Random blebbing motion: A simple model linking cell structural properties to migration characteristics

If the plasma membrane of a cell is able to delaminate locally from its actin cortex a cellular bleb can be produced. Blebs are pressure driven protrusions, which are noteworthy for their ability to produce cellular motion. Starting from a general continuum mechanics description we restrict ourselves to considering cell and bleb shapes that maintain approximately spherical forms. From this assumption we obtain a tractable algebraic system for bleb formation. By including cell-substrate adhesions we can model blebbing cell motility. Further, by considering mechanically isolated blebbing events, which are randomly distributed over the cell we can derive equations linking the macroscopic migration characteristics to the microscopic structural parameters of the cell. This multiscale modelling framework is then used to provide parameter estimates, which are in agreement with current experimental data. In summary the construction of the mathematical model provides testable relationships between the bleb size and cell motility.