1P188 nonlinear stress propagation, anisotropic stiffening, and nonaffine relaxations in cytoskeletal networks(12.Cell biology,Poster,The 51st Annual Meeting of the Biophysical Society of Japan)

Abstract

The mechanics of cells or cytoskeletons have been understood either as a network of semi-flexible polymers or a glass. Here we employ optical-trap based microrheology to apply forces to cytoskeleton and measure the highbandwidth response at an anterior point. Simulating the highly nonlinear and anisotropic stress-strain propagation assuming affinity, we found that theoretical predictions for the quasi-static response are only realized at high frequencies inaccessible to conventional rheometers. We give a theoretical basis for determining the critical frequency when both affinity and quasistaticity are valid, and discuss with experimental evidence that the relaxations at lower frequencies can be characterized by the experimentally obtained non-affinity parameter.