- Spontaneous membrane fusion induced by chemical formation of ceramides in a lipid bilayer
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Mere chemical generation of ceramide and related double-chain lipids in the membrane of small unilamellar vesicles (SUVs) induces fusion of the vesicles. The lipids can be successfully prepared by dehydrocondensation between single-chain lipids (fatty acids and sphingosine or its analogues) in a lipid bilayer of the SUV by using a combination of 2-chloro-4,6-dimethoxy-1,3,5-triazine and amphiphilic tertiary amine catalysts, a process that can be compared to a successive enzyme model system for a fatty acyl-CoA synthetase followed by acyltransferase. The SUV spontaneously undergoes membrane fusion upon this internal chemical stimulation by the artificial enzyme system. Copyright
- Kunishima, Munetaka,Tokaji, Masafumi,Matsuoka, Keisuke,Nishida, Jin,Kanamori, Masanori,Hioki, Kazuhito,Tani, Shohei
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- Method of inducing a phase transition of a bilayer membrane vesicle
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Provided is a bilayer membrane vesicle capable of undergoing a phase transition. The bilayer membrane vesicle includes: (a) a fatty acid salt having 6 to 20 carbon atoms; (b) an alcohol or an amine compound having an aliphatic chain of 6 to 20 carbon atoms; and (c) an artificial synthetic lipid or a phospholipid capable of forming a bilayer membrane. Preferably, this bilayer membrane vesicle further contains (d) a tertiary amine as a component of the membrane. Also provided is a method of inducing a phase transition of a bilayer membrane vesicle, the method including the step of adding a dehydrating condensing agent or a dehydrating condensing agent precursor having the property of accumulating at an interface to the bilayer membrane vesicle. By causing the lipids that form a molecular aggregate to chemically change, it is possible to change the physical property and the morphology of the molecular aggregate and control the timing of phase transitions such as membrane fusion. In the membrane fusion, for example, fusion can occur without leakage of the contents of the bilayer membrane vesicle.
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Page/Page column 13; 14
(2018/11/10)
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- MOLECULAR AGGREGATE CAPABLE OF UNDERGOING PHASE TRANSITION BY DEHYDRATING CONDENSATION AND METHOD OF PHASE TRANSITION THEREOF
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The present invention provides a bilayer membrane vesicle capable of undergoing a phase transition, and the bilayer membrane vesicle comprises as components of the membrane, (a) a fatty acid salt having 6 to 20 carbon atoms; (b) an alcohol or an amine compound having an aliphatic chain of 6 to 20 carbon atoms; and (c) an artificial synthetic lipid or a phospholipid capable of forming a bilayer membrane. Preferably, this bilayer membrane vesicle further comprises (d) a tertiary amine as a component of the membrane. The present invention also provides a method of inducing a phase transition of a bilayer membrane vesicle, the method comprising a step of adding a dehydrating condensing agent or a dehydrating condensing agent precursor having property of accumulating at an interface to the bilayer membrane vesicle. According to the present invention, by causing the lipids that form a molecular aggregate to chemically change, it is possible to change the physical property and the morphology of the molecular aggregate and control the timing of phase transitions such as membrane fusion. In the membrane fusion, for example, fusion can occur without leaking out the contents of the bilayer membrane vesicle.
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- Compositions for topical application to skin, hair and nails
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Compositions for treating skin, hair and nails which contain 25-hydroxycalciferol in combination with a lipid ingredient. The compositions avoid the toxic effects of 1,25-dihydroxycalciferol, yet attain keratinocyte differentiation and provide additional benefits. Also disclosed is a method of improving or preventing the appearance of wrinkled, flaky, aged, photodamaged skin by applying to skin a composition containing in a cosmetically acceptable vehicle 25-hydroxycalciferol and a lipid ingredient.
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- Compositions for topical application to skin, hair and nails
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Compositions for treating skin, hair and nails which contain 25-hydroxycalciferol in combination with a lipid ingredient. The compositions avoid the toxic effects of 1,25-dihydroxycalciferol, yet attain keratinocyte differentiation and provide additional benefits. Also disclosed is a method of improving or preventing the appearance of wrinkled, flaky, aged, photodamaged skin by applying to skin a composition containing in a cosmetically acceptable vehicle 25-hydroxycalciferol and a lipid ingredient.
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- Synthetic ceramides and their use in cosmetic compostions
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A novel pseudoceramide which has improved dispersibility in aqueous solutions and which can be produced by an economical manufacturing process. The process for producing new pseudoceramides and cosmetic compositions containing the new pseudoceramides are also disclosed.
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- A comparative study of the liquid-crystalline behavior of three homologous series of 1,2-propanediol derivatives
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Homologous series (R = n-hexyl to n-tetradecyl) of 3-(alkylamino)-, 3-(alkylthio)- and 3-alkoxy-1,2-propanediols have been synthesized and their thermal behavior studied by thermomicroscopy and differential-scanning calorimetry.The occurence of liquid-crystalline behavior was found to be strongly dependent on both the alkyl-chain length and the hetero-atom that links the alkyl chain to the 1,2-propanediol moiety. No thermotropic liquid-crystalline behavior could be observed for 3-alkoxy-1,2-propanediols; 3-(heptylamino)- through 3-(nonylamino)-1,2-propanediol exhibit a transient smectic A phase on supercooling of the isotropic liquid, whereas 3-(hexylthio)-1,2-propanediol through 3-(nonylthio)-1,2-propanediol form smectic phases that are quite stable.Although the thermal behavior in the pure form differs considerably, all three classes of compounds are capable of lyotropic mesophase formation in the presence of water.
- Doren, Henk A. van,Geest, Ralph van der,Kellogg, Richard M.,Wynberg, Hans
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p. 197 - 203
(2007/10/02)
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