A master relation defines the nonlinear viscoelasticity of single fibroblasts

Abstract

Cell mechanical functions like 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.

12 pages, 11 figures. Accepted for publication in Biophysical Journal, scheduled to appear in May 2006

Cited by in corpus (7)

• Nonlinear elasticity of composite networks of stiff biopolymers with flexible linkers
• The Glassy Wormlike Chain
• Single cell mechanics: stress stiffening and kinematic hardening
• Tension dynamics and viscoelasticity of extensible wormlike chains
• A freely relaxing polymer remembers how it was straightened
• Elasticity of Stiff Biopolymers
• Affine model of stress stiffening in semiflexible filament networks