School of Dentistry, Cardiff Institute of Tissue Engineering & Repair, Cardiff University, Cardiff, CF14 4XY, UK.
Nanoscale. 2011 Mar;3(3):977-84. doi: 10.1039/c0nr00846j. Epub 2011 Feb 4.
Neural stem cells (NSCs) exhibit features that make them suitable candidates for stem cell replacement therapy and spinal cord reconstruction. Magnetic resonance imaging (MRI) offers the potential to track cells in vivo using innovative approaches to cell labeling and image acquisition. In this study, experiments were carried out to optimize the loading condition of magnetic CoPt hollow nanoparticles (CoPt NPs) into neural stem cells and to define appropriate MRI parameters. Both cell viability and multipotency analysis showed that CoPt NPs at a concentration of 16 µg ml(-1) reduced T2 relaxation times in labeled rat NSCs, producing greater contrast on spin echo acquisitions at 4.7 T, yet did not affect cell viability and in vitro differentiation potential compared to controls. After optimizing nanoparticle loading concentrations and labeled cell numbers for MRI detection, CoPt-loaded NSCs were transplanted into organotypic spinal cord slices. The results showed that MRI could efficiently detect low numbers of CoPt-labeled NSCs with the enhanced image contrast. Our study demonstrated that MRI of grafted NSCs labeled with CoPt NPs is a useful tool to evaluate organotypic spinal cord slice models and has potential applications in other biological systems.
神经干细胞（NSCs）具有一些特性，使其成为干细胞替代治疗和脊髓重建的合适候选者。磁共振成像（MRI）具有通过创新的细胞标记和图像采集方法在体内跟踪细胞的潜力。在这项研究中，进行了实验以优化将磁性 CoPt 空心纳米颗粒（CoPt NPs）装入神经干细胞的装载条件，并确定适当的 MRI 参数。细胞活力和多能性分析均表明，浓度为 16 µg ml（-1）的 CoPt NPs 降低了标记的大鼠 NSCs 中的 T2 弛豫时间，在 4.7 T 时产生了更大的自旋回波采集对比度，但与对照相比，并不影响细胞活力和体外分化潜能。在优化用于 MRI 检测的纳米颗粒装载浓度和标记细胞数量后，将负载 CoPt 的 NSCs 移植到器官型脊髓切片中。结果表明，MRI 可以有效地检测到具有增强图像对比度的 CoPt 标记 NSCs 的低数量。我们的研究表明，用 CoPt NPs 标记的移植 NSCs 的 MRI 是评估器官型脊髓切片模型的有用工具，并且在其他生物系统中具有潜在的应用。
