Scale-Dependent Nonaffine Elasticity of Semiflexible Polymer Networks

M. Atakhorrami, G.H. Koenderink, J. F. Palierne, F.C. MacKintosh, C.F. Schmidt

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

The cytoskeleton of eukaryotic cells provides mechanical support and governs intracellular transport. These functions rely on the complex mechanical properties of networks of semiflexible protein filaments. We study the impact of local network deformations on the scale-dependent mobility of probe particles in entangled networks of actin filaments using high-bandwidth microrheology. We find that micron-sized particles in these networks experience two opposing noncontinuum elastic effects: entropic depletion reduces the effective network rigidity, while local nonaffine deformations of the network substantially enhance the rigidity at low frequencies, eventually leading to a size-independent response and strong violation of the generalized Stokes formula. We show that a simple model of lateral bending of filaments embedded in a viscoelastic background leads to an intermediate scaling regime for the apparent elastic modulus G′(ω)∼ω9/16, closely matching the experiments. These results demonstrate that nonaffine bending deformations can be dominant for the mobility of objects of the size of vesicles and organelles in the cell. © 2014 American Physical Society.
Original languageEnglish
Article number088101
JournalPhysical Review Letters
Volume112
Issue number8
DOIs
Publication statusPublished - 2014

Fingerprint

Dive into the research topics of 'Scale-Dependent Nonaffine Elasticity of Semiflexible Polymer Networks'. Together they form a unique fingerprint.

Cite this