Lindemann Antje, Lüdtke-Buzug Kerstin, Fräderich Bianca M, Gräfe Ksenija, Pries Ralph, Wollenberg Barbara
Department of Otorhinolaryngology, University Hospital of Schleswig-Holstein, Luebeck, Germany.
Institute of Medical Engineering, University of Luebeck, Luebeck, Germany.
Int J Nanomedicine. 2014 Oct 29;9:5025-40. doi: 10.2147/IJN.S63873. eCollection 2014.
As a tomographic imaging technology, magnetic particle imaging (MPI) allows high spatial resolution and sensitivity, and the possibility to create real-time images by determining the spatial distribution of magnetic particles. To ensure a prospective biosafe application of UL-D (University of Luebeck-Dextran coated superparamagnetic nanoparticles), we evaluated the biocompatibility of superparamagnetic iron oxide nanoparticles (SPIONs), their impact on biological properties, and their cellular uptake using head and neck squamous cancer cells (HNSCCs).
SPIONs that met specific MPI requirements were synthesized as tracers. Labeling and uptake efficiency were analyzed by hematoxylin and eosin staining and magnetic particle spectrometry. Flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays, and real-time cell analyzer assays were used to investigate apoptosis, proliferation, and the cytokine response of SPION-labeled cells. The production of reactive oxygen species (ROS) was determined using a fluorescent dye. Experimental results were compared to the contrast agent Resovist(®), a standard agent used in MPI.
UL-D nanoparticles and Resovist particles were taken up in vitro by HNSCCs via unspecific phagocytosis followed by cytosolic accumulation. To evaluate toxicity, flow cytometry analysis was performed; results showed that dose- and time-dependent administration of Resovist induced apoptosis whereas cell viability of UL-D-labeled cells was not altered. We observed decreased cell proliferation in response to increased SPION concentrations. An intracellular production of ROS could not be detected, suggesting that the particles did not cause oxidative stress. Tumor necrosis factor alpha (TNF-α) and interleukins IL-6, IL-8, and IL-1β were measured to distinguish inflammatory responses. Only the primary tumor cell line labeled with >0.5 mM Resovist showed a significant increase in IL-1β secretion.
Our data suggest that UL-D SPIONs are a promising tracer material for use in innovative tumor cell analysis in MPI.
作为一种断层成像技术，磁粒子成像（MPI）具有高空间分辨率和灵敏度，并且能够通过确定磁粒子的空间分布来创建实时图像。为确保超顺磁性氧化铁纳米颗粒（SPIONs）标记的超低剂量右旋糖酐（UL-D，吕贝克大学-右旋糖酐包被的超顺磁性纳米颗粒）在生物安全方面的前瞻性应用，我们使用头颈部鳞状细胞癌（HNSCCs）评估了超顺磁性氧化铁纳米颗粒的生物相容性、其对生物学特性的影响以及细胞摄取情况。
合成符合特定MPI要求的SPIONs作为示踪剂。通过苏木精-伊红染色和磁粒子光谱法分析标记和摄取效率。使用流式细胞术、3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）测定法和实时细胞分析仪测定法研究SPION标记细胞的凋亡、增殖和细胞因子反应。使用荧光染料测定活性氧（ROS）的产生。将实验结果与MPI中使用的标准造影剂Resovist(®)进行比较。
UL-D纳米颗粒和Resovist颗粒在体外通过非特异性吞噬作用被HNSCCs摄取，随后在细胞质中积累。为评估毒性，进行了流式细胞术分析；结果表明，Resovist的剂量和时间依赖性给药诱导了细胞凋亡，而UL-D标记细胞的活力未改变。我们观察到随着SPION浓度增加，细胞增殖减少。未检测到细胞内ROS的产生，表明这些颗粒未引起氧化应激。测量肿瘤坏死因子α（TNF-α）和白细胞介素IL-6、IL-8和IL-1β以区分炎症反应。只有用>0.5 mM Resovist标记的原发性肿瘤细胞系显示IL-1β分泌显著增加。
我们的数据表明，UL-D SPIONs是一种有前景的示踪剂材料，可用于MPI中创新的肿瘤细胞分析。
