PAMAM Dendrimers Conjugated with L-Arginine and γ-Aminobutyric Acid as Novel Polymeric Gene Delivery Carriers

In this study, we synthesized functional dendrimer derivatives as nonviral gene delivery vectors. Poly(amidoamine) dendrimer (PAMAM, generation 4) was modified to possess functional amino acids to enhance gene transfection efficiency. PAMAM G4 derivatives conjugated with L-arginine (Arg) and gamma-aminobutyric acid (GABA) showed higher transfection efficiency and lower cytotoxicity compared to the native PAMAM G4 dendrimer. The polyplex of the PAMAM 04 derivative/pDNA was evaluated using an agarose gel retardation assay and Picogreen reagent assay. Additionally, the MTT assay was performed to examine the cytotoxicity of synthesized polymers. All PAMAM 04 derivatives showed lower cytotoxicity than PEI25k.D. Particularly, PAMAM G4-GABA-Arg displayed enhanced transfection efficiency compared to the native PAMAM G4 dendrimer.