86 results on '"Mangiapia G"'
Search Results
2. New tools for grazing incidence neutron scattering experiments open perspectives to study nano-scale tribology mechanisms
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Frielinghaus, H., Gvaramia, M., Mangiapia, G., Jaksch, S., Ganeva, M., Koutsioubas, A., Mattauch, S., Ohl, M., Monkenbusch, M., and Holderer, O.
- Published
- 2017
- Full Text
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3. A diffusion study on the ternary system, sodium cholate–sodium deoxycholate–water
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Vitagliano, V., Sartorio, R., Ortona, O., Paduano, L., D'Errico, G., Capuano, F., and Mangiapia, G.
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- 2010
- Full Text
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4. Tunable Hydrogels with Improved Viscoelastic Properties from Hybrid Polypeptides
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Skoulas, D. Mangiapia, G. Parisi, D. Kasimatis, M. Glynos, E. Stratikos, E. Vlassopoulos, D. Frielinghaus, H. Iatrou, H.
- Abstract
Hydrogels that can respond to a number of external stimuli and at the same time show impressive rheological properties are promising materials for a wide range of bioapplications. Here, we present a series of well-defined linear amphiphilic pentablock hybrid polypeptides of the ABCBA type, where A is poly(l-lysine), B is poly(l-histidine)-co-poly(γ-benzyl-l-glutamate), and C is poly(ethylene oxide) (PEO). The polymers were synthesized by the sequential primary amine ring-opening polymerization of N-carboxy anhydrides using bis amine poly(ethylene oxide) (PEO) as a bifunctional macroinitiator, and the length of all of the blocks was varied. The resulting materials formed novel extrudable in situ forming quickly self-healing hydrogels, responsive to the alteration of pH and increase of temperature. The connection between the alteration of the secondary structure of the polypeptides with the viscoelastic behavior was revealed by means of rheology and circular dichroism. Small-angle neutron scattering and scanning electron microscopy were employed to shed light on the structure of the polymers and how it affects their rheological properties. The obtained polymers were subjected to enzymatic degradation tests with trypsin and leucine aminopeptidase. The results suggest that these biomaterials have the potential to be used in a number of bioapplications like drug delivery, 3D printing, and tissue engineering. © 2021 American Chemical Society.
- Published
- 2021
5. Limiting Partial Molar Volume of Sodium Chloride in 2-Methyl-2,4-pentandiol-Water Mixed Solvents at 25 °C
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Capuano, F., Mangiapia, G., D’Errico, G., and Sartorio, R.
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- 2006
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6. Small-angle neutron scattering (SANS) characterization of 13.5 Cr oxide dispersion strengthened ferritic steel for fusion applications
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Coppola, R., primary, Klimenkov, M., additional, Lindau, R., additional, and Mangiapia, G., additional
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- 2020
- Full Text
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7. Using neutron methods SANS and PGAA to study evolution of structure and composition of alkali-doped polybenzimidazole membranes
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Babcock, E., Szekely, N., Konovalova, A., Lin, Y., Appavou, M.-S., Mangiapia, G., Revay, Z., Stieghorst, C., Holderer, O., Henkensmeier, D., Lehnert, Werner Karl Josef, and Carmo, M.
- Subjects
ddc:570 ,technology, industry, and agriculture - Abstract
Journal of membrane science 577, 12-19 (2019). doi:10.1016/j.memsci.2019.01.026, Published by Elsevier, New York, NY [u.a.]
- Published
- 2019
8. Using neutron methods SANS and PGAA to study evolution of structure and composition of alkali-doped polybenzimidazole membranes
- Author
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Babcock, E., Szekely, N., Konovalova, A., Lin, Y., Appavou, M.-S., Mangiapia, G., Revay, Z., Stieghorst, C., Holderer, O., Henkensmeier, D., Lehnert, W., and Carmo, M.
- Subjects
ddc - Published
- 2018
9. Hybrid vesicles from lipids and block copolymers: Phase behavior from the micro- to the nano-scale
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Magnani, C., primary, Montis, C., additional, Mangiapia, G., additional, Mingotaud, A.-F., additional, Mingotaud, C., additional, Roux, C., additional, Joseph, P., additional, Berti, D., additional, and Lonetti, B., additional
- Published
- 2018
- Full Text
- View/download PDF
10. Effect of benzocaine and propranolol on phospholipid-based bilayers
- Author
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Mangiapia, G., primary, Gvaramia, M., additional, Kuhrts, L., additional, Teixeira, J., additional, Koutsioubas, A., additional, Soltwedel, O., additional, and Frielinghaus, H., additional
- Published
- 2017
- Full Text
- View/download PDF
11. Structural Organization of Poly(vinyl alcohol) Hydrogels Obtained by Freezing and Thawing Techniques: A SANS Study
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Ricciardi, R., Mangiapia, G., Celso, F. Lo, Paduano, L., Triolo, R., Auriemma, F., Rosa, C. De, and Laupretre, F.
- Abstract
The structural organization of matter in poly(vinyl alcohol) (PVA) hydrogels obtained by repeatedly freezing and thawing dilute solutions of PVA in D
2 O is investigated by use of small-angle neutron scattering measurements (SANS). This study is the first systematic and quantitative investigation in the medium range of length scales on PVA hydrogels obtained by freezing and thawing techniques. The studied gels have a complex hierarchical structure, extending over a wide range of length scales. The structural organization on the micron length scale originates from the presence of two separated phases constituted by polymer-rich and polymer-poor regions. The network structure may be interpreted in terms of the connectivity of the regions occupied by the polymer-rich phase, which extend over the macroscopic dimensions of the sample. The organization on the medium length scale is provided by the presence of small crystallites, fringed micelle-like, within the polymer-rich phase. In these regions, the crystals are highly connected by swollen amorphous tie chains. The presence of these tie chains ensures the connectivity of the macroscopic network. The structural organization on the short length scale is essentially provided by the relative arrangement of chains within the crystallites and in the swollen amorphous zones. The PVA hydrogel structure has been modeled as a collection of polydisperse and homogeneous spherical crystallites, interacting via hard-spheres potential. SANS experiments permitted us to obtain values of the crystallite size of about 33 Å, of the volume fraction of polymer-rich phase of the order of 1% and a value of the average crystallite−crystallite correlation distances of the order of a few tens of nanometers, independent of the imposed number of freeze/thaw cycles (n), for n > 1. The present analysis also indicates that the structure of the gel obtained imposing a single freeze/thaw cycle is somehow intermediate between the structure of the homogeneous starting solution and the structure of the already well-formed sample obtained by imposing two consecutive cycles.- Published
- 2005
12. Diffusion Coefficient Matrix in Nonionic Polymer−Solvent Mixtures
- Author
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Vergara, A., Paduano, L., Mangiapia, G., and Sartorio, R.
- Abstract
Recent predictive equations for evaluating the value of diffusion coefficients, developed for two hard sphere−solvent systems, have been extended to n-hard-sphere−solvent systems. This model has been used to predict the diffusion behavior of nonionic polymer−solvent mixtures as a first-order function of volume fraction from the knowledge of the distribution function. Hence, the entire diffusion matrix for polydisperse systems, which include both main- and cross-term diffusion coefficients, has been built up for the first time. The main-terms diffusion coefficients D
ii are mostly affected by the variation in viscosity. The magnitude of the cross-term diffusion coefficients D ij is strictly related to the abundance and diffusivity of solute i and to the molecular volume corresponding to solute j. The predicted diffusion coefficients have been used to calculate the apparent, average diffusion coefficients, which are compared with the experimental values measured by the Gouy interferometry method in the case of the poly(ethylene glycol) homologous series. The agreement between the calculated and experimental Gouy parameters is good. The cross-term diffusion coefficients are found to be significant in the calculation of the apparent diffusion coefficient for a polydisperse solute. Some comments on the study of ternary systems containing a polydisperse solute are done. - Published
- 2001
13. Small-angle neutron scattering (SANS) characterization of 13.5 Cr oxide dispersion strengthened ferritic steel for fusion applications
- Author
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Coppola, R., Klimenkov, M., Lindau, R., and Mangiapia, G.
- Subjects
Small-angle neutron scattering ,Electron microscopy ,ODS steels ,7. Clean energy ,Ferritic/martensitic steels - Abstract
Small-angle neutron scattering (SANS) has been utilized for micro-structural investigation on laboratory heats of oxide dispersion strengthened (ODS) 13.5 Cr wt % ferritic steel, with 0.3 wt% Y$_{2}$O$_{3}$ and with variable Ti and W contents. The results show that increasing the Ti content from 0.2 to 0.4 wt% a distribution of nano-clusters develops, tentatively identified as Y$_{2}$Ti$_{2}$O$_{7}$, with average radii as small as 6.5 Å and volume fractions increasing from 0.021 to 0.032. The measured SANS cross-sections show also the growth of much larger defects, possibly Cr oxides. Furthermore, the ratio of magnetic to nuclear SANS components shows that the defect composition varies both with their size and with the Ti and the W content. These results are in qualitative agreement with transmission electron microscopy (TEM) observations, showing a striking influence of Ti addition on particle size refinement. However, while TEM is limited in statistics and minimum observable size of the Ti-rich nano-clusters, the defect distributions obtained by these SANS measurements provide complementary information useful for morphological characterization of the micro-structure in the investigated material.
14. A NOVEL APPROACH FOR DETERMINING DIFFUSION COEFFICIENTS OF TERNARY SYSTEMS
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Alessandro Vergara, Mangiapia, G., Paduano, Luigi, Sartorio, Roberto, Vergara, Alessandro, G., Mangiapia, Paduano, Luigi, and Sartorio, Roberto
15. The Arctic Fish Haemoglobins
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Riccio, A., Alessandro Vergara, Paduano, Luigi, Giordano, D., Mangiapia, G., Mazzarella, Lelio, Di Prisco, G., Verde, C., A., Riccio, Vergara, Alessandro, Paduano, Luigi, D., Giordano, G., Mangiapia, Mazzarella, Lelio, G., di Prisco, and C., Verde
- Abstract
The urgency to investigate evolutionary adaptations at high latitudes is increasing considerably, especially in the Arctic. Similar to Antarctic notothenioids, Arctic fish endemic to high latitudes have adapted to thermally stable waters and therefore their physiological systems are finely tuned to the narrow temperature range they are experienced to. Given the short evolutionary time at polar temperatures, Arctic fish may provide valuable information on the effects of environmental temperature on specific physiological and biochemical traits (1, 2). Fish hemoglobins have been extensively studied, not only for their structural and functional properties, but also because they offer the possibility to investigate functional differentiation and molecular adaptations in species living in a large variety of environmental conditions. In addition, Arctic fish hemoglobins appear to be good models for studying sickling disorders and hemoglobin-polymerisation processes. In this study we report the structural and functional characterisation of the single hemoglobin of Lycodes reticulatus (family Zoarcidae) living on the sea floor near the coasts of northern Europe and North America. The hemoglobin shows a low Bohr effect and no Root effect;it tends to form high-molecular mass polymers at physiological pH and low temperature (5°C), as shown by gel-filtration chromatography and dynamic light scattering. The elucidation of the primary structure has allowed to establish correlation between functional behaviour (no Root effect) and structural properties (polymerisation). The large number of cysteyl residues in the α and β subunits, typical of hemoglobins of many Arctic species, e.g. several gadids, brings about the capability to produce polymers. Also the hemoglobins of Arctogadus glacialis, Boreogadus saida and Gadus morhua (2), similar to L. reticulatus hemoglobin, contain additional His and Cys residues in their primary structure which potentially account for polymerisation (3). References 1 Verde, C., Carratore, V., Riccio, A., Tamburrini, M., Parisi, E., di Prisco, G. (2002). The functionally distinct hemoglobins of the Arctic spotted wolffish Anarhichas minor. J. Biol. Chem. 277(39):36312-20. 2 Verde, C., Balestrieri, M., de Pascale, D., Pagnozzi, D., Lecointre, G., di Prisco, G. (2006). The oxygen-transport system in three species of the boreal fish family Gadidae. Molecular phylogeny of hemoglobin. J. Biol. Chem. 281(31):22073-84. 3 Koldkjær, P., Berenbrink, M. (2007). In vivo red blood cell sickling and mechanism of recovery in whiting, Merlangius merlangus. J. Exp. Biol. 210:3451-60.
16. RUTHENIUM-BASED ANTICANCER ACTIVITY: A RAMAN-ASSISTED X-RAY CRYSTALLOGRAPHY APPROACH
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Alessandro Vergara, Russo Krauss, Irene, D Errico, Gerardino, Mangiapia, G., Montesarchio, Daniela, Paduano, Luigi, Antonello Merlino, Vergara, Alessandro, RUSSO KRAUSS, Irene, D'Errico, Gerardino, G., Mangiapia, Montesarchio, Daniela, Paduano, Luigi, and Merlino, Antonello
- Subjects
RUTHENIUM-BASED CHEMOTHERAPEUTICS ,Raman spectroscopy ,X-ray crystallography - Abstract
Raman microspectroscopy proved to be a valuable support to protein crystallography in all the steps of 3D structure determination. Authors have been using this approach to study changes in chemical composition [1, 2, 3], in secondary [3,4] and tertiary structure [5], and to follow chemical mechanisms [3, 6, 7]. The binding properties of AziRu (Fig. 1), a Ru(III) complex with high antiproliferative activity, toward hen egg white lysozyme [7], RNase A and human serum albumin have been investigated by X-ray crystallography and Raman microspectroscopy. The data provide clues on the mechanism of AziRu-protein adduct formation and clear evidences of ligand exchange in the crystal state (Figs. 2). The combined use of Raman and X-ray crystallography has provided complementary information that a single technique alone would not produce. For instance, in the case of hen egg white lysozyme [7], Raman spectra show not only the ligand exchange that is apparent in the X-ray structures but also the presence of Ru−O−Ru bonds (Fig. 3), which are not revealed by crystallography. References [1] Vergara, et al., Acta Cryst. Sect D: Biol Crystallogr. 64, 167-171 (2008). [2] Caterino et al., A. Vergara , J. Sol. Chem., in press. [3] Merlino, et al. Vergara, A., Acta Cryst. Sect D: Biol Crystallogr , 69, 137-40 (2013). [4] Merlino, et al. A. Vergara, Biophys. Chem. 137, 24-27 (2008). [5] Vergara, et al., J. Biol. Chem. 285, 32568-32575 (2010) . [6] Vitagliano, L., Vergara, et al.., J Am Chem Soc. 130, 10527-10535 (2008). [7] Vergara, et al, Inorg Chem 52, 4157-9 (2013).
17. Small-angle neutron scattering (SANS) characterization of 13.5 Cr oxide dispersion strengthened ferritic steel for fusion applications
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Michael Klimenkov, G. Mangiapia, R. Coppola, Rainer Lindau, Coppola, R., Klimenkov, M., Lindau, R., and Mangiapia, G.
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Nuclear and High Energy Physics ,Materials science ,Materials Science (miscellaneous) ,Analytical chemistry ,Oxide ,Neutron scattering ,7. Clean energy ,01 natural sciences ,010305 fluids & plasmas ,chemistry.chemical_compound ,0103 physical sciences ,Electron microscopy ,Engineering & allied operations ,Ferritic/martensitic steels ,010302 applied physics ,Fusion ,lcsh:TK9001-9401 ,Small-angle neutron scattering ,Characterization (materials science) ,Nuclear Energy and Engineering ,chemistry ,Transmission electron microscopy ,lcsh:Nuclear engineering. Atomic power ,ODS steels ,Particle size ,ddc:620 ,Dispersion (chemistry) - Abstract
Small-angle neutron scattering (SANS) has been utilized for micro-structural investigation on laboratory heats of oxide dispersion strengthened (ODS) 13.5 Cr wt % ferritic steel, with 0.3 wt% Y$_{2}$O$_{3}$ and with variable Ti and W contents. The results show that increasing the Ti content from 0.2 to 0.4 wt% a distribution of nano-clusters develops, tentatively identified as Y$_{2}$Ti$_{2}$O$_{7}$, with average radii as small as 6.5 Å and volume fractions increasing from 0.021 to 0.032. The measured SANS cross-sections show also the growth of much larger defects, possibly Cr oxides. Furthermore, the ratio of magnetic to nuclear SANS components shows that the defect composition varies both with their size and with the Ti and the W content. These results are in qualitative agreement with transmission electron microscopy (TEM) observations, showing a striking influence of Ti addition on particle size refinement. However, while TEM is limited in statistics and minimum observable size of the Ti-rich nano-clusters, the defect distributions obtained by these SANS measurements provide complementary information useful for morphological characterization of the micro-structure in the investigated material.
- Published
- 2020
- Full Text
- View/download PDF
18. Structural and molecular response in cyclodextrin-based pH-sensitive hydrogels by the joint use of Brillouin, UV Raman and Small Angle Neutron Scattering techniques
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Lucia Comez, Aurel Radulescu, Alessandro Paciaroni, Gaetano Mangiapia, Lucio Melone, Andrea Mele, Carlo Punta, Barbara Rossi, Marco Paolantoni, Alessandro Gessini, Andrea Fiorati, Claudio Masciovecchio, Silvia Corezzi, Cettina Bottari, Rossi, B., Bottari, C., Comez, L., Corezzi, S., Paolantoni, M., Gessini, A., Masciovecchio, C., Mele, A., Punta, C., Melone, L., Fiorati, A., Radulescu, A., Mangiapia, G., and Paciaroni, A.
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Materials science ,Hydrogels Cyclodextrin UV Raman Brillouin spectroscopy Small Angle Neutron Scattering ,Small Angle Neutron Scattering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Light scattering ,Hydrogels ,Cyclodextrin ,UV Raman ,Brillouin spectroscopy ,symbols.namesake ,Materials Chemistry ,Hydrogels, Cyclodextrin, UV Raman, Brillouin spectroscopy, Small Angle Neutron Scattering ,Physical and Theoretical Chemistry ,Nanoscopic scale ,Spectroscopy ,chemistry.chemical_classification ,Brillouin Spectroscopy ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Small-angle neutron scattering ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Brillouin zone ,Hydrogel ,chemistry ,Chemical physics ,Self-healing hydrogels ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
The response to pH variation of polymeric cyclodextrin-based hydrogels has been investigated by a multi-technique approach based on UV Raman and Brillouin light scattering (BLS) together with Small Angle Neutron Scattering (SANS). By exploiting the complementary information of these three investigation methods, the structural, viscoelastic and molecular modifications of the polymer brought about by the pH changes have been examined, over a spatial range going from mesoscopic to nanoscopic length-scale. The data provide a picture where an increase of pH promotes the change of the characteristic size of the hydrophilic pores when the cross-linker has the suitable structural and acid-base properties, and leads to the reinforcement of the polymer domains interconnections, providing a stiffer gel network on the length-scale probed by BLS. Raman signals are sensitive both to structural changes of the polymer network and to changes of the intermolecular ordering of water due to solvent-polymer interactions. The destructuring effect on the tetrahedral ice-like configurations of water is especially evident at high pH, and might be ascribed to an increased exposition to the solvent of the ionic portions of the polymer surface.
- Published
- 2018
19. Eumelanin Buildup at the Nanoscale: Aggregate Growth/Assembly and Visible Absorption Development in Biomimetic 5,6-Dihydroxyindole Polymerization
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Luigi Paduano, Marco d'Ischia, Aurel Radulescu, Marianna Arzillo, Gaetano Mangiapia, Alessandro Pezzella, Richard K. Heenan, Arzillo, M., Mangiapia, G., Pezzella, A., Heenan, R. k., Radulescu, A., Paduano, L., D'Ischia, M., Arzillo, Marianna, Mangiapia, Gaetano, Pezzella, Alessandro, Paduano, Luigi, and D'Ischia, Marco
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Indoles ,Light ,Polymers and Plastics ,Aggregate growth ,Bioengineering ,Nanotechnology ,small angle neutron scattering ,Polymerization ,Biomaterials ,eumelanin ,Biopolymers ,Biomimetics ,Scattering, Small Angle ,Materials Chemistry ,Scattering, Radiation ,Particle Size ,Absorption (electromagnetic radiation) ,Nanoscopic scale ,Melanins ,Chemistry ,aggregation ,dynamic light scattering ,Neutron Diffraction ,Models, Chemical ,indole ,Polyvinyl Alcohol ,Nanoparticles ,Self-assembly ,Oxidation-Reduction ,Algorithms - Abstract
Establishing structure-property relationships in the black insoluble eumelanins, the key determinants of human pigmentation and skin photoprotective system, is a considerable conceptual and experimental challenge in the current drive for elucidation of the biological roles of these biopolymers and their application as advanced materials for organoelectronics. Herein, we report a new breakthrough toward this goal by the first detailed investigation on the nanoscale level of the oxidative polymerization of 5,6-dihydroxyindole (DHI), a model process of eumelanin synthesis. On the basis of a combined use of spectrophotometry, dynamic light scattering (DLS), and small-angle neutron scattering (SANS) investigations, it was possible to unveil the dynamics of the aggregation process before precipitation, the key relationships with visible light absorption and the shape of fundamental aggregates. The results indicated a polymerization mechanism of the type: Polymer(n) + DHI(x) = Polymer(n+x), where DHI(x) indicates monomer, dimer, or low oligomers (x ≤ 5). During polymerization, visible absorption increases rapidly, reaching a plateau. Particle growth proceeds slowly, with formation of 2-D structures ~55 nm thick, until precipitation occurs, that is, when large aggregates with a maximum hydrodynamic radius (R(h)) of ~1200 nm are formed. Notably, markedly smaller R(h) values, up to ~110 nm, were determined in the presence of poly(vinyl alcohol) (PVA) that was shown to be an efficient aggregation-preventing agent for polymerizing DHI ensuring water solubilization. Finally, it is shown that DHI monomer can be efficiently and partially irreversibly depleted from aqueous solutions by the addition of eumelanin suspensions. This behavior is suggested to reflect oxidant-independent competing pathways of polymer synthesis and buildup via monomer conversion on the active aggregate surface contributing to particle growth. Besides filling crucial gaps in DHI polymerization, these results support the attractive hypothesis that eumelanins may behave as a peculiar example of living biopolymers. The potential of PVA as a powerful tool for solution chemistry-based investigations of eumelanin supramolecular organization and for technological manipulation purposes is underscored.
- Published
- 2012
20. Temperature and concentration effects on supramolecular aggregation and phase behavior for poly(propylene oxide)–b-poly(ethylene oxide) –b-poly(propylene oxide) copolymers of different concentration in aqueous mixtures, 2
- Author
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Gerardino D’Errico, Luigi Paduano, Ornella Ortona, Gaetano Mangiapia, Luigi Coppola, Fabrizio Lo Celso, D'Errico, G, Paduano, L, Ortona, O, Mangiapia, G, Coppola, L, Lo Celso, F, D'Errico, Gerardino, Paduano, Luigi, Ortona, ORNELLA GIUSTINA, Mangiapia, Gaetano, L., Coppola, and F., Lo Celso
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Macromolecular Substances ,Surface Properties ,Temperature ,Water ,nanoaggregate ,Reverse Pluronic, Lyotropic Phases, Micellar Aggregates, Defects, Packed Vescicles ,phase diagram ,Polyethylene Glycols ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Colloid and Surface Chemistry ,co-block polymer ,Propylene Glycols ,Settore CHIM/02 - Chimica Fisica - Abstract
The micro- and mesoscopic structure of reverse Pluronic 25R4 in aqueous mixtures has been studied by SANS, SAXS and shear rheology. These techniques have been able to give a deep insight into the complex structure of the system phase diagram, that includes an isotropic water-rich liquid phase L(1), and liquid crystalline phases with hexagonal, E, or lamellar order, D. Particular attention has been paid to the isotropic water-rich phase L(1), which has a large stability region in the temperature-composition phase diagram. This region is crossed by a large "cloudy zone". Below it, namely at low temperature and composition, SANS data show the presence of polymer unimers in a gaussian coil conformation. Above the "cloudy zone", at higher temperature and composition, the L(1) phase is structured as a network of interconnected multimeric micelles. Rheology adds information about the structuring of the L(1) phase showing its incipient hexagonal pre-structuring. This technique is also able to highlight the defective structure of the E phase itself. In the temperature and concentration ranges in which a lamellar phase D is present, SANS and SAXS results are in complete agreement, showing how interlamellar distance is influenced by both polymer composition and temperature according to an "ideal deswelling" or a "not ideal swelling" mechanism. In addition, in the D phase rheology suggests the presence of densely packed vesicles.
- Published
- 2011
21. Peptide modified nanocarriers for selective targeting of bombesin receptors
- Author
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Aurel Radulescu, Rosalba Mansi, Luigi Aloj, Diego Tesauro, Luigi Paduano, Claudio Arra, Antonella Accardo, Anna Morisco, Gaetano Mangiapia, Giancarlo Morelli, Michela Aurilio, Accardo, A., Mansi, R., Morisco, A., Mangiapia, G., Paduano, Luigi, Tesauro, D., Radulescu, A., Aurilio, M., Aloj, L., Arra, C., and Morelli, Giancarlo
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chemistry.chemical_classification ,Liposome ,Hydrodynamic radius ,Molecular Structure ,Stereochemistry ,Bombesin ,Peptide ,Models, Theoretical ,Receptors, Bombesin ,chemistry.chemical_compound ,Heterocyclic Compounds, 1-Ring ,Monomer ,chemistry ,Cell Line, Tumor ,Amphiphile ,Liposomes ,Moiety ,DOTA ,Humans ,Peptides ,Molecular Biology ,Peptide nanocarriers, Bombesin receptors, SANS and DLS techniques ,Biotechnology ,Chelating Agents - Abstract
The present work describes new supramolecular aggregates obtained by co-assembling two different amphiphilic molecules, one containing the bioactive bombesin peptide (BN), or a scramble sequence, and the other, the DOTA chelating agent, (C18)(2)DOTA, capable of forming stable complexes with the radioactive (111)In(III) isotope. The peptide in the amphiphilic monomer is spaced by the lipophilic moiety through ethoxylic spacers of different length: a shorter spacer with five units of dioxoethylene moieties in (C18)(2)L5-peptide, or a longer spacer consisting of a Peg3000 residue in (C18)(2)Peg3000-peptide. Structural characterization by SANS and DLS techniques indicates that, independently from the presence of the peptide containing monomer in the final composition, the predominant aggregates are liposomes of similar shape and size with a hydrodynamic radius R(h) around 200 nm and bilayer thickness, d, of 4 nm. In vitro data show specific binding of the (111)In-(C18)(2)DOTA/(C18)(2)L5-[7-14]BN 90:10 liposomes in receptor expressing cells. However, the presence of the Peg3000 unit on the external liposomal surface, could hide the peptide and prevent the receptor binding. In vivo experiments using (111)In-(C18)(2)DOTA/(C18)(2)L5-[7-14]BN show the expected biological behavior of aggregates of such size and molecular composition, moreover there is an increase in concentration of the GRPR targeting aggregate in the tumors compared to control at the 48 h time point evaluated (2.4% ID/g versus 1.6% ID/g).
- Published
- 2010
22. Design, Synthesis and Characterisation of a Fluorescently Labelled CyPLOS Ionophore
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Daniela Montesarchio, Gaetano Mangiapia, Mariangela Boccalon, Sabina Licen, Luigi Paduano, Cinzia Coppola, Paolo Tecilla, Antonio Paciello, Lorenzo De Napoli, Coppola, C., Paciello, A., Mangiapia, G., Licen, Sabina, Boccalon, Mariangela, De Napoli, L., Paduano, L., Tecilla, Paolo, Montesarchio, D., Coppola, Cinzia, Paciello, A, Mangiapia, Gaetano, Licen, S, Boccalon, M, DE NAPOLI, Lorenzo, Paduano, Luigi, Tecilla, P, and Montesarchio, Daniela
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Macrocyclic Compounds ,Magnetic Resonance Spectroscopy ,Carboxylic acid ,synthetic ionophore ,Ionophore ,Oligosaccharides ,Catalysis ,ion transport ,Dynamic light scattering ,fluorescent probes ,Amphiphile ,Polymer chemistry ,Organic chemistry ,macrocyclic compound ,Fluorescent Dyes ,chemistry.chemical_classification ,chemical synthesi ,Ion Transport ,Ionophores ,Molecular Structure ,amphiphilic oligosaccharide ,Chemistry ,Vesicle ,Organic Chemistry ,Water ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,self-assembly ,Fluorescence ,Membrane ,fluorescent probe ,glycomimetic ,amphiphilic oligosaccharides ,macrocycle ,macrocyclic compounds - Abstract
A novel fluorescently labelled synthetic ionophore, based on a cyclic phosphate-linked disaccharide (CyPLOS) backbone and decorated with four tetraethylene glycol tails carrying dansyl units, has been synthesised in 12 steps in 26% overall yield. The key intermediate in the synthetic strategy is a novel glucoside building block, serving through its 2- and 3-hydroxy groups as the anchor point for flexible tetraethylene glycol tentacles with reactive azido moieties at their ends. To test the versatility of this glucoside scaffold, it was preliminarily functionalised with a set of diverse probes--as fluorescent, redox-active or hydrophobic tags--either by reduction of the azides followed by condensation with activated carboxylic acid derivatives, or by a direct coupling with a terminal alkyne in a Cu(I)-promoted 1,3-dipolar cycloaddition. Tagging of the monomeric building block with dansyl residues allowed us to prepare a fluorescent, amphiphilic macrocycle, which was investigated for its propensity to self-aggregate in CDCl(3)--studied by means of concentration-dependent (31)P NMR spectroscopy experiments--and in aqueous solution, in which combined dynamic light scattering (DLS) and small-angle neutron scattering (SANS) measurements provided a detailed physico-chemical analysis of the self-assembled systems, mainly organised in the form of large vesicles. Its ion-transport properties through phospholipid bilayers, determined by HPTS fluorescence assays, showed this compound to be more active than the previously synthesised CyPLOS congeners. Solvent-dependent fluorescence changes for the labelled ionophore in liposome suspension established that the dansyl moieties are dispersed in environments with polarity intermediate between those of CH(2)Cl(2) and propan-2-ol, suggesting that the CyPLOS tentacles infiltrate the mid-polar region of the membranes.
- Published
- 2010
23. Micelles Obtained by Aggregation of Gemini Surfactants Containing the CCK8 Peptide and a Gadolinium Complex
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Diego Tesauro, Gaetano Mangiapia, Eliana Gianolio, Richard K. Heenan, Anna Morisco, Giancarlo Morelli, Antonella Accardo, Mauro Vaccaro, Luigi Paduano, Accardo, A., Tesauro, D., Morisco, A., Mangiapia, G., Vaccaro, M., Gianolio, E., Heenan, R. K., Paduano, Luigi, and Morelli, Giancarlo
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Circular dichroism ,Molecular Structure ,Chemistry ,Protein Conformation ,Gadolinium ,Supramolecular chemistry ,Analytical chemistry ,chemistry.chemical_element ,Biochemistry ,Micelle ,Fluorescence spectroscopy ,Peptide Fragments ,Inorganic Chemistry ,Crystallography ,Surface-Active Agents ,Peptide gemini surfactant Amphiphilic gadolinium complexes CCK8 peptide Micelles Small-angle neutron scattering (SANS) ,Critical micelle concentration ,Amphiphile ,Microemulsion ,Cholecystokinin ,Nuclear Magnetic Resonance, Biomolecular ,Micelles - Abstract
Two gemini surfactants, [C18CysL5CCK8](2) and [C18CysDTPAGlu](2), containing, respectively, the CCK8 peptide and the DTPAGlu chelating agent or its gadolinium complex have been prepared by linking lipophilic chains through a disulfide bond between two cysteine residues. The two surfactants aggregate in water solution forming pure or mixed micelles, with a critical micellar concentration in the 5 x 10(-6)-5 x 10(-5) mol kg(-1) range, as measured by fluorescence spectroscopy. As indicated by small-angle neutron scattering, the shape and size of the micelles are influenced by the temperature: increasing temperature leads to progressive reduction of the size of the supramolecular aggregates. Cylindrical structures found at lower temperatures (10-40 degrees C) evolve into ellipsoidal micelles at 50-80 degrees C. Furthermore, the surface-exposed CCK8 peptide changes its conformation above a transition temperature of approximately 45 degrees C, going from a beta-sheet to a random-coil structure, as indicated by circular dichroism measurements. The mixed aggregate obtained by coaggregation of the two gemini-based amphiphilic compounds, [C18CysDTPAGlu(Gd)](2) and [C18CysL5CCK8](2) in 70:30 molar ratio, represents the first example of a peptide-containing gemini surfactant as a potential target-selective contrast agent in MRI. In fact, it presents a high relaxivity value of the gadolinium complex, 21.5 mM(-1) s(-1), and the CCK8 bioactive peptide exposed on the external surface is therefore capable of selective targeting of the cholecystokinin receptors.
- Published
- 2009
24. Oxidative polymerization of 5,6-dihydroxyindole in polyvinylalcohol/phosphate buffer: toward innovative bioinspired functional materials with tailored melaninmimicking structure
- Author
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Arzillo m., NAPOLITANO, ALESSANDRA, AMBROGI, VERONICA, Persico P., CARFAGNA, COSIMO, PEZZELLA, ALESSANDRO, D'ISCHIA, MARCO, PADUANO, LUIGI, MANGIAPIA, GAETANO, MOLISSO, ALESSANDRO, Arzillo, M., Pezzella, A, Napolitano, A., D'Ischia, M., Ambrogi, V., Persico, P., Carfagna, C., Paduano, L., Mangiapia, G., Molisso, A., Pezzella, Alessandro, Napolitano, Alessandra, D'Ischia, Marco, Ambrogi, Veronica, Carfagna, Cosimo, Paduano, Luigi, Mangiapia, Gaetano, and Molisso, Alessandro
- Published
- 2009
25. Peptide Containing Aggregates as Selective Nanocarriers for Therapeutics
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Diego Tesauro, Carlo Pedone, Gaetano Mangiapia, Giancarlo Morelli, Laura Tarallo, Luigi Aloj, Claudio Arra, Luigi Paduano, Antonella Accardo, Mauro Vaccaro, Accardo, Antonella, Tesauro, Diego, Aloj, L., Tarallo, L., Arra, C., Mangiapia, G., Vaccaro, M., Pedone, Carlo, Paduano, Luigi, and Morelli, Giancarlo
- Subjects
Stereochemistry ,Peptide ,small angle neutron scattering ,Biochemistry ,Micelle ,chemistry.chemical_compound ,Mice ,Dynamic light scattering ,Drug Discovery ,Amphiphile ,supramolecular aggregates ,Animals ,Scattering, Radiation ,Tissue Distribution ,General Pharmacology, Toxicology and Pharmaceutics ,Micelles ,Pharmacology ,chemistry.chemical_classification ,Drug Carriers ,Vesicle ,Organic Chemistry ,Cryoelectron Microscopy ,Indium Radioisotopes ,CCK8 peptide ,dynamic light scattering ,supramolecular aggrtegates ,Peptide Fragments ,Nanostructures ,chemistry ,Drug delivery ,drug delivery ,Biophysics ,Molecular Medicine ,Female ,Nanocarriers ,Cholecystokinin ,Ethylene glycol - Abstract
New nanocarriers are obtained by assembling two amphiphilic monomers: one containing the bioactive peptide CCK8 spaced, by a polydisperse poly(ethylene glycol), from two hydrophobic tails ((C18)2PEG2000CCK8), and the other containing a chelating agent able to give stable radiolabeled indium-111 complexes linked to the same hydrophobic moiety ((C18)2DTPAGlu). The size and shape of the supramolecular aggregates were structurally characterized by dynamic light scattering, small-angle neutron scattering, and cryogenic transmission electronic microscopy. Under the experimental conditions we investigated (pH 7.4 and molar ratio between monomers 30:70), there is the presence of high polydisperse aggregates: rod-like micelles with a radius of approximately 40 A and length >700 A, open bilayer fragments with thickness approximately 65 A, and probably vesicles. The presence of the bioactive peptide well exposed on the external surface of the aggregate allows selective targeting of nanocarriers towards the cholecystokinin receptors overexpressed by the cancerous cells. In vitro binding assays and in vivo biodistribution studies by nuclear medicine experiments using indium-111 are reported. Moreover, preliminary data concerning the drug loading capability of the aggregates and their drug efficiency on the target cells is reported by using the cytotoxic drug doxorubicin. Incubation of receptor-positive and control cells with peptide-containing aggregates filled with doxorubicin shows significantly lower cell survival in receptor-expressing cells relative to the control, for samples incubated in the presence of doxorubicin.
- Published
- 2008
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26. Mesoscopic and Microscopic Investigation on Poly(vinyl alcohol) Hydrogels in the Presence of Sodium Decylsulfate
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Claudio De Rosa, Gerardino D'Errico, Luigi Paduano, Fabrizio Lo Celso, Finizia Auriemma, Gaetano Mangiapia, Anna Maria Tedeschi, Aurel Radulescu, Roberto Triolo, Richard K. Heenan, Rosa Ricciardi, Mangiapia, Gaetano, R., Ricciardi, Auriemma, Finizia, DE ROSA, Claudio, F., Lo Celso, R., Triolo, R. K., Heenan, A., Radulescu, A. M., Tedeschi, D'Errico, Gerardino, Paduano, Luigi, MANGIAPIA G, RICCIARDI R, AURIEMMA F, DE ROSA C, LO CELSO F, TRIOLO R, HEENAN R K, RADULESCU A, TEDESCHI A M, DERRICO G, and PADUANO L
- Subjects
Vinyl alcohol ,Materials science ,Biophysics ,ANGLE NEUTRON-SCATTERING ,Micelle ,Polyvinyl alcohol ,ELECTRON-PARAMAGNETIC-RESONANCE ,Surface-Active Agents ,chemistry.chemical_compound ,Drug Delivery Systems ,Pulmonary surfactant ,Tensile Strength ,Phase (matter) ,Materials Testing ,Polymer chemistry ,Materials Chemistry ,Scattering, Radiation ,Physical and Theoretical Chemistry ,Polymer ,ULTRA-SMALL-ANGLE ,Neutrons ,chemistry.chemical_classification ,DRUG-DELIVERY SYSTEMS ,Models, Statistical ,Aqueous solution ,integumentary system ,Chemistry, Physical ,SANS ,Electron Spin Resonance Spectroscopy ,Hydrogels ,Surfaces, Coatings and Films ,Hydrogel ,chemistry ,Polyvinyl Alcohol ,Self-healing hydrogels ,Stress, Mechanical ,EPR ,Sulfonic Acids - Abstract
The structure of poly(vinyl alcohol) (PVA) hydrogels formed as a result of freeze/thaw treatments of aqueous solutions of the polymer (11 wt % PVA) in the freshly prepared state is analyzed through the combined use of small (SANS) and ultrasmall (USANS) angle neutron scattering techniques. The structure of these hydrogels may be described in terms of polymer rich regions, with dimensions of the order of 1-2 microm, dispersed in a water rich phase, forming two bicontinuous phases. The PVA chains in the polymer rich phase form a network where the cross-linking points are mainly crystalline aggregates of PVA having average dimensions of approximately 45 A. The structural organization of freeze/thaw PVA hydrogel membranes does not change either after rehydration of dried gels or in the presence of a tensile force. Finally, addition of surfactant micelles inside the gel provides a formulation with both hydrophobic and hydrophilic regions, which demonstrates the potential of the system for drug delivery. Both SANS and EPR measurements show that sodium decylsulfate (C10OS) micelles do not significantly interact with the PVA gel. Variation of the gel structure by the number of freeze/thaw cycles should modulate the rate of release of an active constituent, for example, in a dermal patch.
- Published
- 2007
27. Nanostructures by self-assembling peptide amphiphile as potential selective drug carriers
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Diego Tesauro, Antonella Accardo, Giancarlo Morelli, Carlo Pedone, Gaetano Mangiapia, Accardo, Antonella, Tesauro, Diego, Mangiapia, G., Pedone, Carlo, and Morelli, Giancarlo
- Subjects
Circular dichroism ,Biophysics ,Nanotechnology ,Peptide ,Antineoplastic Agents ,Microscopy, Atomic Force ,Biochemistry ,Sincalide ,peptide amphiphile ,Biomaterials ,Surface-Active Agents ,Amphiphile ,Scattering, Small Angle ,Peptide amphiphile ,CD circular dichroism ,chemistry.chemical_classification ,Drug Carriers ,SANS ,Chemistry ,Circular Dichroism ,Organic Chemistry ,General Medicine ,Combinatorial chemistry ,Small-angle neutron scattering ,Nanostructures ,Neutron Diffraction ,Spectrometry, Fluorescence ,Doxorubicin ,drug delivery ,Drug delivery ,Drug carrier ,Self-assembling peptide - Abstract
The self-assembling behavior, at physiological pH, of the amphiphile peptide (C18)2L5CCK8 in nanostructures is reported. Stable aggregates presenting a critical micellar concentration of 2 × 10−6 mol kg−1, and characterized by water exposed CCK8 peptide in β-sheet conformation, are obtained. Small angle neutron scattering experiments are indicative for a 3D structure with dimensions ≥100 nm. AFM images confirm the presence of nanostructures. Fluorescence experiments indicating the sequestration of pyrene, chosen as drug model, and the anticancer Doxorubicin within the nanostructures are reported. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 115–121, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
- Published
- 2006
28. Formulazione e caratterizzazione chimico-fisica di aggregati supramolecolari, contenenti peptidi e gadolinio complessi, come agenti di contrasto in MRI
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M. VACCARO, G. MANGIAPIA, A. ACCARDO, O. SODERMAM, K. SCHILLEN, PADUANO, LUIGI, MORELLI, GIANCARLO, Vaccaro, M., Mangiapia, G., Paduano, Luigi, Accardo, A., Morelli, Giancarlo, Sodermam, O., and Schillen, K.
- Subjects
micelle ,peptidi ,formulazione - Published
- 2006
29. Mixed micelles composed of Peptides and Gadolinium complexes as tumor-specific contrast agents in MRI: a SANS study
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Fabrizio Lo Celso, Giancarlo Morelli, Gaetano Mangiapia, Diego Tesauro, Luigi Paduano, and Aurel Radulescu, Antonella Accardo, Mangiapia, G., Accardo, A., Celso, F. L., Tesauro, D., Morelli, Giancarlo, Radulescu, A., Paduano, Luigi, G MANGIAPIA, A ACCARDO, LO CELSO F, D TESAURO, G MORELLI, and L PADUANO
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Stereochemistry ,Gadolinium ,Micelles, Peptide Nanocarriers, SANS ,Contrast Media, Gadolinium, amide proton ,chemistry.chemical_element ,Cholecystokinin receptor ,Micelle ,Small-angle neutron scattering ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Amide ,Materials Chemistry ,Moiety ,Molecule ,Chelation ,ddc:530 ,Physical and Theoretical Chemistry - Abstract
A detailed structural investigation on mixed micelle aggregates as target-specific contrast agents for magnetic resonance imaging technique has been carried out by way of small angle neutron scattering measurements. These mixed micelles are formed by two new amphiphilic molecules formed by a bioactive peptide and a claw moiety. The first molecule, C18H37CONH(AdOO)(x)-G-CCK8 (C18LxCCK8, x = 2, 5), contains an 18-carbon-atom alkylic chain bound to the C-terminal of the cholecystokinin octapeptide amide (CCK 26-33 or CCK8) and is able to bind to the overexpressed CCK receptor of some tumor cells. The second molecule, C(18)H(37)CONHLys(DTPAGlu)CONH25- (C18DTPAGlu) or its gadolinium complex [C(18)H(37)CONHLys(DTPAGlu)CONH2Gd](2-), C18DTPAGlu(Gd),contains the same 18-carbon-atom alkylic chain bound, through a lysine residue, to the DTPAGlu chelating agent. Small angle neutron scattering measurements have been performed on ternary systems at different total concentrations and at various ratios of the two molecules. The effect of the concentration on the aggregation number as well as on the shape of the micelle has been investigated. Furthermore in order to optimize the exposure of the peptide on the micelle surface, C18LxCCK8 having the spacer L of different length has been used. The pure binary systems of the synthesized molecules are also presented.
- Published
- 2004
30. MIXED MICELLE AGGREGATES CONTAINING BIO-ACTIVE PEPTIDES AND CHELATING AGENTS FOR METAL COMPLEXES
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D'ERRICO, GERARDINO, ORTONA, ORNELLA GIUSTINA, PADUANO, LUIGI, SARTORIO, ROBERTO, G. MANGIAPIA, G. MORELLI, A. ACCARDO, D. TESAURO, D'Errico, Gerardino, Ortona, ORNELLA GIUSTINA, Paduano, Luigi, Sartorio, Roberto, Mangiapia, G., Morelli, G., Accardo, A., and Tesauro, D.
- Published
- 2003
31. Interaction of nanoparticles with lipid films: the role of symmetry and shape anisotropy.
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Caselli L, Ridolfi A, Mangiapia G, Maltoni P, Moulin JF, Berti D, Steinke NJ, Gustafsson E, Nylander T, and Montis C
- Subjects
- Anisotropy, Lipids, Scattering, Small Angle, Gold, Metal Nanoparticles
- Abstract
The bioactivity, biological fate and cytotoxicity of nanomaterials when they come into contact with living organisms are determined by their interaction with biomacromolecules and biological barriers. In this context, the role of symmetry/shape anisotropy of both the nanomaterials and biological interfaces in their mutual interaction, is a relatively unaddressed issue. Here, we study the interaction of gold nanoparticles (NPs) of different shapes (nanospheres and nanorods) with biomimetic membranes of different morphology, i.e. flat membranes (2D symmetry, representative of the most common plasma membrane geometry), and cubic membranes (3D symmetry, representative of non-lamellar membranes, found in Nature under certain biological conditions). For this purpose we used an ensemble of complementary structural techniques, including Neutron Reflectometry, Grazing Incidence Small-Angle Neutron Scattering, on a nanometer lengthscale and Confocal Laser Scanning Microscopy on a micrometer length scale. We found that the structural stability of the membrane towards NPs is dependent on the topological characteristic of the lipid assembly and of the NPs, where a higher symmetry gave higher stability. In addition, Confocal Laser Scanning Microscopy analyses highlighted that NPs interact with cubic and lamellar phases according to two distinct mechanisms, related to the different structures of the lipid assemblies. This study for the first time systematically addresses the role of NPs shape in the interaction with lipid assemblies with different symmetry. The results will contribute to improve the fundamental knowledge on lipid interfaces and will provide new insights on the biological function of phase transitions as a response strategy to the exposure of NPs.
- Published
- 2022
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32. Mutually Beneficial Combination of Molecular Dynamics Computer Simulations and Scattering Experiments.
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Zec N, Mangiapia G, Hendry AC, Barker R, Koutsioubas A, Frielinghaus H, Campana M, Ortega-Roldan JL, Busch S, and Moulin JF
- Abstract
We showcase the combination of experimental neutron scattering data and molecular dynamics (MD) simulations for exemplary phospholipid membrane systems. Neutron and X-ray reflectometry and small-angle scattering measurements are determined by the scattering length density profile in real space, but it is not usually possible to retrieve this profile unambiguously from the data alone. MD simulations predict these density profiles, but they require experimental control. Both issues can be addressed simultaneously by cross-validating scattering data and MD results. The strengths and weaknesses of each technique are discussed in detail with the aim of optimizing the opportunities provided by this combination.
- Published
- 2021
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33. Gold nanoparticles interacting with synthetic lipid rafts: an AFM investigation.
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Ridolfi A, Caselli L, Montis C, Mangiapia G, Berti D, Brucale M, and Valle F
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- Cell Membrane metabolism, Gold chemistry, Lipid Bilayers chemistry, Membrane Microdomains chemistry, Metal Nanoparticles chemistry, Microscopy, Atomic Force methods
- Abstract
Inorganic nanoparticles (NPs) represent promising examples of engineered nanomaterials, providing interesting biomedical solutions in several fields, like therapeutics and diagnostics. Despite the extensive number of investigations motivated by their remarkable potential for nanomedicinal applications, the interactions of NPs with biological interfaces are still poorly understood. The effect of NPs on living organisms is mediated by biological barriers, such as the cell plasma membrane, whose lateral heterogeneity is thought to play a prominent role in NPs adsorption and uptake pathways. In particular, biological membranes feature the presence of rafts, that is segregated lipid micro and/or nanodomains in the so-called liquid ordered phase (L
o ), immiscible with the surrounding liquid disordered phase (Ld ). Rafts are involved in various biological functions and act as sites for the selective adsorption of materials on the membrane. Indeed, the thickness mismatch present along their boundaries generates energetically favourable conditions for the adsorption of NPs. Despite its clear implications in NPs internalisation processes and cytotoxicity, a direct proof of the selective adsorption of NPs along the rafts' boundaries is still missing to date. Here we use multicomponent supported lipid bilayers (SLBs) as reliable synthetic models, reproducing the nanometric lateral heterogeneity of cell membranes. After being characterised by atomic force microscopy (AFM) and neutron reflectivity (NR), multidomain SLBs are challenged by prototypical inorganic nanoparticles, that is citrated gold nanoparticles (AuNPs), under simplified and highly controlled conditions. By exploiting AFM, we demonstrate that AuNPs preferentially target lipid phase boundaries as adsorption sites. The herein reported study consolidates and extends the fundamental knowledge on NPs-membrane interactions, which constitute a key aspect to consider when designing NPs-related biomedical applications. LAY DESCRIPTION: Inorganic nanoparticles (NPs) represent promising examples of engineered nanomaterials, offering interesting biomedical solutions in multiple fields like therapeutics and diagnostics. Despite being extensively investigated due to their remarkable potential for nanomedicinal applications, the interaction of NPs with biological systems is in several cases still poorly understood. The interaction of NPs with living organisms is mediated by biological barriers, such as the cell plasma membrane. Supported lipid bilayers (SLBs) represent suitable synthetic membrane models for studying the physicochemical properties of natural interfaces and their interaction with inorganic nanomaterials under simplified and controlled conditions. Recently, multicomponent SLBs were developed in order to mimic the lateral heterogeneity of most biological membranes. In particular, biological membranes feature the presence of rafts, that is segregated lipid micro and/or nanodomains, enriched in cholesterol, sphingomyelin, saturated glycerophospholipids and glycosphingolipids: these lipids segregate in the so-called liquid-ordered phase (Lo ), characterised by a high molecular packing degree, which promotes the phase separation from the surrounding liquid-crystalline (disordered, Ld ) phase, where the intermolecular mobility is increased. Rafts are thought to participate in the formation and targeting of nano-sized biogenic lipid vesicles and are also actively involved in multiple membrane processes. Indeed, Lo -Ld phase boundaries represent high energy areas, providing active sites for the preferential adsorption of external material. The selective adsorption of NPs along the phase boundaries of rafted membranes has been theorised and indirectly probed by different research groups; however, a direct proof of this phenomenon is still missing to date. We herein exploit atomic force microscopy (AFM) to directly visualise the preferential adsorption of gold nanoparticles (AuNPs) along the phase boundaries of multicomponent SLBs (previously characterised by neutron reflectivity), obtained from synthetic vesicles containing both an Ld and an Lo phase. The quantitative localisation and morphometry of AuNPs adsorbed on the SLB reveal important information on their interaction with the lipid matrix and directly prove the already theorised differential NPs-lipid interaction at the phase boundaries. The presented results could help the development of future NP-based applications, involving NPs adsorption on membranes with nanoscale phase segregations., (© 2020 Royal Microscopical Society.)- Published
- 2020
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34. 3D printed spherical environmental chamber for neutron reflectometry and grazing-incidence small-angle neutron scattering experiments.
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Widmann T, Kreuzer LP, Mangiapia G, Haese M, Frielinghaus H, and Müller-Buschbaum P
- Abstract
In neutron scattering on soft matter, an important concern is the control and stability of environmental conditions surrounding the sample. Complex sample environment setups are often expensive to fabricate or simply not achievable by conventional workshop manufacturing. We make use of state-of-the-art 3D metal-printing technology to realize a sample environment for large sample sizes, optimized for investigations on thin film samples with neutron reflectometry (NR) and grazing-incidence small-angle neutron scattering (GISANS). With the flexibility and freedom of design given by 3D metal-printing, a spherical chamber with fluidic channels inside its walls is printed from an AlSi10Mg powder via selective laser melting (SLM). The thin channels ensure a homogeneous heating of the sample environment from all directions and allow for quick temperature switches in well-equilibrated atmospheres. In order to optimize the channel layout, flow simulations were carried out and verified in temperature switching tests. The spherical, edgeless design aids the prevention of condensation inside the chamber in case of high humidity conditions. The large volume of the sample chamber allows for high flexibility in sample size and geometry. While a small-angle neutron scattering (SANS) measurement through the chamber walls reveals a strong isotropic scattering signal resulting from the evenly orientated granular structure introduced by SLM, a second SANS measurement through the windows shows no additional background originating from the chamber. Exemplary GISANS and NR measurements in time-of-flight mode are shown to prove that the chamber provides a stable, background free sample environment for the investigation of thin films.
- Published
- 2020
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35. Revealing the interfacial nanostructure of a deep eutectic solvent at a solid electrode.
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Zec N, Mangiapia G, Zheludkevich ML, Busch S, and Moulin JF
- Abstract
Deep eutectic solvents (DESs) are both green and sustainable, making them an increasingly attractive alternative to conventional solvents. One of their applications is the electrochemical deposition of metals that cannot be deposited from aqueous solution because of the limited electrochemical window of water. The electrodeposition process is influenced by the structure and dynamics of the solvent at the solid-liquid interface. Therefore,the nanoscale structure of the interface between a silicon substrate and deep eutectic solvent (choline chloride-ethylene glycol) was studied by neutron reflectometry (NR) and molecular dynamics (MD) simulations. It is not possible to model NR measurements of this system without simulating a dense DES layer at the solid-liquid interface. This study used an MD simulation trajectory to extract the density, thickness, and roughness of this DES layer. With this input, the model reproduces the reflectometry data at all measured H/D contrasts very well. The thickness of the layer does not change appreciably when applying charge or at higher temperatures. Further analysis revealed a reorganization of ions and reorientation of the choline cations in the interface layer when the electrodes are charged. These changes in ion orientation are not observed with the NR technique since they do not influence the neutron scattering length density profile due to the high number of ethylene glycol molecules at the interface. However, the agreement between measured neutron reflectometry data and model parameters obtained from MD simulations justified subnanoscale analysis of the MD trajectory and confirmed that these two complementary techniques can be successfully combined to reveal the solid/DES interface structure.
- Published
- 2020
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36. Surface distortion of Fe dot-decorated TiO 2 nanotubular templates using time-of-flight grazing incidence small angle scattering.
- Author
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Paul N, Moulin JF, Mangiapia G, Kriele A, Müller-Buschbaum P, Opel M, and Paul A
- Abstract
Physical properties of nanoclusters, nanostructures and self-assembled nanodots, which in turn are concomitantly dependent upon the morphological properties, can be modulated for functional purposes. Here, in this article, magnetic nanodots of Fe on semiconductor TiO
2 nanotubes (TNTs) are investigated with time-of-flight grazing incidence small-angle neutron scattering (TOF-GISANS) as a function of wavelength, chosen from a set of three TNT templates with different correlation lengths. The results are found corroborating with the localized scanning electron microscopy (SEM) images. As we probe the inside and the near-surface region of the Fe-dotted TNTs with respect to their homogeneity, surface distortion and long-range order using TOF-GISANS, gradual aberrations at the top of the near-surface region are identified. Magnetization measurements as a function of temperature and field do not show a typical ferromagnetic behavior but rather a supermagnetic one that is expected from a nonhomogeneous distribution of Fe-dots in the intertubular crevasses.- Published
- 2020
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37. Comparing the backfilling of mesoporous titania thin films with hole conductors of different sizes sharing the same mass density.
- Author
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Märkl RS, Hohn N, Hupf E, Bießmann L, Körstgens V, Kreuzer LP, Mangiapia G, Pomm M, Kriele A, Rivard E, and Müller-Buschbaum P
- Abstract
Efficient infiltration of a mesoporous titania matrix with conducting organic polymers or small molecules is one key challenge to overcome for hybrid photovoltaic devices. A quantitative analysis of the backfilling efficiency with time-of-flight grazing incidence small-angle neutron scattering (ToF-GISANS) and scanning electron microscopy (SEM) measurements is presented. Differences in the morphology due to the backfilling of mesoporous titania thin films are compared for the macromolecule poly[4,8-bis-(5-(2-ethyl-hexyl)-thio-phen-2-yl)benzo[1,2- b ;4,5- b ']di-thio-phene-2,6-diyl- alt -(4-(2-ethyl-hexyl)-3-fluoro-thieno[3,4- b ]thio-phene-)-2-carboxyl-ate-2-6-diyl)] (PTB7-Th) and the heavy-element containing small molecule 2-pinacol-boronate-3-phenyl-phen-anthro[9,10- b ]telluro-phene (PhenTe-BPinPh). Hence, a 1.7 times higher backfilling efficiency of almost 70% is achieved for the small molecule PhenTe-BPinPh compared with the polymer PTB7-Th despite sharing the same volumetric mass density. The precise characterization of structural changes due to backfilling reveals that the volumetric density of backfilled materials plays a minor role in obtaining good backfilling efficiencies and interfaces with large surface contact., (© Märkl et al. 2020.)
- Published
- 2020
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38. Capillary condensation and gelling of microemulsions with clay additives.
- Author
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Gvaramia M, Mangiapia G, Falus P, Ohl M, Holderer O, and Frielinghaus H
- Abstract
The capillary condensation in bicontinuous microemulsions takes place when two parallel surfaces are narrowed that result in a completely lamellar microemulsion. We expected that this phase transition is also observable when the amount of hydrophilic surfaces from clay particles is raised, because hydrophilic surfaces induce lamellar ordering locally. Using small angle neutron scattering, the structure of microemulsions was observed as a function of clay content. The critical concentration is indicated by discontinuous structural changes and depends on the platelet diameter and is explained by the free energy of the platelets competing with the fluctuating medium. The gel phase transition is observed in the spectroscopic measurements where the diffusion motion is widely suppressed in the gel phase, but otherwise superimposes with the membrane undulations., (Copyright © 2018. Published by Elsevier Inc.)
- Published
- 2018
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39. A new design for nucleolipid-based Ru(III) complexes as anticancer agents.
- Author
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Montesarchio D, Mangiapia G, Vitiello G, Musumeci D, Irace C, Santamaria R, D'Errico G, and Paduano L
- Subjects
- Antineoplastic Agents pharmacology, Cell Line, Tumor, Cell Survival drug effects, Coordination Complexes pharmacology, Drug Design, Fatty Acids, Monounsaturated pharmacology, Humans, Neoplasms drug therapy, Phosphatidylcholines pharmacology, Quaternary Ammonium Compounds pharmacology, Ruthenium pharmacology, Uridine pharmacology, Antineoplastic Agents chemistry, Coordination Complexes chemistry, Fatty Acids, Monounsaturated chemistry, Phosphatidylcholines chemistry, Quaternary Ammonium Compounds chemistry, Ruthenium chemistry, Uridine analogs & derivatives
- Abstract
In continuation with our studies concerning the synthesis, characterization and biological evaluation of nucleolipidic Ru(III) complexes, a novel design for this family of potential anticancer agents is presented here. As a model compound, a new uridine-based nucleolipid has been prepared, named HoUrRu, following a simple and versatile synthetic procedure, and converted into a Ru(III) salt. Stable formulations of this highly functionalized Ru(III) complex have been obtained by co-aggregation with either the zwitterionic lipid POPC or the cationic DOTAP, which have been subjected to an in-depth microstructural characterization, including DLS, SANS and EPR measurements. The in vitro bioactivity profile of HoUrRu, as a pure compound or in formulation with POPC or DOTAP, reveals high antiproliferative activity against MCF-7 and WiDr human cancer cell lines.
- Published
- 2013
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40. Anticancer cationic ruthenium nanovectors: from rational molecular design to cellular uptake and bioactivity.
- Author
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Mangiapia G, Vitiello G, Irace C, Santamaria R, Colonna A, Angelico R, Radulescu A, D'Errico G, Montesarchio D, and Paduano L
- Subjects
- Allyl Compounds chemistry, Animals, Antineoplastic Agents metabolism, Antineoplastic Agents pharmacology, Cell Survival drug effects, Colloids, Coordination Complexes metabolism, Coordination Complexes pharmacology, Drug Screening Assays, Antitumor, Drug Stability, Electron Spin Resonance Spectroscopy, Half-Life, Humans, Inhibitory Concentration 50, Lipids chemistry, Liposomes metabolism, Liposomes pharmacology, MCF-7 Cells, Nanoparticles chemistry, Neutron Diffraction, Particle Size, Ruthenium metabolism, Ruthenium pharmacology, Scattering, Small Angle, Surface-Active Agents chemistry, Antineoplastic Agents chemistry, Coordination Complexes chemistry, Liposomes chemistry, Ruthenium chemistry
- Abstract
An efficient drug delivery strategy is presented for novel anticancer amphiphilic ruthenium anionic complexes, based on the formation of stable nanoparticles with the cationic lipid 1,2-dioleyl-3-trimethylammoniumpropane chloride (DOTAP). This strategy is aimed at ensuring high ruthenium content within the formulation, long half-life in physiological media, and enhanced cell uptake. An in-depth microstructural characterization of the aggregates obtained mixing the ruthenium complex and the phospholipid carrier at 50/50 molar ratio is realized by combining a variety of techniques, including dynamic light scattering (DLS), small angle neutron scattering (SANS), neutron reflectivity (NR), electron paramagnetic resonance (EPR), and zeta potential measurements. The in vitro bioactivity profile of the Ru-loaded nanoparticles is investigated on human and non-human cancer cell lines, showing IC(50) values in the low μM range against MCF-7 and WiDr cells, that is, proving to be 10-20-fold more active than AziRu, a previously synthesized NAMI-A analog, used for control. Fluorescence microscopy studies demonstrate that the amphiphilic Ru-complex/DOTAP formulations, added with rhodamine-B, are efficiently and rapidly incorporated in human MCF-7 breast adenocarcinoma cells. The intracellular fate of the amphiphilic Ru-complexes was investigated in the same in vitro model by means of an ad hoc designed fluorescently tagged analog, which exhibited a marked tendency to accumulate within or in proximity of the nuclei.
- Published
- 2013
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41. Interaction of anticancer ruthenium compounds with proteins: high-resolution X-ray structures and raman microscopy studies of the adduct between hen egg white lysozyme and AziRu.
- Author
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Vergara A, D'Errico G, Montesarchio D, Mangiapia G, Paduano L, and Merlino A
- Subjects
- Animals, Antineoplastic Agents chemistry, Chickens, Crystallography, X-Ray, Dimethyl Sulfoxide chemistry, Dimethyl Sulfoxide metabolism, Microscopy, Models, Molecular, Muramidase chemistry, Organometallic Compounds chemistry, Protein Binding, Pyridines chemistry, Pyridines metabolism, Ruthenium chemistry, Ruthenium Compounds, Antineoplastic Agents metabolism, Dimethyl Sulfoxide analogs & derivatives, Muramidase metabolism, Organometallic Compounds metabolism, Ruthenium metabolism
- Abstract
The binding properties of AziRu, a ruthenium(III) complex with high antiproliferative activity, toward a hen egg white lysozyme have been investigated by X-ray crystallography and Raman microscopy. The data provide clear evidence on the mechanism of AziRu-protein adduct formation and of ligand exchange in the crystal state.
- Published
- 2013
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42. Octreotide labeled aggregates containing platinum complexes as nanovectors for drug delivery.
- Author
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Accardo A, Mangiapia G, Paduano L, Morelli G, and Tesauro D
- Subjects
- Liposomes chemistry, Receptors, Somatostatin agonists, Antibiotics, Antineoplastic chemistry, Antineoplastic Agents, Hormonal chemistry, Cisplatin chemistry, Doxorubicin chemistry, Drug Delivery Systems, Octreotide chemistry, Platinum chemistry
- Abstract
The synthesis, formulation and a complete physico-chemical characterization, by dynamic light scattering and small angle neutron scattering techniques, of new liposomal aggregates obtained by co-assembling an amphiphilic molecule containing a platinum complex, Peg1500 -Lys(Pt-aminoEtGly)-Lys(C18)2, (abbreviated as (C18)2-PKAG-Pt), with a second amphiphilic monomer, (C18H37)2NCO(CH2)2CO(AdOO)5-Oct ((C18)2 L5-Oct), containing the octreotide bioactive peptide, is reported. Liposomes of (C18)2-PKAG-Pt present a radius of 48 nm, whereas the mixed aggregates (C18)2-PKAG-Pt/(C18)2L5-Oct at 90/10 M ratio give larger liposomes with a radius of 84 nm. In both cases, the bilayer thickness is ~5.3 nm. Encapsulation of doxorubicin in mixed liposomes is also obtained by using the pH gradient method. The obtained liposomes could represent a new target selective cargo system for delivery of cisplatin based drugs and/or doxorubicin on cells overexpressing the sstr2 and sstr5 somatostatin receptors., (Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.)
- Published
- 2013
- Full Text
- View/download PDF
43. Analysis of main- and cross-term diffusion coefficients in bile salt mixtures.
- Author
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Mangiapia G, Paduano L, Ortona O, Sartorio R, and D'Errico G
- Subjects
- Absorption, Bile Acids and Salts analysis, Deoxycholic Acid chemistry, Diffusion, Micelles, Sodium Cholate chemistry, Surface-Active Agents chemistry, Water chemistry, Bile Acids and Salts chemistry
- Abstract
Mutual diffusion coefficients have been measured for several average compositions of the system sodium cholate-sodium deoxycholate-water at 25 °C. The experiments have been grouped in different sets having constant concentration of one component and variable concentration of the other one. Following this approach, it has been found that the trends of the main- and cross-term diffusion coefficients can be interpreted on the basis of the diffusion and equilibrium results of similar experiments performed on the two binary systems sodium cholate-water and sodium deoxycholate-water. Implications of the presented results in the transport of lipids operated by bile salt aggregates are mentioned. The method proposed in this work, able to connect the diffusivities of an n-component system to those of the related n-1 subsystems, can be extended to obtain qualitative prediction on the diffusion coefficient trends for mixtures of other surfactants, of both industrial and biological interest.
- Published
- 2013
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44. Eumelanin buildup on the nanoscale: aggregate growth/assembly and visible absorption development in biomimetic 5,6-dihydroxyindole polymerization.
- Author
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Arzillo M, Mangiapia G, Pezzella A, Heenan RK, Radulescu A, Paduano L, and d'Ischia M
- Subjects
- Algorithms, Biomimetics, Biopolymers chemistry, Light, Melanins chemistry, Models, Chemical, Nanoparticles chemistry, Neutron Diffraction, Oxidation-Reduction, Particle Size, Polyvinyl Alcohol chemistry, Scattering, Radiation, Scattering, Small Angle, Indoles chemistry, Melanins chemical synthesis, Polymerization
- Abstract
Establishing structure-property relationships in the black insoluble eumelanins, the key determinants of human pigmentation and skin photoprotective system, is a considerable conceptual and experimental challenge in the current drive for elucidation of the biological roles of these biopolymers and their application as advanced materials for organoelectronics. Herein, we report a new breakthrough toward this goal by the first detailed investigation on the nanoscale level of the oxidative polymerization of 5,6-dihydroxyindole (DHI), a model process of eumelanin synthesis. On the basis of a combined use of spectrophotometry, dynamic light scattering (DLS), and small-angle neutron scattering (SANS) investigations, it was possible to unveil the dynamics of the aggregation process before precipitation, the key relationships with visible light absorption and the shape of fundamental aggregates. The results indicated a polymerization mechanism of the type: Polymer(n) + DHI(x) = Polymer(n+x), where DHI(x) indicates monomer, dimer, or low oligomers (x ≤ 5). During polymerization, visible absorption increases rapidly, reaching a plateau. Particle growth proceeds slowly, with formation of 2-D structures ~55 nm thick, until precipitation occurs, that is, when large aggregates with a maximum hydrodynamic radius (R(h)) of ~1200 nm are formed. Notably, markedly smaller R(h) values, up to ~110 nm, were determined in the presence of poly(vinyl alcohol) (PVA) that was shown to be an efficient aggregation-preventing agent for polymerizing DHI ensuring water solubilization. Finally, it is shown that DHI monomer can be efficiently and partially irreversibly depleted from aqueous solutions by the addition of eumelanin suspensions. This behavior is suggested to reflect oxidant-independent competing pathways of polymer synthesis and buildup via monomer conversion on the active aggregate surface contributing to particle growth. Besides filling crucial gaps in DHI polymerization, these results support the attractive hypothesis that eumelanins may behave as a peculiar example of living biopolymers. The potential of PVA as a powerful tool for solution chemistry-based investigations of eumelanin supramolecular organization and for technological manipulation purposes is underscored.
- Published
- 2012
- Full Text
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45. Ruthenium-based complex nanocarriers for cancer therapy.
- Author
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Mangiapia G, D'Errico G, Simeone L, Irace C, Radulescu A, Di Pascale A, Colonna A, Montesarchio D, and Paduano L
- Subjects
- Animals, Antineoplastic Agents chemistry, Cell Line, Tumor, Cell Survival drug effects, Drug Carriers, Drug Stability, Humans, Liposomes, Materials Testing, Microscopy, Fluorescence, Nanoparticles chemistry, Organometallic Compounds chemistry, Rats, Ruthenium chemistry, Antineoplastic Agents administration & dosage, Nanoparticles administration & dosage, Neoplasms drug therapy, Organometallic Compounds administration & dosage, Ruthenium administration & dosage
- Abstract
A new organometallic ruthenium complex, named AziRu, along with three amphiphilic nucleoside-based ruthenium complexes, ToThyRu, HoThyRu and DoHuRu, incorporating AziRu in their skeleton, have been synthesized, stabilized in POPC phospholipid formulations and studied for their antineoplastic activity. Self-aggregation behavior of these complexes was investigated, showing that the three synthesized AziRu derivatives able to form liposomes and, under specific conditions, elongated micelles. The formulations prepared in POPC proved to be stable for months and showed high in vitro antiproliferative activity. The here described results open new scenarios in the design of innovative transition metal-based supramolecular systems for anticancer drugs vectorization., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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46. Cholesterol-based nucleolipid-ruthenium complex stabilized by lipid aggregates for antineoplastic therapy.
- Author
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Simeone L, Mangiapia G, Vitiello G, Irace C, Colonna A, Ortona O, Montesarchio D, and Paduano L
- Subjects
- Cell Line, Tumor, Cell Proliferation drug effects, Drug Stability, Humans, Neutron Diffraction, Scattering, Small Angle, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Cholesterol chemistry, Organometallic Compounds chemistry, Organometallic Compounds pharmacology, Ruthenium chemistry
- Abstract
A novel ruthenium complex, linked to a cholesterol-containing nucleolipid (named ToThyCholRu), stabilized by lipid aggregates for antineoplastic therapy is presented. In order to retard the degradation kinetics typically observed for several ruthenium-based antineoplastic agents, ToThyCholRu is incorporated into a liposome bilayer formed by POPC. The resulting nanoaggregates contain up to 15% in moles of the ruthenium complex, and are shown to be stable for several weeks. The liposomes host the ruthenium-nucleolipid complex with the metal ion surrounded by POPC lipid headgroups and the steroid moiety inserted in the more external acyl chain region. These ruthenium-containing liposomes are more effective in inhibiting the growth of cancer cells than a model NAMI-A-like ruthenium complex, prepared for a direct evaluation of their anti-proliferative activity. These results introduce new perspectives in the design of innovative transition-metal-based supramolecular systems for anticancer drug vectorization., (© 2012 American Chemical Society)
- Published
- 2012
- Full Text
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47. Nucleolipid nanovectors as molecular carriers for potential applications in drug delivery.
- Author
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Simeone L, Mangiapia G, Irace C, Di Pascale A, Colonna A, Ortona O, De Napoli L, Montesarchio D, and Paduano L
- Subjects
- 3T3-L1 Cells, Animals, Caco-2 Cells, Cell Line, Tumor, Cell Proliferation drug effects, Drug Carriers chemistry, Drug Carriers toxicity, Drug Delivery Systems, Humans, Hydrophobic and Hydrophilic Interactions, Mice, Oleic Acids chemistry, Oleic Acids toxicity, Prodrugs chemical synthesis, Prodrugs chemistry, Rats, Thymidine chemical synthesis, Thymidine chemistry, Thymidine toxicity, Uridine chemical synthesis, Uridine chemistry, Uridine toxicity, Drug Carriers chemical synthesis, Nanocapsules chemistry, Oleic Acids chemical synthesis, Thymidine analogs & derivatives, Uridine analogs & derivatives
- Abstract
Novel thymidine- or uridine-based nucleolipids, containing one hydrophilic oligo(ethylene glycol) chain and one or two oleic acid residues (called ToThy, HoThy and DoHu), have been synthesized with the aim to develop bio-compatible nanocarriers for drug delivery and/or produce pro-drugs. Microstructural characterization of their aggregates has been determined in pure water and in pseudo-physiological conditions through DLS and SANS experiments. In all cases stable vesicles, with mean hydrodynamic radii ranging between 120 nm and 250 nm have been revealed. Biological validation of the nucleolipidic nanocarriers was ensured by evaluation of their toxicological profiles, performed by administration of the nanoaggregates to a panel of different cell lines. ToThy exhibited a weak cytotoxicity and, at high concentration, some ability to interfere with cell viability and/or proliferation. In contrast, DoHu and HoThy exhibited no toxicological relevance, behaving similarly to POPC-based liposomes, widely used for systemic drug delivery. Taken together, these results show nucleolipid-based nanocarriers as finely tunable, multi-functional self-assembling materials of interest for the in vivo transport of biomolecules or drugs., (This journal is © The Royal Society of Chemistry 2011)
- Published
- 2011
- Full Text
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48. On the interpretation of transport properties of sodium cholate and sodium deoxycholate in binary and ternary aqueous mixtures.
- Author
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Mangiapia G, D'Errico G, Capuano F, Ortona O, Heenan RK, Paduano L, and Sartorio R
- Subjects
- Diffusion, Electron Spin Resonance Spectroscopy, Neutron Diffraction, Scattering, Small Angle, Surface Tension, Deoxycholic Acid chemistry, Sodium Cholate chemistry, Water chemistry
- Abstract
Sodium cholate (NaC) and sodium deoxycholate (NaDC) in binary and ternary aqueous mixtures were investigated by means of surface tension, electron paramagnetic resonance spectroscopy (EPR), small angle neutron scattering (SANS) and mutual diffusion coefficient analysis. Concerning the NaC-H(2)O and NaDC-H(2)O binary mixtures, the surface tension, EPR and diffusion measurements confirmed the formation of micelles above a well detectable critical concentration. The SANS data indicated for both systems, the formation of ellipsoidal micelles whose major axis increased with concentration and minor axis remained constant. The data were interpreted under the assumption that aggregate growth occurred via hydrogen bonding of small aggregates along one preferential direction. For the NaC-NaDC-H(2)O ternary mixtures, the surface tension and EPR results were in good agreement with the Clint model prediction for the ideal mixed micellization. Based on this model, the SANS data enabled a complete description of the mixed aggregates in terms of dimensions, composition and concentration. In turn, this strategy allowed for a satisfactory interpretation of the main and cross-term diffusion coefficient trends, which are quite complex.
- Published
- 2011
- Full Text
- View/download PDF
49. Temperature and concentration effects on supramolecular aggregation and phase behavior for poly(propylene oxide)-b-poly(ethylene oxide)-b-poly(propylene oxide) copolymers of different concentration in aqueous mixtures, 2.
- Author
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D'Errico G, Paduano L, Ortona O, Mangiapia G, Coppola L, and Lo Celso F
- Subjects
- Macromolecular Substances chemical synthesis, Macromolecular Substances chemistry, Surface Properties, Water chemistry, Polyethylene Glycols chemistry, Propylene Glycols chemistry, Temperature
- Abstract
The micro- and mesoscopic structure of reverse Pluronic 25R4 in aqueous mixtures has been studied by SANS, SAXS and shear rheology. These techniques have been able to give a deep insight into the complex structure of the system phase diagram, that includes an isotropic water-rich liquid phase L(1), and liquid crystalline phases with hexagonal, E, or lamellar order, D. Particular attention has been paid to the isotropic water-rich phase L(1), which has a large stability region in the temperature-composition phase diagram. This region is crossed by a large "cloudy zone". Below it, namely at low temperature and composition, SANS data show the presence of polymer unimers in a gaussian coil conformation. Above the "cloudy zone", at higher temperature and composition, the L(1) phase is structured as a network of interconnected multimeric micelles. Rheology adds information about the structuring of the L(1) phase showing its incipient hexagonal pre-structuring. This technique is also able to highlight the defective structure of the E phase itself. In the temperature and concentration ranges in which a lamellar phase D is present, SANS and SAXS results are in complete agreement, showing how interlamellar distance is influenced by both polymer composition and temperature according to an "ideal deswelling" or a "not ideal swelling" mechanism. In addition, in the D phase rheology suggests the presence of densely packed vesicles., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
50. Polymerization of hemoglobins in Arctic fish: Lycodes reticulatus and Gadus morhua.
- Author
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Riccio A, Mangiapia G, Giordano D, Flagiello A, Tedesco R, Bruno S, Vergara A, Mazzarella L, di Prisco G, Pucci P, Paduano L, and Verde C
- Subjects
- Amino Acid Sequence, Animals, Arctic Regions, Hemoglobins genetics, Hemoglobins metabolism, Humans, Molecular Sequence Data, Oxygen metabolism, Polymerization, Sequence Alignment, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Gadus morhua, Hemoglobins chemistry, Protein Conformation
- Abstract
In vitro, and possibly in vivo, hemoglobin polymerization and red blood cell sickling appear to be widespread in codfish. In this article, we show that the hemoglobins of the two Arctic fish Lycodes reticulatus and Gadus morhua also have the tendency to polymerize, as monitored by dynamic light scattering experiments. The elucidation of the primary structure of the single hemoglobin of the zoarcid L. reticulatus shows the presence of a large number of cysteyl residues in α and β chains. Their role in eliciting the ability to produce polymers was also addressed by MALDI-TOF and TOF-TOF mass spectrometry. The G.morhua globins are also rich in Cys, but unlike in L. reticulatus, polymerization does not seem to be disulfide driven. The widespread occurrence of the polymerization phenomenon displayed by hemoglobins of Arctic fish supports the hypothesis that this feature may bea response to stressful environmental conditions., (Copyright © 2011 Wiley Periodicals, Inc.)
- Published
- 2011
- Full Text
- View/download PDF
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