Multivalent oligonucleotide assemblies

A double stranded oligonucleotide molecule comprising:

• (i) a first oligonucleotide strand comprising a first nucleic acid sequence bound to a second nucleic acid sequence through a first spacer, wherein said second nucleic acid sequence is bound to a third nucleic acid sequence through a second spacer;
• (ii) a second oligonucleotide strand comprising a fourth nucleic acid sequence bound to a fifth nucleic acid sequence through a third spacer, wherein said fifth nucleic acid sequence is bound to a sixth nucleic acid sequence through a fourth spacer,
• wherein the second nucleic acid sequence and the fifth nucleic acid sequence are hybridized to form a double stranded nucleic acid core of said double stranded oligonucleotide;
• (iii) a first moiety attached to the first nucleic acid sequence of the first oligonucleotide, wherein the first moiety comprises a first moiety nucleic acid sequence hybridized to at least a portion of the first nucleic acid sequence;
• (iv) a second moiety attached to the third nucleic acid sequence of the first oligonucleotide, wherein the second moiety comprises a second moiety nucleic acid sequence hybridized to at least a portion of the third nucleic acid sequence;
• (v) a third moiety attached to the fourth nucleic acid sequence of the second oligonucleotide, wherein the third moiety comprises a third moiety nucleic acid sequence hybridized to at least a portion of the fourth nucleic acid sequence;
• and
• (vi) a fourth moiety attached to the sixth nucleic acid sequence of the second oligonucleotide, wherein the fourth moiety comprises a fourth moiety nucleic acid sequence hybridized to at least a portion of the sixth nucleic acid sequence;
• wherein the first, second, third and fourth spacers are independently unsubstituted C1-C10 alkylene;
• wherein the first nucleic acid sequence, the third nucleic acid sequence, the fourth nucleic acid sequence and the sixth nucleic acid sequence are single stranded;
• wherein the first, second and third moieties are siRNA moieties and the fourth moiety is an aptamer moiety;
• and
• wherein said first oligonucleotide strand is covalently bound to a substrate through a cleavable linker.