Synthesis and characterization of low molecular weight polyethyleneimine-terminated Poly(β-amino ester) for highly efficient gene delivery of minicircle DNA

Gene therapy has held great promise for treating specific acquired and inherited diseases. However, the lack of safe and efficient gene delivery systems remains as the major challenge. Poly(β-amino ester)s (PBAEs) have attracted much attention due to their outstanding properties in biosafety, DNA delivery efficiency and convenience in synthesis. In this paper, we reported the further enhancement of the PBAE functions by increasing its positive charge through conjugating with low molecular weight polyethylenimine (LPEI). The resulted LPEI–PBAE polymer was able to condense minicircle DNA (mcDNA) forming nanoparticles with a diameter of 50–200   nm. Furthermore, as compared to parental PBAE and a commercial transfection reagent very common in laboratory application, the LPEI–PBAE demonstrated significantly higher transfection efficiency with little cytotoxicity. These results suggested LPEI–PBAEs are worthy of further optimization for gene therapy applications.