A generalized transport model for biased cell migration in an anisotropic environment

A generalized transport model is derived for cell migration in an anisotrop ic environment and is applied to the specific cases of biased cell migratio n in a gradient of a stimulus (taxis; e.g., chemotaxis or haptotaxis) or al ong an axis of anisotropy (e.g., contact guidance). The model accounts for spatial or directional dependence of cell speed and cell turning behavior t o predict a constitutive cell flux equation with drift velocity and diffusi vity tensor (termed random motility tensor) that are explicit functions of the parameters of the underlying random walk model. This model provides the connection between cell locomotion and the resulting persistent random wal k behavior to the observed cell migration on longer time scales, thus it pr ovides a framework for interpreting cell migration data in terms of underly ing motility mechanisms.