DOUBLE TENSEGRITY FE MODEL OF CELL USED IN SIMULATION OF ITS INDENTATION TEST

conference paper

English

Mechanical stimuli represent a very important factor influencing physiological and pathological processes in live tissues. Since these processes are initiated on the cellular level, it is necessary to focus on the eukaryotic cell as a basic structural unit of a tissue. A major interest in the cell mechanics is the regulation of cellular functions by mechanical forces, it means: how the mechanical stimulus is transduced into biochemical response. This process is known as mechanotransduction. The key role in this process plays the cytoskeleton. The cytoskeleton is a closely interwoven network of actin, tubulin, and intermediate filaments that modulates cell sensitivity to mechanical stimuli by adapting its structure to accommodate prolonged mechanical strains [1] Cytoskeletal integrity is important for detection and transduction of mechanical strain and cellular elasticity. For investigation of principles of mechanotransduction in living animal cells is necessary to study of cell as a mechanical framework. The aim of our research is to develop a credible computational model of mechanical behaviour of a single cell and to trying to identify its parameters (e.g. mechanical properties) using computational simulations of the various mechanical tests which are carried out on the cells. The results will contribute to solving of the mechanotransduction problems and to identifying of mechanical properties of the cell components. In this paper, we present the structural 3D finite element model of eukaryotic cell, which can be applied to investigation of mechanical behavior of the cell during indentation test. A new more realistic model of cytoskeleton based on two 30-struts tensegrity structures was applied to creating of the FE model of adherent eukaryotic cell. This model was used for computational simulation of the indentation test From the results of simulation a) (AFM tip was substituted by single force applied to vertex receptor) it can be seen, that the cell stiffness increases approximately linearly with increasing prestrain of microfilament elements (fig.4). It is in contrast with the results of McGarry and Prendergast (their results with similar model show a nonlinear relation between cell stiffness and prestress level in microfilament elements [3]. The results of simulation b) (AFM tip was modeled using contact elements) imply that the reaction force caused by cell decreases nonlinearly with increasing distance of AFM tip to receptor site (fig.5). Our results show that it could be one of the reasons of dispersion of the experimental results of indentation test (fig.6). In future various types of tests carried out with the same type of cells should be simulated with the aim to identify constitutive parameters of the individual components of the model.

Keywords: Mechanotransduction, finite element model, tensegrity, indentation test

BURŠA, J.; LEBIŠ, R.

2006

13. 11. 2006

Brno University of Technology, Institute of Solid Mechanics, Mechatronics and Biomechanics

Hrotovice

80-214-3232-2

Human biomechanics 2006

138

139

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