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Live Cells Exert 3-Dimensional Traction Forces on Their Substrata.

Hur SS, Zhao Y, Li YS, Botvinick E, Chien S - Cell Mol Bioeng (2009)

Bottom Line: The method was evaluated regarding accuracy and precision of displacement measurements, effects of FE mesh size, displacement noises, and simple bootstrapping.This technique can be applied to study live cells to assess their biomechanical dynamics in conjunction with biochemical and functional activities, for investigating cellular functions in health and disease.ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12195-009-0082-6) contains supplementary material, which is available to authorized users.

View Article: PubMed Central - PubMed

ABSTRACT
The traction forces exerted by an adherent cell on a substrate have been studied only in the two-dimensions (2D) tangential to substrate surface (Txy). We developed a novel technique to measure the three-dimensional (3D) traction forces exerted by live bovine aortic endothelial cells (BAECs) on polyacrylamide deformable substrate. On 3D images acquired by confocal microscopy, displacements were determined with image-processing programs, and traction forces in tangential (XY) and normal (Z) directions were computed by finite element method (FEM). BAECs generated traction force in normal direction (Tz) with an order of magnitude comparable to Txy. Tz is upward at the cell edge and downward under the nucleus, changing continuously with a sign reversal between cell edge and nucleus edge. The method was evaluated regarding accuracy and precision of displacement measurements, effects of FE mesh size, displacement noises, and simple bootstrapping. These results provide new insights into cell-matrix interactions in terms of spatial and temporal variations in traction forces in 3D. This technique can be applied to study live cells to assess their biomechanical dynamics in conjunction with biochemical and functional activities, for investigating cellular functions in health and disease. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12195-009-0082-6) contains supplementary material, which is available to authorized users.

No MeSH data available.


A flow chart illustrating the procedures used in the 3D traction force microscopy
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Fig1: A flow chart illustrating the procedures used in the 3D traction force microscopy

Mentions: The present approach in determining cell traction forces is summarized in Fig. 1. It involves three main steps: (1) Experiments: Acquiring the 3D image stack, (2) Image Processing: Determining the displacement field from the image, and (3) Force Computation: Computing traction force field from the displacement field.Figure 1


Live Cells Exert 3-Dimensional Traction Forces on Their Substrata.

Hur SS, Zhao Y, Li YS, Botvinick E, Chien S - Cell Mol Bioeng (2009)

A flow chart illustrating the procedures used in the 3D traction force microscopy
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2749171&req=5

Fig1: A flow chart illustrating the procedures used in the 3D traction force microscopy
Mentions: The present approach in determining cell traction forces is summarized in Fig. 1. It involves three main steps: (1) Experiments: Acquiring the 3D image stack, (2) Image Processing: Determining the displacement field from the image, and (3) Force Computation: Computing traction force field from the displacement field.Figure 1

Bottom Line: The method was evaluated regarding accuracy and precision of displacement measurements, effects of FE mesh size, displacement noises, and simple bootstrapping.This technique can be applied to study live cells to assess their biomechanical dynamics in conjunction with biochemical and functional activities, for investigating cellular functions in health and disease.ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12195-009-0082-6) contains supplementary material, which is available to authorized users.

View Article: PubMed Central - PubMed

ABSTRACT
The traction forces exerted by an adherent cell on a substrate have been studied only in the two-dimensions (2D) tangential to substrate surface (Txy). We developed a novel technique to measure the three-dimensional (3D) traction forces exerted by live bovine aortic endothelial cells (BAECs) on polyacrylamide deformable substrate. On 3D images acquired by confocal microscopy, displacements were determined with image-processing programs, and traction forces in tangential (XY) and normal (Z) directions were computed by finite element method (FEM). BAECs generated traction force in normal direction (Tz) with an order of magnitude comparable to Txy. Tz is upward at the cell edge and downward under the nucleus, changing continuously with a sign reversal between cell edge and nucleus edge. The method was evaluated regarding accuracy and precision of displacement measurements, effects of FE mesh size, displacement noises, and simple bootstrapping. These results provide new insights into cell-matrix interactions in terms of spatial and temporal variations in traction forces in 3D. This technique can be applied to study live cells to assess their biomechanical dynamics in conjunction with biochemical and functional activities, for investigating cellular functions in health and disease. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12195-009-0082-6) contains supplementary material, which is available to authorized users.

No MeSH data available.