Formation of tubules and giant vesicles from large multilamellar vesicles.

This study reports an observation of submicrometer multilamellar vesicles (MLVs) prepared by simply freeze-thawing a phospholipid dispersion at full hydration that transformed into giant vesicles (GVs) and tubules (TUs) when confined between microscope glass slides. Cover slide cleaning and surface treatment did not hamper the formation of GVs or TUs. However, when small unilamellar vesicles (SUV) were prepared or when MLVs were not confined but rather freely moved between the glass slides or when the phospholipid was in its gel phase, neither GVs nor TUs were observed. Altogether, our results suggested that MLVs would play a role as a lipid reservoir and that the liquid flow between the glass slides induces the peeling of the external bilayers, yielding the formation of tubules and giant unilamellar vesicles.