Research Article

- Hybrid polymer/lipid bilayers are interesting alternatives to lipid-based membrane models in many fields of science.

- The tuneable polymeric component allows for fine adjustments of the resulting hybrid bilayers (e.g. thickness, % PEGylation).

- Reducing the polymer MW to values closer to the lipids´one, results in hybrid bilayers with a lipid-like spreading behavior.

A joint research study by:

Gianluca Bello and Lea Ann Dailey, Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna

Francesca Cavallini, Department of Molecular Sciences and Nanosystems, Cà Foscari University of Venice

Eva-Kathrin Ehmoser, Department of Nanobiotechnology, Institute of Synthetic Bioarchitectures, University of Natural Resources and Life Science (BOKU)

Amphiphilic block copolymers form self-assembled bilayers even in combination with phospholipids. They represent an attractive alternative to native lipid-based membrane systems for supported bilayer formation with applications in biomedical research, sensoring and drug delivery. Their enhanced stability and excellent mechanical properties are linked to their higher molecular weight which generates thicker bilayers. Hypothesis: It is hypothesized that reducing the molecular weight of the polymer facilitates the formation of a thinner, more homogeneous polymer/lipid hybrid bilayer which would benefit the formation of supported bilayers on silicon oxide. Experiment: We investigated hybrid bilayers composed of mixtures of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine and increasing amounts of a low molecular weight polybutadiene-b-polyethylene oxide copolymer (1050 g/mol). By assessing the bilayer thickness and the molecular packing behavior we sought to demonstrate how reducing the polymer molecular weight increases the tendency to form supported hybrid bilayers in a lipid-like manner. Findings: The formation of a supported hybrid bilayers occurs at polymer contents <70 mol% in a lipid-like fashion and is proportional to the cohesive forces between the bilayer components and inversely related to the bilayer hydrophobic core thickness and the extended brush regime of the PEGylated polymeric headgroup.

View full article in Biomembranes - Vol. 1863, Issue 1: