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Bourgois A, Saurat D, De Araujo S, Boyard A, Guitard N, Renault S, Fargeau F, Frederic C, Peyret E, Flahaut E, Servonnet A, Favier AL, Lacroix G, François S, Dekali S. Nose-only inhalations of high-dose alumina nanoparticles/hydrogen chloride gas mixtures induce strong pulmonary pro-inflammatory response: a pilot study. Inhal Toxicol 2021; 33:308-324. [PMID: 34772293 DOI: 10.1080/08958378.2021.1996492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Solid composite propellants combustion, in aerospace and defense fields, can lead to complex aerosols emission containing high concentrations of alumina nanoparticles (Al2O3 NPs) and hydrogen chloride gas (HClg). Exposure to these mixtures by inhalation is thus possible but literature data toward their pulmonary toxicity are missing. To specify hazards resulting from these combustion aerosols, a pilot study was implemented. MATERIALS AND METHODS Male Wistar rats were nose-only exposed to Al2O3 NPs (primary size 13 nm, 10 g/L suspension leading to 20.0-22.1 mg/m3 aerosol) and/or to HClg aerosols (5 ppm target concentration) following two exposure scenarios (single exposures (SE) or repeated exposures (RE)). Bronchoalveolar lavage fluids (BALF) content and lungs histopathology were analyzed 24 h after exposures. RESULTS Repeated co-exposures increased total proteins and LDH concentrations in BALF indicating alveolar-capillary barrier permeabilization and cytolysis. Early pulmonary inflammation was induced after RE to Al2O3 NPs ± HClg resulting in PMN, TNF-α, IL-1β, and GRO/KC increases in BALF. Both exposure scenarios resulted in pulmonary histopathological lesions (vascular congestions, bronchial pre-exfoliations, vascular and interalveolar septum edemas). Lung oxidative damages were observed in situ following SE. CONCLUSION Observed biological effects are dependent on both aerosol content and exposure scenario. Results showed an important pro-inflammatory effect of Al2O3 NPs/HClg mixtures on the lungs of rat 24 h after exposure. This pilot study raises concerns toward potential long-term pulmonary toxicity of combustion aerosols and highlights the importance for further studies to be led in order to define dose limitations and exposure thresholds for risk management at the work place.
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Affiliation(s)
- Alexandra Bourgois
- Département EBR, Unité Risques Technologiques Emergents, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Dominique Saurat
- Département EBR, Unité Risques Technologiques Emergents, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Suzanne De Araujo
- Département EBR, Unité Risques Technologiques Emergents, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Alexandre Boyard
- Département EBR, Unité Risques Technologiques Emergents, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Nathalie Guitard
- Département EBR, Unité Radiobiologie, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Sylvie Renault
- Département Plateformes et Recherche Technologique, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Francisca Fargeau
- Département Plateformes et Recherche Technologique, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Christine Frederic
- Département Plateformes et Recherche Technologique, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Emmanuel Peyret
- Unité de toxicologie expérimentale, Institut National de l'Environnement Industriel et des RISques (INERIS), Verneuil-en-Halatte, France
| | - Emmanuel Flahaut
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS, UMR CNRS-UPS-INP No. 5085, Université Toulouse 3 Paul Sabatier, Toulouse cedex 9, France
| | - Aurélie Servonnet
- Département Plateformes et Recherche Technologique, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Anne-Laure Favier
- Département Plateformes et Recherche Technologique, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Ghislaine Lacroix
- Unité de toxicologie expérimentale, Institut National de l'Environnement Industriel et des RISques (INERIS), Verneuil-en-Halatte, France
| | - Sabine François
- Département EBR, Unité Radiobiologie, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
| | - Samir Dekali
- Département EBR, Unité Risques Technologiques Emergents, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge Cedex, France
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Hu SC, Min S, Kang HK, Yang DJ, Lewis SM, Davis KJ, Patton RE, Bryant MS, Sepehr E, Trbojevich R, Pearce MG, Bishop ME, Heflich RH, Maisha MP, Felton R, Chemerynski S, Yee SB, Coraggio M, Rosenfeldt H, Yeager RP, Howard PC, Tang Y. 14-Day Nose-Only Inhalation Toxicity and Haber's Rule Study of NNK in Sprague-Dawley Rats. Toxicol Sci 2021; 183:319-337. [PMID: 34329464 DOI: 10.1093/toxsci/kfab094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the key tobacco-specific nitrosamines that plays an important role in human lung carcinogenesis. However, repeated inhalation toxicity data on NNK, which is more directly relevant to cigarette smoking, are currently limited. In the present study, the subacute inhalation toxicity of NNK was evaluated in Sprague Dawley rats. Both sexes (9-10 weeks age; 16 rats/sex/group) were exposed by nose-only inhalation to air, vehicle control (75% propylene glycol), or 0.8, 3.2, 12.5, or 50 mg/kg body weight (BW)/day of NNK (NNK aerosol concentrations: 0, 0, 0.03, 0.11, 0.41, or 1.65 mg/L air) for 1 hour/day for 14 consecutive days. Toxicity was evaluated by assessing body and organ weights; food consumption; clinical pathology; histopathology observations; blood, urine, and tissue levels of NNK, its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and their glucuronides (reported as total NNK, tNNK, and total NNAL, tNNAL, respectively); O6-methylguanine DNA adduct formation; and blood and bone marrow micronucleus frequency. Whether the subacute inhalation toxicity of NNK followed Haber's Rule was also determined using additional animals exposed 4 hours/day. The results showed that NNK exposure caused multiple significant adverse effects, with the most sensitive endpoint being non-neoplastic histopathological lesions in the nose. The lowest-observed-adverse-effect level (LOAEL) was 0.8 mg/kg BW/day or 0.03 mg/L air for 1 hour/day for both sexes. An assessment of Haber's Rule indicated that 14-day inhalation exposure to the same dose at a lower concentration of NNK aerosol for a longer time (4 hours daily) resulted in greater adverse effects than exposure to a higher concentration of NNK aerosol for a shorter time (1 hour daily).
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Affiliation(s)
- Shu-Chieh Hu
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Seonggi Min
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Hyun-Ki Kang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Dong-Jin Yang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Sherry M Lewis
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Kelly J Davis
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR
| | - Ralph E Patton
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, AR
| | - Matthew S Bryant
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Estatira Sepehr
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Raul Trbojevich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Mason G Pearce
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Michelle E Bishop
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Robert H Heflich
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - MacKean P Maisha
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Robert Felton
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Susan Chemerynski
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Steven B Yee
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Melis Coraggio
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Hans Rosenfeldt
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - R Philip Yeager
- The Center for Tobacco Products (CTP), U.S. Food and Drug Administration, Silver Spring, MD
| | - Paul C Howard
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
| | - Yunan Tang
- National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), Jefferson, AR
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Bartels MJ, Hackett MJ, Himmelstein MW, Green JW, Walker C, Terry C, Rasoulpour R, Challender M, Yan ZJ. Metabolic Basis for Nonlinearity in 1,3-Dichloropropene Toxicokinetics and Use in Setting a Kinetically-derived Maximum Inhalation Exposure Concentration in Mice. Toxicol Sci 2021; 174:16-24. [PMID: 31808915 DOI: 10.1093/toxsci/kfz241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
1,3-Dichloropropene (1,3-D) showed a statistically increased incidence of bronchioloalveolar adenomas in male B6C3F1 mice at 60 ppm air concentration during previous chronic inhalation testing. No tumors were observed in female mice, nor in either sex of F344 rats up to 60 ppm, the highest dose tested. Therefore, to understand if lung tumors observed in high dose male mice are due to saturation of metabolic clearance, the linearity of 1,3-D concentrations in mouse blood was investigated on day 15 of repeated nose-only inhalation exposure to 0, 10, 20, 40, 60, 90, and 120 ppm (6 h/d, 7 d/week). Additional groups were included at 20, 60, and 120 ppm for blood collection at 1.5 and 3 h of exposure and up to 25 or 40 min post-exposure to determine area-under-the-curve. The data provide multiple lines of evidence that systemic exposures to 1,3-D in the mouse become nonlinear at inhalation exposure levels of 30 ppm or above. A reduction in minute volume occurred at the highest exposure concentration. The glutathione (GSH)-dependent metabolism of 1,3-D results in significant depletion of GSH at repeated exposure levels of 30 ppm and above. This loss of GSH results in decreased metabolic clearance of this test material, with a concomitant increase of the 1,3-D isomers in circulating blood at exposure concentrations ≥30 ppm. Shifts in the ratio of cis- and trans-1,3-D also support nonlinear toxicokinetics well below 60 ppm. Based on this data, a kinetically derived maximum dose for 1,3-D in mice for repeated exposures should be at or below 30 ppm. These results support non-relevance of 1,3-D-induced benign pulmonary tumorigenicity in mice for human health risk assessment.
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Affiliation(s)
| | - Michael J Hackett
- Battelle Memorial Institute, Clinical and Nonclinical Research, West Jefferson, Ohio
| | | | - John W Green
- Corteva AgriscienceTM, Research and Development, Newark, Delaware
| | - Carl Walker
- Corteva AgriscienceTM, Data Management and Statistics, Johnston, Iowa
| | - Claire Terry
- Corteva AgriscienceTM, Research and Development, Indianapolis, Indiana
| | - Reza Rasoulpour
- Corteva AgriscienceTM, Research and Development, Indianapolis, Indiana
| | - Mary Challender
- Corteva AgriscienceTM, Regulatory and Stewardship, Johnston, Iowa
| | - Zhongyu June Yan
- Corteva AgriscienceTM, Research and Development, Indianapolis, Indiana
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Kogel U, Wong ET, Szostak J, Tan WT, Lucci F, Leroy P, Titz B, Xiang Y, Low T, Wong SK, Guedj E, Ivanov NV, Schlage WK, Peitsch MC, Kuczaj A, Vanscheeuwijck P, Hoeng J. Impact of whole-body versus nose-only inhalation exposure systems on systemic, respiratory, and cardiovascular endpoints in a 2-month cigarette smoke exposure study in the ApoE -/- mouse model. J Appl Toxicol 2021; 41:1598-1619. [PMID: 33825214 PMCID: PMC8519037 DOI: 10.1002/jat.4149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 11/09/2022]
Abstract
Cigarette smoking is one major modifiable risk factor in the development and progression of chronic obstructive pulmonary disease and cardiovascular disease. To characterize and compare cigarette smoke (CS)-induced disease endpoints after exposure in either whole-body (WB) or nose-only (NO) exposure systems, we exposed apolipoprotein E-deficient mice to filtered air (Sham) or to the same total particulate matter (TPM) concentration of mainstream smoke from 3R4F reference cigarettes in NO or WB exposure chambers (EC) for 2 months. At matching TPM concentrations, we observed similar concentrations of carbon monoxide, acetaldehyde, and acrolein, but higher concentrations of nicotine and formaldehyde in NOEC than in WBEC. In both exposure systems, CS exposure led to the expected adaptive changes in nasal epithelia, altered lung function, lung inflammation, and pronounced changes in the nasal epithelial transcriptome and lung proteome. Exposure in the NOEC caused generally more severe histopathological changes in the nasal epithelia and a higher stress response as indicated by body weight decrease and lower blood lymphocyte counts compared with WB exposed mice. Erythropoiesis, and increases in total plasma triglyceride levels and atherosclerotic plaque area were observed only in CS-exposed mice in the WBEC group but not in the NOEC group. Although the composition of CS in the breathing zone is not completely comparable in the two exposure systems, the CS-induced respiratory disease endpoints were largely confirmed in both systems, with a higher magnitude of severity after NO exposure. CS-accelerated atherosclerosis and other pro-atherosclerotic factors were only significant in WBEC.
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Affiliation(s)
- Ulrike Kogel
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Ee Tsin Wong
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Justyna Szostak
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Wei Teck Tan
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Francesco Lucci
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Patrice Leroy
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Bjoern Titz
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Yang Xiang
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Tiffany Low
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Sin Kei Wong
- Philip Morris International Research Laboratories Pte. Ltd., Science Park II, Singapore
| | - Emmanuel Guedj
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Nikolai V Ivanov
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Walter K Schlage
- Biology Consultant, Max-Baermann-Str. 21, Bergisch Gladbach, Germany
| | - Manuel C Peitsch
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Arkadiusz Kuczaj
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Patrick Vanscheeuwijck
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
| | - Julia Hoeng
- Philip Morris International Research and Development, Philip Morris Products S.A., Neuchatel, Switzerland
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Schwotzer D, Gigliotti A, Irshad H, Dye W, McDonald J. Phytol, not propylene glycol, causes severe pulmonary injury after inhalation dosing in Sprague-Dawley rats. Inhal Toxicol 2021; 33:33-40. [PMID: 33441006 DOI: 10.1080/08958378.2020.1867260] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: The use of vaping pens for inhalation of cannabinoid derived products is rising and has become a popular alternative to smoking combustible products. For efficient product delivery, additives are sometimes added and vaping pens often may include compounds like Phytol or Propylene Glycol as thinning agents. This study aimed at comparing Phytol and Propylene Glycol with respect to potential toxicity and safe use in vaping products.Methods: Male and female Sprague Dawley rats were exposed to 5 mg/L of Phytol or Propylene Glycol for up to 6 hours over up to 14 days and monitored for clinical signs and changes in body weight. Gross necropsy and histopathology of respiratory tissue was performed to assess potential adverse effects.Results: Phytol exposed animals expressed severe clinical signs, body weight loss and mortality after one or two exposure days, leading to termination of all dose groups for this compound. Lung weights were increased and respiratory tissue was severely affected, demonstrating dose-responsive tissue degeneration, necrosis, edema, hemorrhage and inflammation. Propylene Glycol exposed animals did not show any adverse reactions after 14 days of high dose exposure.Conclusions: For Phytol, a low observed adverse effect level (LOAEL) was determined at ≤109.0/10.9 mg/kg/day presented/deposited dose and therefore its use as excipient in vaping product is not recommend; a safe exposure range was not established for Phytol. Propylene Glycol, in contrast, is considered safe with a no observed adverse effect level (NOAEL) at 1151.7/115.2 mg/kg/day presented/deposited dose in rats.
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Affiliation(s)
| | | | | | - Wendy Dye
- Lovelace Biomedical, Albuquerque, NM, USA
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Abstract
The C9 alkylbenzenes, composed mostly of ethyltoluenes and trimethylbenzenes, comprise 75-90% of the naphtha fraction of crude oil. Occupational and environmental exposure to C9 alkylbenzenes occur via inhalation. We conducted short-term inhalation studies on the ethyltoluene isomers (2-, 3- or 4-) to select one isomer for more comprehensive studies. Male Hsd:Sprague Dawley rats and female B6C3F1/N mice (n = 10) were exposed by nose-only inhalation to 2-, 3- or 4-ethyltoluene (0, 1000 or 2000 ppm) or cumene (a reference compound: 0, 500 or 1000 ppm) 3 h/day, 5 days/week, for 2 weeks. Clinical observations included abnormal gait and delayed righting reflex. Rats and mice exposed to 2000 ppm 2-ethyltoluene and mice exposed to 2000 ppm 4-ethyltoluene were euthanized early in moribund condition; no exposure-related deaths were observed with 3-ethyltoluene or cumene. Histopathology of selected tissues revealed that the nose and liver (rats and mice) and lung (mice only) to be toxicity targets. In the mouse lung, all compounds except 4-ethyltoluene produced bronchial and bronchiolar hyperplasia. In rats and mice, 2-ethyltoluene was the only compound to produce lesions in the nose and liver: in mice, squamous metaplasia and neutrophilic inflammation of the respiratory epithelium and atrophy and degeneration of the olfactory epithelium were observed in the nose and centrilobular hypertrophy and necrosis were observed in the liver. In rats, 2-ethyltoluene exposure produced atrophy of the olfactory epithelium in the nose and centrilobular necrosis in the liver. Based on mortality, body weight effects and histopathology, the 2-ethyltoluene isomer was the most potent isomer.
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Affiliation(s)
| | | | - Dorian S Olivera
- c Alion Science and Technology Corporation , RTP , Durham , NC , USA
| | | | - Daniel L Morgan
- a Division of the National Toxicology Program , RTP , NC , USA
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Aweda TA, Zhang S, Mupanomunda C, Burkemper J, Heo GS, Bandara N, Lin M, Cutler CS, Cannon CL, Youngs W, Wooley KL, Lapi SE. Investigating the pharmacokinetics and biological distribution of silver-loaded polyphosphoester-based nanoparticles using (111) Ag as a radiotracer. J Labelled Comp Radiopharm 2015; 58:234-41. [PMID: 25952472 PMCID: PMC4457551 DOI: 10.1002/jlcr.3289] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/24/2015] [Indexed: 11/09/2022]
Abstract
Purified (111) Ag was used as a radiotracer to investigate silver loading and release, pharmacokinetics, and biodistribution of polyphosphoester-based degradable shell crosslinked knedel-like (SCK) nanoparticles as a comparison to the previously reported small molecule, N-heterocyclic silver carbene complex analog (SCC1) for the delivery of therapeutic silver ions in mouse models. Biodistribution studies were conducted by aerosol administration of (111) Ag acetate, [(111) Ag]SCC1, and [(111) Ag]SCK doses directly into the lungs of C57BL/6 mice. Nebulization of the (111) Ag antimicrobials resulted in an average uptake of 1.07 ± 0.12% of the total aerosolized dose given per mouse. The average dose taken into the lungs of mice was estimated to be 2.6 ± 0.3% of the dose inhaled per mouse for [(111) Ag]SCC1 and twice as much dose was observed for the [(111) Ag]SCKs (5.0 ± 0.3% and 5.9 ± 0.8% for [(111) Ag]aSCK and [(111) Ag]zSCK, respectively) at 1 h post administration (p.a.). [(111) Ag]SCKs also exhibited higher dose retention in the lungs; 62-68% for [(111) Ag]SCKs and 43% for [(111) Ag]SCC1 of the initial 1 h dose were observed in the lungs at 24 h p.a.. This study demonstrates the utility of (111) Ag as a useful tool for monitoring the pharmacokinetics of silver-loaded antimicrobials in vivo.
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Affiliation(s)
- Tolulope A. Aweda
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Shiyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Chiedza Mupanomunda
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Jennifer Burkemper
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Gyu Seong Heo
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Nilantha Bandara
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Mai Lin
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Cathy S. Cutler
- University of Missouri, Research Reactor Center, 1513 Research Park Drive, Columbia, MO 65211
| | - Carolyn L. Cannon
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, 407 Reynolds Medical Building, College Station, TX 77843-1114
| | - Wiley Youngs
- Department of Chemistry, University of Akron, Akron, OH 44325-3601
| | - Karen L. Wooley
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Suzanne E. Lapi
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
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Abstract
The ten Berge model, also known as the toxic load model, is an empirical approach in hazard assessment modeling for estimating the relationship between the inhalation toxicity of a chemical and the exposure duration. The toxic load (TL) is normally expressed as a function of vapor concentration (C) and duration (t), with TL equaling C(n) × t being a typical form. Hypothetically, any combination of concentration and time that yields the same "toxic load" will give a constant biological response. These formulas have been developed and tested using controlled, constant concentration animal studies, but the validity of applying these assumptions to time-varying concentration profiles has not been tested. Experiments were designed to test the validity of the model under conditions of non-constant acute exposure. Male Sprague-Dawley rats inhaled constant or pulsed concentrations of hydrogen cyanide (HCN) generated in a nose-only exposure system for 5, 15, or 30 min. The observed lethality of HCN for the 11 different C versus t profiles was used to evaluate the ability of the model to adequately describe the lethality of HCN under the conditions of non-constant inhalation exposure. The model was found to be applicable under the tested conditions, with the exception of the median lethality of very brief, high concentration, discontinuous exposures.
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Affiliation(s)
- Lisa M Sweeney
- * Henry M. Jackson Foundation for the Advancement of Military Medicine, Naval Medical Research Unit Dayton, Wright-Patterson AFB, OH 45433
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