High-frequency affine mechanics and nonaffine relaxation in a model cytoskeleton.
The cytoskeleton is a network of crosslinked, semiflexible filaments, and it has been suggested that it has properties of a glassy state. Here we employ optical-trap-based microrheology to apply forces to a model cytoskeleton and measure the high-bandwidth response at an anterior point. Simulating the highly nonlinear and anisotropic stress-strain propagation assuming affinity, we found that theoretical predictions for the quasistatic response of semiflexible polymers are only realized at high frequencies inaccessible to conventional rheometers. We give a theoretical basis for determining the frequency when both affinity and quasistaticity are valid, and we discuss with experimental evidence that the relaxations at lower frequencies can be characterized by the experimentally obtained nonaffinity parameter.
School of Computing, Leeds University, Leeds LS2 9JT, United Kingdom.
David A
DA
Head
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Emi
E
Ikebe
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Akiko
A
Nakamasu
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Peijuan
P
Zhang
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Lara Gay
LG
Villaruz
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Suguru
S
Kinoshita
Faculty of Biotechnology and Life Science, Sojo University, Kumamoto 860-0082, Japan.
Shoji
S
Ando
Department of Physics, Faculty of Exact Sciences, Kyushu University, Fukuoka 812-8581, Japan.
Daisuke
D
Mizuno
D000818:Animals; D019245:Compressive Strength / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D006801:Humans; D007381:Intermediate Filament Proteins / Q000502:physiology*; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D014783:Viscosity
D003598:Cytoskeletal Proteins; D007381:Intermediate Filament Proteins