Berlin 2012 – scientific programme

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BP: Fachverband Biologische Physik

BP 17: Posters: Physics of Cells

BP 17.30: Poster

Wednesday, March 28, 2012, 17:30–19:30, Poster A

Live Cell Rheology — •Zhanna Santybayeva, Alexander Zielinski, Wolfgang Rubner, Johannes Fleischhauer, Bernd Hoffman, and Rudolf Merkel — Institute of Complex Systems 7, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

Endothelial cells are responsive to mechanical stress. The objective of the current work is to observe immediate reaction of human umbilical vein endothelial cells upon single and cyclic stretch, and to analyze force exertion to an elastic substrate at adhesion sites. With the help of live cell imaging and fluorescence microscopy, whole cell reorientation and its inner reorganization can be detected, both during stretch and at extreme stretch amplitudes. The setup in development and specifically designed software allow observing cell immediate reaction to mechanical stress.

Precise alignment is achieved via programmable xy- and z-stages, enabling live acquisition. Devices are controlled individually or combined in a certain sequence, depending on the demands of an experiment, e.g. frequency and amplitude adjustable cyclic stretch, z-focus control with image processing on fly, multi-channel acquisition during stretch (movie), time-resolved z-stacks, etc. The substrate is a 350 um thick cross-linked silicone rubber (polydimethylsiloxane) with fluorescent beads embedded on the surface. When attaching to the substrate, cells exert point-like forces at adhesion sites, so called focal adhesions (FA). Displacements on the substrate give information on the force exercised at FA. Analyzing image sequences, we can reconstruct dynamics of force, focal adhesions and whole cell reorientation.