Understanding the crosstalk between mechanical and chemical guidance in 3d cell migration

Critical to many physiological and pathological processes, cells exhibit motility responses to both contact guidance and chemotaxis. Independently both cases had been studied extensively, however, some synergistic effects are not fully characterized. To quantitively analyze the strength of their crosstalks, we develop a u-fluidics device to control the strength of chemo- as well as mechno- cues by aligning ECM fibers. Also, to objectively characterize the cell migration, we developed a ML-based cell tracking method. This platform enabled us to observe how cells respond to chemo/mechano cues in three major categories. First, when mechano and chemo cues are perpendicular, we observed two types of behavior. About one-third of the cells following a strong chemotaxis effect through a hopping effect meaning cells hope from an ECM fiber to the neighboring one. The rest of the cells in this category strongly only follow the ECM fibers with about the same speed as the other ones. Second, the ECM fibers are parallel with the chemoattractant gradient vector. Under this condition, the overall migration speed is larger but the hopping effect is much weaker in comparison with the first category while the overall chemotaxis effect is the same.