Abstract
Gene transfer vectors play critical roles in human gene therapy. These vectors are different from existing drug delivery systems, because they deliver DNA, a fragile macromolecule, directly into cells. In addition, DNA should he delivered into a nucleus by an active transport mechanism, as the nuclear membrane is a tight harrier for macromolecules. To satisfy these requirements, gene transfer vectors should be developed based on biological phenomena. In this review, I describe a new vector system called “hybrid vectors”. Hybrid vectors use the mechanism of infection of animal viruses for gene transfer and have the advantages of both viral vectors and non-viral vectors.
