McCormack Andrew, Stone Vicki, McQuat James, Johnston Helinor
Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK.
Publishing Consultant, Winchester, UK.
Part Fibre Toxicol. 2025 May 13;22(1):11. doi: 10.1186/s12989-025-00627-8.
Particles often require dispersion in aqueous media to allow assessment of their hazard profile. The approach used to disperse particles is not consistent in the published literature, with approaches including stirring, vortexing, shaking or sonication, and the use of biological or chemical stabilisers. Such variations in the dispersion protocol can influence the physico-chemical (PC) identity and toxicity of particles. To better understand the protocol variations and their impacts on human health, this work identified and critically reviewed publications with a specific focus on titanium dioxide (TiO), which was dominated by nanomaterials (NMs). This review included consideration of both in vitro and in vivo studies, as well as other NMs to help address knowledge gaps and identify any lessons that can be learnt and applied to TiO. Overall, the evidence gathered showed that variations in the dispersion protocol, specifically the method and parameters of sonication (e.g. power and duration), as well as the dispersion medium choice (and inclusion of biological and chemical stabilisers), were impactful on NM agglomerate size. There is no consensus as to whether a reduction or increase in NM agglomeration enhances or reduces NM toxicity with the outcome of the study dependent on the experimental design (e.g. PC properties of the NM being tested, test model used, time point, and concentrations/doses assessed). Whilst standard protocols for NM dispersion have been generated, they have not been widely adopted and there is unlikely to be one protocol that can be applied to all NMs and test models. Instead, more guidance is needed to inform the considerations that should guide preparation of NM suspensions for hazard testing. These include a recommendation that pilot studies are performed to identify the most suitable dispersion protocol before embarking on a toxicology study. Improved knowledge of the impact of dispersion protocols on PC identity and toxicity of TiO will assist in the interpretation of existing toxicology data and feed into the design of future studies which assess TiO toxicity.
颗粒通常需要在水性介质中分散，以便评估其危害特征。在已发表的文献中，用于分散颗粒的方法并不一致，包括搅拌、涡旋、振荡或超声处理，以及使用生物或化学稳定剂。分散方案的这些差异会影响颗粒的物理化学（PC）特性和毒性。为了更好地理解方案差异及其对人类健康的影响，本研究确定并批判性地回顾了一些出版物，特别关注二氧化钛（TiO₂），其中纳米材料（NMs）占主导地位。该综述包括对体外和体内研究以及其他纳米材料的考虑，以帮助填补知识空白，并确定任何可借鉴并应用于TiO₂的经验教训。总体而言，收集到的证据表明，分散方案的差异，特别是超声处理的方法和参数（如功率和持续时间），以及分散介质的选择（以及生物和化学稳定剂的添加），对纳米材料团聚体大小有影响。关于纳米材料团聚的减少或增加是增强还是降低纳米材料毒性，目前尚无共识，研究结果取决于实验设计（例如所测试纳米材料的PC特性、使用的测试模型、时间点以及评估的浓度/剂量）。虽然已经制定了纳米材料分散的标准方案，但尚未得到广泛采用，而且不太可能有一个适用于所有纳米材料和测试模型的方案。相反，需要更多的指导来告知在为危害测试制备纳米材料悬浮液时应考虑的因素。这些因素包括建议在开展毒理学研究之前进行预实验，以确定最合适的分散方案。提高对分散方案对TiO₂的PC特性和毒性影响的认识，将有助于解释现有的毒理学数据，并为评估TiO₂毒性的未来研究设计提供参考。
