Liposome as delivery system

Borgatti M., Breda L., Cortesi R., Nastruzzi C., Romanelli A., Saviano M., Bianchi N., Mischiatic C, Gambari R. Cationic liposomes as delivery systems for double-stranded PNA-DNA chimeras exhibiting decoy activity against NF-kB transcription factors. Biochem. Pharmacol. 2002 64 609-616. 

Storm, G. (1987). In Liposomes as Delivery System for Doxorubicin in Cancer Chemotherapy. (Ph.D. Thesis.) University of Utrecht, The Netherlands. 

To use liposomes as delivery systems, drug is added during the formation process. Flydrophilic compounds usually reside in the aqueous portion of the vesicle, whereas hydrophobic species tend to remain in the lipid proteins. The physical characteristics and stability of lipsomal preparations depend on pH, ionic strength, the presence of divalent cations, and the nature of the phospholipids and additives used [45 47],... 

Since their discovery by Bangham, a vast amount of technology has been developed using liposomes. Many applications of liposomes as delivery systems have been developed, but only a few of them have reached the commercial stage. These... 

Drulis-Kawa, Z., Dorotkiewicz-Jach, A. 2010. Liposomes as delivery systems for antibiotics. International Journal of Pharmaceutics, 387(1-2) 187-198. 

Felnerova D, et al. Liposomes and virosomes as delivery systems for antigens, nucleic acids, and drugs. Curr Opin Biotechnol 2004 15 518. 

Cullis, P.R., Chonn, A. (1998). Recent advances in liposome technologies and their applications for systemic gene delivery. Adv. Drug Deliv. Rev., 30(1-3), 73-83. Audouy, S.A., de LeiJ, L.F., Hoekstra, D., Molema, G. (2002). In vivo characteristics of cationic liposomes as delivery vectors for gene therapy. Pharm. Res., 19(11), 1599-1605. 

Micro- and nanoparticulate drug delivery systems as well as delivery systems based on liposomes are described in detail in Chapters 9 and 10. Besides other advantages which are discussed in the mentioned chapters, these formulations are capable of protecting incorporated drugs from enzymatic degradation. 

Liposomes have been used for years as components of drug delivery systems, and as transdermal carriers of active ingredients in the cosmetic industry (307, 308). More recently, liposomes have found use in the food and nutritional supplement industries. Keller (308) lists more than a dozen nutritional products on the market that have been formulated with novel liposome-based delivery systems. In the food area, hposomes have been studied for their ability to encapsulate and provide controlled release of enzymes (309, 310), and liposome-encapsulated enzymes have been used to accelerate the ripening of cheese (311). 

Liposomes are phospholipid-based vesicles which have been studied as delivery systems to target drugs to specific sites in the body. " The surface of a liposome can be neutral or negatively or positively charged, depending on the composition of lipids used. For... 

Lee et al. (2007) succeeded in the synthesis of the double-tailed boron cluster lipids, which have a B12H11S moiety as a hydrophilic function, by S-alkylation of B,2H SH with bromoacetyl and chloroacetocarbamate derivatives of diacylglycerols for a liposomal boron delivery system on BNCT. Altieri et al. (2009) reported on the use of some different examples of liposomes as carriers for BNCT active compounds. Two carborane derivatives, i.e., o-closocarboranyl P-lactoside and l-methyl-o-closocarboranyl-2-hexylthioporphyrazine, were loaded into liposomes. 

Encapsulation may be used to deliver traditional active ingredients, such as flavors, vitamins, minerals, sweeteners, and antioxidants, or relatively novel ones, such as probiotic microorganisms. SD and gel microparticles, liposome and emulsified systems, which are under focus in this chapter, have been used for some of these applications. Their functionality as delivery systems is discussed in Sections 32.4.1 through 32.4.5. 

Apart from various biodegradable polymers that can act as drug delivery systems at various physical forms, the most important and widely used is the liposomal drug delivery system. Liposomes are self-closed spherical particles with an aqueous core surrounded by one or more outer layers consisting of lipids arranged in a bilayer constellation. " ... 

Liposomes form spontaneously when lipids are dispersed in aqueous media. They consist of a bilayer membrane which captures a pool of water in its center. The practical value of liposomes derives from two unioue properties 1) their ability to entrap either water-soluble materials in tne internal water reservoir or liposoluble compounds in the lipid bilayer and 2) their compatibility witn natural membranes, making them safe for medical application. They have attracted considerable interest as delivery systems, such as carriers of drugs to specific targets in the treatment of cancer tumors and in enzyme therapy (1) and in various diagnostic tests using fluorescent makers (2) and radiolabels (3). Liposomes are fragile structures created in water as a result of a delicate balance of interacting forces which arise when amphiphilic compounds are added to water. In most practical applications liposomes have to be... 

The use of micelles and liposomes as delivery vehicles of chemotherapeutics has recently been reviewed," and it is worth noting that a number of such systems are already in clinical use with more in trials and that they show both significant increases in dose potency of the drugs delivered and reductions in some of the conunon side effects of chemotherapy such as nausea and vomiting. 

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