Optical rheology of biological cells.
A step stress deforming suspended cells causes a passive relaxation, due to a transiently cross-linked isotropic actin cortex underlying the cellular membrane. The fluid-to-solid transition occurs at a relaxation time coinciding with unbinding times of actin cross-linking proteins. Elastic contributions from slowly relaxing entangled filaments are negligible. The symmetric geometry of suspended cells ensures minimal statistical variability in their viscoelastic properties in contrast with adherent cells and thus is defining for different cell types. Mechanical stimuli on time scales of minutes trigger active structural responses.
Wottawah
Falk
F
Institute for Soft Matter Physics, University of Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany.
Schinkinger
Stefan
S
Lincoln
Bryan
B
Ananthakrishnan
Revathi
R
Romeyke
Maren
M
Guck
Jochen
J
Käs
Josef
J
D000199:Actins / Q000737:chemistry / Q000502:physiology; D000818:Animals; D001696:Biomechanical Phenomena; D048430:Cell Shape; D003599:Cytoskeleton / Q000737:chemistry* / Q000502:physiology*; D004548:Elasticity; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D051379:Mice; D041681:NIH 3T3 Cells; D055095:Optics and Photonics; D012212:Rheology / Q000379:methods*
D000199:Actins