Solid phase synthesis of peptide-siRNA conjugates containing disulfide bond unit

A disulfide-modified nucleoside was designed and synthesized. After loading the modified nucleoside on controlled pore glass (CPG), solid phase synthesis strategy was used to prepare peptide-oligonucleotide conjugates (N-3') containing disulfide bond unit. The 3'-sense strand peptide-siRNA conjugate (Ⅶ) maintained good gene silencing activity, while that of the 3'-antisense strand conjugate decreased somewhat. And the sense strand off-target effect of Ⅶ decreased remarkably.