Dynamic Control of the Self-Assembling Properties of Cyclodextrins by the Interplay of Aromatic and Host-Guest Interactions

Abstract

The presence of a doubly-linked naphthylene clip at the O -2 I and O -3 II positions in the secondary ring of β-cyclodextrin (βCD) derivatives promoted their self-assembly into head-to-head supramolecular dimers in which the aromatic modules act either as cavity extension walls (if the naphthalene moiety is 1,8-disubstituted) or as folding screens that separate the individual βCD units (if 2,3-disubstituted). Dimer architecture is governed by the conformational properties of the monomer constituents, as determined by NMR, fluorescence, circular dichroism, and computational techniques. In a second supramolecular organization level, the topology of the assembly directs host-guest interactions and, reciprocally, guest inclusion impacts the stability of the supramolecular edifice. Thus, inclusion of adamantane carboxylate, a well-known βCD cavity-fitting guest, was found to either preserve the dimeric arrangement, leading to multicomponent species, or elicit dimer disruption. The ensemble of results highlights the potential of the approach to program self-organization and external stimuli responsiveness of CD devices in a controlled manner while keeping full diastereomeric purity.

Tuning the Topological Landscape of DNA–Cyclodextrin Nanocomplexes by Molecular Design

“…Such a one‐ring conformational flip forces a drastic alteration of the overall CD shape, from conical to ellipsoidal torus, as compared with a noninverted structure. The aromatic segment is then projected wide apart from the CD vertical axis, an orientation that was previously found to strongly disfavor the formation of self‐assembled supramolecular dimers [20a,b] …”

Tethered Blatter Radical for Molecular Grafting: Synthesis of 6-Hydroxyhexyloxy, Hydroxymethyl, and Bis(hydroxymethyl) Derivatives and Their Functionalization

“…Tosylates IIb and IIIb can additionally be exploited to attach the Blatter radical to hydroxyl-functionalized partners through the formation of benzyl-type ether linkages. Following prior work on the synthesis and supramolecular properties of cyclodextrin-xylylene hybrids [67][68][69][70], we have conducted preliminary experiments supporting the viability of such an approach, and the results will be published in due course.…”

Cyclodextrin-Based Functional Glyconanomaterials

“…Polycationic cyclodextrins have become the iconic representatives in this category [5,[97][98][99][100][101][102][103][104]. The efficiency in compacting nucleic acids into nanocomplexes (so-called CDplexes) capable of mediating cell entry and subsequent expression of the nucleic acid anticipated activity (transfection) was significantly enhanced for prototypes that can additionally establish cyclodextrin-cyclodextrin interactions through either hydrophobic , host-guest [79,134] or aromatic-aromatic contacts [135][136][137][138][139][140][141][142][143][144][145][146]. As a logical extension, the formulation of CDplexes exposing biorecognizable ligands for the purpose of site-specific gene delivery has been proposed [147][148][149][150][151][152][153][154][155], including the elaboration of carbohydrate decorated CDplexes (glycoCDplexes) conceived for cell receptor glycotargeting [3].…”