Assessing the Safety of Mechanically Fibrillated Cellulose Nanofibers (fib-CNF) via Toxicity Tests on Mice: Single Intratracheal Administration and 28 Days’ Oral Intake
Yoshihiro Yamashita,
Akinori Tokunaga,
Koji Aoki,
Tamotsu Ishizuka,
Hideyuki Uematsu,
Hiroaki Sakamoto,
Satoshi Fujita,
Shuichi Tanoue
Affiliations
Yoshihiro Yamashita
Research Center for Fibers and Materials, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Akinori Tokunaga
Life Science Research Laboratory, University of Fukui, 23-3, Matsuoka Shimoaizuki, Eiheiji-cho, Fukui 910-1193, Japan
Koji Aoki
Organization for Life Science Advancement Programs, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Tamotsu Ishizuka
Organization for Life Science Advancement Programs, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Hideyuki Uematsu
Organization for Life Science Advancement Programs, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Hiroaki Sakamoto
Organization for Life Science Advancement Programs, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Satoshi Fujita
Organization for Life Science Advancement Programs, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Shuichi Tanoue
Research Center for Fibers and Materials, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan
Mechanically fibrillated cellulose nanofibers, known as fib-CNF (fiber length: 500 nm; diameter: 45 nm), are used in composites and as a natural thickener in foods. To evaluate their safety, we conducted a 28-day study in mice with inhalation exposure at 0.2 mg/body and oral administration of 400 mg/kg/day. Inhalation exposure to fib-CNF caused transient weight loss, changes in blood cell counts, and increased lung weights. These changes were attributed to adaptive responses. The oral administration of fib-CNF for 28 days resulted in no apparent toxic effects except for a slight decrease in platelet counts. The fib-CNF administration using the protocols studied appears to be safe in mice.
