Here, the phase behavior of the commercial non-ionic surfactant Solutol HS15 in water was investigated. The focus was on the evolution of the system nanostructure at low water content. Particularly, it was demonstrated that spherical micelles found in dilute surfactant solutions coalesce at a surfactant volume fraction close to 0.5. As consequence, a heterogeneous pseudo-binary mixture occurs. No liquid crystalline phases were detected even at the highest HS15 concentrations in water. Alteration of the micellar morphology induced by the addition of D9-tetrahydrocannabinol to the surfactant/water binary system was also investigated. It was found that the cannabinoid molecules become entrapped within the surfactant hydrophobic tails, thus increasing the surfactant effective packing parameter and inducing a radical change of the micelle shape. At sufficiently low water content (18–35 wt.%), such alteration of the interfacial packing results in a lamellar organization of the surfactant molecules.

Here, the phase behavior of the commercial nonionic surfactant Solutol® HS15 in water was investigated. The focus was on the evolution of the system nanostructure at low water content. Particularly, it was demonstrated that at low water content spherical micelles are present. Micelles coalesce at a surfactant volume fraction close to 0.5. As consequence, a heterogeneous pseudo-binary mixture occurs. No liquid crystalline phases were detected even at the highest HS15 concentrations in water. A morphological change of the micelles occurred on addition of the cannabinoid 9-tetrahydrocannabinol (THC). THC is entrapped within the surfactant tails modifying the micelle shape. At sufficiently low water content (18-35 wt%) such alteration of the interfacial packing results in a lamellar organization of the surfactant molecule

Alkyl-methylimidazolium based ionic liquids are proposed as gating electrolytes in field-effect transistors and the ionic properties are seen to influence the devices electrical performance. Specifically, over a selection of different cations and anions correlations have been established between the ion-pairing occurring in the pure ionic-liquid and the intensity of the current circulating in the transistor channel in the on state. Ion-pairing was determined by means of pulse-gradient-spin-echo (PGSE) NMR experiments. Moreover, the effect of the ions chemical structure and hydrophobicity on the off-current and on the field-effect mobility as well as on the threshold voltage, are discussed. The occurrence of hysteresis in the current–voltage transfer curves is evaluated and associated to the electrolyte molar conductivity and the ions self-diffusion coefficients. The gained understanding allows to optimize the system reaching better device performance level. Moreover, thanks to the well-known bio-compatibility of this class of ionic liquids, application in electrolyte gated biosensors can be foreseen.

The bacterial reaction center (RC) has become a reference model in the study of the diverse interactions of quinones with electron transfer complexes. In these studies, the RC functionality was probed through flash-induced absorption changes where the state of the primary donor is probed by means of a continuous measuring beam and the electron transfer is triggered by a short intense light pulse. The single-beam set-up implies the use as reference of the transmittance measured before the light pulse. Implicit in the analysis of these data is the assumption that the measuring beam does not elicit the protein photochemistry. At variance, measuring beam is actinic in nature at almost all the suitable wavelengths. In this contribution, the analytical modelling of the time evolution of neutral and chargeseparated RCs has been performed. The ability of measuring light to elicit RC photochemistry induces a first order growth of the charge-separated state up to a steady state that depends on the light intensity and on the occupation of the secondary quinone (QB) site. Then the laser

Cardanol is a natural and renewable organic raw material obtained as the major chemical component by vacuum distillation of cashew nut shell liquid. In this work a new sustainable procedure for producing cardanol-based micellar nanodispersions having an embedded lipophilic porphyrin itself peripherally functionalized with cardanol substituents (porphyrin-cardanol hybrid) has been described for the first time. In particular, cardanol acts as the solvent of the cardanol hybrid porphyrin and cholesterol as well as being the main component of the nanodispersions. In this way a “green” micellar nanodispersion, in which a high percentage of the micellar system is derived from renewable “functional” molecules, has been produced.

Addition of small amounts of lauric acid (LA) to a micellar solution of sodium dodecyl sulfate (SDS, 11.5 wt%) and cocamidopropyl betaine (CAPB, 3 wt%) has a dramatic effect on the rheological properties and phase behaviour of the system. The viscosity increases by more than one order of magnitude up to a weight ratio LA/SDS = 0.17 and decreases for further LA loading. The decrease in viscosity is associated to the formation of a birefringent liquid crystalline phase. The evolution of the system from isotropic micelles in absence of LA to lyotropic liquid crystals up to a weight ratio LA/SDS = 0.30 was probed by a combination of 23Na NMR quadrupolar splitting, measurements of water and surfactant self-diffusion coefficients via 1H-PGSE-NMR and rheology. The evolution of the water self-diffusion coefficients indicates that LA induced a dramatic increase in the anisotropy of disk shaped micelles. Birefringent samples always showed a well developed 23Na quadrupolar splitting with a line shape typical of monodomain samples. This suggests that the whole sample is easily oriented within the spectrometer electromagnet as usually observed for nematic liquid crystals. Sample spinning first destroys the alignment (only a single peak is discernible in the 23Na NMR spectrum). Then, upon prolonged spinning, the alignment develops again. This indicates that the system is composed by disk-like micelles aligning themselves with their normal perpendicular to the magnetic field. On the other hand, the linear viscoelastic response close to the nematic transition shows features usually observed in wormlike micellar systems (e.g. nearly Maxwellian behaviour). To reconciliate the rheological data and the NMR evidences of discoid micelles, the formation of columnar stacks of discoid micelles is proposed. The rheology of the isotropic phase can therefore be interpreted in terms of entanglements of “living columnar stacks” of discoid micelles, and the nematic phase observed at high LA content could be attributed to a nematic columnar phase NCol formed by the alignment of such stacks.

Addition of small amounts of lauric acid (LA) to a micellar solution of sodium dodecyl sulfate (SDS, 11.5 wt %) and cocamidopropyl betaine (CAPB, 3 wt %) has a dramatic effect on the rheological properties and phase behavior of the system. The viscosity increases by more than 1 order of magnitude up to a weight ratio LA/SDS ) 0.17 and decreases for further LA loading. The decrease in viscosity is associated with the formation of a birefringent liquid crystalline phase. The evolution of the system from isotropic micelles in the absence of LA to lyotropic liquid crystals up to a weight ratio LA/SDS ) 0.30 was probed by a combination of 23Na NMR quadrupolar splitting, measurements of water and surfactant self-diffusion coefficients via 1H-PGSENMR, and rheology. The evolution of the water self-diffusion coefficients indicates that LA induced a dramatic increase in the anisotropy of disk-shaped micelles. Birefringent samples always showed a well developed 23Na quadrupolar splitting with a line shape typical of monodomain samples. This suggests that the whole sample is easily oriented within the spectrometer electromagnet, as usually observed for nematic liquid crystals. Sample spinning first destroys the alignment (only a single peak is discernible in the 23Na NMR spectrum). Then, upon prolonged spinning, the alignment develops again. This indicates that the system is composed by disklike micelles aligning themselves with their normal perpendicular to the magnetic field. On the other hand, the linear viscoelastic response close to the nematic transition shows features usually observed in wormlike micellar systems (e.g., nearly Maxwellian behavior). To reconciliate the rheological data and the NMR evidence of disklike micelles, the formation of columnar stacks of disklike micelles is proposed. The rheology of the isotropic phase can therefore be interpreted in terms of entanglements of “living columnar stacks” of disklike micelles, and the nematic phase observed at high LA content could be attributed to a nematic columnar phase NCol formed by the alignment of such stacks.

Dioxiranes are used as reagents in a myriad of synthetically useful oxidations performed in aqueous medium. To extend such an approach also to substrates that are highly hydrophobic, we propose here the use of microemulsions based on the surfactant hexadecyltrimethylammonium hydrogen sulphate (CTAHS) because of its high stability against peroxide species. In this paper, we examine the dioxirane (isolated or generated in situ) reactivity in different CTAHS microemulsions. Yield and selectivity of the oxidation of -methylstyrene (2) by dimethyldioxirane (DDO, 1a) generate “in situ” and of laurolactam (3) by isolated methyl(trifluorometyl)dioxirane (TFDO, 1b) were studied. For each microemulsion, the aggregate size and the localization of the components were determined by a combination of NMR and light scattering techniques. The hydrodynamic radius of the micelles is close to the length of the surfactant and this suggests they are spherical in shape. When acetone (the precursor of 1a) is present in the formulation, it partitions itself between the aqueous bulk and the micellar palisade so that the dioxirane eventually formed is readily available to oxidize substrates secluded in the micelle. Apolar substrates, confined within the micelles, are protected from uncontrolled oxidations, leading to an astonishing high selectivity of oxidation of laurolactam (3) to 12-nitro-lauric acid (3a) by TFDO (1b). This opens the way to an easy and green procedure (performed in water under mild conditions) to synthetize omega-nitroacids.

Among various phospholipid-mediated drug delivery systems (DDS) suitable for topic and oral administration, phytosome technology represents an advanced innovation, widely used to incorporate standardized bioactive polyphenolic phytoconstituents into phospholipid molecular complexes. In order to extend their potential therapeutic efficiency also to other routes of administration, we proposed a novel phytosome carrier-mediated vesicular system (phyto-liposome) as DDS for the flavonolignan silybin (SIL), a natural compound with multiple biological activities related to its hepatoprotective, anticancer and antioxidant (radical scavenging) effects. We screened the optimum fraction of its phytosome, available in the market as SiliphosTM, into liposomes prepared by extrusion, such that vesicle sizes and charges, monitored through dynamic light scattering and laser doppler velocimetry, satisfied several quality requirements. Special emphasis was placed on the study of host-guest interaction by performing UV–vis absorption, spectrofluorimetry and NMR experiments both in aqueous and non-polar solvents to probe the effect of the presence of phospholipids on the electronic properties of SIL and its propensity to engage H bonding with the lipid headpolar groups. Finally, fluorescence microscopy observations confirmed the ability of phyto-liposomes to be internalized in human hepatoma cells, which was promising for their potential application in the treatment of acute or chronic liver diseases.

In this work unilamellar liposomes doped with a novel non-ionic 5-Uridine-head nucleolipid, Lauroyl Uridine (LU), were prepared and characterized for their ability to interact with the polynucleotide polyadenylic acid (poly-A). Vesicles, were made up of the cationic lipid DOTAP (1,2-Dioleoyl-3-Trimethylammonium-Propane), the zwitterionic lipid DOPE (1,2-Dioleoyl-sn-Glycero- 3-Phosphoethanolamine), and the novel amphiphile Lauroyl Uridine. The influence of the non-ionic nucleolipid on essential liposomes properties, such as the structure and net charge was first investigated by a comparative analysis performed on the different lipoplex preparations by means of -potential and size measurements. Both structure and net charge of liposomes were shown to be not modified by the presence of the non-ionic nucleolipid. The role of the synthetic lipid inserted as anchor in the liposome bilayer in the condensation process between vesicles and the polynucleotide poly-A was then analyzed by UV–vis, Circular Dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopies. The data presented comparative UV–vis analyses that evidenced the occurrence of staking interactions in the poly-A only in LU containing lipoplexes. CD and NMR studies indicated the presence of H-bonding interaction between Lauroyl Uridine containing vesicles and the polynucleotide poly-A. The results presented in this work support a role for Lauroyl Uridine in A-U molecular recognition, thus, suggesting that cationic liposomes doped with the non-ionic nucleolipid Lauroyl Uridine could represent a model system to study molecular interactions among single stranded polynucleotides and lipid anchor bearing the complementary bases.

Here we investigate the structural evolution of TX100 micelles upon loading with several linear and cyclic alkanes by DLS, PGSE-NMR, 2D NOESY NMR, viscosity measurements, and molecular dynamic simulations. Our results confirm that TX100 alone forms spherical, onion-like micelles made of several partially interpenetrating surfactant layers where the polyethylene glycol chains are in contact with the tetramethyl-butyl-phenyl moieties. Loading with non-penetrating oils larger than decane induces a decrease in micellar size and hydration because the alkane molecules compete with both water and tetramethyl-butyl-phenyl groups for the polyethylene glycol chains. This results in the partial peeling of the “onion” and in the dehydration of polyethylene glycol chains so that the micelles increase in number and decrease in size upon alkane loading. In contrast, small and penetrable oils (mainly cyclo-alkanes) first swell the onion-like micelles (inducing an increase in size) and only above a critical oil/surfactant ratio does the oil induce the weakening of the multilayer structure and the dehydration of polyethylene glycol chains found in long linear alkanes.

A new optical biosensor for trehalose determination has been realized immobilizing three glycoenzymeson a transparent support. Trehalase, glucose oxidase and horseradish peroxidase have been alternatedwith layers of Concanavalin A by a “layer-by-layer” (LbL) deposition. The driving force of this assembly isthe biospecific complexation between Concanavalin A and sugar residues in the glycoenzymes. As con-firmed by UV–vis spectroscopy, the LbL deposition allowed a high ordinate architecture with high loadingof enzymes. After the assembly, the functionality of immobilized enzymes was spectrophotometricallyproven, demonstrating also that they can act in series catalyzing cascade reactions.The prepared biosensor was used to optically detect trehalose, giving a LOD of 10 M and a linearresponse up to 4 mM, and it showed also good time stability. The trehalose content in a real sample(eyewash) was successfully determined by the biosensor.