Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing 100191, China.
Small. 2013 May 27;9(9-10):1742-52. doi: 10.1002/smll.201201185. Epub 2012 Sep 4.
Titanium dioxide nanoparticles (TiO2 NPs) have potential applications as food additives, but concerns persist about their safety. Children are identified as having the highest exposure and may face the greatest health risks. However, the toxicological sensitivity of TiO2 NPs in different ages is not clear. Here, a comparative toxicity study of TiO2 NPs in 3-week (youth) and 8-week (adult) old Sprague-Dawley rats is reported following oral exposure at doses of 0, 10, 50, 200 mg kg(-1) body weight per day for 30 days. The organ mass and histology, blood biochemistry and redox state, intestinal function, and biodistribution of NPs are characterized. The results show that TiO2 NPs induce different toxic effects on young and adult rats. The liver edema, heart injuries and non-allergic mast cell activation in stomach tissues are found in young rats. On the other hand, only slight injury in the liver and kidney and decreased intestinal permeability and molybdenum contents are found in adult rats. Furthermore, TiO2 NP exposure can provoke reductive stress (i.e., increased reduced glutathione (GSH)/oxidized glutathione (GSSG) ratios) in plasmas through enhancing the glucose and GSH levels in young rats or reducing the glutathione peroxidase (GSH-Px) acitivity and GSSG levels in adult rats. These results suggest that different ages may require different biomarkers for identifying and monitoring oral toxicity of nanoparticles.
二氧化钛纳米粒子（TiO2 NPs）在食品添加剂方面具有潜在的应用，但人们对其安全性仍存在担忧。儿童被认为是暴露量最高的人群，可能面临最大的健康风险。然而，不同年龄段 TiO2 NPs 的毒理学敏感性尚不清楚。本研究通过对 3 周龄（青年）和 8 周龄（成年）SD 大鼠进行为期 30 天的口服暴露（剂量分别为 0、10、50、200 mg kg-1 体重/天），报道了 TiO2 NPs 在这两个年龄段的比较毒性研究结果。研究了器官质量和组织学、血液生物化学和氧化还原状态、肠道功能以及 NPs 的体内分布。结果表明，TiO2 NPs 对青年和成年大鼠产生不同的毒性作用。青年大鼠的肝脏水肿、心脏损伤和胃组织非过敏性肥大细胞激活。另一方面，成年大鼠仅观察到肝脏和肾脏的轻微损伤，以及肠道通透性和钼含量降低。此外，TiO2 NP 暴露可通过增加青年大鼠的葡萄糖和 GSH 水平或降低成年大鼠的谷胱甘肽过氧化物酶（GSH-Px）活性和 GSSG 水平，引起血浆中的还原应激（即增加还原型谷胱甘肽（GSH）/氧化型谷胱甘肽（GSSG）比值）。这些结果表明，不同年龄段可能需要不同的生物标志物来识别和监测纳米颗粒的口服毒性。
