In vitro and in vivo gene delivery mediated by Lactosylated dendrimer/alpha-cyclodextrin conjugates (G2) into hepatocytes.

The purpose of this study is to evaluate in vitro and in vivo gene delivery efficiency of polyamidoamine (PAMAM) starburst dendrimer (generation 2, G2) conjugates with alpha-cyclodextrin (alpha-CDE (G2)) bearing lactose (Lac-alpha-CDE) with various degrees of substitution of the lactose moiety (DSL) as a novel hepatocyte-selective carrier in hepatocytes. Lac-alpha-CDE (DSL 2.6) was found to have much higher gene transfer activity than dendrimer, alpha-CDE, Lac-alpha-CDE (DSL 1.2, 4.6, 6.2 and 10.2) and lactosylated dendrimer (Lac-dendrimer, DSL 2.4) in HepG2 cells, which are dependent on the expression of cell-surface asialoglycoprotein receptor (ASGP-R), reflecting the cellular association of the plasmid DNA (pDNA) complexes. The physicochemical properties of pDNA complex with Lac-alpha-CDE (DSL 2.6) were almost comparable to that with alpha-CDE. Lac-alpha-CDE (DSL 2.6) provided negligible cytotoxicity up to a charge ratio of 150 in HepG2 cells. Lac-alpha-CDE (DSL 2.6) provided gene transfer activity higher than jetPEI-Hepatocyte to hepatocytes with much less changes of blood chemistry values 12h after intravenous administration in mice. These results suggest the potential use of Lac-alpha-CDE (DSL 2.6) as a non-viral vector for gene delivery toward hepatocytes.