Biodistribution of adenoviral vector to nontarget tissues after local in vivo gene transfer to arterial wall using intravascular and periadventitial gene delivery methods

Expressionof transgene other than in the target tissue may cause side effects and safety problems in gene therapy. We analyzed biodistribution of transgene expression after intravascular and periadventitial gene delivery methods using the first generation nuclear-targeted lacZ adenovirus. RT-PCR and X-Gal stainings were used to study transgene expression 14 days after the gene transfer. After intravascular catheter-mediated gene transfer to rabbit aorta mimicking angioplasty procedure, the target vessel showed 1.1% ± 0.5 gene transfer efficiency. Other tissues showed varying lacZ gene expression indicating a systemic leakage of the vector with the highest transfection efficiency in hepatocytes (0.7% ± 0.5). X-Gal staining of blood cells 24 h after the intravascular gene transfer indicated that a significant portion (1.8% ± 0.8) of circulating monocytes was transfected. X-Gal-positive cells were also found in testis. After periadventitial gene transfer using a closed silicon capsule placed around the arter...