Liposomes thin film hydration method

Figure 1 Cryo-TEM microscopy of DSPC DSPG CHOL liposomes obtained by thin-film hydration method and extruded through 0.2-pm polycarbonate membranes. Abbreviations. DSPC, l,2-distearoyl-s -glycerol-3-phosphocholine DSPG, 2,2-distearoyl-5 -glycerol-3[phosphor-rac-(l-glycerol)] CHOL, cholesterol.

Liposomes are mostly prepared by the thin film hydration method in which a thin fihn is produced by dissolving the phospholipids in suitable organic solvent... 

There are many methods to prepare liposomes. This review will discuss only some of the commonly used methods. These include liposomes made by thin film hydration, reverse phase evaporation, freeze-drying, and proliposome methods. 

One of the most popular methods for preparation of liposomes is the hydration of thin lipid films, combined with freeze/thaw and extrusion cycles. 

Zhang and Zhu [60] have combined two methods in preparing liposomes, by hydrating particulate-based proliposomes followed by freeze-drying. This approach has been reported to enhance the entrapment of amikacin compared to the same vesicles before freeze-drying or vesicles prepared by the thin film method. 

One of the first methods for the preparation of giant liposomes was described by Reeves and Dowben [45]. They deposited a thin lipid film from chlorofomi methanol 2 1 (v/v). After drying, the film was hydrated without agitation or shaking. This method results in the preparation of a heterogeneous dispersion, and when giant vesicles became of interest other methods and improvements were developed. Many researchers deposit lipid film on a roughened (with sandpaper) Teflon surface and, prior to hydration, equilibrate the dry lipid film in a moist atmosphere [46,47]. The use of spinners allows very even film deposition [38] and it is very likely that other tools from microelectronics will be used to determine the shape and hydrophilici-ty/hydrophobicity of surfaces for the deposition of thin lipid films. 

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