| 1. |
- Angelico, Ruggero, et al.
(författare)
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Impact of branching on the viscoelasticity of wormlike reverse micelles
- 2012
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 8:42, s. 10941-10949
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Tidskriftsartikel (refereegranskat)abstract
- We present an investigation on the effect of inter-micellar connections (branches) on the rheology of wormlike micelles. The system chosen is made of lecithin, minute amounts of water and organic solvents. Lecithin and water self-assemble into wormlike reverse micelles that can be branched or unbranched depending on the oil composition (and on the water content). In this respect, cyclohexane favours disconnected reverse micelles while isooctane promotes the formation of branches. By using mixtures of cyclohexane and isooctane as the oil phase and different water/lecithin ratios, the branch density of the system can be finely tuned. PGSE-NMR experiments allowed us to distinguish between branch-free (unbranched) and branched systems and the response of the very same samples to mechanical stress was measured by rheology. This allows, for the first time, an experimental correlation between rheological properties and the presence of branches. It turned out that the presence of a few inter-micellar connections sensibly decreases the zero-shear viscosity measured in steady state flow curves. Comparison with oscillatory rheology experiments indicates that the main effect of branches is to shorten the terminal relaxation time by speeding-up the reptation.
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| 2. |
- Biffi, Stefania, et al.
(författare)
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Cubosomes for in vivo fluorescence lifetime imaging
- 2017
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 28:5
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Caltagirone, Claudia, et al.
(författare)
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Solvatochromic fluorescent BODIPY derivative as imaging agent in camptothecin loaded hexosomes for possible theranostic applications
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:30, s. 23443-23449
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Tidskriftsartikel (refereegranskat)abstract
- We here discuss the potential theranostic nanomedicine application of an innovative formulation consisting of monoolein-based nanoparticles with a two-dimensional hexagonal inner structure stabilized in water using a mixture of PEO132-PPO50-PEO132 block copolymers with and without conjugated folate for targeting. The proposed tumor-cell targeted formulation was shown to be able to simultaneously host the model anticancer drug camptothecin and a pyrene-modified BODIPY fluorophore, based on dynamic light scattering, small-angle X-ray scattering, and cryogenic transmission electron microscopy. The photophysical properties of the fluorophore were studied in solution in various solvents. A marked fluorescent solvatochromism, whose origin was explained by time-dependent density functional theory theoretical calculations, was observed. Fluorescence microscopy showed that HeLa cells readily internalize these nanoparticles, and that the fluorophore localizes within the lipid droplets. In addition, cytotoxicity test revealed that these nanoparticles are not toxic at the concentration used for the imaging analysis.
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| 4. |
- Lo Nostro, Pierandrea, et al.
(författare)
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Interconnected Networks : Structural and Dynamic Characterization of Aqueous Dispersions of Dioctanoylphosphatidylcholine
- 2008
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 112:40, s. 12625-12634
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous dispersions of the phospholipid dioctanoylphosphatidylcholine (diC8PC) phase-separate below a cloud-point temperature, depending on lipid concentration. The lower phase is viscous and rich in lipid. The structure and dynamics of this system were explored via cryo-transmission electron microscopy (cryo-TEM), small-angle X-ray scattering (SAXS), and NMR. The lower phase comprises a highly interconnected tridimensional network of wormlike micelles. A molecular mechanism for the phase separation is suggested.
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| 5. |
- Mele, Stefania, et al.
(författare)
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Phase behavior in the biologically important oleic acid/sodium oleate/water system
- 2018
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Ingår i: Chemistry and Physics of Lipids. - : Elsevier. - 0009-3084 .- 1873-2941. ; 211, s. 30-36
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Tidskriftsartikel (refereegranskat)abstract
- The phase behavior in the oleic acid/sodium oleate/normal saline (0.15M NaCl aqueous solution) system has been determined. For this purpose visual inspection of samples between crossed polarizers, and Small Angle X-ray diffraction was used to identify the various phases and their unit cell dimensions. A rich phase behavior was observed for the ternary system, featuring reverse micellar, micellar cubic, hexagonal, and cubic phases, and large regions with lamellar phases. As expected the ratio the 'oleic acid/sodium oleate' determines the pH and as a consequence the phase behavior. The results could be modeled by an extended Henderson-Hasselbalch (HH) equation, which takes into account the electrostatic potential at the aqueous lipid interface. The knowledge obtained is important for understanding the lipolysis of triglycerides, as the phase behavior of the end-product of the reaction regulates how well the insoluble product can be dispersed and consequently the kinetics of the process.
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| 6. |
- Meli, Valeria, et al.
(författare)
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Docetaxel-Loaded Fluorescent Liquid-Crystalline Nanoparticles for Cancer Theranostics.
- 2015
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 31:35, s. 9566-9575
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Meli, Valeri, et al.
(författare)
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Theranostic hexosomes for cancer treatments : an in vitro study
- 2017
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1144-0546 .- 1369-9261. ; 41:4, s. 1558-1565
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Tidskriftsartikel (refereegranskat)abstract
- We have formulated and investigated innovative lipid-based nanoparticles characterized by a reverse hexagonal liquid crystalline inner structure (hexosomes). These nanoparticles were doped with a potent, highly water insoluble anticancer drug, namely docetaxel, and stabilized by a mixture of commercial and folate- and rhodamine-conjugated Pluronic F108. Thus, they simultaneously possess therapeutic, imaging, and targeting properties toward cancer cells. The morphological and structural aspects of the hexosomes were investigated at different temperatures (10, 25, 37, and 50 °C), and our results demonstrate good performance in terms of stability of these nanoparticles. The latter was furthermore confirmed by the very slow and continuous release profile of docetaxel observed in drug release experiments. Although it was not possible to assess a specific compartmentalization of the dye, this formulation allowed the successful visualization of HeLa cells. Finally, cytotoxic assays showed a 20-fold higher toxic effect of the drug-doped hexosomes against HeLa cells with respect to the free (not loaded in hexosomes) anticancer drug. On the whole, these results indicate that this formulation is a potential theranostic tool in oncology.
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| 8. |
- Monduzzi, Maura, et al.
(författare)
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Effect of electrolytes on the sol–gel phase transitions in a Pluronic F127/carboxymethyl cellulose aqueous system : Phase map, rheology and NMR self-diffusion study
- 2022
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Ingår i: European Polymer Journal. - : Elsevier BV. - 0014-3057. ; 181
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Tidskriftsartikel (refereegranskat)abstract
- This investigation aims to obtain a thermosensitive platform useful for specific nanomedicine applications through the addition of suitable salts. An aqueous mixture consisting of the copolymer Pluronic F127 and sodium carboxymethyl-cellulose, in a ratio of 20/4 by weight, in the presence of different concentrations of Na2SO4, NaCl, and NaSCN, was investigated using the visual inversion tube approach to estimate a phase map, and then characterized through rheological measurements. The formation of a cubic liquid crystalline phase at temperatures higher than 37 °C was suggested in all systems. The complex viscosity, decreases in the presence of salts in the order Na2SO4 > NaCl > NaSCN with more marked effect for lower concentrations. Salt addition allows to tune the crowding effect of NaCMC. For the polymer mixture and for a sample containing NaCl, 1H NMR self-diffusion experiments display a non-mono-exponential decay of the echo signals of Pluronic F127, caused by the polydispersity of commercial Pluronic F127. The rheological properties along with the diffusion behaviour of the liquid crystal micelles suggest that a sample containing NaCl 0.07 mol/kg, with a sol-hard gel transition temperature around 35 °C, close to that of the body, may be a suitable and biocompatible thermosensitive platform to administer both hydrophobic and hydrophilic drugs such as antibiotics, anticancer drugs or growing factors. Synopsis: A simple thermoresponsive platform for drug delivery: Pluronic F127, NaCMC and NaCl.
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| 9. |
- Monduzzi, Maura, et al.
(författare)
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Lipid and surfactant self-assembly : Significance of NMR in developing our understanding
- 2019
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Ingår i: Current Opinion in Colloid and Interface Science. - : Elsevier BV. - 1359-0294. ; 44, s. 14-22
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Forskningsöversikt (refereegranskat)abstract
- This review, devoted to the memory of Kåre Larsson, deals with surfactant and lipid self-assembly. The focus is on the crucial role of NMR techniques in the understanding, at a molecular level, molecular dynamics and microstructure. The strength of NMR self-diffusion in determining size and shape of supramolecular aggregates as well as microstructural features, in terms of water-in-oil, oil-in-water and bicontinuity, is emphasized.
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| 10. |
- Murgia, Sergio, et al.
(författare)
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Cubosome formulations stabilized by a dansyl-conjugated block copolymer for possible nanomedicine applications.
- 2015
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Ingår i: Colloids and Surfaces B: Biointerfaces. - : Elsevier BV. - 1873-4367 .- 0927-7765. ; 129, s. 87-94
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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