Micropipette aspiration Cells
The micropipette aspiration technique has been used extensively to study the mechanical properties of both fluid-like and solid-like cells Hochmuth, 2000 , including circulating cells such as red blood cells Evans, 1989 and neutrophils Sung et al., 1982 Dong etal., 1991 Ting-Beallet al., 1993 , or adhesion-dependent cells such as fibroblasts Thoumine and Ott, 1997 , endothelial cells Theret et al., 1988 Sato et al., 1990 , or chondrocytes Jones et al., 1999 Trickey et al., 2000 Guilak et al.,...
Info Inb
the stress. During activation of the smooth muscle, however, stress shifts from these extracellular constituents to the contractile cells, and the vessel constricts to a diameter much smaller than that associated with the passive wall stiffness. In the case of cardiac tissue, the contractile cells, or myocytes Fig. 1-5 , constitute a large fraction of the tissue volume and are primarily responsible for the stresses and deformations of the myocardium that are time varying through the cardiac...
Biphasic solidfluid models of cell mechanics
Viscoelastic behavior in cells can arise from both flow-dependent fluid-solid interactions and fluid viscosity and flow-independent mechanisms for example, intrinsic viscoelasticity of the cytoskeleton . Previous studies have described the cytoplasm of solid-like cells as a gel or as a porous-permeable, fluid-saturated meshwork Oster, 1984 Oster, 1989 Pollack, 2001 such that the forces within the cell exhibit a balance of stresses arising from hydrostatic and osmotic pressures and the elastic...
Theory of soft glassy rheology What are soft glassy materials
The master relationships shown in Figs. 3-8 and 3-9 demonstrate that when the mechanical properties of the cell change, they do so along a special trajectory. This trajectory is found to be identical in a large variety of cell types that are probed via different receptor-ligand pathways and over many frequency decades. In all those cases, changes of stiffness and friction induced by pharmacological interventions could be accounted for solely by changes in x. This parameter x appears to play a...
dLpm1 RpK
where n is the viscosity, R is the diameter of the cell outside the pipette, and m is a constant with a value around 9 Evans and Yeung, 1989 . Fig. 2-4. Experimental study of cell response to mechanical forces. Cells are deposited on the stage of an inverted microscope equipped with a video camera. The video output is connected to a digitizer mounted on a desk computer. Cells are aspirated into micropipettes connected to a syringe mounted on a syringe holder. Pressure is monitored with a sensor...
Info Wmm
The elastic properties of actin filaments and microtubules are approximately consistent with a prediction based on the force of van der Waals attraction between two surfaces J. Howard, 2001 . Persistence length lp and bending stiffness Kb are related through the expression lp Kb kB T. Bending stiffness and Young's modulus E are related through the expression Kb EI 4 a4 E for a solid rod of circular cross-section with radius a, and I 4 a J a4 for a hollow cylinder with inside and outside radii...
Roger D Kamm
Massachusetts Institute of Technology Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, Sao Paulo The Edinburgh Building, Cambridge cb2 2ru, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title www.cambridge.org 9780521846370 Cambridge University Press 2006 This publication is in copyright. Subject to statutory exception and to the provision of relevant collective licensing agreements, no reproduction of any...