利用靶向性纳米体内示踪技术研究间充质干细胞减轻肝脏脏缺血-再灌注损伤的作用

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.

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。

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，有望成为减轻IRI、提高移植生存率的有效临床手段。但对于MSCs在体内分布代谢规律仍知之甚少，动态监测MSCs在治疗过程中体内的分布情况，有助于对于进行优于改造，制定临床应用方案。基于课题组前期研究成果，本项目拟对MSCs胞膜行flag标记后，利用Flag单链抗体靶向化的纳米造影剂与之结合，形成干细胞-纳米造影剂体内示踪的可视化体系，并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，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。. 本课题通过SPIO标记MSCs，通过体外实验验证了SPIO对MSCs的性质无显著影响；同时通过构建大鼠缺血再灌注损伤模型，良好了示踪了MSCs在大鼠体内的分布规律。此外，我们进一步研究了MSCs通过增强肝细胞的自噬水平，从而改善缺血再灌注损伤的分子机制。由于MSCs潜在的致瘤作用，我们通过分离提纯MSCs来源的胞外囊泡，证实其具有与MSCs相似的治疗效果并深入探讨了其抗氧化机制；最后，我们还利用Fa-PEG-g-PEI-SPION/pDNA载体，特异性靶向肝癌细胞上的TBLR1蛋白，实现了动态观察肿瘤变化及评价基因治疗效果(Hepatology, 2016;63:1240-1255)。. 本课题研究过程中，发表了相关SCI论文15篇，组织次了3国内会议。