Synthesis of a novel biodegradable poly(ester amine) (PEAs) copolymer based on low-molecular-weight polyethyleneimine for gene delivery.

In this paper, a novel biodegradable poly(ester amine) (PEA) copolymer was successfully prepared from low-molecular-weight polyethyleneimine (PEI, Mn=1800) and poly(epsilon-caprolactone)-Pluronic-poly(epsilon-caprolactone) (PCFC) copolymers. According to the results of agarose gel electrophoresis, particle sizes and zeta potential measurement and transfection efficiency, these PEA copolymers showed great ability to condense plasmid DNA effectively into nano-complexes with small particle size (< or =200 nm) and moderate zeta potential (> or =12 mV) at proper polymeric carrier/DNA weight ratio. Compared with low-molecular-PEI (Mn=1800), the obtained PEAs exhibited higher transfection efficiency as well as lower cytotoxicity. These results indicated that such PEAs might have great potential application in gene delivery system.