A magnetic gene delivery nanosystem based on cationic liposomes

Magnetic nanoparticles-loaded cationic liposomes (MCLs), as gene delivery nanosystems, showed a great promise in treatment of solid tumors due to their advantages of enhancing transfection efficacy by the physical passive targeting and magnetic hyperthermia as a adjuvant therapy. In this job, we synthesized monodisperse Fe₃O₄ nanoparticles capped by oleic acid molecule (Fe₃O₄-OA) with ultra-small size. Water-soluble Fe₃O₄-DMSA nanoparticles were obtained via surface double-exchange of oleic acid with 2,3-dimercaptosuccinic acid (DMSA), which were then encapsulated into bilayer liposomes formed by 3-(N-(N’, N’-Dimethylaminoethane) carbamoyl) cholesterol (DC-Chol) and cholesterol through electrostatic interaction. The particle size, distribution, and zeta potential of Fe₃O₄-DMSA and MCLs were determined by dynamic light scattering and TEM images displayed their morphology. Additionally, the magnetic responsiveness of Fe₃O₄-OA, Fe₃O₄-DMSA and MCLs were observed by macroscopic photos and physical properties measurement system. The binding affinity of MCLs to EGFP-N1 plasmid was examined by gel retardation assay. Finally, the delivering gene ability of MCLs was evaluated on PC-3 cells by determining the green fluorescence protein signals using inverted fluorescence microscopy. Our findings suggest that engineered MCLs, as a novel gene vehicle, may have the potential application in tumor therapy.