  We study the entanglement of closed strings degrees of freedom in order to
investigate the microscopic structure and statistics of objects as D-branes. By
considering the macroscopic pure state (MPS) limit, whenever the entanglement
entropy goes to zero (in such a way that the macroscopic properties of the
state are preserved), we show that boundary states may be recovered in this
limit and, furthermore, the description through closed string (perturbative)
degrees of freedom collapses. We also show how the thermal properties of branes
and closed strings could be described by this model, and it requires that
dissipative effects be taken into account. Extensions of the MPS analysis to
more general systems at finite temperature are finally emphasized.
