Folate-PEG modified poly(2-(2-aminoethoxy)ethoxy)phosphazene/DNA nanoparticles for gene delivery: Synthesis, preparation and in vitro transfection efficiency

Target-specific technique can significantly enhance the efficacy of gene delivery system which was limited by many cellular barriers. In this work, a new folate-PEG modified poly(2-(2-aminoethoxy)ethoxy)phosphazene (PAEP), namely, folate-PEG-PAEP was synthesized as a folate receptor (FR) targeted carrier, and the cytotoxicity, transfection efficiency, cellular uptake and intracellular trafficking of folate-PEG-PAEP/DNA nanoparticles (FPPN) were investigated. Compared with the PAEP/DNA nanoparticles (PN), the cytotoxicity of FPPN decreased significantly at high dose. FPPN showed much higher transfection efficiency (15.85 ± 1.23%) compared with PN (6.71 ± 0.42%) in FR overexpressing Hela cells, but no significant difference was observed in CHO-k1 cells lacking FR. The transfection activity of FPPN could be reversed in the presence of 1.0 mM free folic acid in Hela cells. The cellular uptake of FPPN was 37.38% higher than that of PN in Hela cells. These results indicated that FPPN could be a potential targeted gene delivery system.