Molecular Dynamics Simulation of Vascular Network Formation

TL;DR

This paper uses molecular dynamics simulations to model vascular network formation by endothelial cells, revealing how chemical gradients influence network structures and exploring model improvements affecting network formation.

Contribution

It introduces a two-dimensional molecular dynamics model of endothelial cells, incorporating chemotaxis, and examines how cell shape dynamics impact network formation.

Findings

Point-like cell models form networks influenced by chemical gradient length.

Adding repulsive and persistence forces affects network stability.

Static cell geometry limits realistic network formation.

Abstract

Endothelial cells are responsible for the formation of the capillary blood vessel network. We describe a system of endothelial cells by means of two-dimensional molecular dynamics simulations of point-like particles. Cells' motion is governed by the gradient of the concentration of a chemical substance that they produce (chemotaxis). The typical time of degradation of the chemical substance introduces a characteristic length in the system. We show that point-like model cells form network resembling structures tuned by this characteristic length, before collapsing altogether. Successively, we improve the non-realistic point-like model cells by introducing an isotropic strong repulsive force between them and a velocity dependent force mimicking the observed peculiarity of endothelial cells to preserve the direction of their motion (persistence). This more realistic model does not show a clear network formation. We ascribe this partial fault in reproducing the experiments to the static geometry of our model cells that, in reality, change their shapes by elongating toward neighboring cells.