脐带来源间充质干细胞（UC-MSC）临床来源丰富且不受伦理和法律限制，具有我更新和有多向分化能力等生物特性，在组织修复、血管新生中发挥重要作用。我们临床研究发现UC-MSCs可以改善肝移植缺血性胆管炎症状，提示其在促进血管生成，促进胆管上皮细胞损伤修复的作用。在本人前期T淋巴细胞体内示踪基础上，本研究利用带有大量小腔的金纳米胶束，增强超声成像效果，联接CD44抗体，特异靶向UC-MSCs，输入肝移植缺血型胆道病变模型。利用超声显影及荧光成像，重点观察UC-MSCs在体内迁移、定植、存活等情况；结合病理学、免疫组化，研究UC-MSCs的活动与改善体内血管狭窄，促进上皮细胞或周围细胞增殖、迁移等的相关性，纵向定量评价UC-MSCs在组织修复、血管新生中作用，对我们深入了解其作用机制及运用于组织替代治疗均具有重要意义。为实现UC-MSCs移植从动物研究到临床人体应用的转化奠定基础。

Multipotent mesenchymal stem cells derived from the umbilical cord(UC-MSC) , avoiding ethical problems and easy to obtain, harbors an important population of cells that possess stem cell-like characteristics including self renewal and differentiation capacities. And our preclinical research found that UC-MSCs can improve symptoms of ischemic-type biliary lesion, indicating the possibility of stem cell delivery to ischemic regions to promote neovascularization and biliary epithelium cells regeneration. So longitudinal monitoring of cells is required in order to understand the role of delivered UC-MSCs in therapeutic neovascularization and tissue regeneration. In this study, in vivo and in vitro experiments were performed to demonstrate the efficacy of ultrasound imaging to monitor UC-MSCs labeled with Gold nanoparticles (AuNPs), based on my preliminary study of T cells in vivo imaging. And the better understanding the process of neovasularization and tissue regeneration would improve the clinical applicability of UC-MSCs.