Abstract
Nucleic acid delivery applications require the development of carrier systems that are effective, selective, and non-toxic. Many different viral and non-viral approaches, including the use of retroviruses, adenoviruses, liposomes, and dendrimers, have been investigated. Unfortunately, issues still remain with regard to the safety and efficiency of these delivery vehicles. In this Perspective, the challenges of designing a stable vector that is capable of effective gene therapy are highlighted. Progress in the area is also presented, including the work of Kostarelos and co-workers appearing in this issue of ACS Nano, in which they describe a novel delivery vehicle that consists of lipid envelopes encasing viral nanoparticles.