title: Characterisation of biotinylated liposomes for in vivo targeting applications.
abstract: Liposomes containing monosialoganglioside (GM1) or polyethylene glycol (PEG) lipid derivatives have prolonged circulation in the blood. This favours liposome extravasation to tumour sites. In this report it is shown that inclusion of GM1, PEG550-DPPE or PEG2000-DPPE in liposomes containing biotin-DPPE significantly diminished the ability of vesicles to bind to streptavidin in vitro. Steric inhibition due to the bulky head group of these lipids was least for biotin-DPPE liposomes containing GM1. Biodistribution studies in C26 tumour-bearing mice showed that GM1-liposomes containing small amounts of biotin-DPPE have long circulation life-times in the blood. Using fluorescent microscopic techniques, liposomes containing both GM1 and biotin-DPPE were detected within extra-vascular spaces in tumours. In addition it was shown that biotin-DPPE in GM1-liposomes bound streptavidin in situ. These results suggest that GM1-liposomes containing biotin-DPPE have potential use as diagnostic or therapeutic reagents in pre-targeting applications dependent on the high-affinity interaction of biotin with streptavidin.
authors.affiliation: Department of Biochemistry, University College Galway, Ireland.
authors.forename: H C
authors.initials: HC
authors.lastname: Loughrey
authors.forename: A
authors.initials: A
authors.lastname: Ferraretto
authors.forename: A M
authors.initials: AM
authors.lastname: Cannon
authors.forename: G
authors.initials: G
authors.lastname: Acerbis
authors.forename: F
authors.initials: F
authors.lastname: Sudati
authors.forename: G
authors.initials: G
authors.lastname: Bottiroli
authors.forename: M
authors.initials: M
authors.lastname: Masserini
authors.forename: M R
authors.initials: MR
authors.lastname: Soria
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D001710:Biotin / Q000378:metabolism*; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D005260:Female; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000188:drug therapy; D010714:Phosphatidylethanolamines / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D019809:Streptavidin
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D008081:Liposomes; D010714:Phosphatidylethanolamines; C007510:1,2-dipalmitoyl-3-phosphatidylethanolamine; D001710:Biotin; D019809:Streptavidin