Murdock Richard C, Braydich-Stolle Laura, Schrand Amanda M, Schlager John J, Hussain Saber M
Applied Biotechnology Branch, Human Effectiveness Directorate Air Force Research Laboratory/HEPB, Wright-Patterson Air Force Board, Ohio 45433, USA.
Toxicol Sci. 2008 Feb;101(2):239-53. doi: 10.1093/toxsci/kfm240. Epub 2007 Sep 13.
The need to characterize nanoparticles in solution before assessing the in vitro toxicity is a high priority. Particle size, size distribution, particle morphology, particle composition, surface area, surface chemistry, and particle reactivity in solution are important factors which need to be defined to accurately assess nanoparticle toxicity. Currently, there are no well-defined techniques for characterization of wet nanomaterials in aqueous or biological solutions. Previously reported nanoparticle characterization techniques in aqueous or biological solutions have consisted of the use of ultra-high illumination light microscopy and disc centrifuge sedimentation; however, these techniques are limited by the measurement size range. The current study focuses on characterizing a wide range of nanomaterials using dynamic light scattering (DLS) and transmission electron microscopy, including metals, metal oxides, and carbon-based materials, in water and cell culture media, with and without serum. Cell viability and cell morphology studies were conducted in conjunction with DLS experiments to evaluate toxicological effects from observed agglomeration changes in the presence or absence of serum in cell culture media. Observations of material-specific surface properties were also recorded. It was also necessary to characterize the impact of sonication, which is implemented to aid in particle dispersion and solution mixture. Additionally, a stock solution of nanomaterials used for toxicology studies was analyzed for changes in agglomeration and zeta potential of the material over time. In summary, our results demonstrate that many metal and metal oxide nanomaterials agglomerate in solution and that depending upon the solution particle agglomeration is either agitated or mitigated. Corresponding toxicity data revealed that the addition of serum to cell culture media can, in some cases, have a significant effect on particle toxicity possibly due to changes in agglomeration or surface chemistry. It was also observed that sonication slightly reduces agglomeration and has minimal effect on particle surface charge. Finally, the stock solution experienced significant changes in particle agglomeration and surface charge over time.
在评估体外毒性之前对溶液中的纳米颗粒进行表征是当务之急。粒径、粒径分布、颗粒形态、颗粒组成、表面积、表面化学性质以及颗粒在溶液中的反应活性是准确评估纳米颗粒毒性所需明确的重要因素。目前，尚无用于表征水性或生物溶液中湿态纳米材料的明确技术。先前报道的用于水性或生物溶液中纳米颗粒表征的技术包括使用超高照明光学显微镜和圆盘离心沉降法；然而，这些技术受测量尺寸范围的限制。当前的研究重点是使用动态光散射（DLS）和透射电子显微镜对多种纳米材料进行表征，包括金属、金属氧化物和碳基材料，在水和细胞培养基中，有血清和无血清的情况。结合DLS实验进行细胞活力和细胞形态学研究，以评估细胞培养基中存在或不存在血清时观察到的团聚变化所产生的毒理学效应。还记录了材料特定表面性质的观察结果。表征超声处理的影响也很有必要，超声处理用于帮助颗粒分散和溶液混合。此外，对用于毒理学研究的纳米材料储备溶液进行分析，以观察材料的团聚和zeta电位随时间的变化。总之，我们的结果表明，许多金属和金属氧化物纳米材料在溶液中会团聚，并且根据溶液的不同，颗粒团聚要么加剧要么减轻。相应的毒性数据表明，在细胞培养基中添加血清在某些情况下可能会对颗粒毒性产生显著影响，这可能是由于团聚或表面化学性质的变化。还观察到超声处理会略微减少团聚，并且对颗粒表面电荷的影响最小。最后，储备溶液的颗粒团聚和表面电荷随时间发生了显著变化。
