1,721,086 research outputs found
Liposomes in cosmetics: which kind of phospholipid? Which loading method?
No full textPhospholipids of different origin (egg and soya) and purity were used to prepare liposomes by sonication. Loading of these vesicles was performed by means of two different techniques using a fluorescent lipophilic model molecule. The stability of the aggregated structures was checked by addition of increasing amounts of a surfactant to the liposome dispersion. No remarkable differences were observed in either the stability in regard to surfactant-induced breakage or the loading capacity of liposomes respectively prepared with 99% pure egg phosphatidylcholine or with the vegetable phospholipid, a commercial product that had a much lower purity. The comparison of the two loading methods indicated that incorporation of the model molecule within the vesicle structure was higher when the fluorescent marker was added before sonication
Egg and soya phospholipids, sonication and dialysis: a study onliposome characterization
No full textLiposome-Triton X-100 interactions were studied by turbidity measurements and two detergent concentrations, corresponding to the maximum (i.e., detergent-saturated vesicles; Rsat) and minimum (i.e., completely disruped liposomes; Rsat) turbidity values, were identified. The tested liposomes (SUV) were prepared with phospholipids of different origin (egg and soya) and according to different methods (sonication and dialysis). The data obtained, together with size measurements carried out by electron microscopy, were related to the stability of the vesicles. © 1995
Liposomes in cosmetics (II): entrapment of a hydrophylic probe
No full textPhospholipids of different origin (egg and soya) and purity were used to prepare liposomes by sonication. Loading of these vesicles with a fluorescent hydrophilic model molecule (calcein) was carried out by means of two different methods. No appreciable differences were observed in the loading capacities of liposomes prepared with the two products. Obtained results indicated that the fraction of incorporated or absorbed calcein was always very small with respect to the total amount of this substance used for the preparation of the vesicles; furthermore, the quantity of hydrophilic probe in the vesicle structure was remarkably affected by the loading method.
The results of this investigation allowed us to consider the possible incorporation, inion the vesicles, of additives that can be present in a formulation containing liposomes
Lipid peroxidation of L-alpha-phosphatidylcholine from fresh egg yolk and from soybean during liposome preparation andstorage
No full textOxidative processes that may occur when susceptible materials like phospholipids are processed and stored should be avoided because they can lead to undesired byproducts. Our attention was focused on the formation of hydroperoxides of conjugated dienes of the esterified polyunsaturated fatty acids that are present in phospholipids. The method used for the evaluation of lipid peroxidation was based on the determination of the "oxidation index" calculated from UV absorbance. The investigated products were phospholipids of different origin and purity, with and without antioxidants; their autooxidation process was evaluated in the presence of air and under nitrogen. A comparison of the behavior of the various tested products, under the different experimental conditions, indicate how important it is to acquire informations on the autooxidation process for a correct preparation of cosmetic, dermatological or other formulations containing liposomes. © 1993 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
L'insediamento neolitico nella media valle ofantina: l'area di Palata (Canosa di Puglia)
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