Cucurbit[n]urils‐related Multitopic Supramolecular Components: Design, Properties, and Perspectives

Abstract

Cucurbit[n]urils (CBns) are an intriguing family of macrocyclic hosts whose chemistry has undergone rapid developments in recent decades. The initial interest in the synthesis, modifications and binding properties has shifted to areas focused on applications in drug storage, delivery, and release, external‐stimuli responsive devices, and molecular nano‐reactors. Since CBns are fruitfully complemented by cyclodextrins (CDs) in such systems, guest molecules that contain several binding sites are needed. These multitopic guests provide not only a scaffold for holding CBns and CDs together in appropriate arrangements but also allow for manipulation with supramolecular aggregates, e. g., reorganization or release of macrocycles. In this review, we summarize recent studies related to the design of multitopic guests. Binding motifs properties, the role of attractive or repulsive lateral interactions, the competition‐compensation effect, and rotaxane versus pseudorotaxane manner are discussed.

Cucurbituril-Oriented Nanoplatforms in Biomedical Applications

“…Because of its high solubility, CD has frequently been used to improve the solubility of poorly soluble drugs and in drug delivery systems over past decades, even in current systems. − However, the encapsulation of guest molecules by CD occurs only through hydrophobic and van der Waals forces, and the monotonicity of the mechanism of attachment of CD to the guest molecule allows the encapsulation of only a single type of guest. In addition, the association constant between CD and a guest molecule does not exceed 10 7 M –1 . Cucurbituril (CB), named after its pumpkin-like shape, is a novel type of host molecule whose properties have gained recognition since the new millennium, although originally published by Behrend in 1905. − Compared with CD, CB displays significant advantages.…”