10th Annual Symposium
Physics of Cancer
Leipzig, Germany
September 25-27, 2019
Invited Talk
Viscoelastic properties of cell cortices - implications for cellular adhesion
Andreas Janshoff
Institute of Physical Chemistry, University of Göttingen, Germany
Contact:  | Website
Cellular mechanics and adhesion are two related properties that need to be balanced in order to permit cells to migrate on suitably functionalized substrates dieplaying a compatible surface chemistry. Therefore, organisms that cope with varying environmental surface cues require an adaptive strategy to survive under different conditions. We found that the model organism Dictyostelium discoideum faces the challenge of coping with hightly variable chemistry in the search of food. Employing AFM-based single cell force spectroscopy we could show that experimental force curves upon retraction of cells from the surface exhibit two regimes. The first part up to the maximum adhesion force can be described in terms of a continuum model that permits to relate the mechanical properties of cells to their capability to adhere onto a wide variety of substrates, while the second regime of the curve beyond the critical rupture force is governed by stochastic unbinding of individual binding partners and bond clusters extending the life time of the bonded state. .This versatile adhesion mechanism, which works on almost all surface chemistries, allows the cells to adapt to a large variety of natural surfaces and conditions.

In order to relate the viscoelastic properties found for living cells to the mechanics of the cellular cortex we devised a top-down and bottom-up strategy to measure the viscoelasticity of isolated cortices. Our findings go hand in hand with a theoretical model to unify the different geometries encountered in experiments.
University of Leipzig  |  Faculty of Physics and Earth Sciences  |  Peter Debye Institute  |  Soft Matter Physics Division
© Soft Matter Physics Division, University of Leipzig. Designed and created by sp design. Imprint & Disclaimer