Development of a simplified FEM model for cellECM mechanical interaction

Cellular mechanical properties have a significant impact on the regulation of various physiological and pathological processes. Research has demonstrated a correlation between pathological conditions and alterations in the mechanical properties of cells, which respond to mechanical stimuli in a non-physiological way. In this work, we propose a finite element method (FEM) numerical model, developed in the Ansys environment, with the aim of simulating the mechanical behaviour of an adherent cell on elastic substrates of different stiffness, replicating experimental conditions of stretching. Indeed, in a previous study, we developed and validated a noninvasive optical technique for measuring the strain drop of cells adhering to substrates of different stiffness, a parameter related to cell elasticity and cell-substrate interaction. The cell was modelled using a simplified three-dimensional ellipsoidal geometry, which includes cytoplasm, nucleus and extracellular membrane (ECM). Adhesion to the substrate was obtained by discrete contact points, representing real focal adhesions. Results highlighted a distribution of deformations in the substrate consistent with experimental observations. A close correspondence is observed for the 3 0 ~ k P a substrate with an applied deformation of 1 %(0. 7 5 pm 0. 1 5 % vs 0. 7 4 %, respectively experimental and numerical data). They emphasised the importance of cellular elasticity and the related mechanical contributions, providing a basis for extending the analysis to other cell types and cell-matrix interaction scenarios.