Clinical translation of siRNA therapeutics has been limited by the inability to effectively overcome the rigorous delivery barriers associated with intracellular-acting biologics. Here, in order to address both potency and longevity of siRNA gene silencing, siRNA conjugated to palmitic acid (siRNA-PA) was paired with pH-responsive micellar nanoparticle (NP) carriers in order to improve siRNA stability and endosomal escape, respectively. Conjugation to hydrophobic PA improved NP loading efficiency relative to unmodified siRNA, enabling complete packaging of siRNA-PA at a lower polymer:siRNA ratio. PA conjugation also increased intracellular uptake of the nucleic acid cargo by 35-fold and produced a 3.1-fold increase in intracellular half-life. The higher uptake and improved retention of siRNA-PA NPs correlated to a 2- to 3-fold decrease in gene silencing IC50 in comparison to siRNA NPs in both mouse fibroblasts and mesenchymal stem cells for both the model gene luciferase and the therapeutically relevant gene PHD2. PA conjugation also increased longevity of silencing activity, as indicated by an increase in silencing half-life from 24 hours to 186 hours. Thus, conjugation of PA to siRNA paired with endosomolytic NPs is a promising approach to enhance the functional efficacy of siRNA in tissue regenerative and other applications.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-11202014-143013 |
| Date | 25 November 2014 |
| Creators | Sarett, Samantha Mara |
| Contributors | Craig Duvall, Hak-Joon Sung |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-11202014-143013/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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