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Single-Cell Biophysics: Measurement, Modulation, and Modeling
Poster Abstracts
106
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.