Cyclodextrin-Adamantane Host–Guest Interactions on the Surface of Biocompatible Adamantyl-Modified Glycodendrimers

A series of adamantyl-modified glycodendrimers (mPPI-Gx-AdaA-C) was prepared in a two-step synthesis using two efficient reactions: (1) urea bond formation from amine and isocyanate and (2) reductive amination. H-1 NMR spectroscopy (host guest titration and ROESY experiments) was used to evaluate the graded effect of steric hindrance as a function of the number and type of oligosaccharide molecules and of the number of adamantyl (Ada) units on the complexation with monomeric beta-cyclodextrin (beta-CD). Glycosylated fourth generation PPIs showing an average substitution in adamantyl groups of 13% were found to interact with beta-CD effectively, and were considered, as candidates for further complexation studies with a polymeric cyclodextrin derivative (poly-beta-CD). The host-guest interaction features of the maltosylated dense shell glycodendrimer along with the low cytotoxicity provided the rational basis for the use of these adamantyl-functionalized glycodendrimers in the design of supramolecular systems potentially useful as healthcare materials.