Pegylation effect of chitosan based polyplex on DNA transfection.

The aim of this study was to develop hepatocyte-targeting non-viral polymeric nono-carriers for gene delivery. Chitosan was selected as the main polymer. An asialoglycoprotein receptor recognized sugar, galactose, was introduced. The methoxy poly(ethylene glycol) (mPEG) or short chain poly(ethylene glycol) diacid (PEGd) was further grafted onto galactosylated chitosan. All polyplex possessed positive charge character. The compaction of DNA by grafted chitosan was in order of chitosan-galactose-mPEG>chitosan-galactose-PEGd>chitosan-galactose where the chitosan-galactose-mPEG and pDNA formed the most stable polyplex. The polyplex prominently enhanced DNA cellular transfection as compared to naked DNA in HepG2 cells in order of chitosan-galactose/pDNA (11.6±0.6-33.0±4.4%)>chitosan-galactose-PEGd/pDNA (12.7±2.5-15.5±3.0%)>chitosan-galactose-mPEG/pDNA (9.0±1.1-12.9±2.4%).