Regensburg 2004 – scientific programme

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AKB: Biologische Physik

AKB 10: Cytoskeleton and Polymer Networks

AKB 10.4: Invited Talk

Monday, March 8, 2004, 11:00–11:30, H40

Models of Biological Fiber Systems — •Camilla Mohrdieck and Eduard Arzt — Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, 70569 Stuttgart

Biological fiber systems have to be able to sustain large loads but they must also be capable of undergoing large deformations, depending on which environmental conditions they are subject to. Many fiber systems meet these needs by responding in a nonlinear way to external loads. Key to this nonlinearity is the crosslinking of fibers into a meshwork and in some cases also a prestress in the fibers. To relate the influence of topology and prestress to the mechanical stability and flexibility of a fiber system, we perform computer simulations in which fiber systems are iteratively deformed by applying forces to their nodal points. To this end, we construct fiber sytems that reflect characteristic features of their biological counterparts as for example the icosahedral capsids of some viruses or the spherical actin cortex as it can be observed in quiescent cells. In our study we combine large deflection analysis with a determination of the topological properties such as the connectivity of the meshwork, states of self stress and inextensional modes of deformation. This allows to evaluate the mechanical properties of the fiber system as well as to follow the evolution of its intrinsic structural properties as the whole system deforms under a given load.