A Finite Element Bendo-Tensegrity Model of Eukaryotic Cell

Abstract

Mechanical interaction of cell with extracellular environment affects its function. The mechanisms by which mechanical stimuli are sensed and transduced into biochemical responses are still not well understood. Considering this, two finite element (FE) bendo-tensegrity models of a cell in different states are proposed with the aim to characterize cell deformation under different mechanical loading conditions: a suspended cell model elucidating the global response of cell in tensile test simulation and an adherent cell model explicating its local response in atomic force microscopy (AFM) indentation simulation. The force-elongation curve obtained from tensile test simulation lies within the range of experimentally obtained characteristics of smooth muscle cells (SMCs) and illustrates a nonlinear increase in reaction force with cell stretching. The force-indentation curves obtained from indentation simulations lie within the range of experimentally obtained curves of embryonic stem cells (ESCs) and exhibit the influence of indentation site on the overall reaction force of cell. Simulation results have demonstrated that actin filaments (AFs) and microtubules (MTs) play a crucial role in the cell stiffness during stretching, whereas actin cortex (AC) along with actin bundles (ABs) and MTs are essential for the cell rigidity during indentation. The proposed models quantify the mechanical contribution of individual cytoskeletal components to cell mechanics and the deformation of nucleus under different mechanical loading conditions. These results can aid in better understanding of structure-function relationships in living cells.

A Biophysical Model for Curvature-Guided Cell Migration

“…The cell basically consists of an elastic impermeable membrane encapsulating a viscous cytosol and a deformable nucleus. In addition, the cytoskeleton is introduced as a dynamic assembly of competing compressive and contractile networks (45,47,48).…”

Sensing and Modelling Mechanical Response in Large Deformation Indentation of Adherent Cell Using Atomic Force Microscopy

“…This single layer membrane hyperelastic model is capable of simulating comprehensive mechanical responses of the cell, including the overall deformation, the strain-stress relationship within the membrane and the force-distance relationship [22][23][24]. For a more realistic description of the cell, multi-layer hyperelastic models were also established by separately defining the material properties of the nucleus, cytoplasm and cell membrane of the cell, which are the continuum components [25,26]. Finite element method (FEM) has been widely used to resolve the increased complexity of the multi-layer hyperelastic model [25][26][27].…”

“…For a more realistic description of the cell, multi-layer hyperelastic models were also established by separately defining the material properties of the nucleus, cytoplasm and cell membrane of the cell, which are the continuum components [25,26]. Finite element method (FEM) has been widely used to resolve the increased complexity of the multi-layer hyperelastic model [25][26][27]. Apart from nano-indentation, various forms of mechanical stimuli, such as indentation, compression and elongation, were simulated by the hyperelastic models [22][23][24][25][26][27].…”

“…Finite element method (FEM) has been widely used to resolve the increased complexity of the multi-layer hyperelastic model [25][26][27]. Apart from nano-indentation, various forms of mechanical stimuli, such as indentation, compression and elongation, were simulated by the hyperelastic models [22][23][24][25][26][27]. Many other non-linear elastic theories, such as viscoelastic and poroelastic, have also been investigated to characterize the time dependent stress-relaxation behaviour of the cell during nano-indentation [28].…”

“…Many other non-linear elastic theories, such as viscoelastic and poroelastic, have also been investigated to characterize the time dependent stress-relaxation behaviour of the cell during nano-indentation [28]. Because of the versatility of the multi-layer hyperelastic model in describing the mechanical response of living cells under mechanical stimuli [25][26][27], it is adopted in this paper to simulate the continuum components of the cell during central indentation.…”