Investigations of Host-Guest Interactions with Shape-persistent Nonionic Dendritic Micelles
R. Tyagi, S. Malhotra, A. Thünemann, A. Sedighi, M. Weber, A. Schäfer, R. Haag – 2013
The interaction of self-assembled dendritic amphiphiles with drugs and dyes in aqueous solutions is of great significance for designing and optimizing shape-persistent delivery systems. Here we present deeper insight for two examples of low molecular weight (LMW) nonionic dendritic amphiphiles as host molecules and a series of selected aromatic guest model molecules (benzene, naphthalene, biphenyl, terphenyl, anthracene, and pyrene). Aromatic guest molecules were incorporated into the self-assemblies of dendritic nanocarriers, and the resultant complexes were studied by a combination of UV, NMR, computational simulation, and small-angle X-ray-scattering (SAXS) techniques in order to determine the loading capacity, localization, and specific interactions in dendritic amphiphiles with guest molecules. Our findings revealed that the localization of guest molecules in the hydrophobic region and the loading capacity of guest molecules are dependent on their size and the arrangement of aromatic rings instead of the loading amount. Furthermore, the shape of self-assembled host molecules was found to be ellipsoidal and highly persistent even after loading the guest molecules. To the best of our knowledge, this is the first systematic host–guest study, particularly with low molecular weight nonionic dendritic amphiphilies and aromatic guest molecules. Thus, this study opens new possibilities and ways to explore the transport behavior of aromatic drugs with such nanocarriers.