| Abstract
| - A novel aqueous dispersion of particles with bicontinuous cubic phases in their interior (cubosomes) wasprepared. A nonionic triblock copolymer, Pluronic F127, was used as an emulsifier of a liquid crystal phaseof hydrated monoolein (MO). Dynamic light scattering showed that particles with an average diameterof 160−270 nm were formed by high-pressure emulsification. Particle size decreased as the weight ratioof F127 to MO increased up to 10%, whereas it was constant at higher than 10%. Small-angle X-rayscattering experiments confirmed the presence of two kinds of cubic structures (CD and CP). At 3% F127,the diffraction pattern corresponding to the CD was dominant and the diffraction of the CP was minimallydetected, suggesting that the polymer preferably emerges to the surface of the particles and the interiorhas a CD structure consisting mostly of hydrated MO. The proportion of the CP increased with F127content, which suggests that preferentially concentrated F127 at the surface participates in the formationof the CP phase. 13C NMR experiments with a paramagnetic shift reagent showed that the signal of thecarbonyl carbon of oleic-1-13C acid mixed in the particles readily shifted to a lower magnetic field byaddition of europium ion (Eu3+), indicating high accessibility of the ion into the water channel inside theparticles.
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