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Biological effects of molybdenum(IV) sulfide nanoparticles and microparticles in the rat after repeated intratracheal
Z Sobańska1, K Sitarek1, J Gromadzińska1
1Nofer Institute of Occupational Medicine, Łódź, Poland.
Abstract:
In this study, molybdenum(IV) sulfide (MoS2 ) nanoparticles (97 ± 32 nm) and microparticles (1.92 ± 0.64 μm) stabilized with poly (vinylpolypyrrolidone) (PVP) were administered intratracheally to male and female rats (dose of 1.5 or 5 mg/kg bw), every 14 days for 90 days (seven administrations in total). Blood parameters were assessed during and at the end of the study (hematology, biochemistry including glucose, albumins, uric acid, urea, high density lipoprotein HDL, total cholesterol, triglycerides, aspartate transaminase, and alanine transaminase ALT). Bronchoalveolar lavage fluid (BALF) analyses included cell viability, biochemistry (total protein concentration, lactate dehydrogenase, and glutathione peroxidase activity), and cytokine levels (tumor necrosis factor α, TNF-α, macrophage inflammatory protein 2-alpha, MIP-2, and cytokine-induced neutrophil chemoattractant-2, CINC-2). Tissues were subjected to routine histopathological and electron microscopy (STEM) examinations. No overt signs of chronic toxicity were observed. Differential cell counts in BALF revealed no significant differences between the animal groups. An increase in MIP-2 and a decrease in TNF-α were observed in BALF in the exposed males. The histopathological changes in the lung evaluated according to a developed classification system (based on severity of inflammation, range 0-4, with 4 indicating the most severe changes) showed average histopathological score of 1.33 for animals exposed to nanoparticles and microparticles at the lower dose, 1.72 after exposure to nanoparticles at the higher dose, and 2.83 for animals exposed to microparticles at the higher dose. In summary, it was shown that nanosized and microsized MoS2 can trigger dose-dependent inflammatory reactions in the lungs of rats after multiple intratracheal instillation irrespective of the animal sex. Some evidence indicates a higher lung pro-inflammatory potential of the microform.
Insights
Molybdenum(IV) sulfide (MoS2) particles induced dose-dependent lung inflammation in rats. Microparticles showed a higher pro-inflammatory potential than nanoparticles, with males exhibiting specific cytokine changes.
Area of Science:
- Materials Science and Toxicology
- Nanotechnology and Environmental Health
Background:
- Molybdenum(IV) sulfide (MoS2) is utilized in various applications, necessitating an understanding of its toxicological profile.
- Investigating the pulmonary effects of intratracheal instillation of MoS2 nanoparticles and microparticles is crucial for risk assessment.
Purpose of the Study:
- To evaluate the potential toxicity and inflammatory responses in rats following repeated intratracheal administration of MoS2 nanoparticles and microparticles.
- To compare the pulmonary pro-inflammatory effects of MoS2 in nano- and micro-sized forms.
Main Methods:
- Male and female rats received intratracheal instillations of MoS2 nanoparticles or microparticles (1.5 or 5 mg/kg bw) every 14 days for 90 days.
- Comprehensive analyses included blood parameters, bronchoalveolar lavage fluid (BALF) cytology and biochemistry, cytokine profiling, and histopathological examination of lung tissues.
- Scanning Transmission Electron Microscopy (STEM) was used for tissue examination.
Main Results:
- No overt signs of chronic toxicity or significant differences in BALF differential cell counts were observed.
- Exposed male rats showed increased macrophage inflammatory protein 2-alpha (MIP-2) and decreased tumor necrosis factor-alpha (TNF-α) in BALF.
- Histopathological scores indicated dose-dependent lung inflammation, with microparticles at the higher dose causing more severe changes (average score 2.83) compared to nanoparticles (average score 1.72).
Conclusions:
- Repeated intratracheal instillation of nanosized and microsized MoS2 triggers dose-dependent inflammatory reactions in rat lungs, irrespective of sex.
- MoS2 microparticles appear to possess a higher pro-inflammatory potential in the lungs compared to their nano counterparts.
- These findings highlight the importance of particle size in the pulmonary toxicity of MoS2.
