title: Airway deposition of nebulized gene delivery nanocomplexes monitored by radioimaging agents.
abstract: Receptor-targeted nanocomplexes are nonviral vectors developed for gene delivery to the airway epithelium for the treatment of pulmonary disease associated with cystic fibrosis. The present study aimed to optimize the delivery of the nanocomplex by nebulization, and to monitor the in vivo deposition of radiolabeled vector in the airways of a large animal model by γ-camera scintigraphy. Large White weaner pigs were nebulized with nanocomplexes mixed with technetium-99m radiopharmaceuticals. The aerosol deposition scans suggested that the nebulized radiovectors were deposited mainly in the trachea-main bronchi and in the midregion of the lungs. The plasmid biodistribution, assessed by real-time PCR, correlated with the scintigraphy images. The highest plasmid copy numbers were found in the bronchial areas and in the tissues proximal to the main bronchi bifurcation. Immunohistochemistry detected transgene expression in the tracheal and bronchial ciliated epithelium. Histological analysis of lung tissue showed no evidence of inflammation, and no increase in inflammatory cytokines or inflammatory cells was detected in the bronchoalveolar lavage. The deposition of nebulized nanocomplexes coassociated with technetium-99m can be monitored by nuclear medicine techniques. The use of a noninvasive strategy to follow the delivery of the vector could improve the clinical management of patients undergoing cystic fibrosis gene therapy.
authors.affiliation: Wolfson Centre for Gene Therapy of Childhood Disease, UCL-Institute of Child Health, University College London, 30 Guilford St., London, United Kingdom.
authors.forename: Maria D I
authors.initials: MD
authors.lastname: Manunta
authors.forename: Robin J
authors.initials: RJ
authors.lastname: McAnulty
authors.forename: Amy
authors.initials: A
authors.lastname: McDowell
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.forename: Deborah
authors.initials: D
authors.lastname: Ridout
authors.forename: John
authors.initials: J
authors.lastname: Fleming
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Bottoms
authors.forename: Livia
authors.initials: L
authors.lastname: Tossici-Bolt
authors.forename: Geoffrey J
authors.initials: GJ
authors.lastname: Laurent
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Biassoni
authors.forename: Christopher
authors.initials: C
authors.lastname: O'Callaghan
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Hart
mesh_terms: D000818:Animals; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D058726:Nanoconjugates / Q000008:administration & dosage / Q000737:chemistry; D009330:Nebulizers and Vaporizers; D010957:Plasmids; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics*; D020545:Respiratory Mucosa / Q000000981:diagnostic imaging* / Q000648:ultrastructure; D012137:Respiratory System / Q000000981:diagnostic imaging* / Q000648:ultrastructure; D013552:Swine; D013667:Technetium / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D058726:Nanoconjugates; D019275:Radiopharmaceuticals; D013667:Technetium