Lipids liposomes

Janoff, A.S., Lipids, liposomes, and rational drug design, Laboratory Investigation, 1992, 66, 655-658. 

Another possibility is described by Chapman et al. (27). Bacteria cells can incorporate diacetylene carbonic acids into their membrane, if they are grown on these lipids. Brief irradiation of the cells causes visible spectral changes similar to those observed when synthetic lipid liposomes are irradiated. 

Song L, et al. Characterization of the inhibitory effect of PEG-lipid conjugates on the intracellular delivery of plasmid and antisense DNA mediated by cationic lipid liposomes. Biochim Biophys Acta 2002 1558 1. 

Definity/phospholipid -1- PEG-phospho-lipid liposome aqueous dispersion with gas headspace requires preactivation by high-speed mixing CjFg Approved in US [24]... 

M. Fresta and G. Puglisi, Corticosteroid dermal delivery with skin-lipid liposomes. J. Contr. Rel. 44 141-151 (1997). 

Gray, G.M. and White, R.J., Epidermal lipid liposomes. A novel non-phospholipid membrane system, Biochem. Soc. Trans., 7, 1129, 1979. 

Patel, G. B., and Sprott, G. D. (1999), Archaeobacterial ether lipid liposomes (archaeosomes) as novel vaccine and drug delivery systems, Crit. Rev. Biotechnol., 19, 317-357. 

The concentration quenching of the excited singlet state of chlorophyll in lipid liposomes and vesicles has been shown to occur (Beddard et al., 1976). Electron-transfer reactions between diphenylamine and duroquinone and... 

Abraham, W., Wertz, P. W., Landmann, L. and Downing, D. T. (1987). Stratum comeum lipid liposomes Calcium-induced transformation into lamellar sheets. J. Invest. Derm. 88 2 2. 

Key words AFM, GDNT, Tetraether lipids. Liposome, Sulfolobus acidocaldarius, Archae... 

The potential applications of archaebacterial lipid liposomes (archaeosomes) as novel vaccine and drug delivery systems have been reviewed recently.88-90 In general, this type of liposomes exhibited higher stability to oxidation, high temperature, alkaline pH, and action of phopholipases. The safety profile study of these type of liposomes had shown that they are well tolerated after intravenous or oral delivery in mice. The stability and safety profile of these liposomes indicated that they may offer a superior alternative to the use of conventional liposomes. 

Liposomes are stable microscopic vesicles formed by phospholipids and similar amphipathic lipids. Liposome properties vary substantially with lipid composition, size, surface charge, and the method of preparation. They are therefore divided into three classes based on their size and number of bilayers. 

A. Angel, Studies on the compartmentation of lipid in adipose cells. I Subcellular distribution, composition, and transport of newly synthesized lipid liposomes, J. Lipid Res., 1970, 11, 420. 

In a subsequent study, van Hal et al. [40] reported that a decrease in cholesterol content in liquid state bilayers, which increases bilayer fluidity, resulted in an increase in estradiol transport across SC. With confocal laser scanning microscopy, Meuwissen et al. examined the diffusion depth of gel- vs. liquid-state liposomes labeled with fluorescein-dipalmitoylphosphatidylethanolamine (fluorescein-DPPE) with human skin in vitro [41] (Figure 3) and rat skin in vivo [42] and found that the lipophilic label when applied in liquid-state bilayers onto the skin penetrated deeper into the skin than when applied in gel-state liposomes. Recently, Fresta and Puglisi [43] reported that corticosteroid dermal delivery with skin-lipid liposomes was more effective than delivery with phospholipid vesicles, both with respect to higher drug concentrations in deeper skin layers and therapeutic effectiveness. This is a very surprising result, because skin lipid liposomes are rigid and form stacks of lamellae on the surface of the skin [44]. From the previously mentioned studies it seems clear that the thermodynamic state of the bilayer plays a crucial role in the effect of vesicles on dmg transport rate across skin in vitro. 

In addition to calcium phosphate transfection, methods for DNA transfer into mammalian cells by electroporation [31, 32] and by transfection mediated through cationic lipids, liposome [33-35], biohstics [36] and polymers [37, 38] have been developed. Most of these techniques have been reported to mediate higher transfection efficiencies as compared to calcium phosphate-mediated DNA transfer. Such claims must be regarded with some caution, as all DNA transfer techniques estabhshed so far suffer from high variabihty due to technical difficulties. Other factors to cause major variations in transfection efficiency are the type of cells used and the condition of the cells prior to transfection. 

Glycoderm. [Henkel/Cospha] Sphingo-lipid liposomes with glycosaminogly-cans for dry and cracked skin care prods. restores lipid barrier of the stratum comeum. 

It should be stressed that due to very high values of buffer-membrane partition coefficients and low CMC values, the effect of resorcinolic lipids injected into the external medium is different from the effect observed when they were present internally in the membrane. For instance, the same homologues that are highly hemolytic when injected into erythrocyte suspension are not lytic when injected in the form of phosphatidylcholine-resorcinolic lipid liposomes, which indicates that direct exchange of resorcinolic lipids between membranes is limited. 

Fig. 4. Liposome-embedded (Lipid liposome/lipid-heme)...

An alkylimidazole derivative having a vinyl bond was synthesized 1-imidazolyl-dodecadienoylacid ester 20) The phospholipid derivative 18 or 19 was copoly-merized with 20 in the presence of / 7 to give a more advanced poly-lipid liposome/ lipid-heme (Fig. 8) where 17 was more strongly fixed into the poly-lipid liposome. 

By TEM of the poly-lipid liposome/lipid-heme the diameter was ca. 350 A (Fig. 9) and it did not change before and after the polymerization. The gel permeation chromatography and the ultracentrifugation of the liposome/heme showed that all of 77 was entrapped within the liposome. Solution properties of the poly-lipid liposome/ lipid-heme were almost the same as those of human blood specific gravity 1.012, viscosity 3.75-4.12 cp, and osmotic pressure 334 mOsm. The solution of the polylipid liposome/lipid-heme was stable and could be stocked for months without precipitation and change of the particle size, i.e. without aggregation and fusion of the liposome, at ambient temperature. 

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