This is a peptide comprising of 9 Arginine residues and is synthesized with an activated cysteine residue C(Npys), wherein Npys is 3-Nitro-2-pyridinesulfenyl group protects cysteine. This kind of modification has been used to render this peptide as a carrier peptide applicable in conjugation and cell permable studies. The S(Npys) group of this cysteine-containing 9R is capable of reacting selectively with the free thiol group of another cysteine-containing peptide to form an unsymmetrical disulfide bond. Coupling of sulfhydrils has been studied as an effective means to deliver/release therapeutics such as siRNA in the reducing environment within the cell. For example, in a study leukemic-specific SiRNA was delivered by the formation of immunocomplexes that consisted of targeted antibody conjugated to oligo-9-Arg peptides.