Lung response to crystalline nanocellulose exposure in rats

Crystalline nanocellulose (CNC) is an emerging nanomaterial with multiple commercial and industrial applications. Occupational exposure to CNC during the production and/or use of products containing the nanomaterial potentially resulting in adverse health effects among workers is possible. Therefore, there is an immediate need to determine the toxicity potential of CNC. Rats were exposed to either air or CNC (20 mg/m^3, 6 hours/day, 5 days/week, 14 days) and lung toxicity was determined one day following termination of the exposures. Compared to the control rats, the CNC exposed rats exhibited moderate changes in lung histology. Lactate dehydrogenase activity and the number of phagocytes present in the bronchoalveolar lavage were higher in the CNC exposed rats, compared with the controls. Global gene expression profiling identified 531 genes whose expressions were significantly different (fold change >1.5 and FDR p <0.05) in the lungs of the CNC exposed rats, compared with the controls. In summary, the data demonstrated the induction of pulmonary toxicity and global gene expression changes in the lungs of the rats in response to inhalation exposure to CNC.结晶纳米纤维素（Crystalline nanocellulose，CNC）是一类新兴纳米材料，拥有多类商业与工业应用场景。在生产或使用含该纳米材料的产品过程中，作业人员职业性接触CNC，存在引发健康不良影响的潜在风险，因此亟需明确CNC的毒性潜能。本研究将大鼠分为两组，分别暴露于洁净空气与CNC环境（暴露浓度20 mg/m³，每日6小时、每周5天，持续14天），并于暴露结束后1天检测其肺毒性。与对照组大鼠相比，CNC暴露组大鼠的肺组织病理学呈现中度改变；相较于对照组，CNC暴露组大鼠支气管肺泡灌洗液中的乳酸脱氢酶活性与吞噬细胞数量均显著升高。全基因表达谱分析结果显示，与对照组相比，CNC暴露组大鼠肺部共有531个基因的表达量存在显著差异（倍数变化>1.5，错误发现率校正P值<0.05）。综上，本研究数据证实，大鼠经呼吸道暴露于CNC后，可诱导肺毒性发生，并引发肺部全局性基因表达改变。