Highly selective luminescent nanostructures for mitochondrial imaging and targeting.

Here a luminescent hybrid nanostructure based on functionalized quantum dots (QDs) is used as a fluorescent imaging agent able to target selectively mitochondria thanks to the molecular recognition of the translocator protein (TSPO). The selective targeting of such an 18 kDa protein mainly located in the outer mitochondrial membrane and overexpressed in several pathological states including neurodegenerative diseases and cancers may provide valuable information for the early diagnosis and therapy of human disorders. In particular, the rational design of amino functionalized luminescent silica coated QD nanoparticles (QD@SiO2 NPs) provides a versatile nanoplatform to anchor a potent and selective TSPO ligand, characterized by a 2-phenyl-imidazo[1,2-a]pyridine acetamide structure along with a derivatizable carboxylic end group, useful to conjugate the TSPO ligand and achieve TSPO-QD@SiO2 NPs by means of a covalent amide bond. The colloidal stability and optical properties of the proposed nanomaterials are comprehensively investigated and their potential as mitochondrial imaging agents is fully assessed. Sub-cellular fractionation, together with confocal laser scanning fluorescence microscopy and co-localization analysis of targeted TSPO-QD@SiO2 NPs in C6 glioma cells overexpressing the TSPO, proves the great potential of these multifunctional nanosystems as in vitro selective mitochondrial imaging agents.

ß-cyclodextrin in personal care formulations: role on the complexation of malodours causing molecules.

OBJECTIVE: The aim of this study was to prove the capability of ß-cyclodextrin (ß-CD) to interact with some representative molecules responsible to cause body malodour, such as carboxylic acids, thiols and steroids, present in sweat and body secretions. METHODS: The association constants in guest-CD were determined by (1) H-NMR spectroscopy for thiols and steroids such as 3-mercapto-1-hexanol, androstenone, androstenol and androsterone, and pH-potentiometric titration for acetic acid, l(+) lactic acid, isobutyric acid, isovaleric acid and 3-hydroxy-3-methyl-hexanoic acid. RESULTS: All considered systems are able to interact with relatively weak association constants with ß-cyclodextrin, in a 1 : 1 host-guest ratio. CONCLUSION: From these findings, it is possible to conclude that ß-CD is capable to interact with different components present in the sweat and body secretion, forming inclusion complexes. For this reason, ß-CD could be a component of body care formulations, such as deodorants.

Effects of different cyclodextrins on the morphology, loading and release properties of poly (DL-lactide-co-glycolide)-microparticles containing the hypnotic agent etizolam.

The aim of this study was to gain insight into the feasibility of using microparticles (MPs) constituted by the biodegradable poly (DL-lactide-co-glycolide) (PLGA) and a number of cyclodextrins (CDs) as an orally sustained delivery system of the hypnotic agent etizolam (ETZ). A further aim of the work was to investigate the effects of different CDs on the morphology, loading, and release properties of the MPs prepared. For these purposes, ETZ alone, and ETZ/CD-PLGA loaded MPs were prepared by the W/O/W emulsion-solvent evaporation method. It was found that the release of ETZ in vitro was more prolonged over three days with a kinetic constant proportional to t(1/2). It was also demonstrated that the CDs in these MPs are able to modulate several properties such as morphology, drug loading, and release properties. In fact, marked differences in shape, surface, and encapsulation efficiencies were noted depending on the presence, hydrophilicity, and charge of the CD employed. The obtained results induce us to consider the present ETZ-containing formulations as new valuable tools for the treatment of different insomnia categories.

Inclusion complexation of propofol with 2-hydroxypropyl-beta-cyclodextrin. Physicochemical, nuclear magnetic resonance spectroscopic studies, and anesthetic properties in rat. trapani@ippo.uniba.it.

An aqueous formulations of propofol 1 can be prepared by solubilizing it in the presence of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD). This is potentially useful for parenteral administration of the drug. The aqueous solubility of 1 linearly increased as a function of HP-beta-CD concentration and showed features of an AL type diagram. Thermodynamic parameters were obtained by using the temperature dependence of the stability constant at temperatures of between 25 and 37 degrees C. The results indicate that complex formation is enthalpically, rather than entropically, driven and that it may involve van der Waals (dispersive) forces, rather than hydrophobic interactions. The structure of the inclusion complex propofol/HP-beta-CD was investigated in D2O, using 1H and 13C NMR spectroscopy. These studies revealed that the whole aromatic ring, as well as part of the isopropyl groups of the guest molecule, is located inside the HP-beta-CD cavity, while the hydroxy group is located at the rim of the wider cavity end. The geometrical features of the inclusion complex 1-HP-beta-CD are confirmed by 1D NOE difference spectra and molecular modeling experiments. The anesthetic activity in rat was investigated, and it was found that there are significant differences in induction time and sleeping time between 1 solubilized in the presence of HP-beta-CD and the formulation currently used (Diprivan), which is a 1% w/v oil/water emulsion.