Cationic Lipid-Coated Gold Nanoparticles as Efficient and Non-Cytotoxic Intracellular siRNA Delivery Vehicles

Cationic lipid-coated gold nanoparticles were developed for efficient intracellular delivery of therapeutic siRNA. Particle formation was characterized by UV-visible spectroscopy, atomic force microscopy, and dynamic light scattering analysis. Cellular uptake, gene silencing effect, and cytotoxicity were investigated in multiple human cancer cell lines. Nanoparticles had a spherical nanostructure with highly cationic surface charge and could form stable nanosized polyelectrolyte complexes with siRNA via electrostatic interactions; complexes exhibited efficient intracellular uptake and significant gene silencing effect with markedly low cytotoxicity compared to the widely used polycationic carrier, linear polyethyleneimine. We demonstrated that cationic lipid-coated gold nanoparticles could be widely utilized as efficient and safe siRNA nanocarriers for diverse therapeutic and diagnostic applications.