β‐Cyclodextrin PAMAM Dendrimer: How to Overcome the Tumbling Process for Getting Fully Available Host Cavities

Abstract

The synthesis of a G0 polyamidoamide (PAMAM) dendrimer end‐capped with four β‐cyclodextrin (β‐CD) units, named as Tetra‐CD was performed by using copper(I)‐catalyzed alkyne‐azide cycloaddition (CuAAC). This new platform presents a considerable high water‐solubility in comparison to native β‐CD. Tumbling process involving half of the CD cavities in D2O was evidenced by 1H NMR spectroscopy. Interaction of adamantane with Tetra‐CD has been fully investigated by 1D/2D NMR techniques and mass spectrometry besides a joint study on new β‐CD monomers (named as A and B) and on a dimer (Di‐CD) and a trimer (Tri‐CD). The obtained results demonstrate that the tumbling effect can be shifted in the presence of an appropriate hydrophobic guest resulting in the full host‐ability of the CD units in water for that guest.

Guest-Mediated Reversal of the Tumbling Process in Phosphorus-Dendritic Compounds Containing β-Cyclodextrin Units: An NMR Study

“…This inversion or tumbling causes the spacer that links to the CDs with the platform to deeply insert into the CD cavity. Very recently, this phenomenon has been reported on the surface of CD-functionalized PAMAM dendrimers [15]. This tumbling depends on the type of spacer used, and, when favored, has a direct negative impact on the accessibility to the cavities of the CDs present in the platform.…”

“…Surface engineering deals with the modification of the dendrimer periphery, as it employs elegant strategies to improve the physico-chemical and biological properties of dendrimers [9,10]. In recent years, the development of surfacemodified dendrimers with carbohydrates, specifically with cyclodextrins (CDs), has led to a synergistic effect on the properties of the obtained constructs [11][12][13][14][15].…”

“…Therefore, the inclusion of multiple CD units into complex molecular structures has been shown to endow important features, such as excellent physico-chemical properties [16]. For this reason, in addition to dendrimer design, various CD-containing structures such as dimers [17][18][19][20][21], trimers [15,22], and tetramers [23] have been developed.…”

First Class of Phosphorus Dendritic Compounds Containing β-Cyclodextrin Units in the Periphery Prepared by CuAAC

“…With the focus of developing carbohydrate-conjugated dendrimers, diverse modifications of poly(amidoamines) (PAMAM) dendrimers with cyclodextrin molecules (CDs) have been reported for multiple applications [ 18 , 19 , 20 , 21 ]; however, this strategy has not yet been reported for PDs. CDs are cyclic oligosaccharides, composed of six or more glucopyranose units linked by α (1-4)-glucosidic bonds.…”

Efficient modification of PAMAM G1 dendrimer surface with β-cyclodextrin units by CuAAC: impact on the water solubility and cytotoxicity

“…3,[20][21][22][23][24] There are several works that describe the conjugation of PAMAM dendrimers (G 2-4) with different CD molecules. [25][26][27][28][29][30][31][32] The incorporation from one to ve CD units is carried out in the periphery of dendrimers with applications in the delivery of genetic material for the specic treatment of diseases. On the other hand, since low generations of PAMAM dendrimers do not show encapsulating properties of molecules, and particularly b-CD molecules, have a limited water solubility.…”