Hybridization-sensitive Fluorescent Oligonucleotide Probe Conjugated with Cell-penetrating Peptides for Enhanced Cellular Uptake

Abstract

Intracellular delivery of oligonucleotides is essential not only for antisense- and RNAi-therapeutics, but also for live-cell RNA imaging with fluorescent nucleic acid probes. Herein, we developed oligonucleotide–peptide conjugates synthesized via Cu-catalyzed alkyne-azide cycloaddition between an exciton-controlled hybridization-sensitive oligonucleotide (ECHO) probe and linear or cyclic cell-penetrating peptides (CPPs). When lipofected to living HeLa cells, the CPP-conjugated ECHO probe showed enhanced cellular uptake efficiency compared with that of the unconjugated ECHO probe.