A Toxicological Assessment of Crystalline Nano-Cellulose in Mice

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• Personal Author:
  Joseph P ; Sager TM
• Description:
  Crystalline nanocellulose (CNC) is derived from the natural polymer, cellulose. Considering the numerous applications of CNC, a substantial number of workers could be exposed to CNC. This study investigates the time-course of onset, progression, and resolution, if any, of CNC-induced toxicity. For hazard ranking, the outcome of the CNC toxicity studies was compared to those induced by a larger-sized crystalline micro cellulose; CMC, and to a reference material, Mitsui multi-walled carbon nanotubes (MWCNT). Mice (male, C57BL/6J, 7 weeks old) were administered dispersion medium (DM) or DM containing CNC, CMC (50, 100, and 200 microg/mouse), or MWCNT (50 microg/mouse) as a single pharyngeal aspiration. At 1 day, 7 days, 1 month, 3 months, and 6 months post-exposure toxicity facilitated by exposure to the varying materials was assessed. Serum transaminases were measured to determine hepatotoxicity. Whole lung lavage was conducted to assess pulmonary toxicity (PMN number and LDH activity). Sperm counts and motility analyses were used to assess reproductive toxicity. All doses of CNC caused a significant increase in PMN number and LDH activity at 1- and 7-days post-exposure. For CMC, an increase in PMN number and LDH activity was also found at 1-day post-exposure, for all doses. However, the inflammatory response of CNC (number of infiltrating PMNs) was significantly greater when compared to the response facilitated by CMC. The 200 microg/mouse dose of CNC also caused significant increases in serum ALT and AST at 7-days post-exposure compared to controls. CMC exposure also facilitated a significant increase in serum AST at the 200 microg/mouse dose at 1-day post-exposure. MWCNT resulted in significant pulmonary inflammation. However, at 1-day post-exposure, CNC (50 microg/mouse) caused a 2-fold greater increase in PMN number compared to that by MWCNT. By 7-days post-exposure MWCNT caused a 3-fold greater increase in PMN number compared to CNC. Additionally, there was no treatment related changes in sperm count or motility for any dose/post-exposure time combination of CNC, CMC, or MWCNT. In conclusion, the physico-chemical properties, such as the enhanced surface area of the CNC, are likely driving the more robust pulmonary toxicity response as compared to the pulmonary toxicity caused by the larger micron-sized CMC. Furthermore, MWCNT-facilitated pulmonary inflammation that was more persistent than CNC. [Description provided by NIOSH]
• Subjects:
  Cellulose Chemistry Environmental Exposure Enzymes Hazardous Substances Immune System Laboratories Liver Lung Occupational Health Particulate Matter Respiratory System Safety Toxicology

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• Keywords:
  Carbon Nanotubes Chemical Properties CNT Dispersion Dose Response Enzyme Activity Exposure Assessment Exposure Levels Hepatotoxicity Immune Reaction Laboratory Animals Laboratory Testing Multi-walled Carbon Nanotubes MWCNT Nanocellulose Nanotoxicology Particle Size Physical Properties Pulmonary Effects Surface Properties Toxic Effects Toxic Materials

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; OSHA Region 3 ; OSHA Region 9 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  174
• Issue:
  1
• NIOSHTIC Number:
  nn:20058936
• Citation:
  Toxicologist 2020 Mar; 174(1):265
• CAS Registry Number:
  Cellulose (CAS RN 9004-34-6) ; Carbon nanotubes (CAS RN 308068-56-6)
• Federal Fiscal Year:
  2020
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 59th Annual Meeting and ToxExpo, March 15-19, 2020, Anaheim, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f601fc9223bde82a076fcc607523582f18e770155ded8c7d2dd6681c4ed09ea017c94b13d611824697bcf49589cd34acfdf171977c4be7e665dac2bb24000f4b
• Download URL:
  https://stacks.cdc.gov/view/cdc/223291/cdc_223291_DS1.pdf
• File Type:
  [PDF - 522.26 KB ]