NMR spectroscopy for the determination of mucoadhesive properties of polysaccharides

Applications of nuclear magnetic resonance (NMR) spectroscopy to the structural characterization of polysaccharides with mucoadhesive characteristics are described together with some limited cases of uses in the detection of affinity to mucin. Structural characterization spans from quantification of monomeric units of polysaccharides following degradation procedures to the development of reliable analytical protocols directly on the intact polymeric materials. In these last cases several problems can be solved such as the identification of derivatization sites on monosaccharide units and determination of average length of derivatizing pendants. For non-covalent modifications, the more difficult aspect is the detection of conformational changes. Mucoadhesivity can be determined by exploiting the possibility to detect changes of affinityto mucin of small probe molecules due to the mucin-polysaccharide interaction.