101
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Magazu S, Maisano G, Majolino D, Mallamace F, Migliardo P, Micali N. Structural changes in potassium oleate microemulsions by ultrasound measurements. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100345a073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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102
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Campagna S, Giannetto A, Serroni S, Denti G, Trusso S, Mallamace F, Micali N. Aggregation in Fluid Solution of Dendritic Supermolecules made of Ruthenium(II)- and Osmium(II)-Polypyridine Building Blocks. J Am Chem Soc 2002. [DOI: 10.1021/ja00111a012] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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103
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Lacaille F, Micali N, Lachaux A, Morali A, Sarles J, Rieu D, Chouraqui JP, Maurage C, Gottrand F. [Treatment of chronic hepatitis C with interferon in children]. Arch Pediatr 2002; 9:339-40. [PMID: 11938548 DOI: 10.1016/s0929-693x(01)00773-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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104
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Lauceri R, Raudino A, Scolaro LM, Micali N, Purrello R. From achiral porphyrins to template-imprinted chiral aggregates and further. Self-replication of chiral memory from scratch. J Am Chem Soc 2002; 124:894-5. [PMID: 11829583 DOI: 10.1021/ja017159b] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The presence of 10-13 M of chiral clusters of aromatic amino acids addresses aggregation of opposite-charged achiral porphyrin towards the formation of smart chiral assemblies. The latter supramolecular complexes are able to self-propagate and transfer their chiral information with a 100% yield. The chiral bias occurs through a correlated sequence of induction, memory, and amplification of chirality that strongly recalls possible prebiotic scenarios.
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105
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Micali N, Mallamace F, Castriciano M, Romeo A, Scolaro LM. Separation of scattering and absorption contributions in UV/visible spectra of resonant systems. Anal Chem 2001; 73:4958-63. [PMID: 11681472 DOI: 10.1021/ac010379n] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resonance light scattering (RLS) is a phenomenon due to an enhancement of the scattered light in close proximity to an absorption band. The effect is easily detectable in the case of strongly absorbing chromophores, which are able to interact, thus leading to large aggregates (Pasternack, R. F.; Collings, P. J. Science 1995, 269, 935). The measurement of absorption spectra from solutions containing such resonant systems can lead to misleading results. In this paper, a simple method is described to obtain absorption spectra of aggregated species with a fairly good correction of the scattering component. The RLS spectrum, obtained using a common spectrofluorimeter, is correlated to the extinction spectrum of the same sample, allowing for an estimation of the scattering contribution to the total extinction spectrum. The method has been successfully applied both on real samples containing aggregated chromophores, such as porphyrins, chlorophyll a and gold colloids, and by simulating extinction spectra.
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106
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Abstract
The complete pH-rate profile of the hydrolysis reaction of aspirin, requiring many experiments in the past, was obtained by a single variable-parameter kinetic experiment carried out by varying the hydrogen ion concentration. The experiment was carried out spectrophotometrically, reading automatically absorbance, pH, and temperature inside the reaction vessel. The results obtained by the fast processing of the kinetic profile are identical to those obtained under the same conditions but using traditional constant-pH kinetic runs. This method provides the possibility of reducing the amount of time and chemicals usually spent in collecting kinetic data in such mechanistic studies by nearly two orders of magnitude.
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107
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Micali N, Romeo A, Lauceri R, Purrello R, Mallamace F, Scolaro LM. Fractal Structures in Homo- and Heteroaggregated Water Soluble Porphyrins. J Phys Chem B 2000. [DOI: 10.1021/jp001750y] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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108
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Mallamace F, Gambadauro P, Micali N, Tartaglia P, Liao C, Chen S. Kinetic glass transition in a micellar system with short-range attractive interaction. PHYSICAL REVIEW LETTERS 2000; 84:5431-5434. [PMID: 10990961 DOI: 10.1103/physrevlett.84.5431] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/1999] [Indexed: 05/23/2023]
Abstract
We show that percolation and structural arrest transitions coexist in different regions of the phase diagram of a copolymer-micellar system and relate them to short-range intermicellar attraction. The intermediate scattering function shows a nonergodic transition along a temperature and concentration dependent line. Analyses show a logarithmic time dependence, attributed to a higher-order glass transition singularity predicted by mode-coupling theory, followed by a power law.
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109
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Micali N, Mallamace F, Romeo A, Purrello R, Monsù Scolaro L. Mesoscopic Structure of meso-Tetrakis(4-sulfonatophenyl)porphine J-Aggregates. J Phys Chem B 2000. [DOI: 10.1021/jp991909a] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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110
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Mallamace F, Gambadauro P, Lesieur P, Lombardo D, Micali N, Romeo A, Monsù Scolaro L. Scaling properties in the structure of new complex materials (porphyrins and dendritic polymer systems). J Appl Crystallogr 2000. [DOI: 10.1107/s0021889899013771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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111
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Mallamace F, Micali N, Romeo A, Monsù Scolaro L. Fractal aggregation of dyes such as porphyrins and related compounds under stacking. Curr Opin Colloid Interface Sci 2000. [DOI: 10.1016/s1359-0294(00)00037-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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112
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Lobry L, Micali N, Mallamace F, Liao C, Chen SH. Interaction and percolation in the L64 triblock copolymer micellar system. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 60:7076-87. [PMID: 11970647 DOI: 10.1103/physreve.60.7076] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/1999] [Indexed: 04/18/2023]
Abstract
We present results of analyses of an extensive set of static light scattering (SLS), small angle neutron scattering (SANS), and viscoelastic (frequency dependent complex moduli) measurements of aqueous solutions of a triblock copolymer micellar system. We investigate Pluronic L64 (PEO(13)PPO(30)PEO(13))-water system in a wide range of composition and temperature. We determine phase diagram of the disordered micellar phase, including a cmc-cmt curve, a cloud point curve, the critical concentration, and the critical temperature by means of SLS and SANS. The microstructure and interaction between micelles are determined by analyses of SANS intensities. SANS intensity distributions are well described by combining the cap-and-gown model for the polymer segmental distribution within a micelle and the sticky hard sphere model for the intermicellar structure factor. The existence of percolation loci at well defined poins in the temperature-concentration plane is inferred from an abrupt increase of the stickiness parameter extracted from SANS data and from two order of magnitude jump of the complex moduli at the percolation point. Study of temperature dependence of real (storage) and imaginary (loss) part of the complex modulus at fixed concentration and frequency lends further support to the existence of a percolation line. We observe an increase of some order of magnitude of the real and imaginary part of viscosity at certain temperature and composition, a phenomenon usually ascribed to a gelation process in a polymer solution. The definitive confirmation of the percolation process is obtained by frequency dependent complex viscosity measured in a frequency range 0-160 (rad/sec). From these measurements we clearly observe a well defined frequency scaling behavior of the complex moduli and a loss angle (delta) independent of the frequency. Scaling exponents, determined for frequency-dependent complex moduli satisfy the scaling relations predicted by the scalar elasticity percolation theory.
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113
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Ficarra R, Villari A, Micali N, Tommasini S, Calabrò ML, Di Bella MR, Melardi S, Agresta MF, Coppolino S, Stancanelli R. Stability study of piroxicam and cinnoxicam in solid pharmaceuticals. J Pharm Biomed Anal 1999; 20:283-8. [PMID: 10704033 DOI: 10.1016/s0731-7085(99)00037-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The pseudo-first order rate constant for the hydrolysis of cinnoxicam as a function of temperature was obtained by variable-temperature kinetic experiments. The method used is on a generalization of non-isothermal analysis, and takes advantage of the capabilities of modern data collection and processing systems. A spectrophotometric method under non isothermal conditions was carried out. The results obtained are identical to those obtained under the same conditions by using traditional constant-temperature kinetic runs. This provides the possibility of reducing the amount of time spent and chemicals usually used in collecting kinetic data in mechanistic studies in solution by an order of magnitude.
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114
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Stewart JP, Micali N, Usherwood EJ, Bonina L, Nash AA. Murine gamma-herpesvirus 68 glycoprotein 150 protects against virus-induced mononucleosis: a model system for gamma-herpesvirus vaccination. Vaccine 1999; 17:152-7. [PMID: 9987149 DOI: 10.1016/s0264-410x(98)00190-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Murine gamma-herpesvirus 68 (MHV-68) is a model for the study of the pathogenesis of gamma-herpesviruses. Epstein-Barr virus (EBV) is a highly related gamma-herpesvirus that causes significant disease in humans. The major membrane antigen gp350 of EBV is a candidate vaccine antigen for protection against EBV-related disease. An MHV-68 glycoprotein, gp150, has significant homology to EBV gp350. We have therefore used the MHV-68 gp150 to model the potential efficacy of EBV gp350 in protecting from virus-associated disease. A recombinant vaccinia virus expressing MHV-68 gp150 was constructed. This recombinant vaccinia virus was used to infect mice via the subcutaneous route. This vaccination resulted in production of MHV-68-neutralising antibodies. Mice were then challenged intra-nasally with MHV-68. MHV-68-associated mononucleosis was virtually abrogated in immunised mice. However, mice did establish MHV-68 latency. The results suggest that gp350 may be effective as an immunogen to prevent EBV-associated infectious mononucleosis in humans that are EBV-seronegative.
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115
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Mallamace F, Micali N, Chen SH. Spinodal Decomposition in Bicontinuous Microemulsions Studied by Ultra-Small-Angle Time-Resolved Light Scattering. J Appl Crystallogr 1997. [DOI: 10.1107/s0021889897001908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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116
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Letamendia L, Belkadi M, Eloutassi O, Pru-Lestret E, Nouchi G, Rouch J, Blaudez D, Mallamace F, Micali N, Vasi C. Anomalous effects in the temperature dependence of depolarized Rayleigh spectra of benzene and quinoline. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:5327-5330. [PMID: 9965717 DOI: 10.1103/physreve.54.5327] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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117
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Alibrandi G, Micali N, Trusso S, Villari A. Hydrolysis of aspirin studied by spectrophotometric and fluorometric variable-temperature kinetics. J Pharm Sci 1996; 85:1105-8. [PMID: 8897279 DOI: 10.1021/js950506t] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Pseudo-first-order rate constants for the hydrolysis of acetylsalicylic acid as a function of temperature have been obtained by variable-temperature kinetic experiments. A method, based on a generalization of non-isothermal analysis, has been used that takes advantage of the capabilities of modern data collection and processing systems. Both spectrophotometric and, for the first time under non-isothermal conditions, fluorometric measurements have been carried out. The results obtained are identical to those obtained under the same conditions but using traditional constant-temperature kinetic runs. This provides the possibility of reducing the amounts of time and chemicals usually spent in collecting kinetic data in mechanistic studies in solution by an order of magnitude.
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118
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Micali N, Trusso S, Vasi C, Blaudez D, Mallamace F. Dynamical properties of water-methanol solutions studied by depolarized Rayleigh scattering. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:1720-1724. [PMID: 9965249 DOI: 10.1103/physreve.54.1720] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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119
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Mallamace F, Micali N, Trusso S, Scolaro LM, Romeo A, Terracina A, Pasternack RF. Experimental evidence for self-similar structures in the aggregation of porphyrins in aqueous solutions. PHYSICAL REVIEW LETTERS 1996; 76:4741-4744. [PMID: 10061369 DOI: 10.1103/physrevlett.76.4741] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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120
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Nickolov ZS, Earnshaw JC, Mallamace F, Micali N, Vasi C. Light-scattering study of phase transitions in aqueous solutions of nonionic amphiphiles. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:5241-5249. [PMID: 9964023 DOI: 10.1103/physreve.52.5241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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121
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Fresta M, Puglisi G, Giammona G, Cavallaro G, Micali N, Furneri PM. Pefloxacine mesilate- and ofloxacin-loaded polyethylcyanoacrylate nanoparticles: characterization of the colloidal drug carrier formulation. J Pharm Sci 1995; 84:895-902. [PMID: 7562444 DOI: 10.1002/jps.2600840721] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The entrapment of fluoroquinolones, perfloxacine mesilate (PFX) and ofloxacin (OFX), in polyalkylcyanoacrylate (PECA) nanoparticles could offer some advantages for their biological application; for examples, increasing their bioavailability, controlling the drug time-release in blood, and reducing the formation of bacterial resistance. To load these two drugs in PECA polymeric bulk, the incorporation or adsorption method was performed. These two methods were capable of influencing nanoparticle size, molecular weight, release profile, and drug-polymer association. The incorporation method, particularly for the OFX system, achieved PECA nanoparticle suspensions with a mean size value three times higher than that obtained in the absence of the drug. In contrast, negligible changes were observed for PFX systems. This preparation process also influenced the nanoparticle storage stability. The molecular weight values of the various nanoparticle preparations were also influenced; that is, the PFX-loaded systems showed an enhancement in the average molecular weight values, whereas a reduction was observed for OFX-loaded systems. The adsorption method showed no particular difference in particle size, molecular weight, and storage stability compared with nanoparticles prepared without the drugs. The nanoparticle loading capacity was higher for the colloidal systems obtained following the incorporation preparation procedure. The release of drug from the nanoparticles was biphasic for both preparation processes. The fluoro-quinolone-loaded nanoparticles showed an enhancement of the antimicrobial activity against standard bacteria strains from 2- to 50-fold compared with the free drugs.
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122
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Mallamace F, Micali N, Trusso S, Chen SH. Spinodal decomposition of a three-component water-in-oil microemulsion system. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:5818-5823. [PMID: 9963318 DOI: 10.1103/physreve.51.5818] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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123
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Micali N, Trusso S, Vasi C, Mallamace F, Lombardo D, Onori G, Santucci A. Rotational dynamics of water molecules in a water-short-chain-nonionic-amphiphile mixture: Depolarized light scattering. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:2349-2355. [PMID: 9962896 DOI: 10.1103/physreve.51.2349] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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124
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Mallamace F, Lombardo D, Micali N, Trusso S, Vasi C. Light-scattering studies on water-nonionic-amphiphile solutions. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:2341-2348. [PMID: 9962895 DOI: 10.1103/physreve.51.2341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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125
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Villari A, Micali N, Fresta M, Puglisi G. Spectrofluorimetry at zero angle: determination of salicylic acid in an acetylsalicylic acid pharmaceutical formulation. Analyst 1994; 119:1561-5. [PMID: 7943744 DOI: 10.1039/an9941901561] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this work, a solid-state spectrofluorimetric method for drug assays was developed. In particular, we report the determination of salicylic acid (SA), as a hydrolysis product, in solid pharmaceutical formulations containing acetylsalicylic acid (ASA). Recently, we described a sensitive and accurate fluorescence method that provided, through a mathematical application, the simultaneous determination of ASA and SA. By means of the spectrofluorimetric method reported herein it was possible to carry out the SA determination, without any mathematical calculation and with a sensitivity 100 times that of our previous method. The intra- and inter-day reproducibility of the spectrofluorimetric method, expressed as the relative standard deviation, ranged from 0.1 to 0.3%. The present method requires a fluorescence apparatus with the excitation and detection systems in-line (zero angle). The detection system was not sensitive to the excitation wavelength, but was highly sensitive to emission wavelengths from 350 to 800 nm. The results obtained were compared with those of our previous spectrofluorimetric method, together with those of a high-performance liquid chromatography method and a US Pharmacopeia method. The sensitivity of the method was of the order of 10(-8) g.
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