| Popis: |
The main difference between the various methods of liposome production is the technique employed for the dispersion of phospholipids in aqueous media. This key physical process leads to the spontaneous formation of phospholipid bilayers. Three basic methods [1, 9, 12] have been used for the dispersion step: physical dispersion and two-phase dispersion, and detergent solubilization. In contrast to the physical dispersion and two-phase dispersion techniques, the detergent solubilization technique [4, 7, 8] is a sizing-up procedure starting with very small bilayer structures called mixed micelles in the size range of about 2–15 nm, depending primarily on the chemical as well as physicochemical nature of the detergent and the molar phospholipid/ detergent ratio used. Liposome size reduction by sonication, high-pressure extrusion, membrane extrusion, high speed dispersion, or high-pressure homogenizing has at least one and in most cases several disadvantages regarding vesicle size distribution and vesicle polydispersity. |
