A computational study of amoeboid cell migration through 3D matrices

Locomotion of amoeboid cells is mediated by cellular protrusions known as pseudopods which grow, bifurcate, and retract in a dynamic fashion. This type of motion is observed in leukocytes, embryonic cells, and metastatic cancer cells. It is a complex and multiscale process, involving bio-molecular reactions, cell deformation, and cytoplasmic and extracellular fluid motion. Additionally, cells within the human body are subject to a confined 3D environment known as the extra-cellular matrix (ECM). We present a multiphysics computational approach coupling fluid mechanics, solid mechanics, and a pattern formation model to simulate locomotion of amoeboid cells through a porous matrix composed of a viscous fluid and an array of finite-sized spherical obstacles. The model is able to recreate squeezing and weaving motion of cells through the matrix. We study the influence of matrix porosity, and cell deformability on the motility behavior. It is found that below certain values of these parameters, cell motion is completely inhibited. Phase diagrams are presented depicting such motility limits. The results show a strong coupling between cell deformability and ECM properties, and provide new fluid mechanical insights on amoeboid motility in confined medium.