|M.Sc Student||Ben-David Yaniv|
|Subject||Modeling of Force Application Mechanisms and Morphologies|
of Invasive Cancer Cells
|Department||Department of Biomedical Engineering||Supervisor||Professor Daphne Weihs|
|Full Thesis text|
Measurements of traction forces exerted by cells to their substrate are an increasingly important tool to determine mechanical interactions. Methods such as traction force microscopy (TFM) provide the applied traction forces from the deformation field induced by the cells. In most works, normal forces exerted by cells to their substrate were negligible and were disregarded; indentation depths were quite small ~0.6 μm. However, at our lab, we have measured normal indentations, up to 10 μm in depth, induced by cancer cells. Thus, normal forces may not be disregarded. In our study, we develop a model and finite element (FE) simulation to determine the way that cells may apply forces to achieve those large indentations. We show that while applying only traction (in-plane) forces, the cells can not generate significant indentation. Even after applying forces 100 times larger than there measured values, of even after modifying their size dramatically, no significant indentations were observed. In contrast, when normal force components were added to the traction forces, significant indentations (~10 μm) were attained for the same forces. Furthermore, by simulating morphological changes in the cell, we identify the optimal mechanostructural conditions for force application by the cells and provide a simplified possible, force-application mechanism involving elements of the cytoskeleton.