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Lin K, Wallis C, Wong EM, Edwards P, Cole A, Van Winkle L, Wexler AS. Heterogeneous deposition of regular and mentholated little cigar smoke in the lungs of Sprague-Dawley rats. Part Fibre Toxicol 2023; 20:42. [PMID: 37932763 PMCID: PMC10626780 DOI: 10.1186/s12989-023-00554-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/31/2023] [Indexed: 11/08/2023] Open
Abstract
BACKGROUND Quantifying the dose and distribution of tobacco smoke in the respiratory system is critical for understanding its toxicity, addiction potential, and health impacts. Epidemiologic studies indicate that the incidence of lung tumors varies across different lung regions, suggesting there may be a heterogeneous deposition of smoke particles leading to greater health risks in specific regions. Despite this, few studies have examined the lobar spatial distribution of inhaled particles from tobacco smoke. This gap in knowledge, coupled with the growing popularity of little cigars among youth, underscores the need for additional research with little cigars. RESULTS In our study, we analyzed the lobar deposition in rat lungs of smoke particles from combusted regular and mentholated Swisher Sweets little cigars. Twelve-week-old male and female Sprague-Dawley rats were exposed to smoke particles at a concentration of 84 ± 5 mg/m3 for 2 h, after which individual lung lobes were examined. We utilized Inductively Coupled Plasma Mass Spectrometry to quantify lobar chromium concentrations, serving as a smoke particle tracer. Our findings demonstrated an overall higher particle deposition from regular little cigars than from the mentholated ones. Higher particle deposition fraction was observed in the left and caudal lobes than other lobes. We also observed sex-based differences in the normalized deposition fractions among lobes. Animal study results were compared with the multi-path particle dosimetry (MPPD) model predictions, which showed that the model overestimated particle deposition in certain lung regions. CONCLUSIONS Our findings revealed that the particle deposition varied between different little cigar products. The results demonstrated a heterogenous deposition pattern, with higher particle deposition observed in the left and caudal lobes, especially with the mentholated little cigars. Additionally, we identified disparities between our measurements and the MPPD model. This discrepancy highlights the need to enhance the accuracy of models before extrapolating animal study results to human lung deposition. Overall, our study provides valuable insights for estimating the dose of little cigars during smoking for toxicity research.
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Affiliation(s)
- Kaisen Lin
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, 48824, USA.
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA.
| | - Christopher Wallis
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
| | - Emily M Wong
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
| | - Patricia Edwards
- Center for Health and the Environment, University of California, Davis, Davis, CA, 95616, USA
| | - Austin Cole
- UC Davis Interdisciplinary Center for Plasma Mass Spectrometry, University of California, Davis, Davis, CA, 95616, USA
| | - Laura Van Winkle
- Department of Anatomy, Physiology and Cell Biology, University of California, Davis, Davis, CA, 95616, USA
- Center for Health and the Environment, University of California, Davis, Davis, CA, 95616, USA
| | - Anthony S Wexler
- Air Quality Research Center, University of California, Davis, Davis, CA, 95616, USA
- Department of Mechanical and Aerospace Engineering, University of California, Davis, Davis, CA, 95616, USA
- Department of Civil and Environmental Engineering, University of California, Davis, Davis, CA, 95616, USA
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, 95616, USA
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2
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Chung YH, Gulumian M, Pleus RC, Yu IJ. Animal Welfare Considerations When Conducting OECD Test Guideline Inhalation and Toxicokinetic Studies for Nanomaterials. Animals (Basel) 2022; 12:ani12233305. [PMID: 36496826 PMCID: PMC9737563 DOI: 10.3390/ani12233305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
The OECD test guidelines for animal experiments play an important role in evaluating the chemical hazards. Animal tests performed using OECD guidelines, especially when the good laboratory practice (GLP) principle is applied, reduce the duplication of toxicity testing and ensure the best mutual acceptance of data by the OECD's Mutual Acceptance of Data (MAD). The OECD inhalation toxicity test guidelines 412 (28 days) and 413 (90 days) have been revised. These OECD guidelines now reflect the inclusion of nanomaterials and recent scientific and technological developments. In particular, these test guidelines aim to evaluate the bronchoalveolar lavage fluid in the lungs for objective toxicity evaluation, along with the existing subjective histopathological evaluation. For solid particles, the lung burden measurement of particles is required for toxicokinetic studies and, in order to properly perform a toxicokinetic study, two post-exposure observations are recommended. In light of the revised OECD guidelines, we propose a method to reduce the number of animals when testing is conducted for nanomaterials.
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Affiliation(s)
- Yong Hyun Chung
- H&H Bio, Hoseo-ro 79-20, Baebang-eup, Asan 31499, Republic of Korea
| | - Mary Gulumian
- Haematology and Molecular Medicine, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
- Water Research Group, Unit for Environmental Sciences and Management, North University, Private Bag X6001, Potchefstroom 2520, South Africa
| | | | - Il Je Yu
- HCT Co., Ltd., Icheon 17383, Republic of Korea
- Correspondence: ; Tel./Fax: +82-031-645-6358
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3
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Romanova OL, Chauhan M, Blagonravov ML, Kislov MA, Ershov AV, Krupin KN. Baclofen (fun drug) and ethanol combined poisoning in humans: A histopathology and morphometry model. J Forensic Leg Med 2022; 90:102373. [PMID: 35671675 DOI: 10.1016/j.jflm.2022.102373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/01/2022] [Accepted: 05/23/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND - This study intends to address the scarcity of data regarding the pathogenesis of Baclofen poisoning in humans, which has seen a recent increase, worldwide, especially amongst the young people. Another reason for the conduction of this study was lack of the substantial data about the histo-pathological findings of lungs, in synergistic toxicity of Baclofen with Ethanol, in-spite of it being very common in humans, and both being respiratory depressant with similar mechanism of action. PURPOSE - The authors aimed to understand the pathogenesis of fatal poisonings in humans due to Baclofen in combination with Ethanol via an animal research model. The enhancement of the overall scientific literature by extending research along the lines of the handful studies available in this regard was another adjunct goal of the study. MATERIAL AND METHODS Fifteen Wistar rats were divided into control and test group of five and ten subjects respectively. The test group was further divided into two sub-groups of five each, with Baclofen administered to one, and it in conjunction with Ethanol to the other, in lowest dosages adjusted for the humans. Rats in both the groups were euthanized by dislocation of the cervical vertebrae for the histopathology examination. RESULTS Capillary and venous plethora, hemorrhages in the inter-alveolar septi, hemorrhages into the alveoli and sludging was seen in the 1st sub-group. The plethora of venules, capillaries and arterioles, with sludging by the WBC (white blood corpuscle) infiltrates was seen in the 2nd sub-group. Desquamation of the ciliated epithelium and edematous thickening of the intra-alveolar septi, along with features suggestive of the peri-vascular edema was seen in the 2nd sub-group. The morphometric analysis of the micro vessels showed a significantly higher value of the arteriolar diameter in the 2nd sub-group, in comparison to 1st, but the venular diameter in the two sub-groups did not differ to any extent.
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Affiliation(s)
- O L Romanova
- Department of General Physiology, Medical Institute of Russian University of People Friendship, Research Institute of Human Morphology, Moscow, Russia.
| | - M Chauhan
- Department of Forensic Medicine and Toxicology, Government Medical College and Hospital, Chandigarh, 160030, India.
| | - M L Blagonravov
- Department of General Pathology and Pathological Physiology, Medical Institute of Russian University of People Friendship, Moscow, Russia.
| | - M A Kislov
- Department of Forensic Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.
| | - A V Ershov
- Institute of General Resuscitation Named After V. A. Negovsky Federal State Budgetary Scientific Institution, Federal Scientific and Clinical Center of Reаnimatology and Rehabilitation, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.
| | - K N Krupin
- Department of Forensic Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.
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Smith JN, Skinner AW. Translating nanoparticle dosimetry from conventional in vitro systems to occupational inhalation exposures. JOURNAL OF AEROSOL SCIENCE 2021; 155:10.1016/j.jaerosci.2021.105771. [PMID: 35979194 PMCID: PMC9380399 DOI: 10.1016/j.jaerosci.2021.105771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
As encouraged by Toxicity Testing in the 21st Century, researchers increasingly apply high-throughput in vitro approaches to identify and characterize nanoparticle hazards, including conventional aqueous cell culture systems to assess respiratory hazards. Translating nanoparticle dose from conventional toxicity testing systems to relevant human exposures remains a major challenge for assessing occupational risk of nanoparticle exposures. Here, we explored existing computational tools and data available to translate nanoparticle dose metrics from cellular test systems to inhalation exposures of silver nanoparticles in humans. We used the Multiple-Path Particle Dosimetry (MPPD) Model to predict nanoparticle deposition of humans exposed to 20 and 110 nm silver nanoparticles at 0.9 μg/m3 over an 8 h period, the proposed National Institute of Occupational Safety and Health (NIOSH) recommended exposure limit (REL). MPPD predicts 8.1 and 3.7 μg of silver deposited in an 8 h period for 20 and 110 nm nanoparticles, respectively, with 20 nm particles displaying nearly 11-fold higher total surface area deposited. Peak deposited nanoparticle concentrations occurred more proximal in the pulmonary tract compared to mass deposition patterns (generation 4 vs. generations 20-21, respectively) due to regional differences in lung lining fluid volumes. Assuming 0.4% nanoparticle dissolution by mass measured in previous studies predicted peak concentrations of silver ions in cells of 1.06 and 0.89 μg/mL for 20 and 110 nm particles, respectively. Both predicted concentrations are below the measured toxic threshold of 1.7 μg/mL of silver ions in cells from in vitro assessments. Assuming 4% dissolution by mass predicted 10-fold higher silver concentrations in tissues, peaking at 10.6 and 8.9 μg/mL, for 20 and 110 nm nanoparticles respectively, exceeding the observed in vitro toxic threshold and highlighting the importance and sensitivity of dissolution rates. Overall, this approach offers a framework for extrapolating nanotoxicity results from in vitro cell culture systems to human exposures. Aligning appropriate dose metrics from in vitro and in vivo hazard characterizations and human pulmonary doses from occupational exposures are critical components for successful nanoparticle risk assessment and worker protection providing guidance for designing future in vitro studies aimed at relevant human exposures.
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Affiliation(s)
- Jordan Ned Smith
- Biological Sciences Division, Pacific Northwest National Laboratory (PNNL), Richland, WA, 99354, USA
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
- Corresponding author. PO Box 999, Richland, WA, 99352, USA. (J.N. Smith)
| | - Andrew W. Skinner
- Biological Sciences Division, Pacific Northwest National Laboratory (PNNL), Richland, WA, 99354, USA
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5
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Lee SK, Jo MS, Kim HP, Kim JC, Yu IJ. Quality assurance for nanomaterial inhalation toxicity testing. Inhal Toxicol 2021; 33:161-167. [PMID: 34044734 DOI: 10.1080/08958378.2021.1926602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The recent revision of OECD inhalation toxicology test guidelines 412 and 413 presents new challenges for both the study director (SD) and quality assurance (QA) personnel when conducting GLP (good laboratory practice) studies. In the case of nanomaterial inhalation exposure studies, GLP has rarely been applied, yet the new revisions are applicable to soluble and insoluble nanomaterials, as well as conventional chemicals. For example, the new guidelines require an additional bronchoalveolar lavage (BAL) fluid assay and lung burden measurement during the post-exposure observation (PEO) period, plus nanomaterial physicochemical characterization before and after nano-aerosol generation when exposing experimental animals. Implementing these revised guidelines will prove especially challenging for QA measures related to the physicochemical characterization and aerosolization of test nanomaterials. Therefore, this review examines the key elements involved in nanomaterial inhalation GLP testing under the revised OECD guidelines, suggests an alternative to the increased animal numbers, in consideration of animal welfare and with scientific merits, and discusses the limitation of toxicokinetic estimation using the new testing guidelines.
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Affiliation(s)
- Sung Kwon Lee
- College of Veterinary Medicine, Chonnam National University, Gwangmyung, Korea.,Korea Society of Quality Assurance
| | | | | | - Jong Choon Kim
- College of Veterinary Medicine, Chonnam National University, Gwangmyung, Korea
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Li J, Chang X, Shang M, Niu S, Zhang W, Zhang B, Huang W, Wu T, Zhang T, Tang M, Xue Y. Mitophagy-lysosomal pathway is involved in silver nanoparticle-induced apoptosis in A549 cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 208:111463. [PMID: 33130480 DOI: 10.1016/j.ecoenv.2020.111463] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 09/05/2020] [Accepted: 10/01/2020] [Indexed: 05/11/2023]
Abstract
With the increasing use of silver nanoparticles (AgNPs) in biological materials, the cytotoxicity caused by these particles has attracted much attention. However, the molecular mechanism underlying AgNP cytotoxicity remains unclear. In this study, we aimed to systematically investigate the toxicity induced by AgNP exposure to the lung adenocarcinoma A549 cell line at the subcellular and signaling pathway levels and elucidate the related molecular mechanism. The survival rate of cells exposed to AgNPs at 0, 20, 40, 80, and 160 μg/mL for 24 or 48 h decreased in a dose- and time-dependent manner. AgNPs induced autophagy and mitophagy, determined by the transmission electron microscopy investigation and upregulation of LC3 II/I, p62, PINK1, and Parkin expression levels. AgNP treatment induced lysosomal injury, including the decline of lysosomal membrane integrity and increase in cathepsin B level. The decreased in mitochondrial membrane potential, along with upregulation of cytochrome c, caspases 9 and 3, and BAX/BCL2, further suggested that mitochondrial injury were involved in AgNP-induced apoptosis. In addition, mitochondrial injury may further lead to excessive production of reactive oxygen species and oxidative/ antioxidant imbalance. The results suggested that AgNPs could regulate autophagy via mitochondrial and lysosome injury in A549 cells. The information of the molecular mechanism will provide an experimental basis for the safe application of nanomaterials.
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Affiliation(s)
- Jiangyan Li
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Xiaoru Chang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Mengting Shang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Shuyan Niu
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Wenli Zhang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Bangyong Zhang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Wenyan Huang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Tianshu Wu
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Ting Zhang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Meng Tang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China
| | - Yuying Xue
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
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7
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Kim HP, Kim JK, Jo MS, Park JD, Ahn K, Gulumian M, Oberdörster G, Yu IJ. Even lobar deposition of poorly soluble gold nanoparticles (AuNPs) is similar to that of soluble silver nanoparticles (AgNPs). Part Fibre Toxicol 2020; 17:54. [PMID: 33081787 PMCID: PMC7574491 DOI: 10.1186/s12989-020-00384-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 10/05/2020] [Indexed: 11/26/2022] Open
Abstract
Background Information on particle deposition, retention, and clearance is important when evaluating the risk of inhaled nanomaterials to human health. The revised Organization Economic Cooperation and Development (OECD) inhalation toxicity test guidelines now require lung burden measurements of nanomaterials after rodent subacute and sub-chronic inhalation exposure (OECD 412, OECD 413) to inform on lung clearance behavior and translocation after exposure and during post-exposure observation (PEO). Lung burden measurements are particularly relevant when the testing chemical is a solid poorly soluble nanomaterial. Previously, the current authors showed that total retained lung burden of inhaled soluble silver nanoparticles (AgNPs) could be effectively measured using any individual lung lobe. Methods and results Accordingly, the current study investigated the evenness of deposition/retention of poorly soluble gold nanoparticles (AuNPs) after 1 and 5 days of inhalation exposure. Rats were exposed nose-only for 1 or 5 days (6 h/day) to an aerosol of 11 nm well-dispersed AuNPs. Thereafter, the five lung lobes were separated and the gold concentrations measured using an inductively coupled plasma-mass spectrophotometer (ICP-MS). The results showed no statistically significant difference in the AuNP deposition/retention among the different lung lobes in terms of the gold mass per gram of lung tissue. Conclusions Thus, it would seem that any rat lung lobe can be used for the lung burden analysis after short or long-term NP inhalation, while the other lobes can be used for collecting and analyzing the bronchoalveolar lavage fluid (BALF) and for the histopathological analysis. Therefore, combining the lung burden measurement, histopathological tissue preparation, and BALF assay from one rat can minimize the number of animals used and maximize the number of endpoints measured.
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Affiliation(s)
- Hoi Pin Kim
- Aerosol Toxicology Research Center, HCTm CO.,LTD, Icheon, South Korea
| | - Jin Kwon Kim
- Department of Mechanical Engineering, Hanyang University, Ansan, South Korea
| | - Mi Seong Jo
- Aerosol Toxicology Research Center, HCTm CO.,LTD, Icheon, South Korea
| | - Jung Duck Park
- Deparment of Preventive Medicine, College of Medicine, Chung-Ang University, Seoul, South Korea
| | - Kangho Ahn
- Department of Mechanical Engineering, Hanyang University, Ansan, South Korea
| | - Mary Gulumian
- National Institute for Occupational Health, Johannesburg, South Africa.,Haematology and Molecular Medicine, University of the Witwatersrand, Johannesburg, South Africa.,Water Research Group, Unit for Environmental Sciences and Management, North West University, Private Bag X6001, Potchefstroom, 2520, South Africa
| | - Günter Oberdörster
- Department of Environmental Medicine, University of Rochester, Rochester, NY, USA.
| | - Il Je Yu
- Aerosol Toxicology Research Center, HCTm CO.,LTD, Icheon, South Korea. .,HCT CO.,LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, South Korea.
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8
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Al-Doaiss AA, Jarrar Q, Alshehri M, Jarrar B. In vivo study of silver nanomaterials' toxicity with respect to size. Toxicol Ind Health 2020; 36:540-557. [PMID: 32677580 DOI: 10.1177/0748233720937201] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Silver nanoparticles (Ag NPs) are widely used in nanomedicine, pharmaceutical products, industry and other consumer products owing to their unique physiochemical properties with probable potential risk to human health and the ecosystems. The aim of this work was to investigate the in-life morphological effects, biochemical, histological and histochemical alterations that might be induced by variable sizes of Ag NPs in hepatic, renal and testicular tissues with the hypothesis that variable sizes of nano-Ag could induce variable effects in the vital organs. Five groups of adult healthy male mice (BALB/C) were exposed to 35 intraperitoneal injections of Ag NPs (1 mg/kg bw) using five different particle sizes (10, 20, 40, 60 and 100 nm). All mice were subjected to in-life morphometric, biochemical, histological and histochemical analysis. The findings demonstrated that Ag NPs could induce alterations in the average body weight gain, food consumption, water intake and organ indices. In addition, these NPs significantly altered hepatic and renal biomarkers. Moreover, Ag NPs produced ground glass hepatocyte cytoplasm, with mitotic activity, nuclear alterations, degeneration, glycogen depletion and inflammatory cells infiltration in the liver. The kidneys of treated mice exhibited proximal renal tubules degeneration, distal renal tubules regeneration, glomerular shrinkage, Bowman's capsule thickening and interstitial inflammation. The testicular tissues demonstrated spermatocyte sloughing and spermatid giant cell formation. The findings together indicated that Ag NPs could interact with the anatomical structures of the liver, kidney and testis in ways that could induce injury. In addition, the results indicated that smaller Ag NPs posed a greater potential risk than the larger ones, which might be associated with their behaviour, dissolution rate, bioavailability and their probable variable toxicokinetics.
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Affiliation(s)
- Amin A Al-Doaiss
- Department of Biology, College of Science, 48144King Khalid University, Abha, Saudi Arabia
| | - Qais Jarrar
- Department of Applied Pharmaceutical Sciences and Pharmacy Practice, Faculty of Pharmacy, 108568Isra University, Amman, Jordan
| | - Mohammed Alshehri
- Department of Biology, College of Science, 48144King Khalid University, Abha, Saudi Arabia
| | - Bashir Jarrar
- Nanobiology Unit, Biological Sciences, College of Science, 123295Jerash Private University, Jerash, Jordan
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9
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Jo MS, Kim JK, Kim Y, Kim HP, Kim HS, Ahn K, Lee JH, Faustman EM, Gulumian M, Kelman B, Yu IJ. Mode of silver clearance following 28-day inhalation exposure to silver nanoparticles determined from lung burden assessment including post-exposure observation periods. Arch Toxicol 2020; 94:773-784. [PMID: 32157349 DOI: 10.1007/s00204-020-02660-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/03/2020] [Indexed: 11/26/2022]
Abstract
Recently revised OECD inhalation toxicity testing guidelines require measurements of lung burden immediately after and for periods following exposure for nanomaterials. Lung burden is a function of pulmonary deposition and retention of nanoparticles. Using lung burden studies as per OECD guidelines, it may be possible to assess clearance mechanisms of nanoparticles. In this study, male rats were exposed to silver nanoparticle (AgNP) aerosols (18.1-19.6 nm) generated from a spark generator. Exposure groups consisted of (1) control (fresh air), (2) low (31.2 ± 8.5 µg/m3), (3) moderate (81.8 ± 11.4 µg/m3), and (4) high concentrations (115.6 ± 30.5 µg/m3). Rats were exposed for 6-h/day, 5-days/week for 4 weeks (28-days) based on the revised OECD test guideline 412. Bronchoalveolar lavage (BAL) fluids were collected on post-exposure observation (PEO)-1 and PEO-7 days and analyzed for inflammatory cells and inflammatory biomarkers. The lung burdens of Ag from AgNPs were measured on PEO-1, PEO-7, and PEO-28 days to obtain quantitative mass concentrations per lung. Differential counting of blood cells and inflammatory biomarkers in BAL fluid and histopathological evaluation of lung tissue indicated that exposure to the high concentrations of AgNP aerosol induced inflammation at PEO-1, slowly resolved at PEO-7 and completely resolved at PEO-28 days. Lung burden measurement suggested that Ag from AgNPs was cleared through two different modes; fast and slow clearance. The fast clearance component was concentration-dependent with half-times ranging from two to four days and clearance rates of 0.35-0.17/day-1 from low to high concentrations. The slow clearance had half-times of 100, 57, and 76 days and clearance rates of 0.009, 0.012, and 0.007/day-1 for the high, moderate and low concentration exposure. The exact mechanism of clearance is not known currently. The fast clearance component which was concentration-dependent could be dependent on the dissolution of AgNPs and the slow clearance would be due to slow clearance of the low dissolution AgNPs secondary particles originating from silver ions reacting with biogenic anions. These secondary AgNPs might be cleared by mechanisms other than dissolution such as mucociliary escalation, translocation to the lymphatic system or other organs.
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Affiliation(s)
- Mi Seong Jo
- HCTm CO., LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, Korea
| | - Jin Kwon Kim
- Department of Mechanical Engineering, Hanyang University, Ansan, Korea
| | - Younghun Kim
- HCTm CO., LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, Korea
| | - Hoi Pin Kim
- HCTm CO., LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, Korea
| | - Hee Sang Kim
- HCTm CO., LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, Korea
- Department of Mechanical Engineering, Hanyang University, Ansan, Korea
| | - Kangho Ahn
- Department of Mechanical Engineering, Hanyang University, Ansan, Korea
| | - Ji Hyun Lee
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, USA
| | - Elaine M Faustman
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, USA
| | - Mary Gulumian
- National Institute for Occupational Health, Johannesburg, South Africa
- Haematology and Molecular Medicine, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Il Je Yu
- HCTm CO., LTD, Seoicheon-ro 578 beon-gil, Majang-myeon, Icheon, 17383, Korea.
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