Odintsov Boris, Chun Ju Lan, Berry Suzanne E
Methods Mol Biol. 2013;1052:177-93. doi: 10.1007/7651_2013_13.
Methods to monitor transplanted stem cells in vivo are of great importance for potential therapeutic applications. Of particular interest are methods allowing noninvasive detection of stem cells throughout the body. Magnetic resonance imaging (MRI) is a tool that would allow detection of cells in nearly any tissue in the body and is already commonly used in the clinic. MRI tracking of stem cells is therefore feasible and likely to be easily adapted to patients receiving donor cells. Patients with Duchenne muscular dystrophy are good candidates for stem cell therapy, given the naturally regenerative nature of skeletal muscle, which repairs damage by employing endogenous stem cells from the muscle interstitium to regenerate muscle fibers throughout adulthood. We describe methods for labeling stem cells with superparamagnetic iron oxide nanoparticles (SPIO) to enhance MRI contrast, injecting them locally into skeletal and cardiac muscle, or systemically in mouse models for Duchenne muscular dystrophy, and tracking them in muscle tissue of live mice following injection. We focus on the use of whole body MRI to detect stem cells, as this is necessary for conditions such as muscular dystrophy, in which affected tissues are present throughout the body and systemic delivery of stem cells may be necessary. Emphasis is placed on the development of an MRI coil that is field of view (FOV) adjustable and can be used for both whole body imaging to determine stem cell localization as well as subsequent focusing on smaller, local regions where stem cells are present to obtain high-resolution images. We discuss the coil design and its significance for stem cell tracking. We also describe methods for labeling stem cells with a fluorescent dye and for tracking them in postmortem tissue specimens with fluorescent microscopy to correlate, compare, and contrast with results of whole body MRI in preclinical studies.
在体内监测移植干细胞的方法对于潜在的治疗应用至关重要。特别令人感兴趣的是能够对全身干细胞进行无创检测的方法。磁共振成像（MRI）是一种能够检测体内几乎任何组织中细胞的工具，并且已在临床上广泛使用。因此，通过MRI追踪干细胞是可行的，并且很可能易于应用于接受供体细胞的患者。考虑到骨骼肌具有自然再生的特性，即通过利用肌肉间质中的内源性干细胞在成年期修复损伤，杜氏肌营养不良症患者是干细胞治疗的理想候选者。我们描述了用超顺磁性氧化铁纳米颗粒（SPIO）标记干细胞以增强MRI对比度的方法，将其局部注射到骨骼肌和心肌中，或在杜氏肌营养不良症小鼠模型中进行全身注射，并在注射后在活体小鼠的肌肉组织中追踪它们。我们专注于使用全身MRI来检测干细胞，因为对于诸如肌营养不良症等疾病来说这是必要的，在这些疾病中，受影响的组织遍布全身，可能需要全身递送干细胞。重点是开发一种视野（FOV）可调节的MRI线圈，该线圈可用于全身成像以确定干细胞的定位，以及随后聚焦于存在干细胞的较小局部区域以获得高分辨率图像。我们讨论了线圈设计及其对干细胞追踪的意义。我们还描述了用荧光染料标记干细胞并在死后组织标本中用荧光显微镜追踪它们的方法，以便在临床前研究中与全身MRI的结果进行关联、比较和对比。
