The effects of jet nebulisation on cationic liposome-mediated gene transfer in vitro

Abstract

Nebulisation is currently the most acceptable and practical to the amount of DNA delivered and measurements of both delivery system for repeated applications of gene therapy zeta potential and mean aerodynamic particle size before to the lower airways of cystic fibrosis (CF) patients. We and after nebulisation did not show concentration-related have assessed whether this route of administration offers differences. The increased transfection efficiency did not other benefits with regard to respiratory gene transfer. A relate either to the physical consequences of the nebulisstandard jet nebuliser (Acorn System 22, Medicaid) was ation processes nor the effects of nebulisation on the comused to transfer the reporter gene ␤-galactosidase complexes before instillation. Significantly increased transfecplexed with the cationic liposome DC-Chol/DOPE to three tion efficiency was seen following nebulisation with 95% epithelial cell lines in vitro, two non-CF and one CF, using a O 2 /5% CO 2 in comparison with 21% O 2 /78% N 2 (air); this novel collection system. In all three cell lines, nebulisation did not relate to changes in either the pH or temperature resulted in significantly (P Ͻ 0.05) improved transfection of the solution bathing the cells. The data confirm that nebefficiency compared with instillation. At a constant DNA:liulisation is appropriate for gene delivery to the lower airposome ratio of 1:5 (wt:wt), transfection efficiency was ways in clinical practice and points to factors that may inversely related to increasing concentrations of DNA-lipooptimise gene transfer efficiency. somes before nebulisation. This effect was not related

Effect of jet nebulization on DNA: identifying the dominant degradation mechanism and mitigation methods

“…As a consequence of these trials, aerosol delivery of gene therapeutics via jet or ultrasonic nebulizers has recently become of great interest due to the non-invasive nature, the ability to directly target the lungs, and the observed decrease in systemic toxicity when compared to other drug delivery methods (Bennett et al, 2002). Unfortunately, in vivo transfection experiments using these aerosolization techniques have elicited negligible response from naked DNA ranging in size from 4.7 to 7.2 kilobase pairs (kbp) (Schwarz et al, 1996;Stern et al, 1998).…”

“…Increased transfection rates of gene therapies via the pulmonary delivery route have largely focused on the incorporation of carbon dioxide into the air to increase breath depth as well as the addition of cationic molecules (Gautam, Densmore, Xu, & Waldrep, 2000;Stern et al, 1998). The successful delivery and expression of DNA requires vectors that facilitate the translocation of genes into the nucleus.…”

Evaluation of polyether-polyethyleneimine graft copolymers as gene transfer agents

“…The levels of transgene expression using this system at optimal conditions were in the range of 600 to 1500 of ng of luciferase per mg cell protein (Figures 5 and 7), which compares well with expression levels reported in the literature using other non-viral vectors for gene delivery, such as cationic lipids. 9,20 This system was further examined in in vivo transfection experiments.…”

Electroporation as a method for high-level nonviral gene transfer to the lung

“…By contrast, delivery of lipoplex, polyplex, and viruses via the airways results in gene transfer primarily to cells of the epithelium and resident alveolar macrophages; tight junctions between epithelial cells prevent vector access to other cell types. [9][10][11] Thus, when desired, a limited degree of cell-specific targeting can be accommodated by delivery route. However, gene delivery to all cell types within the lung remains very difficult to achieve by current methods.…”