This collaborative study with the chemical engineering groups from University of Innsbruck, Austria and Aristotle University of Thessaloniki, Greece is part of this large EU funded FP7 project which aims to develop new nanoparticulate drug delivery systems capable of penetrating the mucus barrier. This particular study focuses on the effect of surface tailored particles on both the local and global structure of the mucus gel. In this experiment, changes in mucus gel structure (for both shear-compliant and shear-resistant mucus) induced by novel nanoparticulate delivery systems containing mucolytic agents will be investigated using SANS2D and OFFSPEC (spin-echo mode). This combination of instruments will enable us to characterize the interactions in terms of particle/polymer interaction and the effect of these interactions on the structure of the larger gel network.