Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/18687
Title: Time-scale and other invariants of integrative mechanical behavior in living cells.
Author: Fabry, Ben
Maksym, Geoffrey N.
Butler, James P.
Glogauer, Michael
Navajas Navarro, Daniel
Taback, Nathan A.
Millet, Emil J.
Fredberg, Jeffrey J.
Keywords: Reologia
Física mèdica
Biofísica
Equacions d'estat
Transformacions de fase (Física estadística)
Rheology
Medical physics
Biophysics
Equations of state
Phase transformations (Statistical physics)
Issue Date: 2003
Publisher: The American Physical Society
Abstract: In dealing with systems as complex as the cytoskeleton, we need organizing principles or, short of that, an empirical framework into which these systems fit. We report here unexpected invariants of cytoskeletal behavior that comprise such an empirical framework. We measured elastic and frictional moduli of a variety of cell types over a wide range of time scales and using a variety of biological interventions. In all instances elastic stresses dominated at frequencies below 300 Hz, increased only weakly with frequency, and followed a power law; no characteristic time scale was evident. Frictional stresses paralleled the elastic behavior at frequencies below 10 Hz but approached a Newtonian viscous behavior at higher frequencies. Surprisingly, all data could be collapsed onto master curves, the existence of which implies that elastic and frictional stresses share a common underlying mechanism. Taken together, these findings define an unanticipated integrative framework for studying protein interactions within the complex microenvironment of the cell body, and appear to set limits on what can be predicted about integrated mechanical behavior of the matrix based solely on cytoskeletal constituents considered in isolation. Moreover, these observations are consistent with the hypothesis that the cytoskeleton of the living cell behaves as a soft glassy material, wherein cytoskeletal proteins modulate cell mechanical properties mainly by changing an effective temperature of the cytoskeletal matrix. If so, then the effective temperature becomes an easily quantified determinant of the ability of the cytoskeleton to deform, flow, and reorganize.
Note: Reproducció digital del document publicat a: http://dx.doi.org/10.1103/PhysRevE.68.041914
It is part of: Physical Review E, 2003, vol. 68, núm. 4, p. 041914-1 - 041914-18 pages
URI: http://hdl.handle.net/2445/18687
ISSN: 1063-651X
Appears in Collections:Articles publicats en revistes (Ciències Fisiològiques)

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