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New controlled release systems produced by self-assembly of biopolymers and colloidal particles at fluid-fluid interfaces
The mechanical properties of cytoskeletal actin bundles play an essential role innumerous physiological processes, including hearing, fertilization, cell migration, and growth. Cells employ a multitude of actin-binding proteins to actively regulate bundle dimensions and cross-linking properties to suit biological function. The mechanical properties of actin bundles vary by orders of magnitude depending on diameter and length, cross-linking protein type and concentration, and constituent filament properties. Despite their importance to cell function, the molecular design principles responsible for this mechanical behavior remain unknown. Here, we examine the mechanics of cytoskeletal bundles using a molecular-based model that accounts for the discrete nature of constituent actin filaments and their distinct cross-linking proteins. A generic competition between filament stretching and cross-link shearing determines three markedly different regimes of mechanical response that are delineated by the relative values of two simple design parameters, revealing the universal nature of bundle-bending mechanics. In each regime, bundle-bending stiffness displays distinct scaling behavior with respect to bundle dimensions and molecular composition, as observed in reconstituted actin bundles in vitro. This mechanical behavior has direct implications on the physiological bending, buckling, and entropic stretching behavior of cytoskeletal processes, as well as reconstituted actin systems. Results are used to predict the bending regimes of various in vivo cytoskeletal bundles that are not easily accessible to experiment and to generate hypotheses regarding implications of the isolated behavior on in vivo bundle function. [hide]
Scientific Board
Andreas Bausch
TU Munich, Germany ►
Peter Fischer
ETH Zurich, Switzerland ►
Anne-Marie Hermansson
SIK, Sweden ►
Martin Kroger
ETH Zurich, Germany/Switzerland ►
Erik van der Linden
Wageningen UR, The Netherlands ►
Niklas Loren
SIK, Sweden ►
Leonard Sagis
Wageningen UR, The Netherlands ►
Erich Windhab
ETH Zurich, Switzerland ►
Klaas-Jan Zuidam
Unilever, The Netherlands ►
Scientific Stuff
Manuela Duxenneuner
ETH Zurich, Switzerland ►
Sophia Fransson
SIK, Sweden ►
Nam-Phuong Humblet-Hua
Wageningen UR, The Netherlands ►
Joeska Husny
ETH Zurich, Australia/Switzerland ►
Orit Peleg
ETH Zurich, Israel/Switzerland ►
Cyrille Vezy
TU Munich, Germany ►
Varvara Mitropoulos
ETH Zurich, Switzerland ►
Associated Scientists
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SY Tee, AR Bausch, PA Janmey,
The mechanical cell
CURRENT BIOLOGY 19 (2009) R745 ►Selected conferences (co-)organized by project members
8th World Congress on Computational Mechanics WCCM8 2008
30 June - 5 July 2007, Venice, Italy ►13 May 2025
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