Targeted Gene Delivery to Selected Liver Segments Via Isolated Hepatic Perfusion

Abstract

Development of targeted gene transfer technologies is essential for in vivo gene therapy. In this study, we examined the feasibility of physically targeting an adenoviral vector to selected liver segments in rats by isolating the hepatic perfusion (IHSP) and clamping the portal vein between the upper and lower segments. The rats were divided into two groups: IHSP group and the inferior vena cava (IVC) group. The adenoviral vector, which harbored the beta-galactosidase (beta-gal) gene, was administered via the portal vein, after which unbound vector particles were washed out with phosphate-buffered saline (PBS) and removed via the cannulated inferior vena cava (IVC) in IHSP group, while the IVC group received the transgene directly via the IVC without isolation of the hepatic perfusion. With this configuration (IHSP group), >99% of the beta-gal activity was limited to the targeted hepatic lobes, findings which were confirmed by histochemical staining with X-gal. We also found there to be significant differences in transgene expression among the hepatic lobes in the IVC group. Taken together, these results indicate that the IHSP technique is useful for local gene delivery to selected liver segments, and that when evaluating the efficacy of IHSP in the treatment of liver disease (e.g., nonresectable tumors), interlobar differences must be given careful consideration to ensure that sufficient drug or vector is delivered to all targeted hepatic lobes.