Hepatocyte-targeted gene transfection of galactosylated chitosan-graft low molecular polyethyleneimine/DNA complexes.

OBJECTIVE

To investigate the hepatocyte targeted specific property of galactosylated chitosan-graft-polyethyleneimine (GC-PEI)/DNA complexes in vitro and in vivo.

METHODS

With the plasmid expressing enhanced green fluorescent protein (pEGFP-C1) as the reporter gene, the formation of GC-PEI/DNA complexes was induced to self-assemble in 0.01 mol/L phosphate buffered saline(PBS), 150 mmol/L NaCl, or 5% glucose solution (GS).The complexes were characterized by the particle size, Zeta potential, DNA binding and protection capacity, and further tested for cytotoxicity and hepatocyte targeted transfection activity.

RESULTS

With the GC-PEI/DNA mass ratio from 1:1 to 2.5:1,the GC-PEI/DNA complexes effectively bound and protected the DNA from degradation of DNaseI and the serum, which presented as a well-formed sphere or compacted nucleocapsid structure at a diameter of 50-200 nm. The GC-PEI copolymer showed no obvious toxicity in the tested cell lines. Acute toxicity assay revealed that the mice grew well in 2 weeks with GC-PEI dosage from 50 to 300 μg. The assay by flow cytometry and fluorescent microscope showed that the transfection efficiency in hepatocyte lines (L02, QSG7701/core) was higher than that in non-hepatocyte lines (SGC7901, HBE) in vitro. In vivo, the GFP was obviously expressed in the liver tissue and not expressed in other organs 48 h after the transfection.

CONCLUSION

GC-PEI copolymer may carry the exogenous gene specifically to hepatocytes in vitro and in vivo,which has very good liver targeted specific property.