中文摘要：

本文采用乳酸-羟基乙酸共聚物 （PLGA） 包裹磷酸钙？质粒DNA纳米复合物 （CaPi-pDNA） 得到具有壳核结构的磷酸钙/pDNA PLGA纳米粒 （CS-pDNA-CaPi-PLGA-NPs）, 对其体外相关性质进行了初步评价, 并在形态、粒径、ζ电位、载药量、包封率、在介质中粒径的变化、抗核酸酶降解能力、体外释放性能、细胞毒性及细胞转染效率等方面与嵌入型磷酸钙/pDNA复合物的纳米粒 （embedded-pDNA-CaPi-PLGA-NPs） 进行了比较。结果表明： 所制备的CS-pDNA-CaPi-PLGA-NPs外观圆整光滑, 呈类球形, 大小均匀, 平均粒径为 （155 ± 4.5） nm, zeta电位为 （？0.38 ± 0.1） mV, 包封率为 （80.56 ± 2.5） %, 载药量为 （1.16 ± 0.04） %, 在介质中稳定性较好, 抗核酸酶降解能力强, 并具有缓释效果, 体外转染效率在转染后72 h达到 （24.66 ± 0.46） %, 显著优于裸质粒 [ （0.33 ± 0.04） %, P 〈 0.01] 与普通PLGA纳米粒 [ （1.5 ± 0.07） %, P 〈 0.01], 且持续作用时间较embedded-pDNA-CaPi-PLGA-NPs更 长, 细胞的毒性显著低于聚乙烯亚胺 （PEI）。以上结果提示CS-pDNA-CaPi-PLGA-NPs是一种极富潜力的非病毒类基因传递载体。

英文摘要：

To develop a core-shell structure pDNA-CaPi-PLGA nanoparticles （CS-pDNA-CaPi-PLGA-NPs）, calcium phosphate-pDNA nano complexes （CaPi-pDNA） were encapsulated inside of PLGA shells. The characteristics of the nanoparticles, including morphology, average particle size, zeta potential, entrapment efficiency , loading efficiency , stability in medium, pDNA protection ability from nuclease degradation, in vitro release, cytotoxicity and cell transfection were investigated and compared with the embedded structured CaPi modified PLGA nanoparticles （embedded-pDNA-CaPi-PLGA-NPs）. The results showed that the obtained CS-pDNA-CaPi-PLGA-NPs were spherical in shape with an average particle size of （155 ± 4.5） nm, zeta potentials of （？0.38 ± 0.1） mV, entrapment efficiency of （80.56 ± 2.5） % and loading efficiency of （1.16 ± 0.04） %. The CS-pDNA-CaPi-PLGA-NPs were stable in the release media and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The highest gene transfection efficiency of the CS-pDNA-CaPi-PLGA-NPs in vitro reached （24.66 ± 0.46） % （after 72 h transfection）, which was significantly higher than that of free pDNA [（0.33 ± 0.04） %, P 〈 0.01] and the pDNA-PLGA-NPs [ （1.5 ± 0.07） %, P 〈 0.01]. Besides, the transfection lasted for longer time than that of embedded-pDNA-CaPi-PLGA-NPs and the cytotoxicity of it was significantly lower than that of PEI （P 〈 0.01）. These results indicate that CS-pDNA- CaPi-PLGA-NPs are a promising non-viral gene vector.