Liposomes function

Reichert A, Nagy JO, Spevak W, Charych D (1995) Polydiacetylene liposomes functionalized with sialic-acid bind and colorimetrically detect influenza-virus. J Am Chem Soc 117 829-830... 

Figure 1 Conjugation reactions for coupling peptides to the surface of preformed liposomes. Functionalized lipophilic anchors were incorporated into liposomes and reacted with the peptides in aqueous media. Reactive endgroup functions (A) maleimide (B) bromo- or iodoacetyl (C) 2-pyridyldithio (D) carboxylic acid (E) />-nitrophenyl carbonate and (F) hydrazide. Abbreviations EDC, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide NHS, 7V-hydroxysuccinimide.

Nakanishi, T. Kunisawa, J. Hayashi, A. Tsutsumi, Y. Kubo, K. Nakagawa, S. Nakanishi, M. Tanaka, K. Mayumi, T. Positively charged liposome functions as an efficient immunoadjuvant in inducing cell-mediated immune response to soluble proteins. J. Controlled Rel. 1999, 61, 233-240. 

Newer vehicles include liposomes and microgel formulations. Liposomes are concentric spherical shells of phospholipids in an aqueous medium that may enhance percutaneous absorption. Variations in size, charge, and hpid content can influence liposome function substantially. Liposomes penetrate compromised epidermal barriers more efficiently. Microgels are polymers that may enhance solubilization of certain drugs, thereby enhancing penetration and diminishing irritancy. 

Reichert, A., J.O. Nagy, W. Spevak, and D. Charych. 1995. Polydiacetylene liposomes functionalized with sialic-acid bind and colorimetrically detect influenza-vims. J Am Chem Soc 117 (2) 829-830. Charych, D., Q. Cheng, A. Reichert, G. Kuziemko, M. Stroh, J.O. Nagy, W. Spevak, and R.C. Stevens. 1996. A Htmus test for molecular recognition using artificial membranes. Chem Biol 3 (2) 113-120. 

Another possibility to use vesicles as catalysts sup-port/enhancer is to entrap natural enzymes in their phospholipid bilayers. For instance, the influence of liposomization of prostaglandine synthetase on the rate of prostaglandine E2 (PGE2) formation was demonstrated by Sada et al. Since prostaglandine synthetase is one of the membrane-bound enzymes, the authors used DMPC (oL-a-dimyristoyl-phosphatidylcholine) to generate liposomes that could improve its reaction characteristics. The yield obtained with the liposome functionalized enzyme was more than two times higher compared to the free enzyme, and the liposome sample retained its initial activity for more than two days while the free enzyme sample lost 25% of its own. 

Liposomes Functionalized with Collagen-Mimetic Peptides... 

Recently, stealth liposomes functionalized with PR b were used for the targeted delivery of therapeutics to colon cancer cells (Garg and Kokkoli, 2011 Garg et al., 2009) and prostate cancer cells (Demirgoz et al., 2008). In these studies, PR b-functionalized stealth liposomes loaded with a chemotherapy agent were more effective than RGD-functionalized stealth liposomes or non-targeted stealth liposomes in terms of cell adhesion, internalization, and cancer-cell toxicity (Figure 3). 

Garg, A., and E. Kokkoli. 2011. pH-Sensitive PEGylated liposomes functionalized with a fibronectin-mimetic peptide show enhanced intracellular delivery to colon cancer cells. Current Pharmaceutical Biotechnology in press. 

Some 0-tosyl-lactones (e.g. 20 and 21) have been cyclized to tetrahydrofuran derivatives (22 and 23 respectively) on boiling in dioxane-water and synthesis of 2-deoxy-4-ep/-neuraminic acid and 2,4-dideoxy-neuraminic acid have been recorded. Liposomes functionalized with neuraminic acid by way of a C-... 

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