Non-viral and hybrid vectors in human gene therapy: an update

Non-viral DNA vectors have several advantages over viral vectors. For example, virus production is expensive and there are safety concerns regarding viral manipulations. In addition, the size of the delivered plasmid is limited by the size of the viral capsid, whereas this is not a problem with non-viral vectors. The major disadvantage of using non-viral DNA delivery vectors, compared with their viral counterparts, is the low transfection efficiency. This has resulted in low levels of usage in clinical trials. Consequently, the majority of research into non-viral gene therapy has been focused on developing more efficient vectors.