pubmed:abstractText |
Long "all-purine" oligonucleotides, up to the 20mer, known to be active as antigene effectors, conjugated to high molecular weight monomethoxy poly(ethylene glycol)s (MPEG)s, were successfully synthesized. Through a liquid-phase, MPEG-supported process, both natural and chimeric sequences containing selected phosphorothioate backbone modifications were obtained, purified, and characterized. To follow their cellular trafficking, a fluorescent probe was linked by soluble supported organic reactions to the 5'-terminus, and the efficiency of the different synthetic procedures for the introduction of a fluorescein moiety was compared. The usefulness of the fluorescent marker was estimated by laser confocal microscopy that ascertains that the MPEG-conjugation enhances the oligonucleotide capacity to cross the cellular membranes and to be accumulated inside the nuclei.
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