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1.
Nanoscale ; 10(8): 3654-3662, 2018 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-29431806

RESUMEN

In the field of nanotechnologies, theranostic approaches and fixed-dose combination products require the development of innovative carriers able to co-encapsulate several entities of interest. This communication describes the preparation and characterization of lipid-based Janus compartmented nanoparticles. They were successfully prepared using a scalable process with pharmaceutically approved excipients. The analysis of the microscopic structure and supramolecular organization demonstrated the formation of two physico-chemically different compartments enabling the co-administration at once of both liposoluble and hydrosoluble active pharmaceutical ingredients.


Asunto(s)
Portadores de Fármacos/química , Excipientes/química , Lípidos/química , Nanopartículas/química
2.
Angew Chem Int Ed Engl ; 57(18): 5171-5175, 2018 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-29431894

RESUMEN

Mixtures of water and glycerol provide popular matrices for low-temperature spectroscopy of vitrified samples. However, they involve counterintuitive physicochemical properties, such as spontaneous nanoscopic phase separations (NPS) in solutions that appear macroscopically homogeneous. We demonstrate that such phenomena can substantially influence the efficiency of dynamic nuclear polarization (DNP) by factors up to 20 % by causing fluctuations in local concentrations of polarization agents (radicals). Thus, a spontaneous NPS of water/glycerol mixtures that takes place on time scales on the order of 30-60 min results in a confinement of polarization agents in nanoscopic water-rich vesicles, which in return affects the DNP. Such effects were found for three common polarization agents, TEMPOL, AMUPol and Trityl.

3.
Biochem Biophys Res Commun ; 493(1): 146-151, 2017 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-28917836

RESUMEN

Poorly water-soluble and unstable compounds are difficult to develop as drug products using conventional formulation techniques. The aim of the present study was to develop and evaluate a nanoformulation prepared by a hot high-pressure homogenization method, which was a scalable and solvent-free process. We successfully prepared stable nanodispersions to protect a labile antibiotic, erythromycin. The mean diameter of the dispersed droplets was approximately 150 nm, and size distribution was unimodal. Dispersion was physically stable at room temperature for over six months. Using erythromycin as a model compound, we studied its antimicrobial activity in vitro on Helicobacter pylori. Results showed that drug encapsulation improves API stability in an acidic environment and is conducive to a synergistic effect between the drug and the formulation.


Asunto(s)
Apoptosis/efectos de los fármacos , Preparaciones de Acción Retardada/administración & dosificación , Eritromicina/administración & dosificación , Helicobacter pylori/efectos de los fármacos , Nanocápsulas/administración & dosificación , Nanocápsulas/química , Antibacterianos/administración & dosificación , Antibacterianos/química , Apoptosis/fisiología , Preparaciones de Acción Retardada/química , Difusión , Composición de Medicamentos/métodos , Estabilidad de Medicamentos , Emulsiones/química , Eritromicina/química , Helicobacter pylori/citología , Helicobacter pylori/fisiología , Nanocápsulas/ultraestructura , Tamaño de la Partícula
4.
Nanomedicine (Lond) ; 11(16): 2059-72, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27465123

RESUMEN

AIM: Formulate nanometric oil droplets for encapsulating solid nanoparticles and assess their interactions with cells. MATERIALS & METHODS: Soybean oil droplets, stabilized by Pluronic F68 surfactant, incorporating hydrophobically modified fluorescent silica, nanoparticles were obtained. Cytotoxicity over time, internalization, subsequent intracellular localization and internalization pathways were assessed by microscopy (fluoresence and TEM) in vitro with HeLa cells. RESULTS: Oil droplets encapsulating solid nanoparticles are readily internalized by HeLa cells like free nanoparticles but the intracellular localization differs (nanoemulsions less colocalized with lysosomes) as well as internalization pathway is used (nanoemulsions partially internalized by nonendocytic transport). No cytotoxicity could be observed for either particles tested. CONCLUSION: Our results confirm that nanometric emulsions encapsulating solid nanoparticles can be used for alternative and multifunctional intracellular delivery.


Asunto(s)
Portadores de Fármacos/química , Emulsiones/química , Colorantes Fluorescentes/administración & dosificación , Nanopartículas/administración & dosificación , Dióxido de Silicio/administración & dosificación , Aceite de Soja/química , Colorantes Fluorescentes/farmacocinética , Células HeLa , Humanos , Microscopía Confocal , Nanopartículas/química , Nanopartículas/ultraestructura , Tamaño de la Partícula , Poloxámero/química , Dióxido de Silicio/farmacocinética , Aceite de Soja/farmacocinética
5.
Microsc Res Tech ; 75(4): 425-32, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21919125

RESUMEN

Digestive tubules of Strombidae are composed by three cell types: digestive cells, vacuolated cells, and crypt cells. The last one is characterized by the presence of intracellular granules identified as spherocrystals. Such structures are known to occur in basophilic cells of gastropod digestive gland, where they are supposed to be involved in the regulation of some minerals and in detoxification. In this study, energy-dispersive X-ray analysis (EDX) and energy filtered transmission electron microscopy (EFTEM) were used to determine the elemental content of spherocrystals in two Strombidae, Strombus gigas and Strombus pugilis. In freshly collected individuals of both species, the following elements were detected: Ca, Fe, Mg, P, and Zn. Aluminum and Mn were also detected in S. gigas. Their presence in spherocrystals indicates that, in Strombidae, spherocrystals are involved in the regulation of minerals and essential trace metals. In order to answer the question "are spherocrystals involved in nonessential trace metals scavenging?," artificial cadmium and lead exposure by both waterborne and dietary pathways was applied to S. pugilis. No evidence of cadmium (Cd(NO(3))(2)) or lead (Pb(NO(3))(2)) provided by food was found in spherocrystals. Cadmium provided in water (Cd(NO(3))(2) and CdCl(2)) causes structural modifications of the digestive gland; however, this element was not trapped in spherocrystals. These results suggest that spherocrystals are not involved in detoxification of such nonessential trace metals.


Asunto(s)
Gastrópodos/fisiología , Metales/farmacocinética , Energía Filtrada en la Transmisión por Microscopía Electrónica/métodos , Espectrometría por Rayos X/métodos , Animales , Compuestos de Cadmio/metabolismo , Tracto Gastrointestinal/química , Tracto Gastrointestinal/citología , Tracto Gastrointestinal/fisiología , Tracto Gastrointestinal/ultraestructura , Gastrópodos/química , Gastrópodos/citología , Gastrópodos/ultraestructura , Inactivación Metabólica , Metales/análisis , Nitratos/metabolismo , Fósforo
6.
Mycol Res ; 113(Pt 12): 1351-64, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19737615

RESUMEN

A new genus of a deep-sea ascomycete with one new species, Alisea longicolla, is described based on analyses of 18S and 28S rDNA sequences and morphological characters. A. longicolla was found together with Oceanitis scuticella, on small twigs and sugar cane debris trawled from the bottom of the Pacific Ocean off Vanuatu Islands. Molecular and morphological characters indicate that both fungi are members of Halosphaeriaceae. Within this family, O. scuticella is phylogenetically related to Ascosalsum and shares similar ascospore morphology and appendage ontogeny. The genus Ascosalsum is considered congeneric with Oceanitis and Ascosalsum cincinnatulum, Ascosalsum unicaudatum and Ascosalsum viscidulum are transferred to Oceanitis, an earlier generic name.


Asunto(s)
Ascomicetos/clasificación , Madera/microbiología , Animales , Ascomicetos/genética , Ascomicetos/ultraestructura , Evolución Biológica , Ecosistema , Agua Dulce/microbiología , Variación Genética , Geografía , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Océano Pacífico , Filogenia , ARN Ribosómico 18S/genética , Agua de Mar , Especificidad de la Especie , Esporas Fúngicas/ultraestructura , Vanuatu
7.
Biol Cell ; 98(3): 163-70, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15892692

RESUMEN

BACKGROUND INFORMATION: Lucina pectinata is a large tropical lucinid known to harbour sulphide-oxidizing bacteria in specialized gill cells. Conventional TEM (transmission electron microscopy) has shown that bacteriocytes also harbour visibly 'empty' vesicles whose chemical content remains, to date, only roughly determined. RESULTS: In the present study, L. pectinata gill tissues were cryo-fixed as fast as possible by performing high-pressure freezing before a freeze-substitution process and finally performing a cryo-embedding in Lowicryl. Ultrathin sections were then used for a cryo-EFTEM (where EFTEM stands for energy-filtered TEM) microanalysis. Results show that bacteriocytes within the gill tissues contain elemental sulphur in small vesicles produced by the host itself. In instances of sporadic depletion of sulphur in the environment, such structures may act as energy sources for bacterial endosymbionts. CONCLUSIONS: The cryo-EFTEM techniques represent (i) the only method used to date to locate and preserve sulphur at the cellular level and (ii) a powerful tool for sulphur metabolism analysis in thioautotrophic symbiont relationships.


Asunto(s)
Crioultramicrotomía/métodos , Bacterias Gramnegativas Quimiolitotróficas/química , Energía Filtrada en la Transmisión por Microscopía Electrónica/métodos , Azufre/análisis , Simbiosis , Animales , Bivalvos/microbiología , Congelación , Bacterias Gramnegativas Quimiolitotróficas/ultraestructura , Microscopía Electrónica de Transmisión
8.
Biol Cell ; 94(4-5): 243-9, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12489693

RESUMEN

Microorganisms colonizing the exoskeletons of the tube worm Riftia pachyptila are described at the ultrastructural level. The prokaryotic cells from the worm tube wall differ from those colonizing the exoskeleton outer surface in the presence of an electron dense granule. The morphology and distribution of these bacteria-like cells are described. Prokaryotic organisms are assembled in nodules which increased in size in the oldest part of the exoskeleton. The aspect, location and elemental composition of the intracellular granules are determined. Most of them (100 nm in diameter) are located close to the cell membrane and exhibit a homogeneous and amorphous content. EDX and EFTEM microanalyses show that these structures contain phosphorus, oxygen and iron. All together these data suggest that these granules are iron polyphosphates. These structures may act as energy sources for making ATP during anoxic conditions as existing in hydrothermal environments.


Asunto(s)
Archaea/ultraestructura , Gránulos Citoplasmáticos/ultraestructura , Invertebrados/microbiología , Células Procariotas/ultraestructura , Adenosina Trifosfato/metabolismo , Animales , Archaea/metabolismo , Fuentes de Energía Bioeléctrica/microbiología , Gránulos Citoplasmáticos/metabolismo , Elementos Químicos , Metabolismo Energético/fisiología , Compuestos de Hierro/metabolismo , Microscopía Electrónica , Polifosfatos/metabolismo , Células Procariotas/metabolismo , Simbiosis/fisiología
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