Preparation and characterization of magnetic gene vectors for targeting gene delivery

► PEI is ideal candidate polymer for the design of gene delivery systems. ► PEI-CMD-MNPs exhibited a typical superparamagnetic behavior. ► PEI-CMD-MNPs were well stable over the entire range of pH and NaCl concentration. ► DNA-PEI-CMD-MNPs transfected cells by a magnet have higher transfection efficiency and gene expression efficiency.