The aim of this study was to use a vegetal protein (gliadin) as a wall-forming component to produce microcapsules. The microencapsulation technique employed was the simple coacervation method and the encapsulated product was a non-food oil, hexadecane. Hexadecane was emulsified by a gliadin solution and the coacervation phenomena induced by adding a salt-solution in the continuous phase of the emulsion containing gliadin. The study of the coacervation conditions has shown that the richer in protein the continuous phase, the smaller the quantity of salt required. The main problem of the microencapsulation process by salting-out was to control the capsule size and the agglomeration of the capsules. This study succeeded in preventing the agglomeration phenomenon by adjusting the kinetics of the salt addition. When the feed rate of salt solution was very slow, this aggregation was considerably decreased. The suitable quantity of cross-linker (glutaraldehyde) to harden the microcapsules was determined by an electrophoresis method. The effect of different process parameters (gliadin concentration, quantity and addition kinetics of the coacervation agent, cross-linker concentration) was studied with regard to the final microcapsule characteristics (shape, size, composition, and mechanical resistance evaluated by a centrifugation test).

Cross-Linking Reagents↗

PubMedDate not supplied

Localization of S100 protein in the rat cerebellum: an immunoelectron microscope study.

Immunoelectron microscopy has shown that, in adult rat cerebellum, S100 protein is localized exclusively in the astroyctes of both the cortex and the white matter. The labelling pattern was unaffected by the inclusion of glutaraldehyde in the primary paraformaldehyde fixative. The immunoperoxidase reaction product is observed over both the perikaryal cytoplasm of astrocytes and their processes. S100 proteins was not found in neuronal structures nor in oligodendrocytes.

Animals↗

PubMedDate not supplied

Effects of abnormal thyroid state and undernutrition on carbonic anhydrase and oligodendroglia development in the rat cerebellum.

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Animals↗

PubMedDate not supplied

Effects of thyroid state and undernutrition on S100 protein and astroglia development in rat cerebellum.

The developmental pattern of S100 protein, a specific marker of astroglia, was studied by radioimmunoassay in the cerebellum of thyroid-deficient, thyroxine-treated and undernourished rats during development. In the control animals, the S100 protein content of the cerebellum increased maximally after the 3rd postnatal week, i.e., after cell multiplication had stopped and when the cerebellum had acquired more than 70% of its adult weight and protein content. This developmental pattern of S100 protein reflected essentially the maturation of astroglia. In the thyroxine-treated rats the total amount and the concentration of S100 protein were higher than in controls during the first 3 weeks of postnatal life and returned to normal values thereafter. In the thyroid-deficient rats both the amount and concentration were lower than in controls throughout development. In the undernourished animals the amount of S100 protein per organ was also lower than in controls during the whole experimental period studied; the S100 protein concentration was higher during the first 2 postnatal weeks and became lower thereafter. These results are discussed taking into consideration previous histological and ultrastructural observations on the effects of altered thyroid state and undernutrition on the formation and maturation of cerebellar astrocytes.

Animals↗

PubMedDate not supplied

Study of a microencapsulation process of a virucide agent by a solvent evaporation technique.

A highly water-soluble virucide agent was microencapsulated by a water/oil/water emulsification-solvent evaporation method. An aqueous drug solution was emulsified into a solution of polymer in methylene chloride, followed by emulsification of the primary emulsion in an external aqueous phase. Microcapsules were formed after solvent evaporation, the solidification of the microcapsule walls was followed by an optical method. The influence of stirring speed was analysed to find the optimal hydrodynamic conditions with respect to the process yield, corresponding to the weight of obtained microcapsules per litre of water/oil/water emulsion, the initial virucide agent content and the drug release kinetics. The optimal conditions were obtained for the complete suspension speed. The improvement of the microencapsulation process was attempted by increasing the concentration of the primary emulsion and by the reuse of the external aqueous phase after removal of the microcapsules.

Antiviral Agents↗