The high-efficient assembly of plasmid DNA by polymers has become important for successful delivery of gene materials into the target cells.In this research

four polymers were synthesized by coupling phenylalanine (Phe) and tryptophan (Trp) to poly(amidoamine) dendrimers of generation 2(G2) and 4(G4)

respectively

so as to mimic the function of viral proteins.Then

the assembly of the plasmid DNA and polymeric vectors was investigated with agarose gel electrophoresis

ethidium bromide displacement assay and dynamic light scattering.The results indicated that Phe-G4 and Trp-G4 could self-assembly with the plasmid DNA to form more compact nano-sized particles with hydrodynamic radii of ca. 40 nm.It was driven by electrostatic interaction and structural rearrangement.Moreover

Phe-G4 and Trp-G4 exhibited high cell viability in COS-7 cell lines

meaning low cell toxicity of the polymeric vectors.The plasmid pEGFP-CL was transfected successfully in vitro by both Phe-G4 and Trp-G4 and the transfection efficiency of Phe-G4/plasmid DNA polyplexs was over four-times higher than that of liposome-mediated delivery method.In concern with these results

it is confirmed that Phe-G4 is a potential candidate as a high-efficient gene delivery system.