  In the inner crust of a neutron star, due to the high density and pressure,
nuclei which are still present, are immersed in a neutron superfluid. One then
expects that the dynamical properties of nuclei are significantly affected. In
order to estimate the magnitude of the effect associated with the presence of a
superfluid medium, we formulate the hydrodynamical approach to the nuclear
dynamics in the inner crust of neutron stars. We calculate the renormalized
nuclear mass and the strength of the medium-induced interaction between nuclei.
We argue that these effects noticeably modify the properties of the Coulomb
crystal in the inner crust.
