Cell labeling with magnetic iron oxide nanoparticles (IONPs) is increasingly a routine approach in the cell-based cancer treatment. However, cell labeling with magnetic IONPs and their leading effects on the biological properties of human lung carcinoma cells remain scarcely reported. Therefore, in the present study the magnetic γ-Fe2O3 nanoparticles (MNPs) were firstly synthesized and surface-modified with cationic poly-l-lysine (PLL) to construct the PLL-MNPs, which were then used to magnetically label human A549 lung cancer cells. Cell viability and proliferation were evaluated with propidium iodide/fluorescein diacetate double staining and standard 3-(4,5-dimethylthiazol-2-diphenyl-tetrazolium) bromide assay, and the cytoskeleton was immunocytochemically stained. The cell cycle of the PLL-MNP-labeled A549 lung cancer cells was analyzed using flow cytometry. Apoptotic cells were fluorescently analyzed with nuclear-specific staining after the PLL-MNP labeling. The results showed that the constructed PLL-MNPs efficiently magnetically labeled A549 lung cancer cells and that, at low concentrations, labeling did not affect cellular viability, proliferation capability, cell cycle, and apoptosis. Furthermore, the cytoskeleton in the treated cells was detected intact in comparison with the untreated counterparts. However, the results also showed that at high concentration (400 µg mL-1), the PLL-MNPs would slightly impair cell viability, proliferation, cell cycle, and apoptosis and disrupt the cytoskeleton in the treated A549 lung cancer cells. Therefore, the present results indicated that the PLL-MNPs at adequate concentrations can be efficiently used for labeling A549 lung cancer cells and could be considered as a feasible approach for magnetic targeted anti-cancer drug/gene delivery, targeted diagnosis, and therapy in lung cancer treatment.

中文翻译：

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使用阳离子聚-1-赖氨酸辅助的磁性氧化铁纳米粒子对人类肺癌细胞进行高效标记。

在基于细胞的癌症治疗中，使用磁性氧化铁纳米粒子（IONPs）进行细胞标记越来越成为一种常规方法。然而，几乎没有报道用磁性IONPs标记细胞及其对人肺癌细胞生物学特性的主要影响。因此，在本研究中，首先合成了磁性γ-Fe2O3纳米颗粒（MNP），并用阳离子聚l-赖氨酸（PLL）对其进行了表面修饰，以构建PLL-MNPs，然后将其用于磁性标记人A549肺癌细胞。用碘化丙锭/荧光素二乙酸双酯双染色和标准的3-（4,5-二甲基噻唑-2-二苯基-四唑鎓）溴化物评估细胞的活力和增殖，并对细胞骨架进行免疫细胞化学染色。使用流式细胞仪分析了PLL-MNP标记的A549肺癌细胞的细胞周期。PLL-MNP标记后，通过核特异性染色对凋亡细胞进行荧光分析。结果表明，构建的PLL-MNPs有效地磁性标记了A549肺癌细胞，并且在低浓度下标记不会影响细胞生存力，增殖能力，细胞周期和细胞凋亡。此外，与未处理的对应物相比，已检测到完整处理的细胞中的细胞骨架。但是，结果还显示，在高浓度（400 µg mL-1）下，PLL-MNPs会稍微削弱细胞活性，增殖，细胞周期和细胞凋亡，并破坏治疗的A549肺癌细胞的细胞骨架。所以，