  We propose a model for explanation the "domain-wall" type configuration
states in binary lipid mixtures of cationic and neutral lipids, associated with
observed relaxation effects in their aggregates. We apply the analogy with
formation of Kibble-\.Zurek topological defects, which we suppose connected
with structural dynamics of the lipid phases. In frames of the proposed model,
the density of kink-type defects and the energy of the configurations are
calculated.
