关键词: 纳米二氧化硅, 气管滴注, 组织病理学, 炎症

Abstract: Objective: To study the effects of SiO₂ nanoparticles on the organs of mice in vivo after intratracheal instillation, and to provide the basis for safety evaluation of SiO₂ nanoparticles. Methods: Forty female BALB/c mice aged 6-8 weeks were randomly divided into control group (saline), low dose of SiO₂ group (7 mg·kg^-1), middle dose of SiO₂ group (21 mg·kg^-1), and high dose of SiO₂ group (35 mg·kg^-1). 1 and 15 d after five times of non-exposed intratracheal instilation infection (once every 3 d), the mice were sacrificed and the left lungs,the right kidneys, livers, hearts and spleens were collected and embedded in paraffin. The morphology of tissue sections was observed under light microscope after hematoxylin-eosin (HE) staining. The eyeball blood was obtained and the biochemical indicators of liver and kidndy functions were detected. Results: Compared with control group, there were alveolar interval thickening, inflammatory cell infiltration, and a small amount of small arterial thrombosis in the lungs; granulomatous inflammatory cell infiltration and a small amount of focal necrosis of liver cells in the livers; red pulp enlargement, hyperemia, and more visibly scattered megakaryocytes in the spleens in SiO₂ nanoparticles groups in a dose-dependent manner, especially in middle and high doses of SiO₂ groups. After 15 d of injection, the damages alleviated with the prolongation of time. There was some inflammatory cell infiltration in the kidney tissue of the mice in SiO₂ nanoparticle groups. The biochemical indicator detection results showed that alanine aminotransferase(ALT) and aspartate transaminase(AST) levels in SiO₂ nanoparticles groups varied, suggesting the liver cell damages were at different degrees; the changes of urea nitrogen(BUN) and creatinine(Cr) levels in SiO₂ nanoparticle groups remindered the kidney function alteration, but there were no obvious dose- and time- dependent effects. Conclusion: Intratracheal instillation of SiO₂ nanoparticles can influence the major organs of the mice and mainly displays in the inflammation and injuries in the lung, liver, and spleen.

Key words: SiO₂ nanoparticles, intratracheal instillation, histopathology, inflammation