title: Carboxyl-terminated PAMAM dendrimer interaction with 1-palmitoyl-2-oleoyl phosphocholine bilayers.
abstract: Polyanionic polymers and liposomes have a great potential use as individual drug delivery systems and greater potential as a combined drug delivery system. Thus, it is important to better understand the interactions of polymers with phospholipid bilayers. A mechanistic study of the interaction between carboxyl-terminated poly(amidoamine) (PAMAM) dendrimers with 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayer using fluorescence leakage and quartz crystal microbalance with dissipation monitoring (QCMD) was conducted. Fluorescence leakage experiments demonstrated that carboxyl-terminated generation 2 (G2-COOH) dendrimers caused increased liposome leakage with increasing dendrimer concentration over a 0 to 20μM range. Generation 5 (G5-COOH), on the other hand, reduced leakage over the same concentration range, presumably by increasing lipid packing. QCMD and atomic force microscopy (AFM) measurements demonstrated that G2-COOH interacting with supported bilayers resulted in small defects with some mass loss and no adsorption. In contrast, G5-COOH interaction with a bilayer resulted in adsorption and local bilayer swelling.
authors.affiliation: Renewable Product Technology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 N. University Street, Peoria, IL 61604, USA. Electronic address: Kervin.Evans@ars.usda.gov.
authors.forename: Kervin O
authors.initials: KO
authors.lastname: Evans
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Laszlo
authors.forename: David L
authors.initials: DL
authors.lastname: Compton
mesh_terms: D050091:Dendrimers / Q000737:chemistry*; D005452:Fluoresceins / Q000737:chemistry; D005456:Fluorescent Dyes; D008051:Lipid Bilayers / Q000737:chemistry*; D010539:Permeability; D010713:Phosphatidylcholines / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; C104700:PAMAM Starburst; D010713:Phosphatidylcholines; C028694:1-palmitoyl-2-oleoylphosphatidylcholine; C007740:fluorexon
keywords: 1-Palmitoyl-2-oleoyl phosphocholine bilayer; AFM; Carboxyl-terminated dendrimer; Fluorescence; QCMD