Study on Higher Order Phase Transition of Phospholipid Bilayrs and Stability of Emulsion Formed with These Disperisons

磷脂双层的高阶相变及其分散体乳液的稳定性研究

• 批准号: 06453059
• 负责人: TAJIMA Kazuo
• 金额: $ 4.74万
• 依托单位: Kanagawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06453059/
• 关键词: ESR spectra for phospholipid bilayr; Thermal properties of DMPC; Thermal properties of DMPG; Higher order phase transition in bilayr; Emulsifier of phospholipid; Stability of emulsion; Coalescene kinetics; Preparation of emulsion with phospholipids

This work was carried out to make clear the thermal properties of lamellar liquid crystals of dimyristoylphosphatidylcholine (DMPC) and dimyristoryphosphatidylglycerol (DMPG) dispersed in water, and emulsions of hexadecane formed with these lipids. Main measurements for the lipid dispersions were made on the temperature dependence of heat capacity at constant pressure, equilibrium apread pressure on water, X-ray diffraction analysis, ESR spectra, DSC,and zeta-Potential.As a result, it was confirmed from these experiments that in the lamellar liquid crystals of the (L_<alpha>+H_2O) phase a higher order phase transition of bilayr occurred at the temperatures several degrees higher than their gel-liquid crystral transition temperatures (Tm ; 23.5ﾟC for DMPC and 23.7ﾟC for DMPG). The higher order phase transition for these lipids were observed at 29.0ﾟC for DMPC dispersion and at 31.7ﾟC for DMPG dispersion. The physical and surface-chemical properties of these phospholipids were found to d … More iffer incredibly below and above T^<**>.Subsequently, the emulsification of hexadecane with DMPC dispersion was investigated below and above T^<**> temperature. It was found that the particle size, zeta-potential, and thermal stability of emulsion were changed in paralell with the variation of the thermal properties of DMPC dispersion at T^<**>. Especially, a new finding was that when hexadecane wa emulsified with DMPC at a temperature between Tm and T^<**>, the emulsion surface was covered and stabilized with the triple layrs of DMPC,but above T^<**> the surface of emulsion was composed of a monolayr of DMPC as a usual surfactant. This observation was supported by the precise study on the coalescence kinetics for the DMPC stabilized hexadecane emulsion. The conclusion was that the activation energy for coalescence of the emulsion taking place below T^<**> was twice lager than that for coalescence above T^<**>. This may explain why the emulsion formed with DMPC above T^<**> became less stable. Less

本文研究了二肉豆醇磷脂酰胆碱（DMPC）和二肉豆醇磷脂酰甘油（DMPG）在水中分散的层状液晶的热性质，以及与这些脂质形成的十六烷乳液。脂质分散体的主要测量方法是恒压下的热容、水的平衡扩散压力、x射线衍射分析、ESR谱、DSC和ζ势的温度依赖性。结果表明，在（L_< α >+H_2O）相的层状液晶中，双层膜在比其凝胶-液晶转变温度（Tm； DMPC为23.5ºC， DMPG为23.7ºC）高几度的温度下发生了更高阶的相变。在DMPC分散温度为29.0、DMPG分散温度为31.7时，脂质出现了高阶相变。这些磷脂的物理和表面化学性质在T^<**>以下和高于T^<**>时差别很大。随后，在T^<**>温度下和高于T^<**>温度下，研究了DMPC分散体对十六烷的乳化作用。结果表明，在T^<**>时，DMPC分散体的热性能随乳液粒径、ζ势和热稳定性的变化而变化。特别的是，当十六烷与DMPC在Tm ~ T^<**>之间乳化时，乳剂表面被三层DMPC覆盖并稳定，但在T^<**>以上，乳剂表面由单层DMPC作为通常的表面活性剂组成。对DMPC稳定的十六烷乳液聚结动力学的精确研究支持了这一观察结果。结果表明，在T^<**>以下发生聚结的乳化液活化能是T^<**>以上发生聚结活化能的2倍。这可以解释为什么DMPC在T^<**>以上形成的乳液变得不稳定。少

项目成果

K.Tajima,Y.Imai,et al: "ESR Study on DMPC and DMPG Bilayers in the (L_a+H_2O) Phase" Langmiur. 12. 6651-8 (1996)

K.Tajima、Y.Imai 等人：“(L_a H_2O) 相中 DMPC 和 DMPG 双层的 ESR 研究”Langmiur。

K.Tajima, Y.Imai, K.Ando, A.Nakamura, M.Koshinuma: "X-ray diffraction Study on Smectic Liquid Crystal State of Dimyristoylphosphatidylcholine" Chemistry Lettes. 1995. 527 (1995)

K.Tajima、Y.Imai、K.Ando、A.Nakamura、M.Koshinuma：“二肉豆蔻酰磷脂酰胆碱近晶液晶态的 X 射线衍射研究”化学快报。

K.Tajima,Y.Imai,et al: "Thermal Properties of Hexadecane Emulsion Stabilized with Dimyristoylphosphatidylcholine" J.Jpn.Oil Chem.Soc.46. 283-291 (1997)

K.Tajima、Y.Imai 等人：“用二肉豆蔻酰磷脂酰胆碱稳定的十六烷乳液的热性能”J.Jpn.Oil Chem.Soc.46。

K.Tajima,Y.Imai,et al: "Coalescence Kinetics of Hexadecane Emulsion Formed with Dimyristoylphosphatidylchiline" J.Jpn.Oil Chem.Soc.46. (1997)

K.Tajima、Y.Imai 等人：“用二肉豆蔻酰磷脂酰基啉形成的十六烷乳液的聚结动力学”J.Jpn.Oil Chem.Soc.46。

K.Tajima, Y.Imai, M.Koshinuma, A.Nakamura: "Thermal Properties of Hexadcane Emulsion Stabilized with Dimyristoylphosphatidylcholine" J.Jpn.Oil Chem.Soc.46 (3). 283-291 (1997)

K.Tajima、Y.Imai、M.Koshinuma、A.Nakamura：“用二肉豆蔻酰磷脂酰胆碱稳定的十六烷乳液的热性能”J.Jpn.Oil Chem.Soc.46 (3)。