Design, engineering and preparation of a multi-domain fusion vector for gene delivery

Peptide based gene carriers are among the most promising non-viral vectors for gene delivery to eukaryotic cells. We have engineered a new fusion peptide using recombinant technology with the purpose of overcoming the cell barriers to gene delivery. A His- tagged multi-domain peptide was expressed in Escherichia coli BL21 (DE3) pLysS and purified using Ni-NTA resin. The fusion peptide is composed of two repeats of truncated histone H1 peptide to condense pDNA, a fusogenic peptide to disrupt endosome membranes and a nuclear localization signal to enhance translocation of pDNA towards nucleus. The results demonstrated that the vector can effectively condense plasmid DNA into nanoparticles with average sizes of 200 nm. The fusogenic peptide in the vector structure also showed membrane disruptive effect in the endosomal pH. Overall, the transfection efficiency of the vector demonstrated that it holds great promise as a nontoxic and effective non-viral gene carrier.