Vermette Patrick
Laboratoire de Bioingénierie et de Biophysique de l'Université de Sherbrooke, Department of Chemical and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada.
Methods Enzymol. 2009;465:43-73. doi: 10.1016/S0076-6879(09)65003-5.
This chapter reviews liposome characterization by quartz crystal microbalance (QCM) measurements and atomic force microscopy (AFM). In many studies, AFM imaging is simply used to image liposomes with resolution often that does not allow morphological analysis. Although liposome size can be obtained by processing AFM images, it is found that liposomes flatten upon surface adsorption or immobilization. Liposome stability and stiffness have been characterized by using AFM imaging or AFM force measurements, although the latter method, using a microsphere attached on the AFM cantilever, seems more appropriate to limit liposome damage and to obtain more quantitative analysis, such as the Young's modulus. Investigation of liposome layers by QCM revealed that liposomes can be detected from a combined analysis of frequency and bandwidth shifts. However, QCM by itself provides only limited information on liposomes. QCM can be used to assess the presence of a layer and also to discriminate between rigid and viscoelastic ones. Liposome properties have been derived from QCM curves, but often this requires making hypotheses that are difficult to assess. AFM and QCM analyses need to be combined with other techniques to provide complementary information.
本章回顾了通过石英晶体微天平（QCM）测量和原子力显微镜（AFM）对脂质体的表征。在许多研究中，AFM成像仅用于对脂质体进行成像，其分辨率往往不足以进行形态分析。尽管可以通过处理AFM图像获得脂质体的大小，但发现脂质体在表面吸附或固定时会变平。脂质体的稳定性和硬度已通过AFM成像或AFM力测量进行了表征，尽管后一种方法，即使用附着在AFM悬臂上的微球，似乎更适合限制脂质体损伤并获得更定量的分析，如杨氏模量。通过QCM对脂质体层的研究表明，可以通过频率和带宽变化的综合分析来检测脂质体。然而，QCM本身提供的关于脂质体的信息有限。QCM可用于评估层的存在，也可区分刚性和粘弹性层。脂质体特性已从QCM曲线中推导出来，但这通常需要做出难以评估的假设。AFM和QCM分析需要与其他技术相结合，以提供补充信息。
