The rate of translocation of ingested nanoparticles (NPs) and how the uptake is affected by a food matrix are key aspects of health risk assessment. In this study, female Sprague Dawley rats (N = 4/group) received 0, 1.4, or 13 mg of cerium oxide (CeO₂ NM-212) NPs/rat/day by gavage or in a chocolate spread snack 5 days/week for 1 or 2 weeks followed by 2 weeks of recovery.

A dose and time-dependent uptake in the liver and spleen of 0.1–0.3 and 0.004–0.005 parts per million (ng/mg) of the total administered dose was found, respectively. There was no statistically significant difference in cerium concentration in the liver or spleen after gavage compared to snack dosing. Microscopy revealed indications of necrotic changes in the liver and decreased cellularity in white pulp in the spleen. The snack provided precise administration and a more human-relevant exposure of NPs and could improve animal welfare as alternative to gavage.

摄入的纳米粒子 (NPs) 的易位率以及摄取如何受食物基质的影响是健康风险评估的关键方面。在这项研究中，雌性 Sprague Dawley 大鼠（N = 4/组）接受 0、1.4 或 13 mg 氧化铈 (CeO ₂ NM-212) NPs/大鼠/天，通过灌胃或巧克力涂抹零食 5 天/周1 或 2 周后恢复 2 周。

发现肝脏和脾脏中的剂量和时间依赖性摄取分别为总给药剂量的 0.1-0.3 和 0.004-0.005 ppm (ng/mg)。与零食给药相比，灌胃后肝脏或脾脏中的铈浓度没有统计学上的显着差异。显微镜检查显示肝脏坏死变化和脾脏白髓细胞减少的迹象。这种零食提供了精确的管理和更与人类相关的 NPs 暴露，并且可以改善动物福利作为灌胃的替代方法。