DNA affinity to biological membranes is enhanced due to complexation with hydrophobized polycation

The interaction of negatively charged liquid phosphatidylcholine/cardiolipin liposomes with water-soluble negatively charged DNA/cetylpyridinium bromide and DNA/poly( N-alkyl-4-vinylpyridinium bromide) complexes was studied. It is shown that the DNA/cetylpyridinium bromide complex while interacting with the liposomes is destroyed, so that the cetylpyridinium cation is incorporated into the liposomal membrane and DNA remains in the solution. The DNA/poly-( N-ethyl-4-vinylpyridinium bromide) complex does not interact at all with the liposomes. On the contrary, the complex of DNA with the poly(vinylpyridinium) cation carrying a small amount of N-cetyl groups is adsorbed on the membrane as a whole. The data obtained indicate that complexation of DNA with hydrophobized polycations can be used for enhancing DNA affinity to biological membranes.