Molecular Transport in Anisotropic Fibous Environments

In vivo, specialized eukaryotic cells are embedded in a matrix environment, where they grow and develop. Generally, this extracellular matrix (ECM) is an anisotropic fibrous structure, in which macromolecules and biochemical signaling molecules at the nanometer scale diffuse through. The ECM network geometry is continuously modified by cells, via mechanical interactions, which lead to a potential link between biomechanical and biochemical cell-cell interactions. Using random walk on a 3D lattice, we implement elongated fixed obstacles that mimic the fibrous ECM structure, and measure both diffusion of a tracer molecule and the first passage time it needs to reach a target location from an initial position. We observe that fiber alignment and densification improves transport of molecules by reducing the system’s dimensionality from a 3D to a more efficient 1D process. Our study suggests an alternative mechanism of mechano-biochemical feedback in the regulation of long-range cell-cell communication via the ECM.