Nonviral DNA delivery systems have great therapeutic and prophylactic potential, but their clinical utility has been limited by three major barriers: (1) inefficient uptake by the cell, (2) insufficient release of DNA within the cell, and (3) ineffective nuclear targeting and transport. Since the size of most cells is in the micrometer regime and the space inside a cell is extremely crowded, ideal DNA delivery systems must be in the nanometer range. Advancements in nanoscale science and nanotechnology have provided us with novel nanoparticles that may overcome all of these barriers, leading to higher-efficiency DNA delivery. This review article will focus on the recent developments in nanoscale DNA delivery systems that consist of chemical dendrimers, DNA dendrimers, nanospheres, nanolayers, nanorods, and nanotubes. The future of DNA delivery systems that interface with nanotechnology is also discussed.
