A dual-functionally modified chitosan derivative for efficient liver-targeted gene delivery.

Abstract

Galactosylated chitosan-hydroxypropyltrimethylammonium (gal-HTCC) was synthesized by galactosylating and quaternizing chitosan to endue chitosan with targeting specificity for potential applications as gene vectors. The composition and physicochemical properties of gal-HTCC were characterized by FT-IR, (1) H NMR, elemental analysis, X-ray diffraction, and turbidity measurement. It was found that water-soluble gal-HTCC showed a more amorphous structure than chitosan, and it also had a much better plasmid condensation capability than galactosylated chitosan. Cytotoxicity measurements revealed that gal-HTCC showed significantly lower cytotoxicity in HepG2 and HeLa cell lines compared to branched polyethylenimine (bPEI, 25 kDa) which was used as a positive control. The nanoparticles (NPs) consisted of gal-HTCC and plasmid DNA had desirable particle size (around 250 nm) with a narrow size distribution. Confocal laser scanning microscopy confirmed that NPs could be internalized and transported to the nucleus efficiently within 6 h. In vitro gene transfection results indicated that gal-HTCC had significantly higher transfection efficiency (7- to 32-fold) compared to chitosan and gal-chitosan for targetable delivery of pGL3 luciferase plasmid to HepG2, and its transfection efficiency was highly inhibited in the presence of galactose (20 mM). All these results suggest that gal-HTCC can function as a promising nonviral gene vector for efficient liver-targeted gene delivery.