Chemical transformation and surface functionalisation affect the potential to group nanoparticles for risk assessment
Chemical transformation and surface functionalisation affect the potential to group nanoparticles for risk assessment
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DOI：
10.1039/d0en00578a
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
C. Schultz;J. Adams;K. Jurkschat;S. Lofts;D. Spurgeon
中科院分区：
文献类型：
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作者：
C. Schultz;J. Adams;K. Jurkschat;S. Lofts;D. Spurgeon
纳米材料环境风险评估的一个主要挑战是确定是否需要对不同的人造材料进行单独评估，或者是否可以根据选定的特性对它们进行分组评估。迄今为止，NP基于它们被制造（例如，原始材料），但这些很少存在于环境中，因为许多纳米材料在进入环境之前和之后都会发生变化。为了评估转换如何改变相对危险性，因此，分组的可能性，我们评估了不同尺寸（20，50 nm）和表面功能化（PVP，柠檬酸盐）的银纳米粒子（NP）的毒性，在其金属和硫化形式秀丽隐杆线虫在缺乏有机质的标准介质和提取的土壤孔隙水。金属Ag NP仅显示出小的毒性变化，其中柠檬酸盐官能化降低效力，并且小的柠檬酸盐NP毒性最小。在所有情况下，硫化颗粒的毒性低于原始形式，但转化材料之间的相对差异大于金属形式。暴露在土壤孔隙水中进一步降低了柠檬酸盐的毒性，但PVP功能化的NP没有。总体而言，转化以尺寸依赖性方式降低了柠檬酸盐官能化NP毒性，而PVP涂层在尺寸和转化之间保持了相似性。因此，尽管原始材料具有相似的毒性，但具有相似涂层的NP的分组（与尺寸无关）似乎仅适用于具有更持久PVP表面涂层的材料，并且仅在首先考虑转化时才有可能。
A major challenge in nanomaterial environmental risk assessment is to identify whether different manufactured materials need to be assessed individually or if they can be grouped for assessments based on selected properties. To date, NPs are grouped on the basis that they are manufactured (e.g., pristine materials), but these are rarely present in the environment as many nanomaterials transform before and after entry into the environment. To assess how transformations change relative hazard and, therefore, the potential for grouping, we assessed the toxicity of silver nanoparticles (NPs) of varying sizes (20, 50 nm) and surface functionalisation (PVP, citrate) in their metallic and sulphidised forms to Caenorhabditis elegans in a standard medium lacking organic matter and in extracted soil pore water. The metallic Ag NPs showed only small variations in toxicity, with citrate functionalisation reducing potency and small citrate NPs being least toxic. The toxicity of sulphidised particles was lower than for the pristine forms in all cases, however relative differences among the transformed materials were greater than for the metallic forms. Exposure in soil pore water further reduced toxicity of the citrate, but not PVP functionalised NPs. Overall, transformation reduced citrate functionalised NP toxicity in a size dependent manner, whereas PVP coating preserved similarities across sizes and transformations. Thus despite similar toxicity of the pristine materials, grouping of NPs with a similar coating independent of size appeared only possible for materials with the more persistent PVP surface coating and then only when transformations were first considered.