Table of Contents
ISRN Materials Science
Volume 2012, Article ID 798247, 24 pages
Review Article

Design and Development of Degradable Polyethylenimines for Delivery of DNA and Small Interfering RNA: An Updated Review

Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea

Received 24 September 2012; Accepted 12 October 2012

Academic Editors: K. Hokamoto and A. O. Neto

Copyright © 2012 Chong-Su Cho. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Polyethylenimine (PEI), considered as the most potent and promising alternative carrier to viral vectors, has been studied as the “state of the art” among various polymers for nonviral gene delivery applications for many years. Although PEI-based carrier minimizes the bottlenecks associated with viral vectors such as unwanted immunogenicity and production problems, the toxic side effects of PEI prevent its rapid advancements due to nondegradable nature. In this regard, various degradable cross-linking and/or grafting agents have been linked to synthesize degradable PEIs in order to minimize the toxicity and improve the efficacy of PEI-mediated gene carriers. This paper describes an update on various cross-linkers and grafting agents in the design and development of degradable PEI derivatives and their potential applications for effective delivery of DNA in vitro and in vivo. The molecular weight (MW) of PEI and the structural relationship to its cellular toxicity and transfection ability were also discussed. Finally, the potential applications of various degradable PEIs for small interfering RNA (siRNA)-mediated gene silencing were also covered.