Provided are internalizing nucleic acid molecules (“iNA”) that can bind and internalize into target cells containing a cell surface molecule to which the iNA can bind an iNA further modified to include at least one chemical modification, wherein the at least one modification is selected from the group consisting of a chemical substitution in the nucleic acid sequence of the iNA, incorporation of a modified nucleotide into the iNA, conjugation to a linker, and conjugation to at least one effector moiety comprising one or more of a drug or a detectable moiety or a combination thereof and methods of using modified iNA to deliver at least one effector moiety into the target cells.
