中文摘要：

背景：近年来纳米载体已被视为突破基因转移瓶颈最有前途的技术之一。聚酰胺-胺型树枝状高聚合物（polyamidoamine，PAMAM）是一种新型的纳米材料，体内外实验表明，PAMAM比其他阳离子载体的基因转染效率高、细胞毒性低。目的：探讨PAMAM介导Survivin反义寡核苷酸（Survivin antisense oligonucleotide，Survivin-asODN）对结直肠癌裸鼠移植瘤的抑制作用。设计、时间及地点：肿瘤基因治疗体内实验，于2008-02/08在上海交通大学微纳米科学技术研究院生物纳米工程研究室及南方医科大学珠江医院中心实验室完成。材料：人结直肠癌细胞株SW620购自中科院上海细胞所，PAMAM树形分子由上海交通大学微纳米研究院生物纳米工程研究室提供，脂质体LipolifectmainTM2000购自美国Invitrogen公司。Survivin-asODN由上海生工公司合成。方法：将PAMAM和阳离子脂质体分别与Survivin-asODN混合得到载反义基因转染复合物。透射电镜观察复合物的形态，激光散射粒径分析仪测定粒径，zeta电位分析仪测定复合物的zeta电位，离心法和紫外分光分度仪测定复合物的包封率和体外DNA释放速度。将对数生长期的人结直肠癌细胞SW620细胞接种于18只Balb/C裸鼠皮下建立结直肠癌裸鼠皮下移植瘤模型，随机均分为脂质体组、PAMAM组和空白对照组。分别注射脂质体-survivin-asODN转染复合物、PAMAM-survivin-asODN转染复合物、血清培养液，观察两组移植瘤体积，Western bloting方法检测移植瘤组织中survivin基因的表达。主要观察指标：阳离脂质体-survivin-asODN复合物及PAMAM-survivin-asODN复合物的粒经，zeta电位，基因载药率，包封率，释放率，转染后survivin表达率及对凋亡的诱导率，种植肿瘤生长抑制率，移植瘤细胞Survivin蛋白的表达及活性。结果：PAMAM-survivin-asODN复合物的粒径小于脂质体-survivin-asODN复合物的粒径（P 〈 0

英文摘要：

BACKGROUND： In recent years, nano-carriers have been regarded as the most promising technologies for breakthrough the bottleneck of gene transfer. Polyamidoamine dendrimer （PAMAM） is a kind of new nanometer material. PAMAM can transfer target gene to the cell with high efficiency and lower toxic both in vivo and in vitro. OBJECTIVE： To evaluate the antitumour effects of survivin antisense oligonucleotide （Survivin-asODN） carried by PAMAM on colorectal cancer transplanted subcutaneously in nude mice. DESIGN, TIME AND SETTING： An in vivo experiment regarding tumor gene therapy was performed from February to August in 2008 at the Laboratory of Bionanometer Engineering, Research Institute of Micro/nanometer Science ＆ Technology of Shanghai Jiao Tong University and Central Laboratory of Zhujiang Hospital of Southern Medical University. MATERIALS： Human colorectal cancer cells SW620 were from Shanghai Cell Institute of Chinese Academy of Sciences. PAMAM dendrimer was offered by the Bionanometer Engineering Laboratory, Research Institute of Micro/nanometer Science ＆ Technology, Shanghai Jiao Tong University. LipofectamineTM2000 was purchased from Invitrogen, USA. Survivin-asODN was synthesized by Shanghai Bioengineering Company. METHODS： The PAMAM and cation liposome were respectively mixed with Survivin-asODN to generate the transfection complex carrying antisense gene. The shape of the complex was observed by transmission electron microscope, the particle size was determined by laser particle size analysator and the zeta potential was measured by an analytical tool. The encapsulating efficiency and release progress in vitro were determined by ultraviolet spectrophotometer in centrifuging method. Human colorectal cancer cells SW620 at logarithmic phase were inoculated into the abdominal region of 18 Blab/C nude mice subcutaneously to produce transplanted tumor models in colorectal cancer nude mice, which were randomly divided into 3 groups： liposome, PAMAM and blank control groups. They were inj