  We analyze theoretically the coupled-channel meson-baryon interaction with
global flavor $\bar c c s s n$ and $\bar c c s s s$, where mesons are
pseudoscalars or vectors and baryons have $J ^P=1/2^+$ or $3/2^+$. The aim is
to explore whether the nonlinear dynamics inherent in the unitarization process
within coupled channels can dynamically generate double- and triple-strange
pentaquark-type states ($P_{css}$ and $P_{csss}$ respectively), for which there
is no experimental evidence to date. We evaluate the s-wave scattering matrix
by implementing unitarity in coupled channels, using potential kernels obtained
from t-channel vector meson exchange. The required $PPV$ and $VVV$ vertices are
obtained from Lagrangians derived through appropriate extensions of the local
hidden gauge symmetry approach to the charm sector, while capitalizing on the
symmetry of the spin and flavor wave function to evaluate the $BBV$ vertex. We
find four different poles in the double strange sector, some of them degenerate
in spin. For the triple-strange channel we find the meson-baryon interaction
insufficient to generate a bound or resonance state through the unitary
coupled-channel dynamics.
