【摘要】 目的验证包载反义单核细胞趋化蛋白-1(A-MCP-1)质粒的聚乳酸聚乙醇酸共聚物(PLGA)纳米粒子在不同动物模型上的基因转染效果。方法采用乳化溶剂挥发法制备A-MCP-1纳米粒子并进行体外物化表征。用血管平滑肌细胞进行体外基因转染,PCR法检测其转染效果。兔移植静脉内膜增生模型和大鼠腹主动脉瘤模型体内局部给予A-MCP-1纳米粒子,应用病理形态学分析、斑点杂交、原位杂交、Western blot等方法观察其在体内的基因转染效果和对内源性MCP-1基因表达的抑制作用。结果基因纳米粒子平均粒径为201·4nm,基因含量为4·14%,基因的包封效率为86%,体外可维持稳定释放两周以上。兔移植静脉内膜增生基因纳米粒子组的动脉组织中检测到明显的A-MCP-1表达,并抑制了正义MCP-1表达,内膜/中膜比为0·56±0·06,与对照组比较差异具有显著性(P<0·05),与阳离子脂质体1,2-二油酰-3-三甲铵基丙烷(DOTAP)诱导的A-MCP-1质粒组比较,差异无显著性。大鼠腹主动脉瘤模型体内转染2周后,基因纳米粒子组腹主动脉直径为(1·79±0·12)mm,明显小于空白纳米粒子悬浮液组(2·58±0·21)mm和生理盐水组(2·63±0·29)mm(P<0·01)。MCP-1基因的mRNA和蛋白表达水平分别为12·5±1·5,17·6±2·1,明显低于空白纳米粒子悬浮液组35·7±4·5,42·3±5·7(P<0·01),生理盐水组32·4±3·9,39·8±4·8(P<0·01)。结论A-MCP-1基因纳米粒子用于兔移植静脉内膜增生模型以及大鼠腹主动脉瘤模型成功实现基因转染的研究结果,显示了其应用于临床的巨大潜力。更多还原

【Abstract】 Objective To evaluate the effect of antisense monocyte chemotactic protein-1(A-MCP-1)nanoparticles(NPs)as gene carrier on gene transfer in two kinds of animal models. Methods Poly (lactic acid-co-glycolic acid)(PLGA) was used to make the NPs loaded with A-MCP-1 through a double-emulsion/solvent evaporation technique. NPs size was assessed by dynamic laser defractometer. The particle morphology was observed by scanning electron microscopy. DNA content in the NPs was measured by dissolving known amounts of NPs in chloroform and extracting DNA with water. In vitro release was performed in tris-EDTA buffer at 37℃ using double-chamber diffusion cells. The receiver buffer was replaced daily. The A-MCP-1 NPs was transfected into the cultured smooth muscle cells. PCR was used to evaluate the transfection of A-MCP-1. Cationic lipid (Lipofectamine) was used to transfect A-MCP-1 as control. After 48 hours incubation, cells were digested and examined by polymerase chain reaction. Twenty New Zealand white rabbits under jugular vein to artery bypass grafting procedure were divided into four groups: the first group received grafts treated with A-MCP-1 NPs, the second group received grafts treated with cationic liposome (dioleoyl trimethyl ammonium propane)-A-MCP-1, the third group received grafts treated with plasmid DNA, and the fourth group received grafts without transfection as control. Fourteen days after surgery the grafts were harvested. The expression of A-MCP-1 and its effect on MCP-1 in vein grafts were detected by dot blotting. The morphology of the grafts was investigated. To establish abdominal aortic aneurysms rats model, rats were randomly divided into three groups: A-MCP-1 NPs injection group, shame NPs injection group and control groups (without injection). Two weeks after surgery, diameter of abdominal aorta was measured and aortic tissue was obtained for PCR analysis to evaluate the A-MCP-1expression. Western blot were applied to detect the inhibitory effect to the expression of MCP-1 mRNA and CD68 protein by A-MCP-1 NPs. Results NPs size ranged 198nm to 205nm with average around 201.4 nm. DNA content in the NPs was 4.14 %. NPs showed steady release rate in vitro in Tris-EDTA solution. It released faster in the first week then maintained a slowly sustained release up to 16 days. In cell culture A-MCP-1 gene successfully transfected into smooth muscle cells by NPs vector. In vein grafting animal model, A-MCP-1 expression was detected in the vascular walls of NPs and cationic lipid treated groups. The degree of vascular hyperplasia in the gene NPs treated group was significantly lower than that in control group. There was no significant difference in the inhibition of intimal hyperplasia between NPs and cationic lipid treated groups. Two weeks after transfection in abdominal aortic aneurysm rats models, the abdominal aortic diameter of A-MCP-1 NPs injection group was (1.79±0.12) mm, significantly smaller than that of control groupsshame NPs group was(2.58±0.21)mm, and saline group was(2.63±0.29)mm( P< 0.01). The expressions of MCP-1 mRNA and CD68 protein in A-MCP-1 NPs injection group were 12.5±1.5 and 17.6±2.1, which were much lower than those in control group in shame NPs group, which were 35.7±4.5,42.3±5.7( P< 0.01),and saline group which is 32.4±3.9,39.8±4.8 ( P< 0.01 ). Specific band of A-MCP-1 was detected only in the A-MCP-1 NPs injection group by PCR. Conclusion A-MCP-1 gene NPs can be successfully used in rabbit vein grafting model and abdominal aortic aneurysm rats models, and may be potentially applied in clinical practice.更多还原