title: A chemo-mechanical constitutive model for transiently cross-linked actin networks and a theoretical assessment of their viscoelastic behaviour.
abstract: Biological materials can undergo large deformations and also show viscoelastic behaviour. One such material is the network of actin filaments found in biological cells, giving the cell much of its mechanical stiffness. A theory for predicting the relaxation behaviour of actin networks cross-linked with the cross-linker α-actinin is proposed. The constitutive model is based on a continuum approach involving a neo-Hookean material model, modified in terms of concentration of chemically activated cross-links. The chemical model builds on work done by Spiros (Doctoral thesis, University of British Columbia, Vancouver, Canada, 1998) and has been modified to respond to mechanical stress experienced by the network. The deformation is split into a viscous and elastic part, and a thermodynamically motivated rate equation is assigned for the evolution of viscous deformation. The model predictions were evaluated for stress relaxation tests at different levels of strain and found to be in good agreement with experimental results for actin networks cross-linked with α-actinin.
authors.affiliation: Department of Solid Mechanics, Royal Institute of Technology, Osquars backe 1, 100 44, Stockholm, Sweden. bfa@kth.se
authors.forename: B
authors.initials: B
authors.lastname: Fallqvist
authors.forename: M
authors.initials: M
authors.lastname: Kroon
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000185:Actinin / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D001696:Biomechanical Phenomena / Q000502:physiology; D003432:Cross-Linking Reagents / Q000378:metabolism*; D004548:Elasticity; D008954:Models, Biological; D011485:Protein Binding; D013314:Stress, Mechanical; D013997:Time Factors; D014783:Viscosity
chemical_list: D000199:Actins; D003432:Cross-Linking Reagents; D000185:Actinin