Nanotechnology risk management strategies and environmental regulations continue to rely on hazard and exposure assessment protocols developed for bulk materials, including larger size particles, while commercial application of nanomaterials (NMs) increases. In order to support and corroborate risk assessment of NMs for workers, consumers, and the environment it is crucial to establish the impact of biopersistence of NMs at realistic doses. In the future, such data will allow a more refined future categorization of NMs. Despite many experiments on NM characterization and numerous in vitro and in vivo studies, several questions remain unanswered including the influence of biopersistence on the toxicity of NMs. It is unclear which criteria to apply to characterize a NM as biopersistent. Detection and quantification of NMs, especially determination of their state, i.e., dissolution, aggregation, and agglomeration within biological matrices and other environments are still challenging tasks; moreover mechanisms of nanoparticle (NP) translocation and persistence remain critical gaps. This review summarizes the current understanding of NM biokinetics focusing on determinants of biopersistence. Thorough particle characterization in different exposure scenarios and biological matrices requires use of suitable analytical methods and is a prerequisite to understand biopersistence and for the development of appropriate dosimetry. Analytical tools that potentially can facilitate elucidation of key NM characteristics, such as ion beam microscopy (IBM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), are discussed in relation to their potential to advance the understanding of biopersistent NM kinetics. We conclude that a major requirement for future nanosafety research is the development and application of analytical tools to characterize NPs in different exposure scenarios and biological matrices.

中文翻译：

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纳米材料的生物动力学：生物持久性的作用


纳米技术风险管理策略和环境法规继续依赖于为散装材料（包括较大尺寸颗粒）开发的危害和暴露评估协议，而纳米材料（NM）的商业应用不断增加。为了支持和证实 NM 对工人、消费者和环境的风险评估，确定 NM 在实际剂量下的生物持久性影响至关重要。未来，这些数据将允许对 NM 进行更精细的分类。尽管进行了许多关于 NM 表征的实验以及大量的体外和体内研究，但仍有几个问题尚未得到解答，包括生物持久性对 NM 毒性的影响。目前还不清楚应用什么标准来将 NM 描述为生物持久性。 NM 的检测和定量，特别是确定其状态，即生物基质和其他环境中的溶解、聚集和团聚仍然是具有挑战性的任务；此外，纳米颗粒（NP）易位和持久性的机制仍然存在关键差距。这篇综述总结了目前对 NM 生物动力学的理解，重点关注生物持久性的决定因素。在不同的暴露场景和生物基质中进行彻底的颗粒表征需要使用合适的分析方法，并且是了解生物持久性和开发适当的剂量测定的先决条件。讨论了可能有助于阐明关键 NM 特征的分析工具，例如离子束显微镜 (IBM) 和飞行时间二次离子质谱 (ToF-SIMS)，并讨论了它们促进对生物持久性 NM 理解的潜力动力学。 我们的结论是，未来纳米安全研究的一个主要要求是开发和应用分析工具来表征不同暴露场景和生物基质中的纳米颗粒。