Mode of delivery

The instillation of large volumes of vector-containing fluid into the lung via the nose. However, 1. this mode of delivery poses safety problems because of the potential for aspiration. 2. In addition, the instillation of large volumes of fluid leads to enhanced alveolar exposure, as a result of bulk flow into the lung parenchyma. This exposure is undesirable because it may induce adverse reactions. 3. At the same time, it is likely that airway epithelial cells, rather than alveolar epithelial cells, are the appropriate target for CFTR gene transfer