  The synthetic biopolymeric gels demand a great interest as bio-materials to
mimic many biological scaffolding structures, which can contribute to a better
understanding of the cytoskeleton-like structural building blocks and soft
nanotechnology. In particular semiflexible F-actin and vimentin intermediate
filaments (IF) form complex networks, and are key regulators of cellular
stiffness. While the mechanics of F-actin networks or IF have already been
characterised, the interaction between this two networks is largely unknown.
Experimental studies using large deformations rheology show that
co-polymerisation of F-actin and IF can produce composite networks either
stronger or weaker than pure F-actin networks. We theoretically verify these
effects developing a model into the framework of nonlinear continuum mechanics,
in which we define a free energy functional considering the role of the
entropic-elastic for semiflexible networks with transient crosslinks and also
an energetic term to describe the interaction parameter which allows the
coupling among the two networks. We validate the theoretical model with
measurements performed performed by Jensen et al. on large deformations
rheological experiments with different concentrations of actin and vimentin
