Modelling the contraction of Fibroblast-populated collagen lattices
by
Shakti N. Menon
Discipline of Mathematical Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology
Coauthors: Cameron Hall, Scott McCue, Sean McElwain

Fibroblast-populated collagen lattices (FPCLs) have, in recent years, been used to study traction forces exerted by fibroblasts. It has been observed that when floating lattices seeded with fibroblasts are cultured in serum, they contract significantly. This contraction was shown to be caused by the physical rearrangement of the collagen fibres by the fibroblasts. A consequence of this is that the observed contraction is often permanent, even after the fibroblasts are killed or removed. To analyse a contracting collagen lattice of this type, we shall use a continuum model which takes into account the evolution of the zero stress state of the lattice, which is the state to which the lattice would revert if cellular traction were absent. We model the zero stress state by considering the evolution of the effective strain, while the mechanical behaviour of the collagen lattice is described by considering the net stress (the sum of the elastic, viscous and traction stress). We use this model to describe the changing length of a contracting collagen strip, and compare these results with previously obtained experimental data. In addition, we obtain exact analytic expressions which describe the behaviour of the lattice after the cells are killed.

Date received: January 5, 2010