Effects of charge density and particle size of poly(styrene/(dimethylamino)ethyl methacrylate) nanoparticle for gene delivery in 293 cells

Abstract

To investigate factors for enhancing transfection efficiency, PS and positively charged PS nanoparticles were used as a model gene carrier system. Polymeric nanoparticles were synthesized using a simple and reproducible method of surfactant-free emulsion polymerization and charge densities of nanoparticles controlled by a two-stage shot-growth method. The morphology, charge density, and ξ-potential values of model nanoparticles were measured by SEM, the conductive method, and Zeta Plus, respectively. Four nanoparticles with different surface charge densities were adapted to investigate the capacity of condensing the gene and the enhancement of the transfection efficiency to the target cell. The cell viabilities in the presence of nanoparticles ranged between 75–110% of the control in all experiments. The highly charged nanoparticles (0.01 μC cm −2) fulfilled the requirements for a suitable model gene delivery system with respect to the condensing ability of DNA, complex formation, and transfection efficiency.