Cell migration in disordered porous media

Cell migration is a dynamic process that is of critical importance to various aspects of living organisms, including development, wound healing, and immune responses. Several external factors are known to influence and direct active cell movement, such as chemokine gradients or the composition and mechanical properties of the extracellular matrix (ECM). While some progress has been made in elucidating biochemical pathways that control cell motility, little is known about the impact of the porous structure of the ECM on active cell motion. We will present a computational model for motile cells in 3D disordered porous media. Our approach is based on the Cellular Potts model (CPM) and explicitly accounts for interactions between cell shape and environmental constraints, such as when cells need to squeeze through confining pore spaces. We will discuss how confinement prevents persistent cell motion and instead causes cellular hopping and trapping. Our findings are rationalized by the jump length and waiting time probability distributions of the process, which are linked to the porosity of the media. Furthermore, we will show that spatial heterogeneities in the porosity effectively induce directed cell motion, a mechanism we refer to as porotaxis. Overall, our work highlights the microstructure of the ECM as a key regulator of cell migration.