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Poly(ethylene glycol) amphiphile adsorption and liposome partition

TitlePoly(ethylene glycol) amphiphile adsorption and liposome partition
Publication TypeJournal Article
Year of Publication1996
AuthorsVanAlstine, JM, Malmsten, M, Brooks, DE
JournalJournal of Chromatography B-Biomedical Applications
Volume680
Pagination145-155
Date PublishedMay
Type of ArticleProceedings Paper
ISBN Number0378-4347
KeywordsADSORPTION, AQUEOUS 2-PHASE SYSTEMS, BEHAVIOR, CELL-SEPARATION, critical micelle concentration, ellipsometry, HYDROPHOBIC AFFINITY PARTITION, LIPOSOMES, partitioning, PHASE SYSTEMS, poly(ethylene glycol) (PEG), polymer, PROTEINS, SURFACE-PROPERTIES, WATER-INTERFACE
Abstract

Surface localized poly(ethylene glycol) (PEG) amphiphiles of type C-16:0-EO(151) and C-18:2-EO(1.51) were studied via ellipsometry at macroscopic, hat methylated silica (MeSi), phosphatidic acid (PA), and phosphatidylcholine (PC) surfaces. At these surfaces the amphiphiles adsorb similarly, in a non-cooperative manner, achieving a plateau (approximate to 0.1 PEG chains/nm(2)) well below amphiphile critical micelle concentration (CMC). The resultant PEG-enriched layers were 10-15 nm thick, with a polymer concentration (approximate to 0.07 g/cm(3)) greater than the PEG-enriched phase of many dextran, PEG aqueous two-phase systems. PEG-amphiphile adsorption (mg/m(2)) at hydrophobic and phospholipid flat surfaces correlated with changes in the partition (log K) of PC liposomes in such two-phase systems. PEG-amphiphile adsorption at macroscopic surfaces appears to represent a balance between hydrophobic attraction and repulsive intra-chain interactions which promote chain elongation normal to the surface.

URL<Go to ISI>://A1996UQ82100016