Abstract
Gene therapy for airway diseases requires efficient delivery of nucleic acids to the intrapulmonary airways. In small animal models such as mice, gene delivery reagents are commonly delivered as a bolus dose. Routes of delivery may include either nasal sniffing or direct tracheal instillation. However, using a large animal model for preclinical applications is relevant for translation to human trials. Widespread and uniform distribution of transgene expression is critical for developing a successful lung gene therapy treatment. Aerosolizing viral vectors to the lungs of large animals, such as pigs or sheep, is a strategy to maximize gene transfer efficiency and results in greater airway distribution than a liquid bolus dose. Here we demonstrate a technique for direct aerosolization of a viral vector to the airways of newborn pigs. Briefly, a pig is anesthetized, intubated with an endotracheal tube, and a microsprayer is passed through the endotracheal tube. A syringe is used to push the vector through the microsprayer, resulting in a fine mist being released into the distal trachea. The microsprayer produces ~15-16 μm size particles that deposit across the proximal and distal regions of the lung. Using a microsprayer to deliver an adenoviral-based vector, we previously observed ~30-50% of surface epithelial cells transduced in both the large and small airways of newborn pigs.
