Synthesis of N-oxide Poly(1-vinylimidazole) for pDNA delivery systems in vivo

N-oxide poly(1-vinylimidazole) (PVIm+–O−) has been synthesized as a unique biocompatible polyampholyte. Measurements of solution turbidity prove that PVIm+–O− had no significant effect on rapid aggregate formation with serum proteins. Agarose gel retardation assay, particle size/ζ-potential measurement, and cytotoxicity evaluation prove that the PVIm+–O− coated binary complexes between branched poly(ethyleneimine) (bPEI) and plasmid DNA (pDNA). The resulting PVIm+–O−/bPEI/pDNA ternary complex mediated higher gene expression than the bPEI/pDNA binary complex in vivo mouse skeletal muscle. These results suggest that PVIm+–O− is a polyampholyte for biocompatibility.