Regensburg 2004 – scientific programme

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AKB: Biologische Physik

AKB 12: Active Systems: Complex Cellular Processes

AKB 12.1: Invited Talk

Monday, March 8, 2004, 14:30–15:00, H40

Active Polymer Networks in Biological Cells — •Josef Käs, Claudia Brunner, Jochen Guck, Falk Wottawah, Stefan Schinkinger, Karla Mueller, Timo Betz, Bjoern Stuhrmann, Daniel Koch, Allen Ehrlicher, Michael Goegler, and David Smith — Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig

Cells signify the next fundamental challenge to soft matter physics since they require establishing the physics of networks of active nano-elements. All eukaryotic cells depend in their internal structure and organization on a highly dynamic and active polymer network, the cytoskeleton. Our results demonstrate that switchable nano-sized motors can regulate the structural strength and assembly of such polymer networks. These active mechano-sensitive networks generate motion driven by nano-muscles and polymerization. Scanning force microscopy allows us a precise spatial characterization of the resulting active forces. Lasers provide optomolecular control over these active motions. In neurons weak optical gradient forces can determine the growing nerve’s leading edge’s direction, speed, branching, and contact to other neurons. Moreover, these intracellular networks are closely related to cellular differentiation and thus, cell elasticity measurements with our new laser trap, the optical cell stretcher, provide an unparalleled cell marker distinguishing malignant cells as well as stem cells from other cells.