A miniaturized nebulization catheter for improved gene delivery to the mouse lung.
BACKGROUND
The available methods for administration of gene delivery systems to the lungs of small animals via nebulization have several drawbacks. These include lack of control over the delivered dose and a negative impact on the stability of the formulation. This paper describes a new nebulization catheter device for the administration of plasmid-based gene delivery systems (polyplexes) as aerosols to the mouse lung in vivo.


METHODS
The physical stability of naked pDNA and polyplexes formulated with chitosan oligomers and PEI was examined following nebulization with the catheter device. We also examined the in vitro transfection efficiency of the polyplexes recovered after nebulization. Lung distribution and gene expression after administration of the selected gene delivery systems to the mouse lung were also investigated.


RESULTS
In contrast to previously described nebulization methods, the structural integrity of the unprotected naked pDNA was maintained following nebulization by the catheter device, which indicates relatively mild nebulization conditions. In addition, the nebulization procedure did not affect the physical stability of the formulated polyplexes. Small volumes of the pDNA aerosol (10-20 microl) were delivered in a highly controlled and reproducible manner. The aerosol droplet size varied with the molecular weight of the polycations. Aerosol delivery via this method resulted in improved lung distribution of pDNA polyplexes and a six-fold increase in the efficiency of gene delivery in vivo over that seen with the commonly used intratracheal instillation method.


CONCLUSIONS
The use of the nebulization catheter device provides a promising alternative for aerosol gene delivery to the mouse lung.
Köping-Höggård
Magnus
M
Department of Pharmacy, Uppsala University, Box 580, SE-751 23 Uppsala, Sweden.
Issa
Mohamed M
MM
Köhler
Tamara
T
Tronde
Ann
A
Vårum
Kjell M
KM
Artursson
Per
P
D000280:Administration, Inhalation; D000336:Aerosols; D000818:Animals; D048271:Chitosan; D004587:Electrophoresis, Agar Gel; D018014:Gene Transfer Techniques / Q000295:instrumentation*; D015316:Genetic Therapy / Q000295:instrumentation*; D005822:Genetic Vectors; D066298:In Vitro Techniques; D008156:Luciferases / Q000235:genetics; D008168:Lung; D051379:Mice; D008807:Mice, Inbred BALB C; D009115:Muridae; D009330:Nebulizers and Vaporizers; D014162:Transfection
D000336:Aerosols; D048271:Chitosan; D008156:Luciferases