Polymeric Nanocarriers for Non-Viral Gene Delivery

Gene therapy holds great promise for the treatment of acquired and inherited diseases. Non-viral gene delivery systems are gaining recognition as alternatives to viral gene vectors due to their safety and low immunogenicity. The effective delivery of nucleic acids requires overcoming many biological barriers that would otherwise hinder transfection efficiency. Developing safe and efficient vectors that can overcome these obstacles is at the heart of current gene delivery research. Polymeric nanocarriers, such as polyethylenimine (PEI), poly(L-lysine) (PLL), poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA), polyamidoamine (PAMAM), chitosan and poly(amino-co-ester)s (PAEs), play an important role in gene delivery. In this review, we first describe the current understanding of the biological barriers to non-viral gene delivery and recent progress in addressing these barriers. Several of the most widely used non-viral polymeric nanocarriers are discussed, and detailed strategies that have accumulated from nearly two decades of research aimed at overcoming biological barriers and improving gene transfer are highlighted.