Detection of viability of transplanted beta cells labeled with a novel contrast agent - polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles by magnetic resonance imaging.
Detection of viability of transplanted beta cells labeled with a novel contrast agent - polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles by magnetic resonance imaging.
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DOI：
10.1002/cmmi.461
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发表时间：
2012
影响因子：
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通讯作者：
Bo Zhang;B. Jiang;Ying Chen;Hai Huang;Qiu-ping Xie;Muxing Kang;Hui Zhang;Chuanxin Zhai;
中科院分区：
文献类型：
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作者：
Bo Zhang;B. Jiang;Ying Chen;Hai Huang;Qiu-ping Xie;Muxing Kang;Hui Zhang;Chuanxin Zhai;
在移植过程中用超顺磁性造影剂标记可以在MRI上显示胰岛。然而，信号强度是否反映了细胞数量和细胞活力还没有确定。我们使用自制的新型超顺磁性造影剂-聚乙烯吡咯烷酮包裹的超顺磁性氧化铁纳米颗粒(PVP-SPIO)-标记β-TC-6细胞(小鼠胰岛素瘤细胞系)或原代胰岛，并以商品菲立磁为对照。通过普鲁士蓝染色、细胞内铁含量测定和MR扫描比较两种试剂的标记效率。细胞暴露于低氧、高糖或外源性H₂O₂刺激前后。将正常细胞和损伤细胞移植到肾被膜下。在体外和移植后24小时进行临床使用的3.0T磁共振扫描，以探讨细胞存活率与信号的相关性。我们的PVP-SPIO具有优异的生物相容性和磁性。培养24 h后，所有细胞均能被标记到100µg/ml的铁浓度。当铁浓度为10 0µg/ml时，核磁共振已能在体外观察到1×10⁵β细胞，低于菲立磁的检测阈值。在T-₂加权图像上，标记细胞数与R-₂值呈线性相关。标记细胞的信号强度和细胞内铁含量随着标记细胞存活率的降低而降低。移植后损伤标记细胞与正常标记细胞的信号强度也有显著差异。这些结果表明，PVP-SPIO具有较高的细胞标记效率，可以在不影响细胞活性和功能的情况下标记β细胞。MRI上的信号强度可能是评估PVP-SPIO标记细胞数量和活性的有用指标。
Islets can be visualized on MRI by labeling with superparamagnetic contrast agent during the transplantation procedure. However, whether the signal intensity reflects the cell number and cellular viability has not been determined. We used a self-synthesized novel superparamagnetic contrast agent -polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles (PVP-SPIO) - to label β-TC-6 cells (a mouse insulinoma cell line) or primary islets with commercial Feridex as a control. The labeling efficiency of two agents was compared by Prussian blue staining, intracellular iron content determination and MR scanning. Cells were exposed to hypoxia, high-glucose or exogenous H₂O₂ stimulation before/after PVP-SPIO labeling. Normal and injured cells were also transplanted into renal subcapsule. A clinically used 3.0 T MR scan was performed in vitro and 24 h post-transplantation to investigate the correlation between cellular viability and signal. Our PVP-SPIO displayed superior biocompatibility and magnetic properties. All of the cells could be labeled at 100 µg/ml iron concentration after 24 h incubation. At 100 µg/ml iron concentration, 1 × 10⁵ β cells labeled with PVP-SPIO could already be visualized in vitro by MRI, less than the detection threshold of Feridex. There existed a linear correlation between the number of labeled cells and R₂ value on the T₂ -weighted images. The signal intensity and the intracellular iron content declined along with the decreased viability of labeled cells. There was also a significant difference in signal intensity between injured and normal labeled cells after transplantation. From these results, we concluded that PVP-SPIO possessed superior cell labeling efficiency, and β cells could be labeled without compromising viability and function. The signal intensity on MRI might be a useful predictor to evaluate the number and the viability of PVP-SPIO-labeled cells.