缺血再灌注损伤(IRI)是导致移植器官功能障碍的重要原因。我们前期研究证实间充质干细胞(MSCs)可以有效减轻移植供肝IRI(J Surg Res.2011)，有望成为减轻IRI、提高移植生存率的有效临床手段。但仍需明确其在体内分布代谢规律，以制定临床应用方案。我们发现通过体外预标记造影剂方法，无法对治疗全程进行有效示踪(Eur Radiol.2012)。课题组成员已创建了酸敏细胞内控释纳米多功能载体和靶向性纳米造影技术(Angew Chem Int Ed.2011)，可长期敏感示踪目的细胞的趋化过程(ACS Nano.2012)。因此我们设想在对MSCs胞膜行flag标记后利用上述手段对其治疗全程进行精确示踪，明确体内分布、趋化和代谢规律，这将不仅为制订MSCs临床方案并评估安全性提供理论依据，同时还为探讨MSCs减轻IRI作用机制及其在治疗其他疾病的临床应用研究上提供有效手段。

Ischemia-reperfusion injury (IRI) is an important cause of the transplanted organ dysfunction. Our previous studies have confirmed that mesenchymal stem cells (MSCs) can effectively reduce transplant donor liver IRI (J Surg Res.2011). Stem cell therapy is expected to become an effective clinical means to reduce IRI and improve survival rate of the graft. For the development of its clinical application, its distribution and metabolism in vivo must be cleared. We found that the method of pre-label MSCs with contrast agent in vitro cannot effectively observe the entire process of the treatment (Eur Radiol.2012). The research group has created a targeted acid sensitive intracellular release multifunction nano-imaging technique (Angew Chem Int Ed. 2011). It can observe the chemoattractant process of cells sensitively in the entire course of treatment. We designed a membrane flag-marked stem cell lines. It can be identified by flag-targeted nanocarrier. Then the in vivo distribution, chemotaxis and metabolic processes of MSCs can be cleared. This study will not only provide a theoretical basis for the formulation treatment regimens of MSCs but also can assess its safety. It can also explore the mechanism of MSCs alleviate IRI . MSCs can provide an effective means for the clinical application of the treatment of other diseases. This study is helpful for understand the mechanism of how MSCs relieve IRI and can provide an effective means for clinical research of other diseases.