MRI Research Group, Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi, India.
Division of Stem Cells and Gene Therapy Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), DRDO, Delhi, India.
Methods Mol Biol. 2020;2150:93-111. doi: 10.1007/7651_2019_277.
Traumatic brain injury (TBI) is a leading cause of death and disability. The condition is difficult to treat owing to its heterogeneous nature and complex biological pathways. Stem cell transplantation is an emerging self-deliverable therapeutic modality which could immensely improve the invigorating management of the problem. The synergistic interaction of the stem cells with the paracrine niche molecules at the site of injury is an end point that decides the cells' effective tissue-forming regenerative response. Thus, noninvasive monitoring and tracking of the infused stem cells is quite decisive after transplantation. Here, we have designed and validated a distinctive in vivo magnetic resonance imaging protocol to monitor the transplanted mesenchymal stem cells (MSCs) longitudinally in TBI-induced mice. We have further described the synthesis of improved transverse relaxivity contrast agent, a protocol for the efficient labelling of MSCs, preparation of a TBI model system in mice, and the imaging and tracking of the implanted stem cells at the injury site through 7T MRI. MGE-T2∗ imaging in association with relaxometry-based quantitative assessment using absolute bias correction provided a suitable mechanism to monitor and track the infused labelled stem cells at the TBI site. High transverse relaxivity negative contrast agent synthesis, MSC labelling procedure, and quantitative T2∗ time measurement normalized with absolute bias correction are the key features of this protocol. This procedure has immense application potential and could therefore be extrapolated to stem cell tracking during the treatment of various diseases.
创伤性脑损伤 (TBI) 是死亡和残疾的主要原因。由于其异质性和复杂的生物学途径,该病症难以治疗。干细胞移植是一种新兴的自我传递治疗方式,可以极大地改善该问题的治疗管理。干细胞与损伤部位旁分泌龛分子的协同相互作用是决定细胞有效组织形成再生反应的终点。因此,移植后对输注的干细胞进行非侵入性监测和跟踪非常关键。在这里,我们设计并验证了一种独特的体内磁共振成像方案,以在 TBI 诱导的小鼠中对移植的间充质干细胞 (MSCs) 进行纵向监测。我们进一步描述了改进的横向弛豫率对比剂的合成、MSCs 的高效标记方案、小鼠 TBI 模型系统的制备,以及通过 7T MRI 对植入干细胞在损伤部位的成像和跟踪。MGE-T2∗ 成像与基于弛豫率的定量评估相结合,使用绝对偏差校正提供了一种合适的机制来监测和跟踪 TBI 部位的输注标记干细胞。高横向弛豫率负对比剂合成、MSC 标记程序和使用绝对偏差校正进行定量 T2∗时间测量是该方案的关键特征。该程序具有巨大的应用潜力,因此可以推广到各种疾病的干细胞跟踪治疗中。
Front Bioeng Biotechnol. 2022-7-5