【摘要】 目的 :用低分子量的聚乙亚胺 (PEI)有效地进行基因转染 ,为基因转染在基因治疗中的应用提供一种可靠、廉价、高效的方法。方法 :将带有绿色荧光蛋白 (GFP)报告基因的真核表达质粒与阳离子聚合物聚乙亚胺 (PEI)结合 ,用肝癌细胞系SMMC772 1实验 ,研究PEI分子量与转染活性以及可能引起的细胞毒性之间的关系 ;进一步研究在血清存在的情况下 ,PEG(聚乙二醇 80 0 0 )、叶酸等物质对PEI介导的转染效率的影响。结果 :分子量为 6 0 0Da的PEI在pH值为 6 0时与质粒DNA以 1∶1的质量比混合 ,细胞转染效率最高为 4 3 6 + - 7 3% ,随着分子量的增大 ,转染活性略有下降 ;进一步研究发现 ,在血清存在下 ,2 0 μM的叶酸和 15 %的PEG能有效地改善PEI介导的转染活性 ,使其转染活性提高了 13% ;用光学相差显微镜检测了PEI潜在的细胞毒性 ,结果发现分子量为 6 0 0Da的PEI没有使细胞形态改变或死亡 ,但是随着分子量的增大 ,PEI潜在的细胞毒性也相应增大。结论 :PEI是一种高效、有用的非病毒载体 ,能够在培养的哺乳动物细胞中进行基因转移 ,这对疾病的基因治疗具有潜在的应用价值。更多还原

【Abstract】 Objective:Providing a reliable,low-cost and highly efficient method for delivery of genes by using lower molecular weight polyethylenimine (LMW-PEI).Methods:LMW-PEI was linked to a expressing plasmid of green fluorescence protein (GFP) reporter gene,and effective gene transfer was observed in SMMC7721 cell line tested.The relationship between the molecular weight of PEI and their transfection activity and cytotoxicity on SMMC7721 cell line was examined.Further more,the effect of the folate,PEG,glycerin on PEI-mediated genetransferin the presence of serum was examined.Results:At pH6.0,the highest delivery rate (43.6+/-7.3%) was achieved when DNA was combined with PEI(MW 600Da) at the same mass number ratios.With the increasing of PEI molecular weight,the transfection activity of PEI/DNA complexes was reduced.In the presence of serum,20μmol/L folate and 15% PEG made the transfection activity enhanced about 13%.Possible cytotoxicity was examined by trypan blue staining and phase contrast microscopic observations.Neither cytotoxicity nor morphological change was induced at the optimal dose of PEI of MW 600Da,but the cytotoxicity was enhanced with the increasing of PEI molecular weight.Conclusion:The LMW-PEI described here was a new,highly efficient,and non-cytotoxic vector with a favorable efficiency for gene therapeutic applications.更多还原