Polyacrylate/nanosilica causes pleural and pericardial effusion, and pulmonary fibrosis and granuloma in rats similar to those observed in exposed workers

Abstract

Nanomaterials offer great benefit as well as potential damage to humans. Workers exposed to polyacrylate coatings have pleural effusion, pericardial effusion, and pulmonary fibrosis and granuloma, which are thought to be related to the high exposure to nanomaterials in the coatings. The study aimed to determine whether polyacrylate/silica nanoparticles cause similar toxicity in rats, as observed in exposed workers. Ninety male Wistar rats were randomly divided into five groups with 18 rats in each group. The groups included the saline control group, another control group of polyacrylate only, and low-, intermediate-, and high-dose groups of polyacrylate/nanosilica with concentrations of 3.125, 6.25, and 12.5 mg/kg. Seventy-five rats for the 1-week study were terminated for scheduled necropsy at 24 hours, 3 days, and 7 days postintratracheal instillation. The remaining 15 rats (three males/group) had repeated ultrasound and chest computed tomography examinations in a 2-week study to observe the pleural and pericardial effusion and pulmonary toxicity. We found that polyacrylate/nanosilica resulted in pleural and pericardial effusions, where nanosilica was isolated and detected. Effusion occurred on day 3 and day 5 post-administration of nanocomposites in the 6.25 and 12.5 mg/kg groups, it gradually rose to a maximum on days 7–10 and then slowly decreased and disappeared on day 14. With an increase in polyacrylate/nanosilica concentrations, pleural effusion increased, as shown by ultrasonographic qualitative observations. Pulmonary fibrosis and granuloma were also observed in the high-dose polyacrylate/nanosilica group. Our study shows that polyacrylate/nanosilica results in specific toxicity presenting as pleural and pericardial effusion, as well as pulmonary fibrosis and granuloma, which are almost identical to results in reported patients. These results indicate the urgent need and importance of nanosafety and awareness of toxicity of polyacrylate/nanosilica.

Keywords:

• polyacrylate/nanosilica
• pleural effusion
• pericardial effusion
• pulmonary fibrosis
• granuloma

Acknowledgments

The present study was funded by the National Natural Science Foundation of China (grant numbers 81172614 and 81441089). We thank Professor Wang Rugang and Yu Guixin (Beijing Center for Disease Prevention and Control, People’s Republic of China) for performing hematology analysis and blood biochemical assays. We also thank Dr Zhao Hongying (Department of Pathology, Beijing Chaoyang Hospital) for assistance with pathological analysis, Professor Zhang Dongfeng (Department of Epidemiology and Health Statistics, Qingdao University Medical College, People’s Republic of China) for statistical analysis, and Professor Dai Wei and Han Yehua (Peking Union Medical College, Chinese Academy of Medical Sciences, People’s Republic of China) for transmission electron microscopy analysis.

Disclosure

The authors report no conflicts of interest in this work.