The influence of β-cyclodextrin on the interaction and internalization of PLGA nanoparticles into intestine epithelial cells was assessed. For this purpose β-cyclodextrin was adsorbed on PLGA nanoparticles. Interaction of nanoparticles with Caco-2 cells, determined by fluorescence, was expressed as the number of particles per cell. Confocal microscopy confirmed the localization of the particles in the cell monolayer. The results showed that adsorption of β-cyclodextrin on the surface of PLGA nanoparticles reduces interaction with mucin, enhancing in this way the internalization into the Caco-2 cells. Copyright © 2015 Elsevier B.V. All rights reserved.