Association morphologies of amphiphilic polyelectrolyte diblock copolymers

Korobko, Alexander Viktorovitch (2006)

Doctoral Thesis

In the first part of this thesis, polyelectrolyte copolymer micelles are studied to elucidate the role of the micelle concentration on the intermicelle correlation and the extension of the polyelectrolyte chains in the coronal layer. With increasing packing fraction the corona shrinks and/or interpenetrates in order to accommodate the micelles in the increasingly crowded volume. It is shown that interpenetration of the polyelectrolyte brushes controls the fluid rheology: the viscosity increases dramatically and the dynamic moduli show the formation of a physical gel. In the second part, we study giant vesicles as a superstructure self-assembled by dsDNA fragments, pUC18 or pEGFP-N1 and oppositely charged cationic diblock copolymer poly(butadiene-b-N-methyl 4-vinyl pyridinium. Under a preparation, the PBd brush collapses and a capsule is formed. The compaction of DNA is shown by the appearance of liquid crystalline textures under crossed polarizers and the increase in fluorescence intensity of labelled DNA. To form vesicles, the capsules are dispersed in aqueous medium supported by an osmotic agent. The integrity of the DNA after encapsulation and subsequent release was confirmed. We demonstrate ``reverse'' transfection of in vitro cultured HeLa cancer cells growing on plasmid-copolymer vesicles by the expressed green fluorescent protein in cultured cells.

• Association
• Brushes
• Charge
• Complexes
• Counterion distribution
• Diblock copolymer micelles
• Gene delivery
• Liquid-crystal formation
• Phases
• Rheology
• Small-angle neutron scattering
• Star-branched polyelectrolytes
• Supercoiled DNA

• All authors: Korobko, Alexander Viktorovitch
• Supervisor: Maarel, J.R.C. van der; Fraaije, J.G.E.M.
• Qualification: Doctor (dr.)
• Awarding Institution: Faculty of Science, Leiden University
• Date: 2006-12-12
• Sponsorship: NWO