Directional gene-transfer into the brain by an adenoviral vector tagged with magnetic nanoparticles.

Adenoviral (Ad) vectors are useful for in vivo gene transfer into the brain. If Ad vectors are injected into the ventricle of mouse embryonic brain, Ad vectors introduce a foreign gene into neural progenitor cells on the surface of ventricle. However, Ad vectors were unable to deliver a foreign gene to a targeted region of the embryonic brain because Ad vectors evenly infected the neural progenitor cells on the surface of ventricle. Therefore, the Ad infection to the neural progenitor cells was uncontrollable. To develop a directional gene-transfer with Ad vector, we generated Ad vector tagged with magnetic nanoparticles (Ad-mag) by linking a biotinylated adenovirus vector with a streptavidin-conjugated magnetic nanoparticle. Ad-mags were attracted by magnetic force in vitro and in vivo. When Ad-mags were injected into the ventricle of mouse embryo and a strong magnet was attached to the head of the embryo, Ad-mags were attracted to the restricted direction or region where the magnet was placed. As a result, Ad-mags efficiently introduced a foreign gene into the restricted region of the brain.