Hyperbranched cationic amylopectin derivatives for gene delivery

A series of hyperbranched cationic amylopectin derivatives conjugated with 1,2-ethylenediamine, diethylenetriamine and 3-(dimethylamino)-1-propylamine residues, named as EDA-Amp, DETA-Amp and DMAPA-Amp, were synthesized by the N,N’-carbonyldiimidazole activation method at room temperature. Their structures were characterized by FTIR and 1H NMR analyses, and their buffering capability was assessed by acid-base titration. The amylopectin derivatives exhibited better blood compatibility and lower cytotoxicity when compared to branched polyethyleneimine (bPEI) in the hemolysis and MTT assays. Atomic force microscopy and optical microscopy confirmed that the amylopectin derivatives exhibited lower damage for erythrocytes than bPEI. The amylopectin derivatives could bind and condense plasmid DNA (pDNA) to form the complexes with the size ranging from 100 to 300 nm. The resultant complexes showed higher transfection efficiency in 293T cells than in A549 cells. The DMAPA-Amp derivative-mediated gene transfection for Forkhead box O1 exhibited higher protein expression than that of the EDA-Amp and DETA-Amp derivatives in 293T cells, which was analyzed by western blot, flow cytometry and Hoechst staining assay. On the basis of these data, amylopectin derivatives exhibit potential as nonviral gene vectors.