7.2 Non Viral Systems for Gene Therapy

The viral systems show lack of specificity for the targeting to specific tissues. In addition that they can carry a DNA of limited size up to 7kb, and could be suppressed in certain cells. These facts together with the random integration to chromosome sites and an unwanted immune response to the virus, make the investigators to find other systems for delivery. These systems are using non-viral systems, which are also known as physical mechanisms of gene transfer. The non-viral vectors can be divided into two categories, those which are limited to in vitro applications, and those which have both in vitro and in vivo applications.