Abstract

The cytoskeleton, an internal polymer hybrid network, determines the mechanical strength and morphology of cells. This cytoskeleton evolves during the normal differentiation of cells, is involved in many cellular functions, and is characteristically altered in many diseases, including cancer. We can exploit the deformability of the cytoskeleton as a link between molecular structure and biological function to distinguish between different cells using a microfluidic optical stretcher. We find that optical deformability is sensitive enough to monitor the subtle changes during the progression of cells from normal to cancerous and even metastatic state. We can also distinguish stem cells from more differentiated cells. In both cases, their mechanical properties are tuned to the specific requirements imposed on the cells by physical constraints. This suggests using optical deformability as an inherent cell marker for diagnosis of disease and sorting of stem cells from heterogeneous populations, obviating the need for external markers or special preparation. Further research also focuses on the interplay between cell and tissue mechanics for an improved understanding of axonal pathfinding during development and novel therapeutic approaches in traumatic injuries to the CNS and neurodegenerative diseases.