新型高效、安全非病毒基因传输载体的研究与开发，对于重大疾病的基因治疗具有至关重要的意义。本项目首先通过Michael加成反应实现N-异丙基丙烯酰胺对PEI25K的修饰，制备高基因转染效率、低毒的PEI衍生物；然后通过化学键合技术，将来源于极端环境的重组嗜热组蛋白与该衍生物键合，充分整合天然DNA结合蛋白和高分子基因载体材料的优势，构建新型蛋白质-高分子杂合基因载体材料；以该材料为载体，介导抑癌基因p53转染p53基因缺失和突变肿瘤细胞系，在细胞和动物水平上评价其诱导肿瘤细胞凋亡的能力及分子机制，在体液免疫和细胞免疫两个层面评价该材料的免疫原性。本项目的实施，不仅有效拓宽了极端环境微生物功能基因的应用范围，更重要的是构建了一类具有高基因转染效率和细胞核定位能力、双组分协同作用、体内长循环、安全低毒的新型蛋白质-高分子杂合基因载体材料，为恶性肿瘤基因治疗的研究与临床应用奠定良好的基础。

Development of novel efficient and safe non-viral gene carriers is of great significance for the gene therapy of severe diseases. In this project, PEI25K is first modified by N-isopropyl acrylamide via Michael addition reaction to achieve PEI derivative with high gene transfection efficiency and low toxicity. Then the PEI derivative is chemically conjugated to a thermophilic histone from extreme environment to construct a novel protein-polymer hybride gene carrier. This strategy will integrate the advantages of natural DNA-binding protein and polymeric gene carrier. Using the transfection of tumor suppressor gene p53 to the p53- deletion and mutation tumor cell lines as model, the ability to induce the apoptosis of tumor cells and detailed mechanism are systematically evaluated on both cell and animal levels. Finally, the immunogenecity of this hybride material is investigated on the levels of humoral and cellular immunity. The project will broaden the application scope of functional genes from extremophiles. More importantly, it will construct a novel protein-polymer hybride gene delivery system with high gene transfection efficiency and nuclear location ability, synergism of two components, long circulation time and low toxicity, and thus provide a good foundation for the development and clinic application of cancer gene therapy.