Visualisation of liposomes prepared from skin and stratum corneum lipids by transmission electron microscopy.

Transmission electron microscopy was used to visualize the liposomes prepared from total lipids extracted from mouse, human and porcine skin and stratum corneum. The total lipid composition was monitored by high precision thin layer chromatography coupled with a flame identification detector (HPTLC/FID, Iatroscan) and the fatty acid content of the samples was monitored by gas chromatography. The liposomes were prepared by the thin lipid film hydration method and they were visualized by transmission electron microscopy after negative staining using uranyl acetate. The structure of the vesicular structures present in the formulations largely depended on the lipid composition of the samples. The liposomes with high ceramide content were drop like vesicles with sharp tips, whereas the presence of excessive phospholipid content lead to bag like liposomes with two hemispheres divided by a membrane. Finally, the tendency of triacylglycerides to accumulate in the lipophylic region of the lipid bilayer, forms membranes with uneven thickness, resulting in structures with undulated membranes. A degree of fusion depending on the phospholipid content was also observed.