Bio-Imaging Laboratory, Department of Biomedical Sciences, University of Antwerp, Belgium.
Contrast Media Mol Imaging. 2011 Jan-Feb;6(1):1-6. doi: 10.1002/cmmi.390. Epub 2010 Jul 20.
MR-labeling of endogenous neural progenitor cells (NPCs) to follow up cellular migration with in vivo magnetic resonance imaging (MRI) is a very promising tool in the rapidly growing field of cellular imaging. To date, most of the in situ labeling work has been performed using micron-sized iron oxide particles. In this work magnetoliposomes (MLs), i.e. ultrasmall superparamagnetic iron oxide cores (USPIOs), each individually coated by a phospholipid bilayer, were used as the MR contrast agent. One of the main advantages of MLs is that the phospholipid bilayer allows easy modification of the surface, which creates the opportunity to construct a wide range of MLs optimized for specific biomedical applications. We have investigated the ability of MLs to label endogenous NPCs after direct injection into the adult mouse brain. Whereas MRI revealed contrast relocation towards the olfactory bulb, our data strongly imply that this relocation is independent of the migration of endogenous NPCs but represents background migration of MLs along a white matter tract. Our findings suggest that the small size of USPIOs/MLs intrinsically limits their potential for in situ labeling of NPCs.
用磁共振成像（MRI）对内源性神经祖细胞（NPC）进行 MR 标记以跟踪细胞迁移，这是细胞成像这个快速发展领域中非常有前途的工具。迄今为止，大多数原位标记工作都是使用微米级的氧化铁颗粒来完成的。在这项工作中，我们使用了磁脂质体（MLs），即超顺磁性氧化铁核（USPIO），每个核都由一个磷脂双层单独包裹，用作磁共振对比剂。MLs 的主要优点之一是，磷脂双层允许对表面进行轻松修饰，这为构建一系列针对特定生物医学应用的优化 MLs 提供了机会。我们研究了 MLs 在直接注射到成年小鼠大脑后标记内源性 NPC 的能力。虽然 MRI 显示对比剂向嗅球转移，但我们的数据强烈表明，这种转移与内源性 NPC 的迁移无关，而是代表 MLs 沿着白质束的背景迁移。我们的研究结果表明，USPIO/MLs 的小尺寸本质上限制了它们对内源性 NPC 进行原位标记的潜力。
