Oligonucleotide delivery by a cationic derivative of the polyene antibiotic amphotericin B. I: interaction oligonucleotide/vector as studied by optical spectroscopy and electron microscopy.
Antisense 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 (<10(-6) M), the strong increase of the CD signal, characteristic of self-association, indicated condensation of AMA on the ODN molecules. At a higher concentration (10(-4) M), and for a nucleic acid negative charge/AMA positive charge ratio higher than 1, spectra were interpreted as a reorganisation of free self-associated AMA species into smaller ones 'decorating' the nucleic acid molecule. Electron microscopy data were interpreted according to this scheme.
Blanc
I
I
Laboratoire de Physicochimie Biomoléculaire et Cellulaire, CNRS ESA 7033, Université Pierre et Marie Curie, Case 138, 4 place Jussieu, F-75252, Paris, France.
Bueno Da Costa
M
M
Bolard
J
J
Saint-Pierre Chazalet
M
M
D000666:Amphotericin B / Q000031:analogs & derivatives* / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D004337:Drug Carriers; D004563:Electrochemistry; D008854:Microscopy, Electron; D015394:Molecular Structure; D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D020320:Oligoribonucleotides, Antisense / Q000737:chemistry; D010316:Particle Size; D012996:Solutions
D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D016376:Oligonucleotides, Antisense; D020320:Oligoribonucleotides, Antisense; D012996:Solutions; C408366:amphotericin B3-(N'-dimethylamino)propylamide; D000666:Amphotericin B