Effect of Crosslinking on the Elastic Properties of the Cytoskeleton: A 3D Discrete Modeling Approach

Abstract

In living eukaryotic cells a crosslinked network of polymer fibers, the cytoskeleton, endows the cells with structural integrity and mechanical stability and flexibility. To understand the mechanisms that are at the base of these functions, it is important to know in what way the microstructure and the mechanical behavior of the cytoskeleton change as a function of the type and the density of crosslinking molecules. To address this issue, we have developed a new modeling approach based on the discretization of polymeric fibers that are modeled as homogeneous straight beams in a constant volume. Crosslinks between adjacent fibers are taken into account by creating additional beams between the fibers if their spacing is smaller than a meaningful upper bound. By varying their geometrical and mechanical properties, the influence of the crosslinks on the shear modulus of the network can be studied systematically. Our simulations predict interesting new scaling behaviors that depend on the degree of crosslinking.Mater. Res. Soc. Symp. Proc. Vol. 975