Different instrumental approaches to understand the chitosan coated niosomes/mucin interaction
Span-20 non-ionic surfactant vesicles (niosomes), designed for future applications in brain drug delivery through intranasal route, are prepared and coated with chitosan glutamate, a mucoadhesive agent specifically proposed for brain delivery and for an optimal interaction with nasal mucin, with the aim to promote the vesicles residence time in the nasal cavity. The understanding of the interaction between chitosan coated niosomes with mucin is of great relevance as it can influence their in vivo distribution and physiological behaviour. Complementary and different techniques are then used in a non-conventional combined approach to study this phenomenon. The integrated use of dynamic light scattering (DLS), fluorimetric and spectrophotometric assays, small-angle X-ray scattering (SAXS), atomic force microscopy (AFM) and high speed brightfield microscopy (BFM) allows to shed new light on the physico-chemical behaviour of the mucin-niosomes system, addressing this complex phenomenon by different perspectives.