Send to

Choose Destination
See comment in PubMed Commons below
J Control Release. 2009 Feb 10;133(3):206-13. doi: 10.1016/j.jconrel.2008.10.007. Epub 2008 Nov 1.

Controlled cytoplasmic and nuclear localization of plasmid DNA and siRNA by differentially tailored polyethylenimine.

Author information

  • 1Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA.


To maximize therapeutic effects, targeted delivery of nucleic acids (e.g., DNA and RNA) in their appropriate intracellular targets is highly desirable. In this study, primary amines of a model polymeric nonviral carrier, polyethylenimine (PEI), at two molecular weights (0.8 and 25 kDa) were differentially ketalized (i.e., 17-96%) in order to explore the possibility of precisely modulating intracellular localization of plasmid DNA- and siRNA-containing polyplexes. The size of the polyplexes revealed that the ketalization ratios of 35 to 70% were found to be the most efficient in condensing nucleic acids with the ketalized low molecular weight PEI (LMW PEI), while high molecular weight PEI (HMW PEI) ketalized at the ratio of 23% condensed nucleic acids most efficiently. Ketalization of LMW PEI (up to 70%) enhanced transfection; however, ketalization of HMW PEI reduced its transfection capability. On the contrary, HMW PEI ketalized at 23 and 37% ratios showed significant RNA interference, while LMW PEI could not successfully inhibit gene expression regardless of ketalization ratios. The results were explained by confocal microscopic studies demonstrating that ketalization ratios, molecular weights of ketalized PEI, and types of nucleic acids complexed in the polyplexes play crucial roles in intracellular localization of nucleic acids/ketalized PEI polyplexes and affect DNA transfection and RNA interference efficiencies. All ketalized PEI showed negligible cytotoxicity. This study implies a feasibility of selectively localizing nucleic acids in their intracellular targets by employing differentially tailored polymeric gene carriers.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk