PEI grafted hyperbranched polymers with polyglycerol as a core for gene delivery

Hyperbranched polymers, PG6–PEI25k and PG6–PEI800, were synthesized through grafting branched polyethylenimines (PEIs) with molecular weights of 25 kDa and 800 Da to a polyglycerol core (PG6), respectively. The structure of the polymers was characterized by 1H NMR and FTIR. Through agarose gel electrophoresis retardation assay, PG6–PEI25k and PG6–PEI800 were demonstrated to have capability for DNA binding. PG6–PEI/DNA complexes with different weight ratios were characterized by TEM and particle size analysis. The activity of PG6–PEIs to mediate transfection of reporter plasmids pEGFP-C1 and pGL3-Luc was evaluated on 293T and HeLa cell lines. PG6–PEI25k and PG6–PEI800 showed enhanced levels in transgene expression and decreased cytotoxicities as compared with PEI25k and PEI800, respectively. The results indicated potential applications of PG6–PEIs for efficient gene delivery.