Functionalization of DNA by electrostatic bonding

The approach of solubilizing biomacromolecules in organic phase or realizing their fluids in absence of water is a big progress to further integrate them into technological systems and processes. In this thesis we introduced a two-step method that relies on a water-soluble surfactant, 4-(hexyloxy)anilinium (ANI), to precipitate DNA and cyclodextrin from the aqueous solution, then solubilize them in the organic phase, where ANI can be subsequently exchanged against different amines. In this way, functional amine lipids, like terthiophene and pyrene containing conjugated π-systems were introduced onto DNA to form a multichromophoric light harvesting system. Cyclodextrin complexed with tris[2-(2-methoxyethoxy)ethyl]amine resulted in ionic liquid at room temperature. To extend the scope from primary, secondary and tertiary amine lipids, to quaternary ammonium compounds that can be electrostatically bound to DNA, a new exchange method was developed. Through complexing the negatively charged counterion, acetylacetonate, with tetrakis(decyl)ammonium and (polyethyleneglycol)-trimethylammonium (TMA-PEG), quaternary ammonium compounds were exchanged against ANI that was complexed to DNA in organic phase. The study of resistance to ion displacement in buffers with high ionic strength indicated that the quaternary amine PEG–DNA complexes are more vulnerable than the primary amine PEG–DNA complexes. It is anticipated that the novel methods introduced in this thesis have an impact on DNA used in technical applications and the area of biomedicine.

Dissertation: http://hdl.handle.net/11370/8544f16e-939a-4e5a-8e04-5b3b18ed4765