Structural finite element analysis to explain cell mechanics variability

• Published in: Journal of the mechanical behavior of biomedical materials 2014-10, Vol.38, p.219-231
• Main Authors: Barreto, Sara, Perrault, Cecile M., Lacroix, Damien
• Format: Article
• Language: English
• Subjects: Actin cortex; Biomechanical Phenomena; Cell Adhesion; Cell model; Cells - cytology; Compressing; Cortexes; Cytoskeleton; Finite Element Analysis; Finite element method; Material properties; Mathematical analysis; Mathematical models; Mechanical Phenomena; Mechanical properties; Phenotype; Sensitivity analysis; Shearing
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2013.11.022

The ability to model the mechanical responses of different cell types presents many opportunities to tissue engineering research to further identify changes from physiological conditions to disease. Using a previously validated finite element cell model we aim to show how variation of the material properties of the intracellular components affects cell response after compression and shearing. A parametric study was performed to understand the key mechanical features from different cell types, focussing on specific cytoskeleton components and prestress. Results show that actin cortex does not have a mechanical role in resisting shearing loading conditions. The sensitivity analysis predicted that cell force to compression and shearing is highly affected by changes in cortex thickness, cortex Young's modulus and rigidity of the remaining cytoplasm. Variation of prestress affects mainly the response of cells under shear loads and the model defines a relationship between cell force and prestress depending on the specific loading conditions, which is in good agreement with in vitro experiments. The results are used to make predictions that can relate mechanical properties with cell phenotype to be used as guidelines for individual cytoskeletal structures for future modelling efforts of the structure–function relationships of living cells. Finite element analysis of a single-cell model to identify the mechanical role of intracellular components (such as actin cortex, actin bundles, microtubules, cytoplasm and nucleus), and to explain the variability in cell response under compressive and shearing loading conditions. [Display omitted] •Cytoskeletal components have different mechanical roles to respond to specific external perturbations.•Actin cortex is the main component to resist compressive loads, whereas stretching leads to tension in actin bundles and microtubules.•Isolating the different cytoskeletal networks shows that actin cortex does not have a mechanical role in resisting shearing loads.•The model allows comparison of two stimulation methods, AFM and MTC, to understand the biomechanical differences in observed cell responses.•Higher compressive forces are observed in the model when more actin bundles are aligned with the direction of applied compression.