Evidence map›Paper›PMID 40930818›Full record

ArticleEnvironmental health and preventive medicine2025

Development of a new alternative method to inhalation exposure: intratracheal instillation studies using molecular dispersion.

Toshiki Morimoto, Chinatsu Nishida, Hiroto Izumi, Taisuke Tomonaga, Kazuma Sato, Yasuyuki Higashi, Ke-Yong Wang, Takuma Kojima, Kazuo Sakurai, Akihiro Moriyama and 5 more

Abstract read
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Article in Environmental health and preventive medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

15 authors.

Toshiki MorimotoDepartment of Respiratory Medicine, University of Occupational and Environmental Health, Japan.
Chinatsu NishidaDepartment of Environmental Health Engineering, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.
Hiroto IzumiDepartment of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.
Taisuke TomonagaDepartment of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.
Kazuma SatoDepartment of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.
Yasuyuki HigashiDepartment of Respiratory Medicine, University of Occupational and Environmental Health, Japan.
Ke-Yong WangShared-Use Research Center, School of Medicine, University of Occupational and Environmental Health, Japan.
Takuma KojimaDepartment of Chemistry and Biochemistry, The University of Kitakyushu.
Kazuo SakuraiDepartment of Chemistry and Biochemistry, The University of Kitakyushu.
Akihiro MoriyamaResearch Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST).
Jun-Ichi TakeshitaResearch Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST).
Kei YamasakiDepartment of Respiratory Medicine, University of Occupational and Environmental Health, Japan.
Hidenori HigashiDepartment of Environmental Health Engineering, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.
Kazuhiro YateraDepartment of Respiratory Medicine, University of Occupational and Environmental Health, Japan.
Yasuo MorimotoDepartment of Occupational Pneumology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundOrganic chemicals have been known to cause allergic diseases such as bronchial asthma and hypersensitivity pneumonitis; however, the possibility that they do not cause irreversible pulmonary fibrosis has not been considered. Polyacrylic acid (PAA), an organic chemical, has caused irreversible progressive pulmonary fibrosis in exposed workers, indicating its potential to induce pulmonary inflammation and fibrosis. Although intratracheal instillation studies are commonly used for evaluating lung pathology, traditional methods face challenges with chemical substances, particularly nanoparticles, which tend to aggregate in suspension and prevent uniform pulmonary distribution. Such aggregation alters the qualitative and quantitative responses to lung injury, limiting accurate assessment of lung pathology. To overcome this limitation, we developed a 'molecular dispersion method' that uses pH modification to negative charges to PAA particles, maintaining their dispersion. Using this method, we investigated the effects of PAA on pulmonary inflammation and fibrosis in a rat model.

methodsF344 rats were intratracheally instilled with PAA using molecular dispersion (0.1 mg/rat, 1.0 mg/rat), PAA without molecular dispersion (1.0 mg/rat), and normal saline (control group). Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to examine inflammatory and fibrotic responses.

resultsPAA caused persistent increases in neutrophil influx in the bronchoalveolar lavage fluid (BALF) from 3 days to 1 month following instillation. In histopathological findings, the group with molecular dispersion had almost no inflammatory masses in the lung tissue compared to the group without molecular dispersion, and exhibited relatively uniform dispersion.

conclusionIntratracheal instillation of dispersed PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA might have pulmonary inflammogenicity and fibrogenicity. Intrapulmonary dispersion of PAA particles following intratracheal instillation studies using the molecular dispersion method was similar to that following inhalation studies.

Indexed as

Acrylic ResinsInhalation ExposurePneumoniaPulmonary FibrosisAnimalsBronchoalveolar Lavage FluidLungMaleRatsRats, Inbred F344Acrylic Resinscarbopol 940DispersionOrganic compoundsPolyacrylic acid (PAA)

Identifiers

PMID40930818
PMCPMC12436071

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