Polyethylenimine dendrimer-grafted-dexamethasone as a mucleus targeting water-soluble lipopolymer gene carrier

Abstract

In this study the glucocorticoid steroid dexamethasone was conjugated to 2 kD polyethyleneimine (PEI) dendrimer and the effect of conjugation to the gene delivery efficiency of the polymer was investigated. We report a steroid-conjugated water-solulbe lipopolymer version, PEI-dexamethasone (PEI-Dexa), to introduce a nuclear targeting ligand to increase the transfection efficiency from the nucleus targeting functionality. We synthesized PEI-dexa and characterized its physicochemcial properties, cytotoxicity, and in vitro transfection efficiency. As control polymeric gene carriers, 25 kD PEI and polyamidoamine (PAMAM) dendrimer G4 were also used in the transfection experiments. The cytotoxicity and transfection efficiencies for 293, HepG2, and RAW 264.7 cells were also measured by comparison with PEI and PAMAM. It was observed that dexamethasone conjugation enhanced the transfection efficiency of PEI. Therefore, the technique with dexmethasone may be useful for the gene delivery using polymeric gene carriers and the development of efficient polymeric vectors.