VEGF siRNA delivery system using arginine-grafted bioreducible poly(disulfide amine)

Hwa Kim Sun, Hoon Jeong Ji, Tae Il Kim, Wan Kim Sung, David A. Bull

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


Small interfering RNAs (siRNAs) are able to silence their target genes when they are successfully delivered intact into the cytoplasm. Delivery systems that enhance siRNA localization to the cytoplasm can facilitate gene silencing by siRNA therapeutics. We describe an arginine-conjugated poly(cystaminebisacrylamide-diaminohexane) (poly(CBA-DAH-R)), a bioreducible cationic polymer, as an siRNA carrier for therapeutic gene silencing for cancer. After intracellular uptake of the siRNA/poly(CBA-DAH-R) polyplexes, the reductive environment of the cytoplasm cleaves the disulfide linkages in the polymeric backbone, resulting in decomplexing of the siRNA/poly(CBA-DAH-R) polyplexes and release of siRNA molecules throughout the cytoplasm. The siRNA/poly(CBA-DAH-R) polyplexes, which demonstrate increased membrane permeability with arginine modification, have a similar level of cellular uptake as siRNA/bPEI polyplexes. The VEGF siRNA/poly(CBA-DAH-R) polyplexes, however, inhibit VEGF expression to a greater degree than VEGF siRNA/bPEI in various human cancer cell lines. The improved RNAi activity demonstrated by the VEGF siRNA/poly(CBA-DAH-R) polyplexes is due to enhanced intracellular delivery and effective localization to the cytoplasm of the VEGF siRNAs. These results demonstrate that the VEGF siRNA/poly(CBA-DAH-R) polyplex delivery system may useful for siRNA-based approaches for cancer therapy.

Original languageEnglish (US)
Pages (from-to)718-726
Number of pages9
JournalMolecular Pharmaceutics
Issue number3
StatePublished - Jun 1 2009
Externally publishedYes


  • Bioreducible cationic polymer
  • Cancer therapy
  • Cytoplasmic localization
  • Gene silencing
  • Vascular endothelial growth factor
  • siRNA

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmaceutical Science
  • Drug Discovery


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