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Effects of the Lipophilic Core of Polymer Nanoassemblies on Intracellular Delivery and Transfection of siRNA

1 Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone, Lexington, KY 40536, USA;
2 Markey Cancer Center, University of Kentucky, 800 Rose Street, CC140, Lexington, KY 40536;
3 Department of Surgery, College of Medicine, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA

Special Issues: Protein folding or molecular self-assembly over nanoscale surface

Despite effective gene silencing in vitro, in vivo delivery and transfection of siRNA remain challenging due to the lack of carriers that protect siRNA stably in the body. This study is focused to elucidate the correlation between complex stability and transfection efficiency of siRNA carriers. The carriers were prepared by using polymer nanoassemblies made of a cationic branched polymer [poly(ethylene imine): bPEI] to which hydrophilic poly(ethylene glycol) polymers were tethered covalently. These polymer tethered nanoassemblies (TNAs) were further modified with lipophilic chains (palmitate: PAL) in the core to stabilize siRNA TNAs complexes through ionic and hydrophobic interactions in combination. The effects of PAL in the core of TNAs were investigated with respect to in vitro transfection, intracellular gene delivery, and toxicity of the complexes, using a human colon cancer HT29 cell line stably expressing a luciferase reporter gene. A commercial transfection agent (RNAiMax) was used as a control. TNAs entrapping siRNA showed the greatest complex stability in the absence of PAL although TNAs with a greater PAL content induced effective intracellular siRNA delivery, while luciferase expression decreased as the amount of PAL increased in the core of TNAs. These results demonstrate that lipophilic components in carriers affect not only complex stability but also intracellular distribution and transfection of siRNA in cancer cells.
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Keywords polymer nanoassemblies; gene therapy; siRNA delivery; non-viral vectors; cancer; nanotechnology

Citation: Steven Rheiner, Piotr Rychahou, Younsoo Bae. Effects of the Lipophilic Core of Polymer Nanoassemblies on Intracellular Delivery and Transfection of siRNA. AIMS Biophysics, 2015, 2(3): 284-302. doi: 10.3934/biophy.2015.3.284


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Copyright Info: 2015, Younsoo Bae, et al., licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution Licese (http://creativecommons.org/licenses/by/4.0)

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