A computational study on power-law rheology of soft glassy materials with application to cell mechanics

Response of the cytoskeleton to mechanical stimulus, which involves coordinated assembly and disassembly of cytoskeletal polymers and their coupling to motor proteins, has been shown to be governed by a ubiquitous mechanical behavior called power-law rheology. Various experimental techniques in cell mechanics have yielded similar qualitative observations and quantitative behavior indicating that the power-law rheology is an intrinsic feature of the cell structure. In this study, a biomechanical model of the cell in microbead twisting experiments is developed which incorporates the material law associated with power-law rheology using the finite element method. Such a biomechanical model can help elucidating the mechanics of cytoskeletal responses and relate the microrheology of the cytoskeleton to its overall behavior under mechanical stimulus. This biomechanical model is employed to explore the role of material constants associated with power-law rheology on the overall response of a cell in magnetic twisting cytometry. Furthermore, the computational approach is employed to mimic the experimental observations of [B. Fabry, G.N. Maksym, J.P. Butler, M. Glogauer, D. Navajas, J.J. Fredberg, Scaling the microrheology of living cells, Phys. Rev. Lett. 87 (2001) 148102; B. Fabry, G.N. Maksym, J.P. Butler, M. Glogauer, D. Navajas, N.A. Taback, E.J. Millet, J.J. Fredberg, Time scale and other invariants of integrative mechanical behavior in living cell, Phys. Rev. E, 68(4) (2003) 041914] on living cells. 2007 Published by Elsevier B.V.