Kato Haruhisa, Suzuki Mie, Fujita Katsuhide, Horie Masanori, Endoh Shigehisa, Yoshida Yasukazu, Iwahashi Hitoshi, Takahashi Kayori, Nakamura Ayako, Kinugasa Shinichi
Polymer Standards Section Japan, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, Tsukuba, Ibaraki 305-8565, Japan.
Toxicol In Vitro. 2009 Aug;23(5):927-34. doi: 10.1016/j.tiv.2009.04.006. Epub 2009 May 3.
Dynamic light scattering (DLS) is widely used for the evaluation of the particle size in the toxicity assessment of nanoparticles. However, the many types of DLS instruments and analytical procedures sometimes give different apparent sizes of particles and make it complicated to understand the size dependence on particles for the toxicity assay. In this study, we established an evaluation method of secondary nanoparticle sizes using a DLS analysis. First, we established a practical method for determining size with an appropriate evaluation of uncertainties. This proposed method could be a universal protocol for toxicity assessment that would allow researchers to achieve some degree of concordance on the size of nanoparticles for an assessment. Second, we investigated the processes associated with particles in suspension by examining the changes in the size and the light scattering intensity of secondary nanoparticles during an in vitro toxicity assessment, since the transport mode of particles to cells is significant in understanding in vitro nano-toxicity. In this study, these two points were investigated on TiO(2) nanoparticles suspension as an example. The secondary particles of TiO(2) with a light scattering intensity-averaged diameter (d(l)) of 150-250 nm were characterized with appropriate uncertainties. The sizes were found to be comparable with values determined using other analytical procedures and other instruments. It is suggested that d(l) could be an effective size parameter for toxicity assessments. Furthermore, TiO(2) secondary nanoparticle suspensions are well dispersed with slow gravity settling, no agglomeration, with the diffusion process as the primary transport mode of particles to cells.
动态光散射（DLS）在纳米颗粒毒性评估中被广泛用于评估颗粒大小。然而，多种类型的DLS仪器和分析程序有时会给出不同的颗粒表观尺寸，使得理解毒性测定中颗粒大小的依赖性变得复杂。在本研究中，我们建立了一种使用DLS分析评估二次纳米颗粒大小的方法。首先，我们建立了一种实用的方法来确定尺寸，并对不确定度进行了适当评估。该方法可能是一种通用的毒性评估方案，可使研究人员在纳米颗粒大小评估上达成一定程度的一致性。其次，我们通过在体外毒性评估过程中检查二次纳米颗粒的大小和光散射强度的变化，研究了与悬浮颗粒相关的过程，因为颗粒向细胞的转运模式对于理解体外纳米毒性至关重要。在本研究中，以TiO₂纳米颗粒悬浮液为例对这两点进行了研究。对光散射强度平均直径（d(l)）为150 - 250 nm的TiO₂二次颗粒进行了特征描述，并给出了适当的不确定度。发现这些尺寸与使用其他分析程序和其他仪器测定的值相当。结果表明，d(l)可能是毒性评估的一个有效尺寸参数。此外，TiO₂二次纳米颗粒悬浮液分散良好，重力沉降缓慢，无团聚现象，扩散过程是颗粒向细胞的主要转运模式。
