The present invention relates to antisense oligonucleotide (ASO) compositions and particularly to compositions and methods for the cytosolic delivery of antisense oligonucleotides (ASOs). Hybrid ASOs, part single-stranded and part double-stranded, are provided, hybridizing to form a double-stranded region that can non-covalently bond to nucleic-acid-binding protein regions. In this way, ASO::protein complexes may be produced that facilitate delivery of antisense DNA into target cells. Such complexes may be used to down-regulate gene expression in cells.