Linked nucleosides having at least one functionalized nucleosid that bears
a substituent such as a steroid molecule, a reporter molecule, a non-aromatic lipophilic
molecule, a reporter enzyme, a peptide, a protein, a water soluble vitamin, lipid
soluble vitamin, an RNA cleaving complex, a metal chelator, a porphyrin, an alkylator,
a pyrene, a hybrid photonuclease/intercalator, or an aryl azide photo-crosslinking
agent exhibit increased cellular uptake and other properties. The substituent can
be attached at the 2-position of the functionalized nucleoside via a linking
group. If at least a portion of the remaining linked nucleosides are 2-deoxy-2-fluoro,
2-O-methoxy, 2-O-ethoxy, 2-O-propoxy, 2-O-aminoalkoxy
or 2-O-allyloxy nucleosides, the substituent can be attached via a linking
group at any of the 3 or the 5 positions of the nucleoside or on
the heterocyclic base of the nucleoside or on the inter-nucleotide linkage linking
the nucleoside to an adjacent nucleoside.
