focal adhesion and downward normal traction stress at the proximal site of the focal adhesions and distribute the focal adhesions evenly on a circular cell edge. We found when the interparticle distance between marker beads are more than focal adhesion size or the uncertainty to displacement tracking increases, the recovered normal traction stress will deviate from the proximal site of focal adhesions toward the nucleus. Our results suggests a high resolution 3D traction force microscopy is necessary for consistent traction force measurement.

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