Towards long-acting adrenaline for cardiopulmonary resuscitation: Production and characterization of a liposomal formulation.

The use of adrenaline in cardiopulmonary resuscitation is a long-standing medical procedure, recommended by several international guidelines. However, its unspecific action on adrenergic receptors and the need for repeated administrations pose serious concerns about its safety, the balance between benefits and risks being still under debate. To address this issue, a sustained release nano-formulation of adrenaline was developed. Adrenaline was encapsulated into PEGylated, anionic liposomes by a pH-driven loading technique. Particular attention was devoted to the prevention of oxidation of adrenaline by optimizing the preparative process and including an optimal amount of antioxidants in the formulation. The vesicles obtained were then characterized for size, zeta-potential, and lamellarity, while their morphology was described by cryo-TEM. The controlled release properties were confirmed by two different in vitro release-testing methods, and the biocompatibility was assayed on human endothelial cells in vitro.

Cubosomes for in vivo fluorescence lifetime imaging.

Herein we provided the first proof of principle for in vivo fluorescence optical imaging application using monoolein-based cubosomes in a healthy mouse animal model. This formulation, administered at a non-cytotoxic concentration, was capable of providing both exogenous contrast for NIR fluorescence imaging with very high efficiency and chemospecific information upon lifetime analysis. Time-resolved measurements of fluorescence after the intravenous injection of cubosomes revealed that the dye rapidly accumulated mainly in the liver, while lifetimes profiles obtained in vivo allowed for discriminating between free dye or dye embedded within the cubosome nanostructure after injection.

On the role of a coumarin derivative for sensing applications: Nucleotide identification using a micellar system.

The recognition of nucleotides is of crucial importance because they are the basic constituents of nucleic acids. The present study is focused on the selective interaction between a novel amphiphilic fluorophore containing coumarin and imidazole, CI (1-methyl-3-(12-((2-oxo-2H-chromen-7-yl)oxy)dodecyl)-1H-imidazol-3-ium bromide), and different nucleotide-monophosphates (NMPs). It was supposed that the solubilization of the low water soluble CI in a micelle system of hexadecyltrimethylammonium chloride (CTAC) would make the coumarin moiety of CI available to the interaction with the water-soluble NMPs. Changes in CTAC critical micelle concentration suggested that CI strongly interacted with the host cationic surfactant, thus forming a positively charged interface enriched with coumarin able to interact with the anionic NMPs. Steady-state fluorescence quenching revealed that CI/CTAC system was capable of distinguish between purine- and pyrimidine-based nucleotides. A modified Stern-Volmer equation permitted the use of a quenching model that accounted for the possible interactions between the micelles and the nucleotides. The data analysis allowed calculating selective parameters that differentiated according to the type of nucleotide either at 25 or 50°C. Our results established the utility of the novel coumarin derivative fluorophore, supported by the simple and suitable micellar systems, as a tool for DNA sensing applications.

Monoolein-based cubosomes affect lipid profile in HeLa cells.

Monoolein-based cubosomes are promising drug delivery nanocarriers for theranostic purposes. Nevertheless, a small amount of research has been undertaken to investigate the impact of these biocompatible nanoparticles on cell lipid profile. The purpose of the present investigation was to explore changes in lipid components occurring in human carcinoma HeLa cells when exposed to short-term treatments (2 and 4h) with monoolein-based cubosomes stabilized by Pluronic F108 (MO/PF108). A combination of TLC and reversed-phase HPLC with DAD and ELSD detection was performed to analyze cell total fatty acid profile and levels of phospholipids, free cholesterol, triacylglycerols, and cholesteryl esters. The treatments with MO/PF108 cubosomes, at non-cytotoxic concentration (83µg/mL of MO), affected HeLa fatty acid profile, and a significant increase in the level of oleic acid 18:1 n-9 was observed in treated cells after lipid component saponification. Nanoparticle uptake modulated HeLa cell lipid composition, inducing a remarkable incorporation of oleic acid in the phospholipid and triacylglycerol fractions, whereas no changes were observed in the cellular levels of free cholesterol and cholesteryl oleate. Moreover, cell-based fluorescent measurements of intracellular membranes and lipid droplet content were assessed on cubosome-treated cells with an alternative technique using Nile red staining. A significant increase in the amount of the intracellular membranes and mostly in the cytoplasmic lipid droplets was detected, confirming that monoolein-based cubosome treatment influences the synthesis of intracellular membranes and accumulation of lipid droplets.

Docetaxel-Loaded Fluorescent Liquid-Crystalline Nanoparticles for Cancer Theranostics.

Here, we describe a novel monoolein-based cubosome formulation engineered for possible theranostic applications in oncology. The Docetaxel-loaded nanoparticles were stabilized in water by a mixture of commercial Pluronic (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer) F108 (PF108) and rhodamine- and folate-conjugated PF108 so that the nanoparticles possess targeting, therapeutic, and imaging properties. Nanoparticles were investigated by DLS, cryo-TEM, and SAXS to confirm their structural features. The fluorescent emission characterization of the proposed formulation indicated that the rhodamine conjugated to the PF108 experiences an environment less polar than water (similar to chloroform), suggesting that the fluorescent fragment is buried within the poly(ethylene oxide) corona surrounding the nanoparticle. Furthermore, these nanoparticles were successfully used to image living HeLa cells and demonstrated a significant short-term (4 h incubation) cytotoxicity effect against these cancer cells. Furthermore, given their analogy as nanocarriers for molecules of pharmaceutical interest and to better stress the singularities of these bicontinuous cubic nanoparticles, we also quantitatively evaluated the differences between cubosomes and multilamellar liposomes in terms of surface area and hydrophobic volume.

Cubosome formulations stabilized by a dansyl-conjugated block copolymer for possible nanomedicine applications.

We present here an innovative, fluorescent, monoolein-based cubosome dispersion. Rather than embedded within the monoolein palisade, the fluorescent imaging agent, namely dansyl, was conjugated to the terminal ethylene oxide moieties of the block copolymer Pluronic F108. We discuss the physicochemical and photophysical properties of this fluorescent Pluronic and of a cubosome formulation stabilized by a mixture of dansyl-conjugated and non-conjugated Pluronic, also including an anticancer drug (quercetin). Furthermore, we performed biocompatibility tests against HeLa cells to assess internalization and cytotoxicity features of this nanoparticles aqueous dispersion. Cryo-TEM, SAXS, and DLS analysis, proved the bicontinuous cubic inner nanostructure and the morphology of this fluorescent cubosome dispersion, while photophysical measurements and biocompatibility results basically validate their potential use for theranostic nanomedicine applications.

Cancer-cell-targeted theranostic cubosomes.

This work was devoted to the development of a new type of lipid-based (cubosome) theranostic nanoparticle able to simultaneously host camptothecin, a potent anticancer drug, and a squarain-based NIR-emitting fluorescent probe. Furthermore, to confer targeting abilities on these nanoparticles, they were dispersed using mixtures of Pluronic F108 and folate-conjugated Pluronic F108 in appropriate ratios. The physicochemical characterization, performed via SAXS, DLS, and cryo-TEM techniques, proved that aqueous dispersions of such cubosomes can be effectively prepared, while the photophysical characterization demonstrated that these nanoparticles may be used for in vivo imaging purposes. The superior ability of these innovative nanoparticles in targeting cancer cells was emphasized by investigating the lipid droplet alterations induced in HeLa cells upon exposure to targeted and nontargeted cubosomes.

An OFF-ON chemosensor for biological and environmental applications: sensing Cd2+ in water using catanionic vesicles and in living cells.

A new OFF-ON fluorescent chemosensor (L(1)) for Cd(2+) recognition based on a 5-chloro-8-hydroxyquinoline pendant arm derivative of 1,4,7-triazacyclononane ([9]aneN3) will be presented and its photochemical features in an MeCN-H2O 1 : 1 (v/v) mixture, in pure water, after inclusion within catanionic vesicles, and in living cells will be discussed. The coordination properties of L(1) both in solution and in the solid state were preliminarily studied and its selectivity towards Cd(2+)versus a set of different metal ions (Cu(2+), Zn(2+), Cd(2+), Pb(2+), Al(3+), Hg(2+), Co(2+), Ni(2+), Mn(2+), Mg(2+), K(+), Ca(2+), Ag(+), and Na(+)) was verified in MeCN-H2O 1 : 1 (v/v). In water, upon addition of increasing amounts of Cd(2+) to L(1) an enhancement of the fluorescence emission was detected. To overcome this serious drawback, L(1) was dissolved in an innovative catanionic vesicular solution based on sodium bis(2-ethylhexyl) sulfosuccinate, a traditional surfactant, and 1-dodecyl-3-methylimidazolium bromide, an ionic liquid. When enclosed within the vesicle bilayers in water, L(1) restored its fluorescence emission property upon addition of Cd(2+). Remarkably, L(1) enters the cellular membrane of living cells thus allowing the detection of intracellular Cd(2+). These findings encourage the application of this new fluorescent chemosensor in real samples for histological and environmental analyses.

Drug-loaded fluorescent cubosomes: versatile nanoparticles for potential theranostic applications.

In this work, monoolein-based cubosomes were doped with two fluorescent probes, namely, fluorescein and dansyl, properly modified with a hydrocarbon chain to increase their encapsulation efficiency within the monoolein palisade. The same nanocarriers were also loaded with quercetin, a hydrophobic molecule with potential anticancer activity. Particularly, the cubosomes doped with the modified fluorescein probe were successfully exploited for single living cell imaging. The physicochemical and photophysical characterizations reported here, along with the well-known ability of cubosomes in hosting molecules with pharmaceutical interest, strongly encourage the use of these innovative fluorescent nanocarriers for theranostic purposes.

Colorimetric response to anions by a "robust" copper(II) complex of a [9]aneN3 pendant arm derivative: CN- and I- selective sensing.

The 1 : 1 complex [Cu(L)](BF(4))(2)·MeCN (1) of the tetradentate ligand 1-(2-quinolinylmethyl)-1,4,7-triazacyclononane (L) selectively changes its colour in the presence of CN(-) in H(2)O and MeCN (without undergoing decomplexation from the macrocyclic ligand). The same complex in MeCN assumes different colours in the presence of CN(-) or I(-).