Cationic Oligonucleotides

Sazani P., Kang S.H., Maier M.A., Wei C., Dillman j., Summerton J., Mano-haran M., Kole R. Nuclear antisense ef fects of neutral, anionic and cationic oligonucleotide analogs. Nucleic Acids Res. 2001 29 3965-3974. 

Pons B, Kotera M, Zuber G, Behr JP (2006) Online synthesis of diblock cationic oligonucleotides for enhanced hybridization to their complementary sequence. Chembiochem 7 1173-1176... 

Liposomes have been investigated in the delivery of the gene-based drugs for more than a decade. The cellular transfer of genes and oligonucleotides is obtained with cationic lipo-... 

Peptides have been used for the delivery of gene-based drugs. Several rationales have been utilized. Cationic peptides are used to neutralize the charges of DNA or oligonucleotide. These peptides include polylysines and polyarginines [241,244,245]. They form complexes with DNA or oligonucleotide, thereby resulting in enhanced cellular uptake. 

Ion exchange is actually a far more complicated process than the simple exchange of one cation for another or one anion for another, particularly for complex polyions such as proteins and oligonucleotides. Each ion of the stationary or mobile phase is surrounded by a cluster of counterions and water. When an ion in the mobile phase is transferred to the stationary phase, the cluster of counterions and water surrounding it is partially or completely displaced. A similar event occurs at the binding site of the stationary phase. Ions displaced from the stationary phase undergo the converse process. The... 

Therefore, the sequence of reactions illustrated in Fig. 1 catalytically (the anthraquinone is regenerated) injects a radical cation into a DNA oligonucleotide that does not simultaneously contain a radical anion. As a result, the lifetime of this radical cation is determined by its relatively slow bimolecular reaction with H20 (or some other diffusible reagent such as 02- ) and not by a rapid intramolecular charge annihilation reaction. This provides sufficient time for the long distance migration of the radical cation in DNA to occur. 

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