Functional delivery of siRNA in mice using dendriworms

ACS Nano. 2009 Sep 22;3(9):2495-504. doi: 10.1021/nn900201e.


Small interfering RNAs (siRNAs) mediate cleavage of specific, complementary mRNA sequences and thus regulate gene expression. Not surprisingly, their use for treatment of diseases that are rooted in aberrant gene expression, such as cancer, has become a paradigm that has gained wide interest. Here, we report the development of dendrimer-conjugated magnetofluorescent nanoworms that we call "dendriworms" as a modular platform for siRNA delivery in vivo. This platform maximizes endosomal escape to robustly produce protein target knockdown in vivo, and is tolerated well in mouse brain. We demonstrate that siRNA-carrying dendriworms can be readily internalized by cells and enable endosomal escape across a wide range of loading doses, whereas dendrimers or nanoworms alone are inefficient. Further, we show that dendriworms carrying siRNA against the epidermal growth factor receptor (EGFR) reduce protein levels of EGFR in human glioblastoma cells by 70-80%, 2.5-fold more efficiently than commercial cationic lipids. Dendriworms were well-tolerated after 7-days of convection-enhanced delivery to the mouse brain and in an EGFR-driven transgenic model of glioblastoma, anti- EGFR dendriworms led to specific and significant suppression of EGFR expression. Collectively, these data establish dendriworms as a multimodal platform that enables fluorescent tracking of siRNA delivery in vivo, cellular entry, endosomal escape, and knockdown of target proteins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Central Nervous System / metabolism
  • Central Nervous System / pathology
  • Cytosol / metabolism
  • Dendrimers / chemical synthesis
  • Dendrimers / chemistry*
  • Dendrimers / metabolism*
  • Dendrimers / toxicity
  • Drug Carriers / chemical synthesis
  • Drug Carriers / chemistry*
  • Drug Carriers / metabolism*
  • Drug Carriers / toxicity
  • Endocytosis
  • ErbB Receptors / deficiency
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism
  • Fluorescent Dyes / chemistry
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Gene Silencing
  • Glioblastoma / genetics
  • Glioblastoma / pathology
  • HeLa Cells
  • Humans
  • Magnetics
  • Mice
  • Mice, Transgenic
  • Nanostructures / chemistry*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism*
  • Time Factors


  • Dendrimers
  • Drug Carriers
  • Fluorescent Dyes
  • RNA, Small Interfering
  • epidermal growth factor receptor VIII
  • EGFR protein, mouse
  • ErbB Receptors