Adenovirus-catheter compatibility increases gene expression after delivery to porcine myocardium.

Endomyocardial injection of adenoviral gene vectors enables localized delivery to comprised myocardial tissue. However, many materials used in endomyocardial delivery catheters may not be compatible with adenoviral gene vectors. In this study, a series of catheter-based endocardial and epicardial (direct visualization) procedures were performed to assess catheter-adenovirus compatibility in an in vivo model. A standard Nitinol-stainless steel (Ni-SS) catheter was compared with a novel Stiletto catheter designed for improved biocompatibility. In 4 animals 40 endocardial injections of adenovirus encoding β-galactosidase (β-Gal) were performed with the 2 catheters. After sectioning of the hearts only 8 of 20 Ni-SS β-Gal+ sites could be identified (40% retrieval) whereas 16 of the 20 Stiletto injection sites were identified (80%). Within these areas successful transfection was observed (12.2 ± 4.0 β-Gal+ cells/high-power field [HPF] in the Ni-SS group vs. 30.1 ± 6.8 β-Gal+ cells/HPF in the Stiletto group; p =...