[en] This contribution reports recent investigations on low-energy scaling properties of three-body systems, by considering elastic s –wave collisions of a particle in a bound-state formed by the remaining two-body system. First, some previous results for the case of the halo nucleus ²⁰C will be revised, for the neutron–¹⁹C scattering properties near the critical condition for the occurrence of an excited bound state in ²⁰C, within a neutron–neutron–¹⁸C configuration. In our approach, we consider the Faddeev formalism with renormalized zero-range two-body interactions. Next, by considering the actual possibilities for verification of low-energy scaling properties in cold-atom laboratories, the approach is extended to atomic strongly-mass-imbalanced three-body systems, with two identical heavy particles and a light one. In this case, we consider that the heavy particle is being scattered by the light-heavy weakly-bound dimer. Our preliminary results for scattering observable are evidencing the universal scaling features. (paper)