title: PAMAM dendrimer interactions with supported lipid bilayers: a kinetic and mechanistic investigation.
abstract: The interaction kinetics of polyamidoamine (PAMAM) dendrimers with supported lipid bilayers of 1,2-sn-glycero-dimyristoylphosphocholine prepared by the vesicle deposition has been probed by optical waveguide lightmode spectroscopy and atomic force microscopy (AFM). In particular, the influence of PAMAM dendrimer generation (G2, G4, and G6) and concentration (1 to 100 nM) on the levels of adsorption and lipid bilayer removal have been determined as a function of time; hence interaction kinetics and mechanisms have been further elucidated. Dendrimer interaction kinetics with the lipid bilayer are concentration dependent in a complex manner, with net bilayer removal at 1 and 100 nM and net adsorption at 10 nM; these effects are irrespective of dendrimer generation. The pseudo first order rate constant for bilayer removal (at 1 and 100 nM) follows the order G6 > G4 > G2. In contrast, the pseudo first order rate constant for adsorption at 10 nM follows the order G2 > G4 > G6. AFM has confirmed expansion of lipid bilayer defects, hole formation, and adsorption to the bilayer or bilayer defects, and their concentration and generation dependence. These findings have implications when designing dendrimers for specific biopharmaceutical activities, e.g., as drugs, drug delivery vehicles, transfection agents, or antimicrobials.
authors.affiliation: Ian Wark Research Institute, ARC Special Research Centre for Particle and Material Interfaces, University of South Australia, Mawson Lakes, SA-5095, Australia.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Parimi
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Barnes
authors.forename: Clive A
authors.initials: CA
authors.lastname: Prestidge
mesh_terms: D000327:Adsorption; D050091:Dendrimers / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods; D011073:Polyamines / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D050091:Dendrimers; D008051:Lipid Bilayers; C531249:Poly(amidoamine); D011073:Polyamines; D004134:Dimyristoylphosphatidylcholine