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Updated: Jun 18, 2026
Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry
Published on: March 1, 2013
A poly(ethylene) glycolylated peptide for ocular delivery compacts DNA into nanoparticles for gene delivery to
Sarah Parker Read1, Siobhan M Cashman, Rajendra Kumar-Singh
1Department of Ophthalmology, Tufts University School of Medicine, Boston, MA 02111, USA.
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 beta-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.
