Microstructurally-based constitutive models of cytoskeletal networks for simulation of the biomechanical response of biological cells

The elastic and viscoelastic stress-strain behavior of cytoskeletal networks, important to many cellular functions, is modeled via a microstructurally-informed continuum mechanics approach. The force-extension behavior of the individual filaments is captured with a new analytical expression of the MacKintosh worm-like chain relationship for semiflexible filaments. The filament expression is used in the Arruda-Boyce eight-chain network model to capture the 3D stress-strain behavior, quantifying the effects of isotropic network prestress and tracking microstructural stretch and orientation states during large deformations. The network model captures the initial stiffness of the network as well as the nonlinear strain stiffening observed at large stresses in shear rheological data of bundled/unbundled in vitro F-actin networks. The cytoskeletal network model has also been extended to include the internal energy based mechanical contributions at the filament and network levels from torsional crosslink deformations as well as from direct axial stretching of filaments. This enhanced model effectively captures the stress-strain behavior of F-actin networks cross-linked with two different types of actin binding proteins (filamin and streptavidin). The enhanced model is also used to evaluate the influence of the cross-links' torsional stiffness on the entropic bending configuration space of the cytoskeletal filaments. The 3D constitutive network model provides a framework for capturing time-dependent spatial diffusion of cytosol within a porous, visco hyperelastic filament network. The poroelastic behavior is coupled with the hyperelastic network behavior through a 3D biphasic theory that includes network swelling effects for finite deformations.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Palmer, Jeffrey Shane

Advisor dc:contributor.advisor

• Mary C. Boyce.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/44752

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/44752