超声靶向微泡破坏（UTMD）介导血管新生基因治疗为难治性心肌缺血提供了新策略。然而，胞膜屏障、核酸酶降解及核膜屏障这三个原因导致了外源基因转染效率低下。既往研究仅关注了UTMD促基因入胞，而对UTMD介导基因入核及减少DNA的降解缺乏认识。本项目组前期实验发现UTMD可能促进基因入核。故本研究拟引入核定位信号联合UTMD构建新型亲核型基因转导体系，介导治疗基因入胞后再入核并且保护胞质中的DNA，通过提高入核率来提高血管新生的疗效。主要研究内容为：构建亲核型基因转载体系并鉴定；应用亲核型基因转导体系介导hAng-1基因体外转染大鼠心肌母细胞H9C2，体内转染犬心肌梗死模型，检测转染效率、血管新生效应和心功能改善情况来评价亲核型基因转导体系的可行性及应用价值，同时评价该转载体系的应用安全性。藉此研究提升UTMD作为非病毒基因转导体系在治疗心肌缺血上的潜在应用价值。

Therapeutic angiogenesis provided a new treatment for refractory ischemia. Ultrasound targeted microbubble destruction(UTMD)has been proved to be a feasible exogenous gene delivery system.However,the low gene expression level is the major challenge of this technique. Basically, cytomembrane, nuclear membrane and nuclease degradation are the three major barries of exogenous gene delivery into human cells, while previous studies mostly focused on the cytomembrane entering under UTMD,and little was known about UTMD mediated nucleus entering. This study aimed to construct an nucleophilic gene deliver system which could significantly improve therapeutic gene angiogenesis by boosting UTMD mediated gene enter nuclus. The advantages of this nuclephilic gene transport complex are that could specificlly overcome the three barries of exogenous gene get into nuclus, which known as breakthrough cytomembrane,breakthrouth nuclear membrane and not be degraded by DNA enzymes in cytoplasm.The study scheme include the following four expriments.Part one,construct nuclephilic gene carrier based on ultrasound irradiation energy and nuclear localization signal peptide(NLS)，then make identification.Part two, UTMD mediated hAng-1 gene transfect into rat H9C2 cells via nucleophilic gene delivery system, the gene expression level is detected. Part three, hAng-1 gene are transfected into canian infarcted myocardium by UTMD mediated nuclephilic gene transport complex and non- nuclephilic gene transport complex. Comprare the hAng-1 gene expression in H9C2 cells and ischemic dogs, and angiogenesis effects as well. Finally , evaulate the security of UTMD mediated nuclephilic gene delivery system. This study is trying to stand on a stone different from the past to discover how to upgrade UTMD mediated gene therapy.