Pulmonary distribution of nanoceria: comparison of intratracheal, microspray instillation and dry powder insufflation
| Autor: | Joseph D. Brain, Thomas C. Donaghey, Hugo Hirano, Benoit Adamo, Nagarjun V. Konduru, Ramon M. Molina, Georgios Pyrgiotakis, Brendan Laurenzi |
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| Rok vydání: | 2016 |
| Předmět: |
Insufflation
Male Health Toxicology and Mutagenesis Tracheobronchial lymph nodes Metal Nanoparticles 010501 environmental sciences Toxicology 01 natural sciences Article 03 medical and health sciences 0302 clinical medicine Administration Inhalation medicine Animals Lung Aerosolization 0105 earth and related environmental sciences Neutrons Gastrointestinal tract Inhalation Chemistry Environmental exposure Cerium Rats Trachea medicine.anatomical_structure 030228 respiratory system Anesthesia Powders Respiratory tract |
| Zdroj: | Inhalation toxicology. 28(12) |
| ISSN: | 1091-7691 |
| Popis: | Particles can be delivered to the respiratory tract of animals using various techniques. Inhalation mimics environmental exposure but requires large amounts of aerosolized NPs over a prolonged dosing time, varies in deposited dose among individual animals, and results in nasopharyngeal and fur particle deposition. Although less physiological, intratracheal (IT) instillation allows quick and precise dosing. Insufflation delivers particles in their dry form as an aerosol. We compared the distribution of neutron-activated 141CeO2 nanoparticles (5 mg/kg) in rats after 1) IT instillation, 2) left intrabronchial instillation, 3) microspraying of nanoceria suspension, and 4) insufflation of nanoceria dry powder. Blood, tracheobronchial lymph nodes, liver, gastrointestinal tract, feces and urine were collected at 5 minutes and 24 hours post-dosing. Excised lungs from each rat were dried at room temperature while inflated at a constant 30 cm water pressure. Dried lungs were then sliced into 50 pieces. The radioactivity of each lung piece and other organs was measured. The evenness index (El) of each lung piece was calculated [EI=(μCi/mgpiece)/(μCi/mglung)]. The degree of EI value departure from 1.0 is a measure of deposition heterogeneity. We showed that the pulmonary distribution of nanoceria differs among modes of administration. Dosing by IT or microspraying resulted in similar spatial distribution. Insufflation resulted in significant deposition in the trachea and in more heterogeneous lung distribution. Our left intrabronchial instillation technique yielded a concentrated deposition into the left lung. We conclude that animal dosing techniques and devices result in varying patterns of particle deposition that will impact biokinetic and toxicity studies. |
| Databáze: | OpenAIRE |
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