Development of microfluidic devices for experimental study of cell migration activity, use of numerical methods

Assessment of the migration potential of tumor cells, as well as cells of the immune system in tumor foci, is relevant due to the need for highly informative and fast methods for diagnosing and predicting cancer. To study the active movement of cells, a two-level migration cell was developed and fabricated by soft photolithography. It consists of fluid supply channels and two chambers (“gradient” and “storage”) 50 µm high, which communicate through “migration” channels 10 µm high. A chemoattractant and nutrient medium were supplied to the “gradient” chamber of the cell. Due to diffusion, mass transfer occurs between the two laminar flows of the chemoattractant and the nutrient medium, a concentration gradient of the chemoattractant is formed perpendicular to the direction of flow, stimulating the movement of cells located in the “storage” chamber. The features of the model are smooth transitions at the junctions of channels and in transition zones; sealed containers of the “storage” chamber, degassing of injected liquids. For cell adhesion, the inner walls of the cell were covered with collagen. With the help of numerical simulation in the Comsol Multiphysics program, taking diffusion into account, the distribution of the velocity field in the supply channels and in the “gradient” chamber was found. The velocities in the center of the channels practically coincide with those obtained during the flow of luminescent latex spherules: 180 µm/s in the supply channels and 150 µm/s in the “gradient chamber”. The development of microfluidic devices for monitoring cell migration is an important step towards improving the diagnosis and therapy of cancer.