title: Retention dynamics of amphiphilic polymers PEG-lipids and PVA-Alkyl on the cell surface.
abstract: We tested two kinds of amphiphilic polymers for cell surface modification: a poly(ethylene glycol)-conjugated phospholipid (PEG-lipid) and a poly(vinyl alcohol) that carried alkyl side chains (PVA-alkyl). Both polymers were expected to anchor to the lipid bilayer of the cell membrane through hydrophobic interactions. We followed the kinetics of these fluorescently labeled amphiphilic polymers (fPEG-lipid, fPVA-alkyl) over time on living cells with confocal scanning laser microscopy and flow cytometry. We found that fPEG-lipids and fPVA-alkyl polymers were not cytotoxic, and they were released from the cell surface without triggering endocytosis. The gradual release from the cell surface was influenced by the hydrophobicity of the alkyl chains, which affected their stability. The amphiphilic polymers tended to aggregate on the cell surface; in particular, the aggregation of PVA-alkyl was clearly identified. Although most of PEG-lipids and PVA-alkyl polymers did not appear to in the cytoplasm, the cells were able to endocytose lipid molecules, as expected. These results suggested that the retention time of modified amphiphilic polymers on the cell surface should be a consideration when modifying cell surfaces to enhance cell transplantation.
authors.affiliation: Department of Reparative Materials, Institute for Frontier Medical Sciences, Kyoto University, Shogoin, Sakyo-Ku, Kyoto 606-8507, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Inui
authors.forename: Yuji
authors.initials: Y
authors.lastname: Teramura
authors.forename: Hiroo
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000478:Alkylation; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008055:Lipids / Q000737:chemistry*; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism
chemical_list: D008055:Lipids; D011092:Polyethylene Glycols; D011142:Polyvinyl Alcohol