{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T22:05:39Z","timestamp":1788559539696,"version":"build-2803163510"},"reference-count":38,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,1,28]],"date-time":"2025-01-28T00:00:00Z","timestamp":1738022400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"New Energy and Industrial Technology Development Organization (NEDO) Japan","award":["20001602-0"],"award-info":[{"award-number":["20001602-0"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>An investigation into the acute toxicity of mechanically fibrillated cellulose nanofibers (fib-CNFs), with a fiber length ranging from 500 to 600 nm, was conducted in accordance with the OECD TG412 guidelines. In this study, rats were exposed to fib-CNFs via nasal inhalation for 6 h daily over a 28-day period. The highest exposure concentration was set at 35 mg\/m3, with intermediate and low concentrations at 7.0 mg\/m3 and 1.5 mg\/m3, respectively. No significant differences were observed in body weight, hematological parameters, or biochemical profiles between the fib-CNF-exposed groups and the control group. However, the histopathological examination of lung tissue revealed elevated macrophage counts in both the alveolar spaces and lymph nodes, accompanied by a significant increase in lung weight. The most severe effects were observed in the high-concentration group, while the low-concentration group exhibited only mild inflammatory changes. Based on these findings, the no observable adverse effect level (NOAEL) for the acute toxicity of fib-CNFs is estimated to be below 1.5 mg\/m3.<\/jats:p>","DOI":"10.3390\/nano15030214","type":"journal-article","created":{"date-parts":[[2025,1,29]],"date-time":"2025-01-29T03:26:10Z","timestamp":1738121170000},"page":"214","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Safety of Mechanically Fibrillated Cellulose Nanofibers (CNFs) by Inhalation Exposure Based on TG412"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-8498-5203","authenticated-orcid":false,"given":"Yoshihiro","family":"Yamashita","sequence":"first","affiliation":[{"name":"Research Center for Fibers and Materials, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akinori","family":"Tokunaga","sequence":"additional","affiliation":[{"name":"Life Science Research Laboratory, School of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5854-7015","authenticated-orcid":false,"given":"Koji","family":"Aoki","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, Faculty of Medicine, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8347-3553","authenticated-orcid":false,"given":"Tamotsu","family":"Ishizuka","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1438-6402","authenticated-orcid":false,"given":"Satoshi","family":"Fujita","sequence":"additional","affiliation":[{"name":"Department of Frontier Fiber Technology and Science, Faculty of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuichi","family":"Tanoue","sequence":"additional","affiliation":[{"name":"Research Center for Fibers and Materials, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,1,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9","DOI":"10.32964\/TJ13.5.9","article-title":"Market projections of cellulose nanomaterial-enabled products\u2014Part 1: Applications","volume":"13","author":"Shatkin","year":"2014","journal-title":"TAPPI J."},{"key":"ref_2","first-page":"184","article-title":"Investigation of the durability of cellulose fibres in rat lungs","volume":"41","author":"Muhle","year":"1997","journal-title":"Ann. 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