中文摘要：

目的 探索载短发夹RNA（shRNA）质粒的阳离子高分子脂质体（CPL）的制备方法及其理化性质,确定二者耦合的最佳结合比,优化转染方案.方法 构建CPL,并对其进行表征,通过噻唑兰比色法检测CPL对细胞增殖的影响.将CPL与载shRNA质粒耦合,分为空白对照组（不做任何干预）、Lipofectamine2000转染组及不同质量比（1∶0、1∶0.5、1∶1、1∶1.5、1∶2、1∶2.5、1∶3）的质粒与CPL耦合成pCPL-shRNA组,转染人结肠癌细胞系HCT-116细胞,采用流式细胞仪检测载shRNA质粒的CPL的转染效率.结果 所构建的CPL为近球形、大小较一致、表面较光滑、分散性较好的纳米粒子,平均粒径为（95.58±4.21） nm.随CPL浓度增加,细胞抑制率逐渐升高,两者呈线性相关（R2=0.9851,P＜0.05）,IC50=7.605＆#215; 10-2 g/L.载shRNA质粒与CPL在最佳结合比为1∶2,转染效率为（28.19±5.38）％,优于转染剂Lipofetamine组（21.33±6.11）％（P＜0.05）.结论 构建的载shRNA质粒的CPL是一种较为理想的基因转运载体.

英文摘要：

Objective To investigate the preparation of cationic polymeric liposomes （CPL） carrying short hairpin RNA （shRNA） plasmid and its physicochemical properties,and to determine the optimal coupling ratio,and to further improves the cell transfection protocol.Methods CPL was established for characterization.The effect of CPL on cell proliferation was determined by methyl-thiazolyl-tetrazolium （MTT） colorimetric assay.CPL were coupled with shRNA plasmid,and divided into the control group （without any intervention）,Lipofectamine2000 transfected group and pCPL-shRNA group [different mass ratio of shRNA plasmids coupled with CPL （1 ∶ 0、1 ∶ 0.5、1 ∶ 1、1 ∶ 1.5、1 ∶ 2、1 ∶ 2.5、1 ∶ 3）].The human colon cancer cell line HCT-116 cells were transfected.The transfection efficiency of CPL carrying shRNA plasmid was determined by flow cytometry.Results The established CPL was substantially spherical,with uniform size,smooth surface,and well-dispersed nanoparticles [average particle diameter （95.58±4.21） nm].The cell inhibition rate gradually increased along with the increasing CPL concentration,showing linear correlation （R2=0.9851,P〈0.05）,IC50=7.605× 10^-2 g/L.The optimal coupling ratio of shRNA plasmid and CPL was 1∶2,and the transfection efficiency was （28.19±5.38）%,which was better than that in the transfection agent Lipofetamine group [（21.33±6.11）%] （P〈0.05）.Conclusion The established CPL carrying shRNA may be an ideal gene delivery carrier.