Park Susan, Healy Kevin E
University of California at Berkeley, Department of Bioengineering, 459 Evans Hall, 94270-1762, USA.
Bioconjug Chem. 2003 Mar-Apr;14(2):311-9. doi: 10.1021/bc025623b.
Terpolymers of poly(lysine-g-(lactide-b-ethylene glycol)) (pK-pLL-pEG) were synthesized by using ring-opening polymerization and functional end-group grafting. Synthesis was characterized with gel permeation chromatography, proton nuclear magnetic resonance spectroscopy, and a trinitrobenzene sulfonic acid binding assay. Polymer association behavior with DNA was investigated using an ethidium bromide exclusion assay, static light scattering, and scanning electron microscopy. Polylactide molecular weight was varied to investigate its impact on DNA association and resulting complex characteristics. Polylysine ( = 8800, DP = 42) modified with either 7400 or 10 870 pLL-pEG reduced the minimum amount of primary amines necessary for complete condensation by 23% and 48%, respectively, compared to unmodified polylysine (pK42). Complexes formed with the highest molecular weight terpolymer demonstrated significantly (p < 0.1) greater resistance to DNase I than lyophilized pK42-DNA particles. This study suggests that modification of pK42 with pLL-pEG diblock copolymers impacts polylysine's associative and binding behavior to DNA and resulting particle characteristics. Modulation of terpolymer composition in complexes can enable control over intracellular plasmid dissociation rates to improve transfection efficiency.
通过开环聚合和官能端基接枝合成了聚（赖氨酸 - g -（丙交酯 - b - 乙二醇））（pK - pLL - pEG）三元共聚物。通过凝胶渗透色谱、质子核磁共振光谱和三硝基苯磺酸结合测定对合成进行了表征。使用溴化乙锭排除测定、静态光散射和扫描电子显微镜研究了聚合物与DNA的缔合行为。改变聚丙交酯的分子量以研究其对DNA缔合和所得复合物特性的影响。与未修饰的聚赖氨酸（pK42）相比，用7400或10870 pLL - pEG修饰的聚赖氨酸（ = 8800，DP = 42）分别将完全缩合所需的伯胺的最小量降低了23%和48%。与冻干的pK42 - DNA颗粒相比，由最高分子量三元共聚物形成的复合物对DNase I表现出显著（p < 0.1）更高的抗性。这项研究表明，用pLL - pEG二嵌段共聚物修饰pK42会影响聚赖氨酸与DNA的缔合和结合行为以及所得颗粒的特性。调节复合物中三元共聚物的组成可以控制细胞内质粒的解离速率，以提高转染效率。
