Amphiphilic cyclodextrins - Advances in synthesis and supramolecular chemistry

Amphiphilic cyclodextrins represent a new generation of these oligosaccharides, which are well known previously as host molecules in water. Cyclodextrins are now being modified with polar groups, lipophilic groups and conjugates which elaborate further their amphiphilicity and molecular recognition. The resulting amphiphiles are host molecules capable of forming all the assemblies expected of amphiphiles, but showing additional supramolecular properties. Examples of these macrocyclic amphiphiles are by now known that form thermotropic liquid crystals, while lyotropic assemblies include micelles, unimolecular micelles, nanoparticles, monolayers and bilayer vesicles. The assembly properties ties are modulated by both the lipidic and hydrophilic additions to the original cyclodextrin, however due to the mesomolecular size range substantial changes such as multiple glycosylation can be carried out without disrupting self-assembly. The assemblies in certain cases show molecular recognition both by the cyclodextrin cavities and by the conjugated groups such as glycosyls. Multiple noncovalent interactions, delivery to biological cells and DNA delivery are among the capabilities of those amphiphilic cyclodextrins that form bilayer vesicles.