Wang Guan, Fu Yingli, Shea Steven M, Hegde Shashank Sathyanarayana, Kraitchman Dara L
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, 600 N. Wolfe Street, 314 Park Building, Baltimore, MD, 21287, USA.
Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA.
MAGMA. 2019 Feb;32(1):147-156. doi: 10.1007/s10334-018-0728-2. Epub 2018 Dec 10.
Peripheral artery disease (PAD) affects 12-14% of the world population, and many are not eligible for conventional treatment. For these patients, microencapsulated stem cells (SCs) offer a novel means to transplant mismatched therapeutic SCs to prevent graft immunorejection. Using c-arm CT and F-MRI for serial evaluation of dual X-ray/MR-visible SC microcapsules (XMRCaps) in a non-immunosuppressed rabbit PAD model, we explore quantitative evaluation of capsule integrity as a surrogate of transplanted cell fate.
XMRCaps were produced by impregnating 12% perfluorooctylbromine (PFOB) with rabbit or human SCs (AlloSC and XenoSC, respectively). Volume and F concentration measurements of XMRCaps were assessed both in phantoms and in vivo, at days 1, 8 and 15 after intramuscular administration in rabbits (n = 10), by 3D segmenting the injection sites and referencing to standards with known concentrations.
XMRCap volumes and concentrations showed good agreement between CT and MRI both in vitro and in vivo in XenoSC rabbits. Injected capsules showed small variations over time and were similar between AlloSC and XenoSC rabbits. Histological staining revealed high cell viability and intact capsules 2 weeks after administration.
Quantitative and non-invasive tracking XMRCaps using CT and F-MRI may be useful to assess graft immunorejection after SC transplantation.
外周动脉疾病（PAD）影响着全球12% - 14%的人口，许多患者不符合传统治疗的条件。对于这些患者，微囊化干细胞为移植不匹配的治疗性干细胞以防止移植物免疫排斥提供了一种新方法。我们使用C形臂CT和F - MRI对非免疫抑制兔PAD模型中的双X射线/磁共振可见干细胞微囊（XMRCaps）进行系列评估，探索将微囊完整性的定量评估作为移植细胞命运的替代指标。
通过用兔或人干细胞（分别为同种异体干细胞和异种干细胞）浸渍12%的全氟辛基溴（PFOB）来制备XMRCaps。在兔（n = 10）肌肉注射后第1、8和15天，通过对注射部位进行三维分割并参考已知浓度的标准物，在体模和体内评估XMRCaps的体积和F浓度测量值。
在异种干细胞兔的体外和体内实验中，CT和MRI对XMRCap体积和浓度的测量结果显示出良好的一致性。注射的微囊随时间变化较小，同种异体干细胞兔和异种干细胞兔之间相似。组织学染色显示给药2周后细胞活力高且微囊完整。
使用CT和F - MRI对XMRCaps进行定量和非侵入性追踪可能有助于评估干细胞移植后的移植物免疫排斥。
