Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
J Magn Reson Imaging. 2013 Jun;37(6):1409-18. doi: 10.1002/jmri.23897.
To evaluate the feasibility of using micron-sized superparamagnetic iron oxide particles (MPIOs) as an effective labeling agent for monitoring bone marrow-derived mesenchymal stromal cell (BMSC) migration in the brain using magnetic resonance imaging (MRI) in a rat model of stroke and whether the accumulation of MPIO-labeled BMSCs can be differentiated from the accumulation of free MPIO particles or hemoglobin breakdown at a site of neuronal damage.
In this study BMSCs were labeled with iron oxide and their pattern of migration following intravenous injection in a rat stroke model was monitored using a clinical MRI system followed by standard histopathology. The migration pattern was compared between intravenous injection of BMSCs alone, BMSCs labeled with MPIOs, and MPIO particles alone.
The results demonstrated that while MRI was highly sensitive in the detection of iron oxide particle-containing cells in areas of neuronal ischemia, the true origin of cells containing iron oxide particles remains ambiguous. Therefore, detection of iron particles may not be a suitable strategy for the detection of BMSCs in the brain in a stroke model.
This study suggests that the use of MPIOs as labeling agents are insufficient to conclusively determine the localization of iron within cells in regions of neuronal ischemia and hemorrhage.
评估使用微米级超顺磁性氧化铁颗粒 (MPIO) 作为标记剂，通过磁共振成像 (MRI) 监测骨髓间充质基质细胞 (BMSC) 在脑卒中大鼠模型中向脑内迁移的可行性，以及是否可以区分 MPIO 标记的 BMSC 的积累与神经元损伤部位游离 MPIO 颗粒或血红蛋白分解产物的积累。
在这项研究中，使用氧化铁对 BMSC 进行标记，并在脑卒中大鼠模型中通过临床 MRI 系统进行监测，随后进行标准组织病理学检查，以观察 BMSC 静脉注射后的迁移模式。比较单独静脉注射 BMSC、MPIO 标记的 BMSC 和单独 MPIO 颗粒的迁移模式。
结果表明，虽然 MRI 对检测神经元缺血区域含氧化铁颗粒的细胞非常敏感，但细胞内氧化铁颗粒的真实来源仍不清楚。因此，检测铁颗粒可能不是脑卒中模型中检测脑内 BMSC 的合适策略。
本研究表明，使用 MPIO 作为标记剂不足以确定神经元缺血和出血区域细胞内铁的定位。
