Lee A. Davies, Lincoln College, 2001.
Gene therapy has been proposed as a possible treatment for cystic fibrosis lung disease in which a normal copy of the CFTR gene would be introduced into CF cells, in order to direct synthesis of functional CFTR protein and reverse the primary biochemical abnormality of the disease. Plasmid DNA vectors containing the functional CFTR gene have been investigated for CF gene therapy. However, the aerosolisation of such gene transfer agents for targeted delivery to respiratory epithelium results in considerable vector degradation and loss of biological efficacy due to the mechanical shear forces generated within conventional nebuliser devices.
Electrohydrodynamic (EHD) comminution is a novel aerosolisation technique that utilises strong electric fields and minimal shear forces to break up bulk liquids into fine aerosols. The aim of this study was to investigate the viability of using EHD comminution for the targeted delivery of plasmid DNA to the lung. The physical integrity of aerosolised plasmid was investigated using gel electrophoresis and biological activity was investigated both in vitro and in vivo using the mouse lung and trachea as a model system. Following aerosol delivery, plasmid deposition and mRNA production in the murine lung were quantitated using an Applied Biosystems ABI PRISM 7700 sequence detector (TaqMan). Results showed that plasmid DNA can be aerosolised effectively using EHD comminution without degradation or loss of biological efficacy.