Imura T, Sakai H, Yamauchi H, Kaise C, Kozawa K, Yokoyama S, Abe M
Faculty of Science and Technology, Science University of Tokyo, 2641, Yamazaki, Noda, 278-8510, Chiba, Japan
Colloids Surf B Biointerfaces. 2001 Jan 15;20(1):1-8. doi: 10.1016/s0927-7765(00)00149-1.
Liposomes composed of Ceramide 3, [2S,3S,4R-2-stearoylamide-1,3,4-octadecanetriol], and L-alpha-dipalmitoylphosphatidylcholine (DPPC) were prepared by varying the amount of Ceramide 3, and the effects of Ceramide 3 on the liposome formation, particle size, dispersibility, microviscosity and phase transition temperature were examined by means of a microscopy, a dynamic light scattering method, a fluorescence polarization method, a differential scanning calorimetry (DSC) and so on. All the DPPC was able to contribute to the formation of liposomes up to 0.130 mol fraction of Ceramide 3. The particle size of liposomes was almost unaffected by the addition of Ceramide 3. The dispersibility of liposomes containing Ceramide 3 was maintained for at least 15 days. The microviscosity of liposomal bilayer membranes in the liquid crystalline state was increased with increasing the mole fraction of Ceramide 3, while that in the gel state was independent of the mole fraction of Ceramide 3. The phase transition temperature from gel to liquid crystalline states of DPPC bilayer membranes was shifted upwards with the addition of Ceramide 3, indicating a cooperative interaction between DPPC and Ceramide 3 molecules. However, a sharp DSC peak became broad and split at higher mole fractions of Ceramide 3, suggesting a phase separation in the mixed DPPC/Ceramide 3 liposomal bilayer membranes. These phenomena were suggested to be related to the previously observed fact for the mixed DPPC/Ceramide 3 monolayers that Ceramide 3 interacts with DPPC in the liquid-expanded phase with consequent phase separation accompanied with domain formation.
通过改变神经酰胺3的量制备了由神经酰胺3（[2S,3S,4R-2-硬脂酰胺基-1,3,4-十八烷三醇]）、L-α-二棕榈酰磷脂酰胆碱（DPPC）组成的脂质体，并通过显微镜、动态光散射法、荧光偏振法、差示扫描量热法（DSC）等方法研究了神经酰胺3对脂质体形成、粒径、分散性、微粘度和相变温度的影响。在神经酰胺3的摩尔分数达到0.130之前，所有的DPPC都能够促进脂质体的形成。脂质体的粒径几乎不受神经酰胺3添加的影响。含有神经酰胺3的脂质体的分散性至少维持了15天。液晶态脂质体双层膜的微粘度随着神经酰胺3摩尔分数的增加而增加，而凝胶态的微粘度与神经酰胺3的摩尔分数无关。随着神经酰胺3的添加，DPPC双层膜从凝胶态到液晶态的相变温度向上移动，表明DPPC和神经酰胺3分子之间存在协同相互作用。然而，在较高的神经酰胺3摩尔分数下，尖锐的DSC峰变宽并分裂，表明在混合的DPPC/神经酰胺3脂质体双层膜中发生了相分离。这些现象被认为与之前在混合的DPPC/神经酰胺3单层中观察到的事实有关，即神经酰胺3在液胀相中与DPPC相互作用，随后伴随着域形成的相分离。
