Laboratoire de Biomécanique et Bioingénierie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 7338, Université de Technologie de Compiègne, BP 20529, 60205 Compiègne Cedex, France.
Langmuir. 2012 Sep 25;28(38):13660-7. doi: 10.1021/la302219v. Epub 2012 Sep 12.
In the context of rapid development of nanoparticles (NPs) for industrial applications, the question of their toxicity and biological effects must be considered. In this work, we have assessed the influence of titanium dioxide NPs on the adhesion and spreading of MC-3T3 pre-osteoblasts by using a cell subclone that does not produce its own extracellular matrix. Petri dishes were coated with the important adhesion protein fibronectin (Fn). By incubating these Fn-coated surfaces with different amounts of TiO(2) NPs, we have shown that the adhesion of pre-osteoblasts is disturbed, with an important decrease in the number of adherent cells (from 40 to 75% depending upon the concentration and type of NPs). Petri-dish surfaces were analyzed with environmental scanning electron microscropy (ESEM), with images showing that TiO(2) NP aggregates are bound to the layer of adsorbed Fn molecules. The cells cultured on these Fn/NP surfaces adopted an irregular shape and an aberrant organization of actin cytoskeleton, as revealed by fluorescence microscopy. Most importantly, these results, taken together, have revealed that the actin cytoskeleton forms abnormal aggregates, even on top of the nucleus, that coincide with the presence of large aggregates of NPs on top of cells. On the basis of these observations, we propose that some Fn molecules are able to desorb from the Petri dish surface to coat TiO(2) NPs. Fn/NP complexes are not attached firmly enough on the surface to allow for normal cell adhesion/spreading and the development of tense actin fibers. These results stress the paramount need for the assessment of the toxicology of NPs, with special attention to their interactions with biomolecules.
在纳米颗粒（NPs）快速发展应用于工业的背景下，必须考虑它们的毒性和生物效应问题。在这项工作中，我们评估了二氧化钛 NPs 对不产生自身细胞外基质的 MC-3T3 前成骨细胞黏附和铺展的影响。使用细胞亚克隆，在 Petri 培养皿中涂覆重要的黏附蛋白纤连蛋白（Fn）。通过用不同量的 TiO2 NPs 孵育这些 Fn 涂覆的表面，我们表明前成骨细胞的黏附受到干扰，黏附细胞的数量显著减少（取决于 NPs 的浓度和类型，从 40%减少到 75%）。使用环境扫描电子显微镜（ESEM）对 Petri 培养皿表面进行了分析，图像显示 TiO2 NP 聚集体与吸附的 Fn 分子层结合。在这些 Fn/NP 表面培养的细胞呈现不规则形状和肌动蛋白细胞骨架异常组织，这通过荧光显微镜显示。最重要的是，这些结果表明，肌动蛋白细胞骨架形成异常聚集体，甚至在核的顶部，与细胞顶部存在大量的 NPs 聚集体一致。基于这些观察结果，我们提出一些 Fn 分子能够从 Petri 培养皿表面解吸以涂覆 TiO2 NPs。Fn/NP 复合物在表面上不够牢固，不能允许正常的细胞黏附和铺展以及紧张的肌动蛋白纤维的发育。这些结果强调了评估 NPs 毒理学的必要性，特别注意它们与生物分子的相互作用。
