Co-delivery of chemosensitizing siRNA and an anticancer agent via multiple monocomplexation-induced hydrophobic association

Eunjung Lee, Changhwoa Oh, In San Kim, Ick Chan Kwon, Sehoon Kim

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


Synergistic combination of gene targeting and chemotherapy by co-delivering siRNA and anticancer drugs has widely been investigated to develop siRNA-based therapeutics for cancer treatment. Despite clinical potential of this approach, big challenges still remain such as delivery efficiency or stability/biocompatibility of the siRNA delivery system. Here we report a simple and biocompatible co-delivering formulation based on a unique complexation method, i.e., multiple monocomplexation-induced hydrophobic association between Bcl-2 targeting siRNA and a monocationic anticancer agent (benzethonium chloride, BZT). A colloidal formulation of the hydrophobically associated multiple monocomplex (HMplex) composed of siRNA, BZT and Pluronic F-68 was spontaneously constructed by physical mixing of the ternary constituents. In vitro and in vivo studies revealed that the ternary HMplex with a low charge ratio (N/P = 4) possesses a tightly complexed stable nanostructure with Pluronic surface and small colloidal size less than 10 nm, which allowed for 1) suitable protection of siRNA in serum-rich physiological environment, 2) efficient intracellular transfection into the cytoplasm, and 3) successful peritumoral co-delivery into the tumor tissue with dense interstitial matrix. Compared to non-targeting HMplexes between scrambled siRNA and BZT, Bcl-2 targeting HMplexes enhanced significantly both mRNA down-regulation by siRNA and apoptosis induction by BZT, and thus greatly suppressed the tumor volume when administered to highly aggressive and resistant human breast cancer xenografts (MDA-MB-231) in mice. These results elucidate that the co-complexed siRNA and BZT were liberated by intracellular decomplexation to trigger a synergistically combined therapeutic action. The successful siRNA/chemodrug co-delivery in vivo via peritumoral route and the greatly promoted therapeutic efficacy thereby represent the clinical potential of HMplexes for adjuvant locoregional cancer treatment by gene-targeted combination therapy.

Original languageEnglish
Pages (from-to)105-114
Number of pages10
JournalJournal of Controlled Release
Publication statusPublished - 2015 May 25
Externally publishedYes


  • Co-delivery
  • Combination therapy
  • Gene therapy
  • Nanocomplexes
  • Triple-negative breast cancer
  • siRNA delivery

ASJC Scopus subject areas

  • Pharmaceutical Science


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