Carboxyl-terminated PAMAM dendrimer interaction with 1-palmitoyl-2-oleoyl phosphocholine bilayers

• Published in: Biochimica et biophysica acta Vol. 1838; no. 1; pp. 445 - 455
• Main Authors: Evans, Kervin O., Laszlo, Joseph A., Compton, David L.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-01-2014
• Subjects: 1-Palmitoyl-2-oleoyl phosphocholine bilayer; AFM; Carboxyl-terminated dendrimer; Dendrimers - chemistry; Fluoresceins - chemistry; Fluorescence; Fluorescent Dyes; Lipid Bilayers - chemistry; Permeability; Phosphatidylcholines - chemistry; QCMD; 1-Palmitoyl-2-oleoyl phosphocholine bilayer; Fluorescence; AFM; QCMD; Carboxyl-terminated dendrimer
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2013.08.012

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.
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•G2 and G5 carboxyl-terminated dendrimers and POPC interactions were evaluated.•G2 created defects that resulted in increased leakage in liposomes.•G5 binding increased lipid packing in liposomes and local swelling in SPB.