Large unilamellar liposomes

Allen, T. M., and Chonn, A. (1987). Large unilamellar liposomes with low uptake into the reticuloendothelial system, FEBS Lett., 223. 42-46. 

Ellens, H., Morselt, H. W. M., Dontje, B. H. J., Kalicharan, D., Hulstaert, C. E., and Scherphof, G. L. (1983). Effects of liposome dose and the presence of lymphosarcoma cells on blood clearance and tissue distribution of large unilamellar liposomes in mice, Cancer Res.. 43. 2927-2934. 

Nichols, J. W. and Deamer, D. W. (1980). Net proton hydroxyl permeability of large unilamellar liposomes measured by an acid-base titration technique, Proc. Natl Acad. Sci. USA, 77, 2038-2042. 

SUV = small unilamellar liposomes, LUV = large unilamellar liposomes. 

Intermediate-sized unilamellarvesicles (lUVs) have diameters of the order of magnitude of 100 nm, and are called large unilamellarvesicles (LUVs) if the size is more than 100 nm and they consist of a single bilayer. For unilamellarvesicles, the phospholipid content is related to the surface area of the vesicles, which is proportional to the square of the radius, while the entrapped volume varies with the cube of the radius. In addition, because of the Lnite thickness of the membrane (ca. 4 nm), as thf vesicles become smaller, their aqueous volume is further reduced since the phospholipids occupy more of the internal space. Consequently, for a given quantity of lipid, large unilamellar liposomes... 

The partition coefficients of triphenylalkylphosphonium homologs have been determined in gel bead-immobilized small or large unilamellar liposomes by chromatography [8]. It was claimed that the technique, immobilized liposome chromatography (ILC), is suitable for the determination of membrane partition coefficients of drugs. 

Emulsions of water and CO2 have been used to form liposomes in one step without any organic solvent (57). The liposomes were made by forming a W/C emulsion stabilized with/L-i -dipalmitoylphosphatidylcholine. The pressure was reduced to form the liposomes by a reversed phase evaporation method. Large unilamellar liposomes with diameters of 0.1 to 1.2 pm were formed and used to trap D-( + )-glucose. 

Large unilamellar liposomes (LUVs, as described in Note 8) and plasmid DNA will not be pelleted by this procedure (94). 

Chonn A, Semple SC, Cullis PR. Association of blood proteins with large unilamellar liposomes in vivo relation to circulation lifetimes. J Biol Chem 1992 267 18759-18765. 

Addition of increasing amount of amphiphysinl to a reaction mixture containing large unilamellar liposomes (1779.5 461.7 nm in diameter) produced a prominent increase of the GTPase activity. The activity was maximal when the molar ratio of dynamin to amphiphysin 1 was in the 1 1-2 range (Fig. 2A). In contrast, amphiphysin drastically decreased the GTPase activity of dynamin in the presence of the small liposomes. 

Fig. 2. GTPase activity of dynamin with amphiphysin. Dynamin GTPase activity was assayed in the presence of large unilamellar liposome (A) or small liposome (B). Note that the different effect of amphiphysin on dynamin GTPase activity was observed by the size of liposomes. (Reproduced with permission from Y. Yoshida et al [2004]. EMBO J. 23, 3483-3491.)...

Liu, D. and L. Huang, 1989, Role of cholesterol in the stability of pH-sensitive, large unilamellar liposomes prepared by the detergent-dialysis method. Biochim Biophys Acta 981 254-260. 

Figure 3. Both a-tocopherol and y-tocopherol have similar abilities to quench in vitro lipid peroxidation. The addition of 16 iM i ,i ,i -a-tocopherol ( ) or 16 pM / ,/ ,/ -Y-tocopherol (+) separately, or a mixture of both 8 pM i ,i ,i -a-tocopherol and 8 pM R,R,R-y-tocophero (A), equally inhibited the formation of fluorescent lipid peroxidation products (assayed as described by Shimasaki, 1994) compared with levels seen in control samples ( ) of large unilamellar liposomes oxidized in the presence of 7.4 mM 2,2 -azobis(2-amidinopropane) dihydrochloride.

Maruyama, K., Yuda, T., Okamoto, Ishikura, C, Kojima. S., and Iwatsuru, M., 1991, Effect of molecular weight in amphipathic polyethyleneglycol on prolonging the circulation time of large unilamellar liposomes. Chem. Pharm. Bull.,39 1620-1622. 

---