title: PEGylated phospholipid membrane on polymer cushion and its interaction with cholesterol.
abstract: By employing poly(ethylene glycol) (PEG) shielding and a polymer cushion to achieve air stability of the lipid membrane, we have analyzed PEG influence on dried membranes and the interaction with cholesterol. Small unilamellar vesicles (SUVs) formed by the mixture of 1,2-dimyristoylphosphatidylcholine (DMPC) with different molar fraction of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE-PEG(2000)) adsorb and fuse into membranes on different polymer-modified silicon dioxide surfaces, including chitosan, poly(L-lysine) (PLL), and hyaluronic acid. Dried membranes are further examined by ellipsometer and atomic force microscopy (AFM). Only chitosan can support a visible and uniform lipid array. The thickness of dry PEGylated lipid membrane is reduced gradually as the molar fraction of PEG increases. AFM scanning confirms the lipid membrane stacking for vesicles containing low PEG, and only a proper amount of PEG can maintain a single lipid bilayer; however, the air stability of the membrane will be destroyed if overloading PEG. Cholesterol incorporation can greatly improve the structural stability of lipid membrane, especially for those containing high molar fraction of PEG. Different amounts of cholesterol influence the thickness and surface morphology of dried membrane.
authors.affiliation: Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215125, PR China.
authors.forename: Yibang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Jin
mesh_terms: D048271:Chitosan / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D006820:Hyaluronic Acid / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D008081:Liposomes; D010714:Phosphatidylethanolamines; D011108:Polymers; C107570:polyethylene glycol-distearoylphosphatidylethanolamine; D011107:Polylysine; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; D006820:Hyaluronic Acid; D048271:Chitosan; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine