聚乙二醇化聚乙烯亚胺-腺病毒复合策略，构建长效、低免疫原性、肿瘤靶向基因载体的基础研究

项目名称： 聚乙二醇化聚乙烯亚胺-腺病毒复合策略，构建长效、低免疫原性、肿瘤靶向基因载体的基础研究

项目编号： No.81201180

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 影像医学与生物医学工程

项目作者： 雷宁

作者单位： 成都理工大学

项目金额： 23万元

中文摘要： 溶瘤腺病毒的全身用药一直受到其在体内快速代谢和机体免疫反应的限制。我们提出以双侧聚乙烯亚胺修饰的聚乙二醇多聚物（PEI-PEG-PEI）物理吸附策略，构建"长效、低免疫原性"肿瘤靶向的溶瘤腺病毒复合基因载体。PEG经PEI的静电作用包裹于病毒表面，产生延长半衰期，降低免疫原性的作用，较弱的物理作用使PEG逐渐脱离，暴露出病毒表面，减少对病毒-细胞表面受体相互作用的阻碍。同时，在部分PEG外侧连接RGD环肽，利用其肿瘤靶向作用，配合少量外侧PEI的静电吸附，干扰肿瘤细胞膜的稳定性，进一步增强治疗性基因的转染效率。我们拟优化病毒载体的"疏松包裹"工艺，然后表征，考察粒径、表面电荷、形态、稳定性等参数，利用荧光显微镜和流式细胞技术研究携带基因的转录效率，在大鼠体内考察清除半衰期、抗病毒抗体滴度，在小鼠肺转移瘤模型上研究抗肿瘤作用来验证我们的策略是否可行。

中文关键词： 腺病毒；聚合物；免疫原性；抗肿瘤；

英文摘要： Although system delivery of oncolytical adenoviral vectors have been regarded as a promising stratge of tumor treatment to date, several issues still need to be addressed, such as fast clarence from the blood and immune response to the virus. Here we propose that, modified by the linear polyethylenimine - poly ethylene glycol (PEI-PEG-PEI) triblock copolymers, a "long lasting and low immunogeneicity" hybird polymer-adenoviral gene delivery vector can be constructed. By the cationic effect, the polymers can softly anchor to the viral surface, presenting the antibodies from recognizing the viral antigens, thus extend the viral half-life and reduce the immune response. Then, the polymers will disassociate from the virus slowly, the exposed envelope protein can bind the virus to the specific cellular receptors on the tumor surface. Additionally, the cyclic arginine-glycine-aspartate (cRGD) peptide, a selective αvβ3 integrin ligand, will be linked to the distal end of some polymors, constructing PEI-PEG-RGD trimers, to further enhance the tumor selectivity and transgenic efficacy of the virus, together with the electrostatic interactions of PEI. We plan to optimize the synthesis conditions of the triblock polymers, construct the polymer loose encapsulated Ad5 vector then characterize it. To test our hypothesis, the

英文关键词： adenovirus；polymers；PEG；immune response；