Functionalized halloysite multivalent glycocluster as a new drug delivery system

Abstract

A new design for halloysite nanotube materials was obtained by grafting chemically modified cyclodextrin units onto the nanotube surface. In particular, grafted cyclodextrins were decorated with thiosaccharide pendants, in order to mimic the well-known binding of sugars to proteins and the glyco-cluster effect occurring during cellular recognition events. The obtained materials were characterized by using a combination of varied techniques (FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, turbidimetry), and their potential drug-delivery abilities were tested by studying their interactions with the common naturally occurring anticancer agent curcumin. A suitable model describing the interaction between our materials and curcumin is proposed.

Covalently modified halloysite clay nanotubes: synthesis, properties, biological and medical applications

“…Another dual-drug HNT delivery system was obtained by the covalent linkage of b-cyclodextrin (b-CD) units on the HNT external surface. 64 The covalent binding of cyclodextrin instead of a supramolecular approach to the HNT surface allows the fabrication of an organic-inorganic hybrid material with great stability, control over the degree of functionalization, and the data reproducibility. Moreover, the presence of two cavities offers the remarkable possibility for a simultaneous encapsulation of two or more drug molecules with different physicochemical properties, followed by a different path release in agreement with the cavity that encapsulates each drug.…”

Dual drug-loaded halloysite hybrid-based glycocluster for sustained release of hydrophobic molecules

“…34 In particular, thiol functionalized halloysite was reacted with heptakis-6-(tert-butyldi-methylsilyl)-2-allyloxy-b-cyclodextrin under microwave irradiation for 1 h, at 100 C. Then, the obtained material was further functionalized by decorating the secondary rim of CD units with thiomannoside units (Fig. 3); this strategy afforded a nanomaterial with 1.5 wt% of mannose units, as estimated by thermogravimetric analysis (TGA).…”

Synthesis and Characterization of Halloysite–Cyclodextrin Nanosponges for Enhanced Dyes Adsorption

“…25 As previously reported, 26 halloysite nanotubes were reacted with an excess of 3-mercaptopropyltrimethoxysilane in solvent-free conditions under microwave irradiation, affording HNT-SH, which represents a versatile starting point for subsequent functionalization. After workup, the amount of organic moiety grafted on the HNT external surface was estimated by TGA to be ca.…”

“…Compared to pristine HNT, 25 the HNT-CDs (40%) nanosponge hybrid exhibits the vibration bands for C−H stretching of methylene groups around 2980 cm −1 and a broad and wide band around 3000 cm −1 due to the −OH groups of cyclodextrin (see Figure S1). These findings provide evidence for the presence of organic moieties in the new material.…”

“…25 Since the cyclodextrin is added in excess relative to the moles of −SH groups, the double bonds that do not react in the thiolene reaction can undergo a self-addition reaction, leading to the formation of a cyclodextrin cross-linked network. Therefore, due to the peculiar reticulated structure of the hybrid materials so obtained, constituted by a network of supramolecular host units joined by means of suitable cross-linkers, the hybrid polymer obtained could be considered a sort of nanosponge.…”