Nuclear localization signal peptides enhance transfection efficiency of chitosan/DNA complexes delivery

Abstract

The purpose of this study was to investigate the effect of nuclear localization signal “KPKKKRKV” (NLS) on the enhancement of transfection efficiency of chitosan/DNA complexes delivery. The gene transfer efficiency of chitosan/DNA complexes with and without NLS was evaluated in a human cervical carcinoma cell line (Hela cells). The chitosan/DNA complex containing NLS increased transfection efficiencies in a NLS‐dose dependent manner on Hela cells, compared to control (chitosan/DNA complex or NLS). Cytotoxicity of the NLS/chitosan/DNA complexes increased as the amount of the peptide increased, however, over 80 % average cell viability was observed for complexes at the effective concentration of the peptide for transfections. Therefore, the NLS is expected to be a potent transfection enhancing agent without a covalent modification of pDNA or chitosan. Our findings suggest that the high gene expression with the negligible cytotoxicity can be achieved by adding the NLS peptide to chitosan/DNA complexes at optimal ratio. This research was supported by the Thailand Research Fund and Silpakorn University Research and Development Institute, Thailand.