Plasmid DNA Mono-Ion Complex for in Vivo Sustainable Gene Expression

Yuki Kobayashi; Sakura Taneichi; Hiroyoshi Kawakami; Yoichi Negishi; Shoichiro Asayama

doi:10.1021/acsomega.9b01323

Plasmid DNA Mono-Ion Complex for in Vivo Sustainable Gene Expression

ACS Omega. 2019 Jul 1;4(7):11464-11471. doi: 10.1021/acsomega.9b01323. eCollection 2019 Jul 31.

Authors

Yuki Kobayashi¹, Sakura Taneichi¹, Hiroyoshi Kawakami¹, Yoichi Negishi², Shoichiro Asayama¹

Affiliations

¹ Department of Applied Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan.
² Department of Drug Delivery and Molecular Biopharmaceutics, Tokyo University of Pharmacy and Life Sciences, Horinouchi, Hachioji, Tokyo 192-0392, Japan.

Abstract

To cleave biocompatible poly(ethylene glycol) (PEG) from the mono-ion complex (MIC) for sustainable cellular uptake in vivo, ω-amide-pentylimidazolium end-modified PEG with an ester bond, that is, APe-Im-E-PEG, has been synthesized. The hydrolysis of the resulting APe-Im-E-PEG proceeded during the incubation for 2 weeks under physiological conditions, which was confirmed by gel filtration chromatography. APe-Im-E-PEG formed the MIC with plasmid DNA (pDNA), assessed by agarose gel retardation assay. Furthermore, dynamic light scattering measurement and transmission electron microscopy observations have estimated that the particle size of the resulting MIC was approximately 30 nm, with a rather flexible structure. The APe-Im-E-PEG/pDNA MIC incubated for 2 weeks exhibited hemolytic activity at endosomal pH, presumably because the pH-sensitive carboxyl groups revealed after the hydrolysis of an ester bond of APe-Im-E-PEG. The APe-Im-E-PEG/pDNA MIC enhanced the gene expression 2 weeks after transfection in vivo by intramuscular administration in mice. Consequently, in vivo sustainable gene expression has been achieved by the molecular design of APe-Im-E-PEG for cellular uptake and endosomal escape proceeded by temporal hydrolysis of the ester bond.