本项目首次通过Michael加成反应，实现N-异丙基丙烯酰胺对PEI25K的修饰，合成了高基因转染效率、低毒的基因传输载体PEN；通过NHS-PEG5K-Mal键合策略，将全新的、特性异针对恶性肿瘤细胞表面高表达的HLA-G的单克隆抗体与PEN偶联，并引入亲水性PEG分子，构建靶向型、体内长循环基因传输载体；通过静电组装的策略，将该肿瘤靶向型基因传输载体与对肝癌细胞中IGF-II P3 mRNA具有特异性识别与切割能力的脱氧核酶形成纳米复合物，并在细胞和动物水平上系统评估其诱导肿瘤细胞凋亡的能力与靶向作用机制，实现脱氧核酶的高效、稳定、靶向传输。本项目的实施，将构建一类单克隆抗体精确定位肿瘤细胞和脱氧核酶靶向切割癌基因序列的具有双重精准识别功能的基因药物传输体系，为靶向型基因治疗药物的研究开发及肿瘤基因治疗的临床应用提供新的思路。

In this project, PEI25K is first modified by N-isopropyl acrylamide via Michael addition reaction to achieve PEI derivative (PEN) with high gene transfection efficiency and low toxicity. Through NHS-PEG5K-Mal strategy, PEN is chemically conjugated to an anti-HLA-G monoclonal antibody. As HLA-G is highly expressed in many tumor cells, the antibody-PEN conjugate can be a novel specific gene carrier with high tumor-targeting ability. Meanwhile, the involvement of hydrophilic PEG segment could efficiently facilitate the circulation time of carriers in the blood. Then, the electrostatic assemble strategy is employed to construct a nanocomplex of the tumor-targeting gene carrier and anti-IGF-II P3 mRNA DNAzyme with high sequence recognition specificity and cleavage ability. Finally, using the transfection assay of this nanocomplex, the ability to induce the apoptosis of tumor cells and detailed tumor-targeting mechanism are systematically evaluated on both cell and animal levels. In conclusion, the project constructs a novel gene delivery system with dual precise recognition, in which monoclonal antibody realizes the location of carrier in the tumor cells and DNAzyme achieves the specific recognition and cleavage towards the targeting mRNA sequence. Thus, the project provides a new insight into the development of tumor-targeting gene medicine and the clinic appliction of cancer gene therapy.