Microwave-assisted synthesis of novel cyclodextrin–cucurbituril complexes

Thixotropic Hydrogels Based on Laponite® and Cucurbituril for Delivery of Lipophilic Drug Molecules

Nowadays the use of hydrogels for biomedical purposes is increasing because of their interesting features that allow the development of targeted drug delivery systems. Herein, hydrogel based on Laponite® (Lap) clay mineral as gelator and cucurbit[6]uril (CB[6]) molecules were synthetized for the delivery of flufenamic acid (FFA) for potential topical application. Firstly, the interaction between CB[6] and FFA was assessed by UV-vis spectroscopic measurements and molecular modeling calculations. Then, the obtained complex was used as filler for Lap hydrogel (Lap/CB[6]/FFA). The properties of the hydrogel in terms of viscosity and, self-repair abilities were investigated; its morphology was imaged by scanning electron and polarized optical microscopies. Furthermore, the changes in the hydrodynamic radii and in the colloidal stability of CB[6]/Lap mixture were investigated in terms of translational diffusion from dynamic light scattering and ζ-potential measurements. Finally, the kinetic in vitro release of FFA, from Lap/CB[6]/FFA hydrogel, was studied in a medium mimicking the pH of skin and the obtained results were discussed both by an experimental point of view and by molecular modeling calculations.

An Overview of the Supramolecular Systems for Gene and Drug Delivery in Tissue Regeneration

Tissue regeneration is a prominent area of research, developing biomaterials aimed to be tunable, mechanistic scaffolds that mimic the physiological environment of the tissue. These biomaterials are projected to effectively possess similar chemical and biological properties, while at the same time are required to be safely and quickly degradable in the body once the desired restoration is achieved. Supramolecular systems composed of reversible, non-covalently connected, self-assembly units that respond to biological stimuli and signal cells have efficiently been developed as preferred biomaterials. Their biocompatibility and the ability to engineer the functionality have led to promising results in regenerative therapy. This review was intended to illuminate those who wish to envisage the niche translational research in regenerative therapy by summarizing the various explored types, chemistry, mechanisms, stimuli receptivity, and other advancements of supramolecular systems.

Delivering anion transporters to lipid bilayers in water

Cyclodextrins have been employed as delivery agents for lipophilic anion transporters, which allow their incorporation into lipid bilayers without using an organic solvent or pre-incorporation.

β-Cyclodextrin-grafted hyaluronic acid as a supramolecular polysaccharide carrier for cell-targeted drug delivery

β-Cyclodextrin (β-CD) was grafted onto hyaluronic acid (HA) in a single step to generate a supramolecular biopolymer (HA-β-CD) that was explored for targeted drug delivery applications. Along with its excellent biocompatibility, the prepared HA-β-CD exhibits not only exceptionally high loading capacity for the model drugs doxorubicin and Rhodamine B through the formation of inclusion complexes with the β-CD component, but also the capability of targeted drug delivery to cancerous cells with a high level of expression of CD44 receptors, attributable to its HA component. The polymer can release the drug under slightly acidic conditions. With all its attributes, HA-β-CD may be a promising cancer-cell-targeting drug carrier.

Hyaluronic-acid-based β-cyclodextrin grafted copolymers as biocompatible supramolecular hosts to enhance the water solubility of tocopherol

Hyaluronic acid (HA), a common biopolymer found in the extracellular fluid, was grafted with β-cyclodextrin (β-CD) to form a composite polymer that could form inclusion complexes with tocopherol (VE), enhancing its water-solubility and serving as a model drug delivery system. Herein, different copolymers were prepared with varying HA:β-CD ratios and characterized. VE loading capacity was directly correlated with increased β-CD composition in the polymers and morphological changes were observed upon VE binding. The host materials and their VE inclusion complexes are not cytotoxic, and are thus useful for VE and drug delivery.

Mass Spectrometry as a Complementary Approach for Noncovalently Bound Complexes Based on Cyclodextrins

An important and well-designed solution to overcome some of the problems associated with new drugs is provided by the molecular encapsulation of the drugs in the cyclodextrins (CDs) cavity, yielding corresponding inclusion complexes (ICs). These types of non-covalent complexes are of current interest to the pharmaceutical industry, as they improve the solubility, stability and bioavailability of the guest molecules. This review highlights several methods for cyclodextrin ICs preparation and characterization, focusing mostly on the mass spectrometry (MS) studies that have been used for the detection of noncovalent interactions of CDs inclusion complexes and binding selectivity of guest molecules with CDs. Furthermore, the MS investigations of several ICs of the CD with antifungal, antioxidants or fluorescent dyes are presented in greater details, pointing out the difficulties overcome in the analysis of this type of compounds.

Cyclodextrin–calixarene co-polymers as a new class of nanosponges

Novel nanosponge materials, obtained by co-polymerization of cyclodextrin and calixarene derivatives, have been characterized by various techniques and tested for the removal of model pollutants from aqueous solution.

Molten salt-supported polycondensation of optically active diacid monomers with an aromatic thiazole-bearing diamine using microwave irradiation

Microwave heating was used to prepare optically active thiazole-bearing poly(amide-imide)s. Polymerization reactions were carried out in the molten tetrabutylammonium bromide as a green molten salt medium and triphenyl phosphite as the homogenizer. Structural elucidation of the compounds was performed by Fourier transform infrared and NMR spectroscopic data and elemental analysis results. The polymeric samples were readily soluble in various organic solvents, forming low-colored and flexible thin films via solution casting. They showed high thermal stability with decomposition temperature being above 360 °C. They were assembled randomly in a nanoscale size.