Mechanical properties and stability measurement of cholesterol-containing liposome on mica by atomic force microscopy
Mechanical properties and stability measurement of cholesterol-containing liposome on mica by atomic force microscopy
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DOI：
10.1016/j.jcis.2004.05.042
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发表时间：
2004-10-01
影响因子：
9.9
通讯作者：
Ng, KYS
中科院分区：
文献类型：
--
作者：
Liang, XM;Mao, GZ;Ng, KYS
利用原子力显微镜（AFM）在云母表面研究了超声处理制备的蛋黄磷脂酰胆碱（EggPC）囊泡及其胆固醇修饰囊泡的微观力学性质。通过接触模式获得了AFM针尖与未破裂囊泡之间的作用力曲线。在接近过程中，观察到两个排斥区域，两个中断。的两个排斥力制度的纯EggPC囊泡的斜率被确定为低于几倍的EggPC/胆固醇囊泡。基于赫兹模型的力图分析的弹性性质表明，与纯EggPC囊泡相比，胆固醇修饰的囊泡的杨氏模量（E）和弯曲模量（k（c））增加了几倍。显著差异归因于由于胆固醇分子的掺入而增强的EggPC囊泡的刚性。胆固醇修饰的囊泡在吸附时的行为与溶液中的不同，如机械性质所揭示的。结果表明，原子力显微镜可以提供一种直接的方法来测量吸附的小脂质体的机械性能，并检测脂质体的稳定性变化。(C)2004年爱思唯尔公司All rights reserved.
The micromechanical properties of pure and cholesterol modified egg yolk phosphatidylcholine (EggPC) vesicles prepared by sonication were studied by atomic force microscopy (AFM) on mica surface. The force curves between an AFM tip and an unruptured vesicle were obtained by contact mode. During approach, two repulsion regions with two breaks were observed. The slopes of the two repulsive force regimes for the pure EggPC vesicles are determined to be several times lower than that of EggPC/cholesterol vesicles. The elastic properties from force plot analysis based on the Hertzian model showed that Young's modulus (E) and the bending modulus (k(c)) of cholesterol-modified vesicles increased several-fold compared with pure EggPC vesicles. The significant difference is attributed to the enhanced rigidity of the EggPC vesicles as a result of the incorporation of cholesterol molecules. The behavior of cholesterol-modified vesicles upon adsorption is different from that in solution as revealed by mechanical properties. The results indicate that AFM can provide a direct method to measure the mechanical properties of adsorbed small liposomes and to detect the stability change of liposomes. (C) 2004 Elsevier Inc. All rights reserved.