Improved in vivo gene transfer into tumor tissue by stabilization of pseudodendritic oligoethylenimine-based polyplexes

Verena Russ, Thomas Fr̈ohlich, Yunqiu Li, Anna Halama, Manfred Ogris, Ernst Wagner

Research output: Contribution to journalArticle

23 Citations (Scopus)


Background: HD O is a low molecular weight pseudodendrimer containing oligoethylenimine and degradable hexanediol diacrylate diesters. DNA polyplexes display encouraging gene transfer efficiency in vitro and in vivo but also a limited stability under physiological conditions. This limitation must be overcome for further development into more sophisticated formulations. Methods: HD O polyplexes were laterally stabilized by crosslinking surface amines via bifunctional crosslinkers, bioreducible dithiobis(succimidyl propionate) (DSP) or the nonreducible analog disuccinimidyl suberate (DSS). Optionally, in a subsequent step, the targeting ligand transferrin (Tf) was attached to DSP-linked HD O polyplexes via Schiff base formation between HD O amino groups and Tf aldehyde groups, which were introduced into Tf by periodate oxidation of the glycosylation sites. Results: Crosslinked DNA polyplexes showed an increased stability against exchange reaction by salt or heparin. Disulfide bond containing DSP-linked polyplexes were susceptible to reducing conditions. These polyplexes displayed the highest gene expression levels in vitro and in vivo (upon intratumoral application in mice), and these were significantly elevated and prolonged over standard or DSS-stabilized HD O formulations. DSP-stabilized HD O polyplexes with or without Tf coating were welltolerated after intravenous application. High gene expression levels were found in tumor tissue, with negligible gene expression in any other organ. Conclusions: Lateral stabilization of HD O polyplexes with DSP crosslinker enhanced gene transfer efficacy and was essential for the incorporation of a ligand (Tf) into a stable particle formulation.

Original languageEnglish
Pages (from-to)180-193
Number of pages14
JournalJournal of Gene Medicine
Issue number2
Publication statusPublished - 1 Feb 2010



  • Cancer
  • Degradable polymer
  • Gene transfer
  • Polyplex
  • Targeting
  • Transferrin

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology
  • Genetics
  • Drug Discovery
  • Genetics(clinical)

Cite this