A poly(ethylene) glycolylated peptide for ocular delivery compacts DNA into nanoparticles for gene delivery to post-mitotic tissues in vivo

• Published in: The journal of gene medicine 2010-01, Vol.12 (1), p.86-96
• Main Authors: Read, Sarah Parker, Cashman, Siobhan M., Kumar-Singh, Rajendra
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; cell penetrating peptide; Deoxyribonuclease I - metabolism; DNA - chemistry; DNA - ultrastructure; gene delivery; Gene therapy; Gene Transfer Techniques; Humans; Injections, Intravenous; Luciferases - metabolism; Mice; Mitosis; Nanoparticles - chemistry; Nanoparticles - toxicity; Nanoparticles - ultrastructure; nonviral; Peptides - chemistry; Peptides - toxicity; POD; Polyethylene Glycols - chemistry; Polyethylene Glycols - toxicity; Protein Structure, Quaternary; Retinal Pigment Epithelium - cytology; Retinal Pigment Epithelium - drug effects; Retinal Pigment Epithelium - metabolism; Transfection
• ISSN: 1099-498X; 1521-2254; 1521-2254
• DOI: 10.1002/jgm.1415

Background We have previously shown that a novel synthetic peptide for ocular delivery (POD) can efficiently compact DNA and deliver it to cells in vitro. This observation prompted us to develop use of POD as a nonviral vector in vivo. Methods POD peptide was modified using poly(ethylene) glycol (PEG‐POD) and used to compact DNA into nanoparticles that were then analysed using electron microscopy, dynamic light scattering, and fluorescent labeling. Transfection efficiency and localization were determined 48 h post‐injection into the subretinal space of the mouse eye using luciferase and LacZ, respectively. Efficiency of ocular transfection was compared to two other PEGylated peptides: PEG‐TAT and PEG‐CK30. Results PEG‐POD can compact DNA and form discrete nanoparticles of approximately 136 nm that can penetrate and transduce the retinal pigment epithelium (RPE) in vivo. PEG‐POD significantly increased expression of plasmid DNA by 215‐fold, PEG‐TAT by 56.52‐fold, and PEG‐CK30 by 24.73‐fold relative to DNA injected alone. In all cases β‐galactosidase was observed primarily in the RPE layer after subretinal injection. Electrophysiological analyses of PEG‐POD transduced retina indicates an absence of PEG‐POD‐mediated toxicity. PEG‐POD can protect plasmid DNA from DNaseI digestion, resulting in significant transfection of the lung after intravenous injection in mice. Conclusions PEG‐POD was found to significantly increase gene delivery relative to both DNA alone and other pegylated peptides. These findings highlight the use of pegylated peptides, and specifically PEG‐POD, as novel gene delivery vectors. Copyright © 2009 John Wiley & Sons, Ltd.