Multilamellar liposomes

Multilamellar liposomes, absorbed on paper, containing extrapped peroxidase permit the quantitative determination of alcohol sulfates by measuring the amount of peroxidase released from the liposomes as this amount varies with the amount of surfactant [272]. 

Grliner, S. M., Lenk, R. P., Janoff, A. S., and Ostro, M. J. (1985). Novel multilayered lipid vesicles Comparison of physical characteristics of multilamellar liposomes and stable plurilamellar vesicles, Biochemistry. 24. 2833-2842. 

Perez-Soler, R., Lopez-Berestein, G., Kasi, L. P., Cabanillas, F., Jahns, M., Glenn, H., Hersh, E. M., and Haynie, T. (1985). Distribution of technetium labeled multilamellar liposomes in patients with Hodgkin s disease, J. Nucl. Med., 26, 743-749. 

There has been considerable discussion regarding the mode of action of the sea cucumber and starfish saponins. Both the triterpene and steroidal glycosides inhibit both Na/K ATPase and Ca/Mg ATPase 06) possibly as a result of their aglycone structures. However, their detergent properties cause membrane disruption which will influence the activity of membrane-bound enzymes such as the ATPases. In investigating the actions of saponins on multilamellar liposomes, it was found that cholesterol serves as the binding site for such saponins and that cholesterol-free lip-somes are not lysed by saponins 107). 

Loidl-Stahlhofen, A. Hartmann, T. Schottner, M. Rohring, C. Brodowsky, H. Schmitt, J. Keldenich, J., Multilamellar liposome and solid-supported lipid membranes (TRAN-SIL) Screening of lipid-water partitioning toward a high-throughput scale, Pharm. Res. 

The binding of carotenoids within the lipid membranes has two important aspects the incorporation rate into the lipid phase and the carotenoid-lipid miscibility or rather pigment solubility in the lipid matrix. The actual incorporation rates of carotenoids into model lipid membranes depend on several factors, such as, the kind of lipid used to form the membranes, the identity of the carotenoid to be incorporated, initial carotenoid concentration, temperature of the experiment, and to a lesser extent, the technique applied to form model lipid membranes (planar lipid bilayers, liposomes obtained by vortexing, sonication, or extrusion, etc.). For example, the presence of 5 mol% of carotenoid with respect to DPPC, during the formation of multilamellar liposomes, resulted in incorporation of only 72% of the pigment, in the case of zeaxanthin, and 52% in the case of (1-carotene (Socaciu et al., 2000). A decrease in the fluidity of the liposome membranes, by addition of other... 

Stahl, W, Junghans, A, de Boer, B, Driomina, ES, Briviba, K, and Sies, H, 1998. Carotenoid mixtures protect multilamellar liposomes against oxidative damage Synergistic effects of lycopene and lutein. FEBS Lett 427, 305-308. 

Morphology. Structural details were visualized by cryo-TEM. Figure 1A is a cryo-TEM image of a sample with an entrapped oligonucleotide-to-lipid ratio of 0.13 mg/mg. It confirms the coexistence of unilamellar liposomes with bi- and multilamellar liposomes. The membranes of the latter are in close contact. The inset of Figure 1A is an expanded view of a multilamellar... 

Maurer N, Wong KF, Stark H, et al. Spontaneous entrapment of polynucleotides upon electrostatic interaction with ethanol destabilized cationic liposomes formation of small multilamellar liposomes. Biophys J 2001 80 2310. 

Liposomes can be created by shaking or sonicating phospholipids in water. Low shear rates create multilamellar liposomes, which have many layers like an onion. Continued high-shear sonication tends to form smaller unilamellar liposomes. In this technique, the liposome contents are the same as the contents of the aqueous phase. Sonication is generally considered a gross method of preparation, and newer methods such as extrusion are employed to produce materials for human use. 

Abra, R.M., Mihalko, P.J., and Schreier, H. (1990). The effect of lipid composition upon the encapsulation and in vitro leakage of metaprotemol sulfate from 0.2 im diameter, extruded, multilamellar liposomes. J. Control. Release, 14, 71-78. 

Honzak L, Sentjurc M, Swartz H. In vivo EPR of topical delivery of a hydrophilic substance encapsulated in multilamellar liposomes applied to the skin of hairless and normal mice. J Control Release 2000 66 221-228. 

Multilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and dicetyl phosphate (DCP) were prepared by the formation of a thin lipid film and subsequent sonication, and coated with chitosan (Ch) [36], Liposomes with a size of approximately 5 pm were used in the experiment. The Ch-coated and plain liposomes were compared in terms of mucoadhesion to the rat stomach and intestinal parts. Although both the liposomes were less adhesive to the stomach, Ch-coated liposomes displayed much higher mucoadhesion to all the intestinal parts in vitro than the plain liposomes. The intestinal adhesion of the plain liposomes were minimal. Further, Ch-coated liposomes showed a great mucoadhesion to the intestine at acidic and neutral pH values. This was also confirmed by fluorescence microscopy when pyrene-loaded Ch-coated liposomes were used in the mucoadhesion test. 

Liposomes applied on the skin were also investigated for their delivery proprieties to the pilosebaceous units [15,23 28]. The in vitro skin penetration behavior of carboxyfluorescein incorporated in multilamellar liposomes (phosphatidylcholine cholesterol phosphatidylser-ine) and in another four nonliposomal systems (HEPES pH 7.4 buffer 5% propylene glycol 10% ethanol and 0.05% sodium lauryl sulfate) was studied by Lieb et al. [25]. Using two fluorescent techniques the authors found a higher accumulation of the probe within skin follicles when delivered from liposomes [25], Further, in an interesting setup of in vitro and in vivo experiments in mice, Hoffman s group observed liposomal delivery of the active Lac-Z gene and its expression mostly in the hair follicles [26,28]. 

Lieb, L.M., et al. 1992. Topical delivery enhancement with multilamellar liposomes into pilosebaceous units I. In vitro evaluation using fluorescent techniques with the hamster ear model. J Invest Dermatol 99 108. 

Multilamellar structure the DNA strand is intercalated in multilamellar liposome membrane. 

Figure 14.2 Illustration of a large multilamellar liposome (top) and a small unilamellar liposome (bottom). In each case lipid bilayers are the structural units (inset). From Yang and Alexandridis [890]. Copyright 2000, Elsevier.

Multilamellar liposomes were prepared by standard methods (6), and prior to incorporation into the delivery systems, were passed through a 0.8 pm filter (Nucleopore, Pleasanton, CA) to remove very large structures and/or aggregates. 

Loidl-Stahlhofen A, Hartmann T, Schottner M et al. (2001) Multilamellar liposomes and solid-supported lipid membranes (TRANSIL) Screeening of lipid-water... 

Momo, F., Fabris, S., Bindoli, A., Scutari, G., and Stevanato, R. (2002), Different effects of propofol and nitrosopropofol on DMPC multilamellar liposomes, Biophys. Chem., 95, 145-155. 

Lee, V. H., and Carson, L. W. (1986), Ocular disposition of inulin from single and multiple doses of positively charged multilamellar liposomes Evidence for alterations in tear dynamics and ocular surface characteristics,/. Ocul. Pharmacol, 2, 353-364. 

Mizuno, M., and Yoshida, J. (1998), Improvement of transduction efficiency of recombinant adeno-associated virus vector by entrapment in multilamellar liposomes, Jpn. J. Cancer Res., 89,352-354. 

Liposomes have been successfully used to deliver a range of oil-soluble bioactives. Banville et al. (2000) showed that incorporation of Vitamin D in cheese was improved with liposomal delivery compared to the use of a water-soluble preparation, but after long term storage (3-5 months) the stability of the liposome-encapsulated vitamin decreased. Multilamellar liposomes made from soy lecithin will incorporate P-carotene. Using a lecithin to P-carotene ratio of 1 0.05, efficiencies of up to 99.7% were obtained (Rhim et al. 2000). 

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