由于其抗氧化和催化性能以及模拟多种内源酶活性，氧化铈纳米酶（CeO2NZs）受到了广泛关注。然而，就像一般纳米医药品一样，尽管其在展示其独特医学应用方面取得了成功，但其药代动力学的理解却没有获得相应的进展，这延缓了其在临床应用中的实施。此外，关于其在体液中的改变及其对活性的影响的数据十分有限。本文通过将两种广泛使用的CeO2NZs（静电稳定和包覆有介孔二氧化硅壳层的）暴露于模拟唾液、肺、胃和肠液以及细胞培养基中，跟踪其物理化学改变和生物活性的变化，并结合不同的表征技术和生物试验数据，对其进行了长达15天的观察。结果表明，尽管在不同液体中存在不同的演变行为，包括聚集现象，但在所有情况下，其生物相容性和抗氧化活性均得到保持。该研究从药代动力学的角度为CeO2NZs的治疗效果提供了实验基础，该效果在体内用于治疗与慢性炎症和癌症相关的许多疾病时观察到，并且表明它们可通过不同的入口途径安全地给予，包括静脉注射、口服或吸入。

Cerium oxide nanozymes (CeO2NZs) are attracting vast attention due to their antioxidant and catalytic properties and mimic the activities of multiple endogenous enzymes. However, as is the case for nanomedicines in general, the success in showing their unique medical applications has not been matched by an understanding of their pharmacokinetics, which is delaying their implementation in clinical settings. Furthermore, the data of their modifications in body fluids and the impact on their activity are scarce. Herein, two types of widely used CeO2NZs, electrostatically stabilized and coated with a mesoporous silica shell, were exposed to simulated saliva and lung, gastric and intestinal fluids, and cell culture media. Their physicochemical modifications and bioactivity were tracked over time up to 15 days combining the data of different characterization techniques and biological assays. The results show that the biocompatibility and antioxidant activity are retained in all cases despite the different evolution behaviors in different fluids, including agglomeration. This work provides an experimental basis from a pharmacokinetic perspective that supports the therapeutic effectiveness of CeO2NZs observed in vivo for the treatment of many conditions related to chronic inflammation and cancer, and suggests that they can be safely administered through different portals of entry including intravenous injection, oral ingestion or inhalation.