Single-Cell Biophysics: Measurement, Modulation, and Modeling

Single-Cell Biophysics: Measurement, Modulation, and Modeling

Poster Abstracts

16-POS Board 8 Robust Three-Dimensional Traction Force Recovery of Micro-Patterned Epithelial Cell Colonies Wen-hung Chou 1,2 , Hsuan Yang 2 , Giovanni J. Paylaga 3,2 , Jia-yang Juang 4 , Keng-hui Lin 2 . 1 National Taiwan University, Taipei, Taiwan, 2 Academia Sinica, Taipei, Taiwan, 3 National Central University, Taoyuan, Taiwan, 4 National Taiwan University, Taipei, Taiwan. Epithelial cells move collectively and exert force to their surrounding and to each other. In previous studies on collective cell migration, most traction force measurements are done on very large epithelial cell sheets. In this work, we study confined cells in small patterned regions and performed three-dimensional traction force microscopy (TFM). TFM is carried out by imaging the positions of fluorescent nanoparticles with and without cells adhering to the substrate, and finite element method (FEM) is used to recover stress from displacement field. To validate our FEM calculation, we performed numerical simulation to estimate the accuracy of our traction recovery results based on experimental parameters such as nanoparticle density and tracking accuracy. Criteria for robust force recovery is then determined in terms of the parameters. Experimentally, we observe that traction forces of Madin-Darby canine kidney (MDCK) cell colonies are concentrated at the periphery, but occasional non-vanishing forces at cell-cell junctions exist. Time-lapse observations can shed light on the transient dynamics of cell-cell interaction. Finally, the magnitude sum of normal traction force under a cell colony is independent of cell density but dependent on colony area, which agrees with previous shear force findings.

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