The Dispersion State of Tangled Multi-Walled Carbon Nanotubes Affects Their Cytotoxicity.
The medical applications of carbon nanotubes (CNTs) have garnered much attention. However, evaluating the safety of CNTs remains difficult, and no consensus has been reached. Moreover, assessing the biosafety of multi-walled CNTs (MWCNTs), which can become tangled during manufacturing, is challenging because they do not readily disperse. We studied how the dispersion state of tangled MWCNTs affects their cytotoxicity, using three sonicators. Flotube 9110 (FT9110), tangled MWCNTs, were dispersed in two dispersants (fetal bovine serum and polysorbate 80) using a new type of sonicator (PR-1) and two conventional sonicators. The size and cytotoxicity of the dispersed FT9110 were measured using the BEAS-2B human bronchial epithelial cell line. The PR-1 dispersed the FT9110 to agglomerates <200 nm in diameter; FT9110 dispersed with the PR-1 did not show cytotoxicity regardless of dispersant. The other sonicators dispersed the FT9110 to particles >1000 nm in diameter, and cytotoxicity depended on the dispersant. We found that excluding cells adhered to agglomerated FT9110 before evaluating cytotoxicity can lead to false-positive results. The PR-1 sonicator dispersed tangled FT9110 to many single fibers, which showed lower cytotoxicity than conventionally-sonicated MWCNTs. We suggest that dispersion state should be accounted for when evaluating the cytotoxicity of MWCNTs.
Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. 15mz011b@shinshu-u.ac.jp.|Physical and Occupational Therapy Division, Graduate School of Medicine, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. 15mz011b@shinshu-u.ac.jp.
Chika
C
Kuroda
Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. hhaniu@shinshu-u.ac.jp.|Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. hhaniu@shinshu-u.ac.jp.|Biomedical Engineering Division, Graduate School of Science and Technology, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. hhaniu@shinshu-u.ac.jp.
Hisao
H
Haniu
Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. ajima@shinshu-u.ac.jp.
Kumiko
K
Ajima
Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. m990054e@shinshu-u.ac.jp.
Manabu
M
Tanaka
Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. soba@shinshu-u.ac.jp.
Atsushi
A
Sobajima
Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. 16bs203j@shinshu-u.ac.jp.|Biomedical Engineering Division, Graduate School of Science and Technology, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. 16bs203j@shinshu-u.ac.jp.
Haruka
H
Ishida
Department of Molecular Pharmacology and Neuroscience, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan. ttamotsu@nagasaki-u.ac.jp.
Tamotsu
T
Tsukahara
Clinical Pharmacology Educational Center, Nihon Pharmaceutical University, 10281 Komuro, Ina-machi, Saitama 362-0806, Japan. yomatsuda@nichiyaku.ac.jp.
Yoshikazu
Y
Matsuda
Physical and Occupational Therapy Division, Graduate School of Medicine, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. kin29men@shinshu-u.ac.jp.
Kaoru
K
Aoki
Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. hirokato@shinshu-u.ac.jp.
Hiroyuki
H
Kato
Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. saitoko@shinshu-u.ac.jp.|Physical and Occupational Therapy Division, Graduate School of Medicine, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. saitoko@shinshu-u.ac.jp.|Biomedical Engineering Division, Graduate School of Science and Technology, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. saitoko@shinshu-u.ac.jp.
Naoto
N
Saito
AlamarBlue assay; cytotoxicity; multi-walled carbon nanotube; sonicator; tangle