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Updated: Mar 9, 2026
Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry
Published on: March 1, 2013
Poly(ethylene glycol) Crowding as Critical Factor To Determine pDNA Packaging Scheme into Polyplex Micelles for
Kaori M Takeda, Kensuke Osada1,2, Theofilus A Tockary2
1Japan Science and Technology Agency, PRESTO , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
Abstract:
A critical role of polyethylene glycol (PEG) crowding in the packaging of plasmid DNA (pDNA) into polyplex micelles (PMs) was investigated using a series of PEG-b-poly(l-lysine) (PEG-PLys) block copolymers with varying molecular weights of both PEG and PLys segments. Rod-shaped PMs preferentially formed when the tethered PEG chains covering pDNA in a precondensed state were dense enough to overlap one another (reduced tethering density (RTD) > 1), whereas globular PMs were obtained when they were not overlapped (RTD < 1). These results submitted a scheme that steric repulsive effect of PEG regulated packaging pathways of pDNA either through folding into rod-shape or collapsing into globular depending on whether the PEG chains are overlapped or not. The rod-shaped PMs gave significantly higher gene expression efficacies in a cell-free system compared to the globular PMs, demonstrating the practical relevance of regulating packaging structure of pDNA for developing efficient gene delivery systems.
