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Interfacial thickness of liposomes containing poly(ethylene glycol)-cholesterol from electrophoresis

TitleInterfacial thickness of liposomes containing poly(ethylene glycol)-cholesterol from electrophoresis
Publication TypeJournal Article
Year of Publication1996
AuthorsJanzen, J, Song, X, Brooks, DE
JournalBiophysical Journal
Volume70
Pagination313-320
Date PublishedJan
Type of ArticleArticle
ISBN Number0006-3495
KeywordsCELLS, CHAINS, grafted polymer brush, mobility, PARTICLES
Abstract

The electrophoretic mobilities of liposomes incorporating a polyethylene glycol (PEG) headgroup coupled to cholesterol for PEG of average chain index 3.0, 13.2, and 22.3 have been determined as a function of PEG-cholesterol mole fraction between 5% and 40% and ionic strength between 2 and 200 mM. The liposome compositions were 40 mole % cholesterol plus PEG-cholesterol, 10 mole % 1,2-dipalmitoyl-sn-glyerco-3-phosphoglycerol and 50 mole % egg phosphatidylcholine. The mobilities were fit to a model in which the PEG forms a surface layer of polymer subject to viscous drag arising I from electroosmotic flow within this layer. The model provides estimates of the average layer thickness that are comparable to those determined from contemporary models of surface-attached polymer.

URL<Go to ISI>://A1996TY68300026