Finite Element Modelling of Single Cell Based on Atomic Force Microscope Indentation Method

Abstract

The stiffness of cells, especially cancer cells, is a key mechanical property that is closely associated with their biomechanical functions, such as the mechanotransduction and the metastasis mechanisms of cancer cells. In light of the low survival rate of single cells and measurement uncertainty, the finite element method (FEM) was used to quantify the deformations and predict the stiffness of single cells. To study the effect of the cell components on overall stiffness, two new FEM models were proposed based on the atomic force microscopy (AFM) indentation method. The geometric sizes of the FEM models were determined by AFM topography images, and the validity of the FEM models was verified by comparison with experimental data. The effect of the intermediate filaments (IFs) and material properties of the cellular continuum components on the overall stiffness were investigated. The experimental results showed that the stiffness of cancer cells has apparent positional differences. The FEM simulation results show that IFs contribute only slightly to the overall stiffness within 10% strain, although they can transfer forces directly from the membrane to the nucleus. The cytoskeleton (CSK) is the major mechanical component of a cell. Furthermore, parameter studies revealed that the material properties (thickness and elasticity) of the continuum have a significant influence on the overall cellular stiffness while Poisson’s ratio has less of an influence on the overall cellular stiffness. The proposed FEM models can determine the contribution of the major components of the cells to the overall cellular stiffness and provide insights for understanding the response of cells to the external mechanical stimuli and studying the corresponding mechanical mechanisms and cell biomechanics.

Finite Element Simulations of Mechanical Behaviour of Endothelial Cells

“…The recent study in cell mechanics simulated the mechanical behaviour of a cell with an oversimplified tensegrity structure, and the role of individual filaments was not accessed [ 44 , 58 ]. However, there are studies analysing the role of the cytoskeleton in cell mechanics [ 30 , 59 ]. Moreover, some published FE models on cell mechanics deal with the degradation of the cytoskeleton using more simplified cytoskeletal arrangements [ 60 ].…”

Modeling stem cell nucleus mechanics using confocal microscopy

“…Our model provides a number of advantages over finite element analyses of the cell nucleus that tend to model the nucleus as a homogenous material with idealized geometry. 24,25 While comparisons between homogenous and heterogenous nuclear structures showed no significant changes in the “bulk” structural response under in silico AFM experiments, stresses throughout the nuclear structures were different where stresses concentrations were dependent upon the chromatin and LaminA/C distribution density obtained from the original images. As chromatin condensation has been shown to change due to external nuclear loading 26 , these models may provide useful predictions of which regions of chromatin are experiencing larger loads.…”

Synthetic Data in Quantitative Scanning Probe Microscopy

“…Such methods have potential of sub-surface imaging on soft samples, which however needs advanced data interpretation methods. Numerical calculations based on a synthetic structural model and FEM was used to interpret data measured on living cells [ 152 ] when responding to external mechanical stimuli.…”