Oligonucleotide delivery by a cationic derivative of the polyene antibiotic amphotericin B I: Interaction oligonucleotide/vector as studied by optical spectroscopy and electron microscopy

AbstractAntisense strategy requires efficient systems for the delivery of oligodeoxyribonucleotides (ODN) into target cells. Cationic amphiphiles have shown good efficiency in vitro and a lot of attention is currently paid to their interaction with nucleic acids. In the present study, this interaction was, for the first time, analysed at the molecular level, taking advantage of the spectroscopic properties of the positively charged chiral polyene molecule amphotericin B 3-dimethylaminopropyl amide (AMA), the efficiency of which, as delivery system, has been demonstrated [Garcia et al., Pharmacol. Ther. (2000), in press]. By UV-visible absorption and circular dichroism (CD) we studied its self-association properties in pure water, saline and RPMI medium. Drastic changes were observed upon ODN addition, stronger in pure water than in media of high ionic strength. At low AMA concentration (