A convenient and adjustable surface-modified complex containing poly-L-glutamic acid conjugates as a vector for gene delivery

Ye Sun¹, Yuzhao Tang¹, Maoquan Chu², Shuxian Song¹, Yanfei Xin³

¹School of Life Science and Technology, Shanghai Jiaotong University, Shanghai, China; ²Institute of Life Science and Technology, Tongji University, Shanghai, China; ³School of Pharmacy, Shanghai Jiaotong University, Shanghai, China

Abstract: In order to quantify the amount of ligands or poly(ethylene glycol) (PEG) on each vector, here we developed a system in which poly-L-glutamic acid (PLG) was used as surface modification loading backbone, to which one PEG (MW 5000, 10000, 20000) or epidermal growth factor (EGF) was linked. The PLG conjugates can electro-statically adsorb upon DNA/polycation complex with positive charge, and, the amount of EGF or PEG on the surface of complexes could be varied. We have made a series of complexes containing the various PLG conjugates and examined their physicochemical properties, and made a comparison of properties and transfection efficiency between these complexes. EGF- and PEG-modified complexes showed 10–25-folds higher cell transfection efficiency than unmodified complexes in medium with or without serum.

Keywords: gene delivery, poly(ethylene glycol), poly-L-glutamic acid, epidermal growing factor, poly-L-lysine