Biomechanical models based on the finite element method have already shown their potential in the simulation of the mechanical behaviour of cells. For instance, development of atherosclerosis is accelerated by damage of the endothelium, a monolayer of endothelial cells on the inner surface of arteries. Finite element models enable us to investigate mechanical factors not only at the level of the arterial wall but also at the level of individual cells. To achieve this, several finite element models of endothelial cells with different shapes are presented in this paper. Implementing the recently proposed bendotensegrity concept, these models consider the flexural behaviour of microtubules and incorporate also waviness of intermediate filaments. The suspended and adherent cell models are validated by comparison of their simulated force-deformation curves with experiments from the literature. The flat and dome cell models, mimicking natural cell shapes inside the endothelial layer, are then used to simulate their response in compression and shear which represent typical loads in a vascular wall. The models enable us to analyse the role of individual cytoskeletal components in the mechanical responses, as well as to quantify the nucleus deformation which is hypothesized to be the quantity decisive for mechanotransduction.

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Recently hybrid models of the endothelial cell were created by using the bendo-tensegrity concept to complete the continuum parts of the cell with an adequate cytoskeleton model. The proposed model of endothelial cell includes a network of actin filaments (AFs) as tension supporting cables and microtubules (MTs) as bended beams supporting primarily compression. It is created by adopting the geometrical shape of a short hexagonal prism with its 12 vertices that results in a nearly isotropic behaviour of the model without a preferred orientation. To achieve the synergistic effect of cytoskeletal components, the elements representing AFs, MTs, and Intermediate filaments (IFs) are sharing the same end nodes (representing focal adhesions) with the cell membrane (CM). The AFs are prestressed (i.e. stressed without application of external load), which is essential for the cell shape stability, while the IFs are wavy, thus not bearing load until straightened. The objective is to create different FE models of endothelial cells which will be used to simulate mechanical responses of the cell under different loading conditions. Endothelial cell dysfunction has been linked to atherosclerosis through their response to mechanical loads, especially hemodynamic forces.