An understanding of such cellular processes is essential to explain a wide variety of biological phenomena. These include phagocytosis, wound healing, and assembly of individual cells into tissues. Currently I am investigating extension and retraction of pseudopodia in the neutrophil with a desire to understand how the outward pushing force is produced. The actin network then swells due to interfilament repulsion and filament-solvent attraction and pushes the membrane outward, thus forming a pseudopodium. Using finite element analysis, I have implemented the swelling model to simulate pseudopodial protrusion and retraction in the presence of a chemoattractant.
Preliminary results indicate that the swelling model is able to explain a number of observations.
These include data on the kinematics of pseudopodial extension and retraction, the redistribution of the cytoskeleton, and the geometry of extending and retracting pseudopodia. In the future I plan to simulate pseudopodial protrusion based on other theories such as the surface growth model in which the actin filaments individually push against the cell membrane. A Membrane-based Displacement Flow Immunoassay.