Nasal application of the cationic liposome DC-Chol:DOPE does not alter ion transport, lung function or bacterial growth.

Liposome-mediated gene transfer is commonly used for in vitro transfection of deoxyribonucleic acid (DNA) into mammalian cells. We and others have recently demonstrated that this can be an effective method for in vivo delivery of plasmid DNA containing the human cystic fibrosis transmembrane conductance regulator (CFTR) gene to mouse models of cystic fibrosis (CF). This suggests that cationic liposomes may be useful for transferring CFTR complementary DNA (cDNA) into the airways of CF subjects. In such trials, measurement of nasal potential difference (PD) will be used to monitor the efficacy of correction of the CF bioelectric defect and to provide a sensitive assay of epithelial integrity [corrected]. We therefore assessed whether the cationic liposome DC-Chol: DOPE altered nasal ion transport parameters, in six normal and three CF subjects. Lung function was also measured as a further marker of safety. Finally, as CF airways are chronically infected, we studied whether DC-Chol:DOPE or DC-Chol:DOPE-DNA complexes altered the bacterial growth and sensitivities of CF sputum. No significant effect was seen on any of these parameters, suggesting that DC-Chol:DOPE may be appropriate for use in human trials of liposome-mediated gene therapy for CF.