RESUMEN
The atomic-force microscopy-based method of irreversible chemical AFM-fishing (AFM-IF(Ch)) has been developed for the detection of proteins at ultra-low concentrations in solution. Using this method, a very low concentration of horseradish peroxidase (HRP) protein (10(-17) M) was detected in solution. A theoretical model that allows the description of obtained experimental data, is proposed. This model takes into consideration both the transport of the protein from the bulk solution onto the AFM-chip surface and its irreversible binding to the activated area.
Asunto(s)
Avidina/aislamiento & purificación , Proteínas del Huevo/aislamiento & purificación , Peroxidasa de Rábano Silvestre/aislamiento & purificación , Microscopía de Fuerza Atómica/métodos , Simulación por Computador , Cinética , Dispositivos Laboratorio en un Chip , Microscopía de Fuerza Atómica/instrumentación , Modelos Químicos , Unión Proteica , SolucionesRESUMEN
The ultrafine formulation on the base of plant phosphatidylcholine and antiinflammatory remedy indomethacin with nanoparticles less than 50 nm was obtained. Drug bioavailability after its peroral administration to rats was more than 2 fold higher as compared with free indomethacin. Increased antiinflammatory activity of indomethacin in phospholipids nanoparticles as compared with its free form was shown in two models of inflammation - adjuvant arthritis in rats and conconavalin A induced edema in mice. The increased bioavailability of indomethacin after administration of its phospholipid formulation allows to decrease a dose for achievement of therapeutic effect, that reduces risks of occurrence of collateral displays.
Asunto(s)
Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/sangre , Portadores de Fármacos/química , Indometacina/administración & dosificación , Indometacina/sangre , Fosfolípidos/química , Administración Oral , Animales , Antiinflamatorios no Esteroideos/inmunología , Antiinflamatorios no Esteroideos/uso terapéutico , Artritis Experimental/tratamiento farmacológico , Disponibilidad Biológica , Modelos Animales de Enfermedad , Indometacina/inmunología , Indometacina/uso terapéutico , Masculino , Ratones , Ratones Endogámicos CBA , Nanopartículas , Tamaño de la Partícula , Ratas , Ratas WistarRESUMEN
Comparative analysis of oils, prepared from flax, sesame and silybum seed composition, and adequate oil blends, prepared by mixing flax oil, sesame oil and silybum oil was performed. Antiradical activity was evaluated for the oils, both for their methanol-soluble phase and the fraction insoluble in methanol. DPPH radical scavenging activity expressed in Trolox equivalent antioxidant capacity. Oxidative stability during 6-month store was evaluated by peroxide value and dienic conjugates content. Oils from seed composition show the more high antiradical activity and oxidative stability than adequate oil blends. A significant correlation was found between antiradical activity and gamma-/alpha-tocopherol ratio in oils.
Asunto(s)
Antioxidantes/análisis , Radicales Libres/química , Aceite de Linaza/química , Aceite de Sésamo/química , Silybum marianum/química , Ácidos Grasos/análisis , Análisis de los Alimentos , Lignanos/análisis , Aceite de Linaza/aislamiento & purificación , Oxidación-Reducción , Aceites de Plantas/química , Aceite de Sésamo/aislamiento & purificación , Tocoferoles/análisisRESUMEN
Antioxidant activity and the oxidative stability were investigated in flax, sesame, silybum oils and oils with different omega-6/omega-3 fatty acid ratio. The content of antioxidants (AO) in crude oils and their reactivity towards peroxyl radicals were studied using kinetic method for addition of oil in a model reaction of cumol oxidation. There were correlations between PUFA/omega-9 and thermal stability (50 degrees C); between gamma-tocopherol content and resistantance to oxidative changes after storage at (10 +/- 2) degrees C for 6 months.
Asunto(s)
Antioxidantes/química , Ácidos Grasos Omega-3/química , Ácidos Grasos Omega-6/química , Aceites de Plantas/química , Derivados del Benceno/química , Radicales Libres/química , Calor , Oxidación-Reducción , gamma-Tocoferol/químicaRESUMEN
The recent studies in nanotechnology resulted in the development of novel formulations with improved bioavailability. This is especially important for oral administered drugs as the most convenient formulations. The current review deals with the processes occurring at the gastro-intestinal (GI) tract and their influence on the drug form. The increase of bioavailability of the drug may be achieved through designing novel formulations according to the specific drug properties. They include capsules that release pharmaceutical agents at various parts of the GI tract, floating systems that prolong the presence of the drug in the GI tract, dispersed forms with surface-active soluble polymers, micelles that carry poor-soluble drugs inside their non-polar core, agents that facilitate tight junction opening, such as caprate and chitosan, and lipid-based formulations. The own data show the stimulating influence of phospholipid nanoparticles on peroral absorption of drug indomethacin in rats and on passage of transport marker and drugs through Caco-2 cell monolayer in vitro. The review summarizes current understanding of factors that influence the bioavailability of the oral drug forms, currently used models for pharmacokinetic studies, and various approaches to developing novel pharmaceutical forms that increase the bioavailability of the drugs.