Preparation and characterization of biopolymeric nanoparticles used in drug delivery.

Nanotechnology plays an important role in advanced biology and medicine research particularly in the development of potential site-specific delivery systems with lower drug toxicity and greater efficiency. These include microcapsules, liposomes, polymeric microspheres, microemulsions, polymer micelles, hydrogels, solid nanoparticles etc. In the present study, preparation and characterization of biopolymeric gelatin nanoparticles for encapsulating the antimicrobial drug sulfadiazine and its in vivo drug release in phosphate buffer saline (PBS) have been investigated. The nanoparticles prepared by second desolvation process varied in a size range 200 nm and 600 nm with a drug entrapment efficiency of 50% characterized by atomic force microscopy and dynamic light scattering. The drug release from the nanoparticles occurred up to 30% in a controlled manner.

Organic and inorganic selenium compounds produce different protein patterns in the blood plasma of rats

Some selenium compounds offer important health benefits when administered at supranutritional doses, such as improvement of the immune system and of male fertility, and the prevention of some types of cancer. The traditional selenium indexes do not account for the metabolic status of this element among replete individuals. As a consequence, there is a need for new indexes that distinguish between repletion statuses of selenium. The aim of this work was to indentify some plasmatic proteins that respond to supranutritional doses of selenium, which could be proposed as new protein markers of selenium intake. The effect on rats of dietary supplementation with either selenomethylselenocysteine (SMSeC) or sodium-selenate on some blood plasma proteins was investigated. Two experimental groups consisting of six rats each were fed a basic diet supplemented with either SMSeC or sodium-selenate at 1.9 mg-Se / g-diet for ten weeks. The control group was fed a diet that contained the recommended selenium dose (0.15 mg-Se / g-diet). The changes in the abundance of a group of plasmatic proteins were quantified and analysed statistically. Haptoglobin, apolipoprotein E and transthyretin increased their abundance after diet supplementation with either form of selenium. HNF6 was responsive only to SMSeC, whereas fibrinogen responded only to sodium-selenate. We postulate that the protein patterns observed in this work could be proposed as new molecular biology-based markers of selenium intake.

Inhibición del crecimiento de pseudomonas aeroginosa en la determinación de salmonellae / Growth inhibit of pseudomonas aeroginosa to salmonellae determination

Los caldos selectivos con cisteina HCL 0.05 por ciento, cubiertos con parafina resularon ser mas efectivas para la inhibición de pseudomonas aeroginosa que los caldos cisteinadas sin cubiertas de parafina. El caldo selenita fue más efectivo para dicha inhibición que el calcio tetrationate. El agar desoxicolato citrato (incubado aeróbica o anaeróbicamente) resultó el más efectivo para la inhibición, especialmente cuando se aisló a partir de caldos cisteinados parafinadas. El agar verde brillante rojo de fenal-lactosa incubada aeróricamente tambien resultó util para dicha inhibición, cuando se aisló a partir de caldo solenito cisteinado y parafinado. Siendo no recomendable la incubación anaeróbica debido a las variaciones de forma y color de las colonias. El agar bismuto sulfito es muy buen medio de cultivo respecto a la diferenciación de las colonias de ambos microorganismos, pero no se logró inhibir totalmente el crecimiento de pseudomonas, aunque hubo una notable disminución del crecimiento, cuando se incubó el agar bajo condiciones anaeróbicas.