Polyelectrolyte flexibility effect on the morphology of charged lipid multilayers

Department of Physics, Biomolecular Self-Assembling Nanomaterials Center Korea Advanced Institute of Science and Technology 373-1 Guseong-dong Yuseong-gu, Daejeon city, 305-701, South Korea

Corresponding author: syzerox@kaist.ac.kr

Received: 3 August 2004
Accepted: 29 March 2005

Abstract

Coupling of flexible (PAAS: polyacrylic acid sodium salt) and semiflexible (λ DNA) polyelectrolytes onto an oppositely charged lipid monolayer (DOTAP: dioleoyl trimethylammonium propane chloride) at the air-liquid interface leads distinctive collapse behavior with lateral compression. In both cases, trilayer domains form by nucleation growth mechanism followed by multilayer formation with further compression. The flexible chain induces circular, fluid domains while the semiflexible chain induces elongated, solid-like domains. These morphological differences show that the flexibility of adsorbed polymers strongly affects the rigidity of the lipid membrane.