Image-guided, lobe-specific hydrodynamic gene delivery to swine liver

Image-guided, lobe-specific hydrodynamic gene delivery to liver was assessed in pigs. The procedure involved image-guided insertion of a balloon catheter to the hepatic vein of the selected lobe from the jugular vein and hydrodynamic injection of plasmid DNA using a newly developed computer-controlled injection device. We demonstrated that the impact of the procedure was regional with minimal effects on neighboring lobes. Level of gene expression resulted from the procedure was 10(7) relative light units (RLU)/mg in the targeted lobes and 10(2)-10(5) RLU/mg in the nontargeted lobes 4 hours after hydrodynamic injection of pCMV-Luc plasmids. Occlusion of blood flow in the inferior vena cava (IVC) or IVC plus portal vein (PV) was effective in elevating hydrodynamic pressure in the targeted vasculature but did not enhance gene delivery efficiency. Physiological examination on pigs with IVC occlusion revealed transient decreases of blood pressure and respiration rate. Removal of occlusion from IVC resulted in a rapid and transient increase in heart rate. Occlusion of the PV and hepatic vein showed no effect on physiological and cardiac activities. No major changes in serum composition were observed. These results suggest that (i) image-guided, lobe-specific hydrodynamic procedure is effective for regional gene delivery to liver, (ii) blockade in IVC should be avoided for hydrodynamic gene delivery to the liver, and (iii) clinical application of hydrodynamic gene delivery to liver is feasible.