Title:	Master relation defines the nonlinear viscoelasticity of single fibroblasts
Authors:	Fernandez, Pablo Pullarkat, Pramod A. Ott, Albrecht
Issue Date:	2006
Publisher:	Biophysical Society
Citation:	Biophysical Journal, 2006, Vol.90, p3796–3805
Abstract:	Cell mechanical functions such as locomotion, contraction, and division are controlled by the cytoskeleton, a dynamic biopolymer network whose mechanical properties remain poorly understood. We perform single-cell uniaxial stretching experiments on 3T3 fibroblasts. By superimposing small amplitude oscillations on a mechanically prestressed cell, we find a transition from linear viscoelastic behavior to power law stress stiffening. Data from different cells over several stress decades can be uniquely scaled to obtain a master relation between the viscoelastic moduli and the average force. Remarkably, this relation holds independently of deformation history, adhesion biochemistry, and intensity of active contraction. In particular, it is irrelevant whether force is actively generated by the cell or externally imposed by stretching. We propose that the master relation reflects the mechanical behavior of the force-bearing actin cytoskeleton, in agreement with stress stiffening known from semiflexible filament networks.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/4628
ISSN:	0006-3495 1542-0086 (Online)
Alternative Location:	http://arxiv.org/abs/physics/0603119 http://dx.doi.org/10.1529/biophysj.105.072215
Copyright:	2006, Biophysical Society
Appears in Collections:	Research Papers (SCM)

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