Glyco-poly-l-lysine is better than liposomal delivery of exogenous genes to rat of liver

Abstract

AIM:To compare the effects of liposomes and glyco-poly-L-lysine on liver targeted uptake and expression of plasmid in rat liver.METHODS:After binding with lipofectamine or galactose-terminal glyco-poly-l-lysine, the plasmid could be expressed in eukaryotic cells when injected in to Wistar rats by intravenous route. At different time intervals after the injection, the distribution and expression of the plasmid in liver of rats were observed and compared using in situ hybridization and immunohistochemistry.RESULTS:The expression of the plasmidbinding to liposomes or G-PLL cou ld be markedly observed 24 h later, and began to decrease one week later,but it still could be observed up to three weeks.Both liposomes and G-PLL coul d deliver the plasmid to the liver effectively, but the effect of the latter was better than the former concerning the distribution and expression of the plasmid targeted uptake in the liver.

Figure 1

Determination of the optimal proportion of liposome bound to plasmid by 1% agarose electrophoresis. Lane 1-8 are respectively 1-8 μL lipofectamine mixed with 1 μg pTM/MMP-1 plasmid. Plasmid 1 μg could only be encapsulated complet ely by more than 5 μL lipofectamine.

Figure 2

Determination of the optimal proportion of G-PLL bound to plasmid by 1% agarose electrophoresis. Lane 1-8 are respectively 0.05 μg, 0.1 μg, 0.2 μg, 0.3 μg , 0.4 μg, 0.5 μg, 1.0 μg, and 1.5 μg G-PLL mixed with 1 μg pTM/ MMP-1 plasmid. Plasmid 1 μg could only been bound completely by more than 0.4 μg G-PLL.

Figure 3

Immunostaining of flag-domain tag in the liver of rat 24 h after the admini stration of the plasmid bound to G-PLL (galactose-terminal glyco-poly-L-lysine) via cauda vein. × 200

Figure 4

In situ hybridization with biotin labeled oligonucleotide probe in the liver 3 wk after the administration of the plasmid encapsulated by liposome (lipofectamine) via cauda vein. × 100

Figure 5

The distribution and expression of the plasmid bound to liposomes or G-PLL (gal actose-terminal glyco-poly-L-lysine) in different tissues and at differe nt time points. A: liver, B: spleen, C: lung, D: kidney. LI: plasmid encapsulate d by liposomes given through cauda vein, PI: plasmid bound to G-PLL introduced intravenously.