下肢缺血发病率逐年提高，严重影响患者生活质量。我们前期研究及文献均证实干细胞治疗性血管生成初步有效，但临床应用并不理想，主要原因是体内干细胞转染成活率低。本课题采用EGCG-铜配位-干细胞表面工程化技术，通过外层半透膜屏障保护干细胞且维持细胞功能，利用EGCG抗炎抗氧化作用改善缺血微环境，发挥铜离子促血管生成作用并清除过量H2O2。通过临床病例检测H2O2浓度、炎症因子及铜离子水平，分析铜离子与侧枝血管数量的关系。沿用既往方法修饰干细胞后，在体外与SMC、IW及EC细胞共培养，评估EGCG抑制IL-6、TNF-a等炎症因子及铜离子上调CTR1-ATP7A信号通路的作用，及两者对H2O2清除实现ROS响应性的效果。最后在小鼠后肢缺血模型中验证分子机制及促血管生成的效果。希望阐明该技术发挥“屏障保护、缺血微环境改善、材料协同促血管生成”的多重作用及机制，为下肢缺血性疾病的干细胞治疗提供新策略。

The incidence of lower limb ischemia disease increased gradually, seriously affecting the quality of patients’life. Our previous researches confirmed that treatment of angiogenesis with stem cells is effective on mice, but the application in clinical practice did not gain ideal effect, which is due to the low survival rate of stem cells transfection in vivo. With EGCG-copper coordination-stem cell surface engineering technology, stem cells will be protected by the outer semipermeable membrane barrier to maintain cell function. EGCG anti-inflammatory and anti-oxidation are conducive to the improvement of ischemic microenvironment and reconstruction of microvascular, and copper ions can promote the generation of blood vessels and remove excess H2O2. The concentration of H2O2, the inflammatory cytokines and the changes of copper ions will be tested in clinical cases to figure out the potential relationship between the quantity of copper ions and the number of collateral vessels. Stem cells modified by previous methods will be cultured together with SMC, IW and EC cells in vitro to evaluate the inhibition of EGCG on inflammatory factors such as IL-6 and TNF-a and the regulation of copper ion in the CTR1-ATP7A signaling pathway, both of which clear H2O2 to achieve the responsiveness of ROS, to enhance the pro-angiogenic effect. Finally, it will be validated in the mouse limb ischemia model. The purpose is elucidating that this technology can play multiple functions of “protection of stem cells, improvement of ischemic microenvironment, and material synergistic angiogenesis”, it provides a new strategy for stem cell treatment of ischemic diseases of the lower extremities.