Abstract

The cytoskeleton, an intracellular polymeric scaffold, stabilizes and organizes biological cells. As a compound of highly dynamic protein filaments and active nano-sized molecular motors it mechanically senses a cell’s environment and generates forces for cellular motion sufficiently strong to push rigid AFM cantilevers out of the way. The study of the cytoskeleton from a polymer physics perspective with novel optical micro and nano-manipulation techniques, scanning force microscopy, time lapse image analysis of intracellular processes, and modern genetic manipulation methods leads to results, which simultaneously promote physics and medicine (diagnosis as well as therapy). The extremely sensitive polymeric properties of single cells’ cytoskeletons measured with the laser-based Optical Stretcher distinguish different cell types and monitor cellular changes such as cancer progression and stem cell differentiation proving recent theories on semiflexible polymers. Cellular motion required for neuronal plasticity and nerve regeneration – but also found in cancer metastasis – inspire the emerging field of active polymer networks. The resulting, novel perception of cell migration will impact therapies for reducing metastatic aggressiveness and inspire new strategies for nerve regeneration.