  Context: Star clusters form within giant molecular clouds that are strongly
altered by the feedback action of the massive stars, but the cluster still
remains embedded in a dense, highly turbulent medium and interactions with
ambient structures may modify its dynamical evolution from that expected if it
were isolated.
  Aims: We aim to study coupling mechanisms between the dynamical evolution of
the cluster, accelerated by the mass segregation process, with harassment
effects caused by the gaseous environment.
  Methods: We simulated the cluster dynamical evolution combining $N$-body and
hydrodynamic codes within the Astronomical Multipurpose Software Environment
(AMUSE).
  Conclusions: Tidal harassment produces a sparser configuration more rapidly
than the isolated reference simulations. The evolution of the asymptotic
power-law density distribution exponent also shows substantially different
behaviour in the two cases. The background is more effective on clusters in
advanced stages of dynamical development.
