Nonionic Amphiphilic Block Copolymers Promote Gene Transfer to the Lung

Abstract

Various pulmonary disorders, including cystic fibrosis, are potentially amenable to a treatment modality in which a therapeutic gene is directly delivered to the lung. Current gene delivery systems, either viral or nonviral, need further improvement in terms of efficiency and safety. We reported that nonionic amphiphilic block copolymers hold promise as nonviral gene delivery systems for transfection of muscular tissues. To evaluate the efficiency of these vectors in the lung, intratracheal instillation or aerosolization of reporter genes complexed with Lutrol or PE6400 was performed. Lutrol-DNA and, to a lesser extent, PE6400-DNA complexes promoted efficient gene transfection into mouse airways in a dose-dependent manner. This improvement over naked DNA was observed irrespective of the reporter gene. Lutrol enabled us to deliver significantly higher DNA amounts than current nonviral vectors, with even greater increases in gene expression and without the formation of colloidally unstable complexes. Time course studies showed that Lutrol-DNA complexes permitted prolonged gene expression for up to 5 days whereas with poly(ethylenimine) (PEI)-DNA polyplexes, expression peaked on days 1-2 postinstillation, was strongly reduced by day 5, and reached background levels on day 7. Aerosolized delivery of Lutrol-DNA complexes, a less invasive approach to deliver genes to the lung, gave 5- to 15-fold higher reporter gene expression compared with PEI-DNA polyplexes administered via the same delivery route. After intratracheal instillation of Lutrol-DNA complexes, histochemical staining for beta-galactosidase expression showed the presence of large blue areas. Histopathological analysis showed that Lutrol alone did not elicit inflammation, and that the inflammatory response after intratracheal instillation of Lutrol-DNA complexes was reversible and was observed only with the highest amounts of DNA. We also found that Lutrol can efficiently deliver genes to the airways of cystic fibrosis mice. Thus, we conclude that Lutrol is a highly promising vector for gene delivery to the lung.

In vivo animal models for drug delivery across the lung mucosal barrier☆

“…Delivery of large doses of aerosol to mice is difficult to achieve in short periods of time and the amount of biological fluids that can be collected is small. Nevertheless, mice have been used to investigate drug delivery in disease states such as cystic fibrosis [63] and lung cancer [64].…”

Fine Tuning of CFTR Traffic and Function by PDZ Scaffolding Proteins

“…Thereby, we are currently investigating the effects of NHERF1 overexpression on F508del-CFTR expression and activity in vivo by non viral gene transfer using block copolymers in homozygous F508del-CFTR mice (Desigaux et al, 2005).…”

Effect of fractalkine-Fc delivery in experimental lung metastasis using DNA/704 nanospheres

“…At indicated time points, mice were anesthetized with ketamine/xylazine (70 and 15 mg kg À1 , respectively) and intracheally instillated or sprayed as already described. 20 For the induction of pulmonary nodules, CT26 cells (3 Â 10 4 ) and K7M2 cells (7.5 Â 10 5 ) were delivered by intravenous tail injection into syngeneic BALB/c mice, 6-8 weeks old and purchased from Harlan (Gannat, France). At 28 days after tumor cell injection, mice were killed and subjected to post-mortem examinations by a veterinary pathologist.…”

“…Mouse lungs were dissected and quantified for CAT expression as described by Desigaux et al 20 Bronchoalveolar lavage fluid was collected after washing three times the lungs with 500 ml of sterile phosphate-buffered saline containing a protease inhibitor cocktail (Roche Diagnostics, Meyland, France). The bronchoalveolar lavage fluid was centrifuged (10 000 g, 5 min, 4 1C), and the supernatants were used for protein analysis.…”

“…18,19 In this regard, a novel system for gene delivery to the lung was developed. 20 Aerosolized delivery of DNA formulated with non-ionic amphiphilic block copolymers was found to increase and prolong gene expression to the lung for several days with a lesser proinflammatory activity when compared to polyethyleneimine (PEI), so far proven the most potent non-viral vectors. The particles formed by non-ionic polymers and DNA are, however, ill-defined and exhibit complex morphologies not suitable for an immediate lung gene therapy.…”