  In this paper a lattice model for the diffusional transport of particles in
the interphase cell nucleus is proposed. The dynamic behaviour of single chains
on the lattice is investigated and Rouse scaling is verified. Dynamical dense
networks are created by a combined version of the bond fluctuation method and a
Metropolis Monte Carlo algorithm. Semidilute behaviour of the dense chain
networks is shown. By comparing diffusion of particles in a static and a
dynamical chain network, we demonstrate that chain diffusion does not alter the
diffusion process of small particles. However, we prove that a dynamical
network facilitates the transport of large particles. By weighting the mean
square displacement trajectories of particles in the static chain network data
from the dynamical network can be reconstructed. Additionally, it is shown that
subdiffusive behaviour of particles on short time scales results from trapping
processes in the crowded environment of the chain network. In the presented
model a protein with 30 nm diameter has an effective diffusion coefficient of
1.24E-11 m^2/s in a chromatin fiber network.
