9.1 Gene Therapy
Gene Therapy is a popular target for gene mutations as it combats the source of the disease rather than the surpressing the symptoms. However this therapy has many limitations. The review paper of T.R. Flotte and Beth L. Laube  have published facts about gene therapy which will be shortly reviewed in the following paragraphs.
To begin with there are two major pathways for gene therapy: Transduction and Transfection. For Transduction one needs a virus which transfers a piece of DNA, in this case the CFTR gene into target cells. In Transfection on the other hand a plasmid is inserted in the eukaryotic cell via transformation of eg. E. Coli. This can also be performed in ...view middle of the document...
However, recent research by Fisher K.J. et al  suggests that deleting the whole viral genome is the next step in Ad virus modification. The now called “High Capacity Ad Vectors” have the benefit of enhanced expression duration and are less prone to be attacked by human immune system. Unfortunately the humoral immune system against the capsule of the virus still prevails  and the responsible antibodies cannot be suppressed without increasing the risk of inducing tolerance of wild-type Ads. 
9.1.2 Non-viral Infection
To avoid the problems with virus infections an alternative pathway with cationic liposomes has been developed. These are special complexes which consist of DNA and lipid.  It can form a large complex where on one side it interacts with the DNA and at the other hydrophobic part it interacts with the cell membrane or enhances the condensation of the complex.  Even though its side effects are lower than virus transfection, the low efficiency remains a problem. On the other hand its low inflammatory response makes repeated dosage possible. Other molecular conjugates which consist of protein and DNA complexes are tested as an alternative. Using proteins as a ligand which triggers receptor mediated endocytosis, offers great results in in vivo experiments. 
9.1.3 Augmentation and Gene Targeting
The last few paragraphs have shown how to introduce DNA into a cell but one also has to differentiate how the mutated gene should be influenced. In Augmentation the entire CFTR locus is being replaced by a functioning one by a bacterial artificial chromosome (BAC) as practiced in the study of Auriche et al. . This approach has the advantage that the exact mutation does not have to be specified to show good results in in vitro experiments. Yet a problem they are facing refers to the regulation of the newly inserted gene. Needless to say a gene does not only contain genetic material but also regulators of expression which are artificially added in augmentation but they...