TY - JOUR
T1 - Computation of adherent cell elasticity for critical cell-bead geometry in magnetic twisting experiments
AU - Ohayon, Jacques
AU - Tracqui, Philippe
PY - 2005/2
Y1 - 2005/2
N2 - Quantification of the cell elastic modulus is a central issue of micromanipulation techniques used to analyze the mechanical properties of living adherent cells. In magnetic twisting cytometry (MTC), magnetic beads of radius R, linked to the cell cytoskeleton through transmembrane receptors, are twisted. The relationships between imposed external torque and measured resulting bead rotation or translation only provide values of the apparent cell stiffness. Thus, specific correcting coefficients have to be considered in order to derive the cell elastic modulus. This issue has been highlighted in previous studies, but general relationships for handling such corrections are still lacking while they could help to understand and reduce the large dispersion of the reported values of cell elastic modulus. Thiswork establishes generalized abacuses of the correcting coefficients from which the Young's modulus of a cell probed byMTCcan be derived. Based on a 3Dfinite element analysis of an hyperelastic (neo-Hookean) cell, we show that the dimensionless ratio hu/2R, where hu is the cell height below the bead, is an essential parameter for quantification of the cell elasticity. This result could partly explain the still intriguing question of the large variation of measured elastic moduli with probe size.
AB - Quantification of the cell elastic modulus is a central issue of micromanipulation techniques used to analyze the mechanical properties of living adherent cells. In magnetic twisting cytometry (MTC), magnetic beads of radius R, linked to the cell cytoskeleton through transmembrane receptors, are twisted. The relationships between imposed external torque and measured resulting bead rotation or translation only provide values of the apparent cell stiffness. Thus, specific correcting coefficients have to be considered in order to derive the cell elastic modulus. This issue has been highlighted in previous studies, but general relationships for handling such corrections are still lacking while they could help to understand and reduce the large dispersion of the reported values of cell elastic modulus. Thiswork establishes generalized abacuses of the correcting coefficients from which the Young's modulus of a cell probed byMTCcan be derived. Based on a 3Dfinite element analysis of an hyperelastic (neo-Hookean) cell, we show that the dimensionless ratio hu/2R, where hu is the cell height below the bead, is an essential parameter for quantification of the cell elasticity. This result could partly explain the still intriguing question of the large variation of measured elastic moduli with probe size.
KW - Cell stiffness
KW - Correcting coefficients
KW - Cytomechanical model
KW - Finite element method
KW - Magnetic twisting cytometry
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U2 - 10.1007/s10439-005-8972-9
DO - 10.1007/s10439-005-8972-9
M3 - Article
C2 - 15771267
AN - SCOPUS:17044371148
VL - 33
SP - 131
EP - 141
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
SN - 0090-6964
IS - 2
ER -