Smooth/rough layering in liquid-crystalline/gel state of dry phospholipid film, in relation to its ability to generate giant vesicles

Morphological changes in a dry phospholipid film on a solid substrate were studied below and above the main transition temperature, between the gel and liquid-crystalline phases by phase-contrast microscopy and atomic force microscopy. A phospholipid film in the liquid-crystalline phase exhibits flat, smooth layering, whereas that in the gel phase shows rough, random layering. These film morphologies are discussed in relation to the ability to form giant vesicles through the natural swelling method.