Cationic Liposome-Mediated Gene Delivery In Vivo

The cationic liposomes provide a versatile in vivo delivery system for plasmid-based genes and anti-gene constructs. They offer a number of potential advantages over the competing viral vector systems, including relative ease and simplicity of formulation, an often reduced incidence of toxic inflammatory and immune-mediated anti-DNA carrier responses, and the ability to deliver very large (Mb) DNA vectors. Their utility as an in vivo delivery system remains limited because of the low level and duration of expression of cationic liposome–DNA complexes (CLDC)-delivered genes. Recent advances in both DNA carrier and DNA vector technologies have significantly improved their in vivo efficiency; these factors still limit their utility in assessing gene function and gene regulation, as well as their ability to achieve successful gene therapy endpoints. It is likely that ongoing improvement in carrier and vector technologies, as well as improved understanding of the host factors that control CLDC-mediated gene transfer and expression, produce much more powerful generations of non-viral gene delivery systems in vivo.