Further, the opinions and views presented here are those of the author and not of the Editor. There is a great deal of optimism surrounding the development of gene therapy as an effective strategy for management of many different human diseases. The active agent used to procure gene therapy is likely to consist of oligonucleotides, ribozymes or a DNA sequence that can be transcribed into a message capable of eliciting a therapeutic response. Unlike conventional small molecule therapeutics however, gene therapy requires the use of a carrier system to deliver the active agent directly into the target cell population. Although there are a variety of delivery systems available to achieve DNA transfer, lipid-based carriers are proving to be a versatile and pharmaceutically viable technology.
Numerous approaches are available to prepare effective lipid-based DNA delivery systems.
A practical guide to some of the methods used in the preparation and characterization of these DNA transfer formulations is presented here. The transfer process is likely to be a consequence of the physical and chemical attributes of the complex, which insure that DNA is maintained in a form that is protected from enzymatic hydrolysis and readily taken into a cell. These are, however, rather non-specific functions that can be fulfilled by many DNA binding molecules or structures. We believe that bound lipids may play a more active role in gene transfer as well as gene expression. The former may involve the well established role of lipids in membrane fusion while the latter concerns the role of lipids in destabilization of condensed DNA structures.