Nanoparticle Cytometrics: a quantitative analysis of the toxic effect of nanoparticles

在过去的十年中，纳米技术和材料的开发和使用出现了爆炸式增长，这一趋势无疑将在未来一段时间内继续下去。因此，很明显，人类暴露于纳米颗粒的情况将急剧增加，这引发了人们对纳米颗粒安全性的严重担忧，这些安全性与人类健康和我们生活的更广泛的生态系统有关。这在很大程度上是由于向纳米尺度发展所带来的范式转变，这种转变使目前基于整体性质的化学品风险评估失效，因此对纳米系统非常不合适。一个明显的例子是贵金属，如金;这些传统上被认为是惰性的，因此是生物相容的，但在纳米颗粒形式下，其表面积的巨大增加使它们具有高度反应性。表面积的问题使人们认识到，将潜在毒素量化为纳米颗粒形式是重要的，健康风险评估必须考虑到特定的颗粒数量，而不是基于重量/体积的化学溶液的总测量值。人们也越来越认识到，由于尺寸、形状和化学性质，颗粒的功能很重要。在纳米尺度上对化学危害的理解上的这种差距导致了政府机构和皇家委员会的一些报告，强调需要开发新的测量技术来量化纳米颗粒剂量的水平并评估潜在的毒性。我们建议使用流式细胞术，一种基于激光的技术，在活细胞群中光学跟踪荧光纳米颗粒。这种光学测量方法将与电子显微镜联系起来，以纳米级对细胞内的颗粒进行成像。这些技术一起将提供完全校准的计量，该计量提供关于测量组（通常为一百万个单元）内的每个单元的每个单元的颗粒数量的信息。我们的目标是提供一个基本的理解，其中纳米颗粒剂量是由细胞通过自然摄取机制（内吞作用），然后在生长的组织中稀释，因为颗粒在细胞分裂（有丝分裂）时在子细胞之间分裂。将使用一系列细胞类型来反映纳米颗粒的主要暴露途径，即皮肤、肺和循环（血液）系统。将进行纳米颗粒对细胞的任何毒性作用的详细研究，这与剂量的绝对定量一起将使我们能够将任何潜在的纳米毒性与给定细胞类型内纳米颗粒的数量和形式相关联。

The last decade has seen an explosion in the development and use of nanoscale technologies and materials and this trend will undoubtedly continue for some time to come. It is clear therefore that human exposure to nanoscale particles will grow dramatically and this has triggered serious concerns over the safety of nanoparticles in relation to human health and the wider ecosystems within which we live. Much of this stems from the paradigm shift incorporated in the move to nano scales which invalidates current chemical risk assessments that are based on bulk properties and hence grossly inappropriate for nano-systems. A marked example of this is provided by noble metals such as Gold; these are traditionally viewed as inert and hence bio-compatible however in nano-particulate form the huge increase in their surface area makes them highly reactive. The issue of surface area has led to the realisation that the quantisation of potential toxins into nano-particulate form is important and that assessment of health risk must take account of specific particle number rather than gross measures of chemical solution based on weight per volume. There is also a growing realisation that the function of particles due to size, shape and chemistry is important. This gap in understanding of chemical hazard at the nanoscale has led to a number of reports from government agencies and royal commissions emphasising the need to develop new measurement techniques to quantify the level of nanoparticle dose and to assess potential toxicity. We propose to use flow cytometry, a laser-based technology, to optically track fluorescent nanoparticles within populations of living cells. This optical measurement approach will be linked to electron microscopy to image particles within cells at the nanoscale. Together these techniques will provide a fully calibrated metrology providing information on number of particles per cell for each and every cell within a measured set (typically a million cells). Our objective is to provide a fundamental understanding of the way in which nanoparticle dose is acquired by cells through natural uptake mechanisms (endocytosis) and then diluted within growing tissue as particles are divided between daughter cells upon cell division (mitosis). A range of cell types will be used to reflect the main exposure routes to nanoparticles, i.e. skin, lung and circulatory (blood) systems. A detailed study of any toxic effects of nanoparticles on the cells will be undertaken and this together with the absolute quantification of dose will allow us to correlate any potential nanotoxicity to the number and form of nanoparticle within a given cell type.