Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
Int J Mol Sci. 2019 Jan 8;20(1):196. doi: 10.3390/ijms20010196.
The use of titanium suboxides, known as Magnéli phase TiO, is expected to increase in the near future due to their desirable properties. In order to use Magnéli phase TiO nanoparticles safely, it is necessary to know how nanoparticles interact with biological systems. In this study, the cytotoxicity of three different Magnéli TiO nanoparticles was evaluated using human lung A549 cells and the results were compared with hazard data on two different TiO₂ nanoparticles whose biological interactions have already been extensively studied. After A549 cells were exposed to nanoparticles, the metabolic activity was measured by the Resazurin assay, the amount of cellular proteins was measured by the Coomassie Blue assay, and lysosomal integrity was measured by the Neutral Red Uptake assay. In order to investigate possible modes of particle actions, intracellular Ca level, reactive oxygen species (ROS) production, and photo-oxidative disruptions of lysosomal membranes were assessed. All experiments were performed in serum-containing and in serum-deprived cell culture mediums. In addition, the photocatalytic activity of Magnéli TiO and TiO₂ nanoparticles was measured. The results show that Magnéli TiO nanoparticles increase intracellular Ca but not ROS levels. In contrast, TiO₂ nanoparticles increase ROS levels, resulting in a higher cytotoxicity. Although Magnéli TiO nanoparticles showed a lower UV-A photocatalytic activity, the photo-stability of the lysosomal membranes was decreased by a greater extent, possibly due to particle accumulation inside lysosomes. We provide evidence that Magnéli TiO nanoparticles have lower overall biological activity when compared with the two TiO₂ formulations. However, some unique cellular interactions were detected and should be further studied in line with possible Magnéli TiO application. We conclude that Magnéli phase nanoparticles could be considered as low toxic material same as other forms of titanium oxide particles.
由于其理想的特性，钛的亚氧化物，即 Magnéli 相 TiO，预计在不久的将来会得到更多的应用。为了安全地使用 Magnéli 相 TiO 纳米粒子，有必要了解纳米粒子如何与生物系统相互作用。在这项研究中，使用人肺 A549 细胞评估了三种不同的 Magnéli TiO 纳米粒子的细胞毒性，并将结果与两种不同的 TiO₂纳米粒子的危险数据进行了比较，这两种 TiO₂纳米粒子的生物相互作用已经得到了广泛的研究。A549 细胞暴露于纳米粒子后，通过 Resazurin 测定法测量细胞代谢活性，通过 Coomassie 蓝测定法测量细胞内蛋白质含量，通过中性红摄取测定法测量溶酶体完整性。为了研究可能的颗粒作用模式，评估了细胞内 Ca 水平、活性氧 (ROS) 的产生以及溶酶体膜的光氧化破坏。所有实验均在含血清和无血清细胞培养基中进行。此外，还测量了 Magnéli TiO 和 TiO₂纳米粒子的光催化活性。结果表明，Magnéli TiO 纳米粒子增加细胞内 Ca 但不增加 ROS 水平。相比之下，TiO₂纳米粒子增加 ROS 水平，导致更高的细胞毒性。尽管 Magnéli TiO 纳米粒子表现出较低的 UV-A 光催化活性，但溶酶体膜的光稳定性降低的程度更大，这可能是由于颗粒在溶酶体内的积累。我们提供的证据表明，与两种 TiO₂配方相比，Magnéli TiO 纳米粒子的整体生物活性较低。然而，检测到一些独特的细胞相互作用，应根据可能的 Magnéli TiO 应用进一步研究。我们的结论是，与其他形式的氧化钛颗粒一样，Magnéli 相纳米颗粒可被视为低毒性材料。
