Efficient siRNA delivery using osmotically active and biodegradable poly(ester amine)

Biodegradable and hyperbranched poly(ester amine) (PEA) was prepared by reaction of glycerol dimethacrylate (GDM) with low molecular weight polyethylenimine (LMW-PEI) by Michael addition reaction. This novel gene carrier showed excellent physicochemical properties and relatively low cytotoxicity compared with PEI 25K. It showed excellent transfection efficiency and siRNA delivery. The higher silencing efficiency of PEAs could be attributed to the synergistic effect arising from hyperosmotic glycerol and proton sponge active PEI residues in the PEA backbone.