Design and Formulation of Polyplexes Based on Pluronic-Polyethyleneimine Conjugates for Gene Transfer

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• 作者：Catherine L. Gebhart ; Srikanth Sriadibhatla ; Sergey Vinogradov ; Pierre Lemieux ; Valery Alakhov ; and Alexander V. Kabanov
• 刊名：Bioconjugate Chemistry
• 出版年：2002
• 出版时间：September 2002
• 年：2002
• 卷：13
• 期：5
• 页码：937 - 944
• 全文大小：313K
• 年卷期：v.13,no.5(September 2002)
• ISSN：1520-4812

文摘

Previously, we reported the evaluation of several polyplex-based gene delivery systems with respectto their effectiveness, toxicity, and cell type dependence in vitro. One system, P123-g-PEI(2K), a cationicgraft block copolymer, is of particular interest as it has been demonstrated to successfully delivergenetic material to murine liver following systemic delivery [Nguyen, H. K., Lemieux, P., Vinogradov,S. V., Gebhart, C. L., Guerin, N., Paradis, G., Bronich, T. K., Alakhov, V. Y., and Kabanov, A. V.(2000) Evaluation of Polyether-Polyethyleneimine Graft Copolymers as Gene Transfer Agents. GeneTher. 7, 126-138 (1)]. The P123-g-PEI(2K) system requires nonmodified Pluronic P123 as an excipientto stabilize the dispersion. The purpose of the current work was to more closely characterize thissystem, to assess the role of each component of the system to the overall transfection process. Weevaluated particle size, stability, and resistance to nuclease degradation. In addition, cellular uptakeand localization of plasmid, as well as transgene expression, were evaluated following in vitrotransfection of prostate cancer cells (PC-3) with various individual components of the system.Nonmodified Pluronic alone did not significantly enhance DNA uptake, transgene expression, or DNaseprotection. Therefore, we conclude that nonmodified Pluronic acted primarily by optimizing the sizeof the polyplex. Furthermore, though this system displays several characteristics thought desirableof a nonviral gene delivery system, these studies did discriminate a potential limitation of this systemfor in vivo applications, namely, the insufficient level of protection of plasmid DNA from nucleasedegradation. This may limit the effective dose delivered, as well as limiting the effective circulationtime. These studies provide vital information that will guide modification of this system to enhancethe current in vivo profile.