Preparation and characterization of poly (D,L-lactide-co-glycolide) microspheres for controlled release of poly(L-lysine) complexed plasmid DNA
Preparation and characterization of poly (D,L-lactide-co-glycolide) microspheres for controlled release of poly(L-lysine) complexed plasmid DNA
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DOI：
10.1023/a:1018862827426
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发表时间：
1999-04-01
影响因子：
3.7
通讯作者：
DeLuca, PP
中科院分区：
文献类型：
--
作者：
Capan, Y;Woo, BH;DeLuca, PP
目的.制备和表征载于聚（D，L-丙交酯-共-乙交酯）（PLGA）微球中的质粒DNA（pDNA）以游离形式和作为与聚（L-赖氨酸）的复合物的控释制剂。使用聚（L-赖氨酸）（PLL）形成pDNA/PLL复合物，复合比为1：0.125和1：0.333w/w，以增强微球制备过程中pDNA的稳定性并保护pDNA免受核酸酶攻击。研究了pDNA的结构、粒径、Zeta电位、载药量、体外释药性能以及对DNase I的保护作用。发现微球为球形，平均粒径为3.1-3.5 μ m，目标载药量为0.6%。pDNA和pDNA/PLL微球的包埋率分别为35.1%和29.4-30.6%。总体而言，初始突释后的pDNA释放动力学与空白微球聚合物降解曲线不相关，表明pDNA释放是对流扩散控制的。pDNA和pDNA/PLL微球中超螺旋pDNA的比例分别为16.6%和76.7-85.6%。未包封的pDNA和pDNA/PLL在加入DNase I后30分钟内完全降解。PLGA微球中DNA/PLL的包封保护了pDNA免受酶降解。结果表明，使用一种新的方法，pDNA可以稳定和封装在PLGA微球，以保护pDNA免受酶降解。
Purpose. To produce and characterize controlled release formulations of plasmid DNA (pDNA) loaded in poly (D,L-lactide-co-glycolide) (PLGA) microspheres both in free form and as a complex with poly (L-lysine).Methods. Poly (L-lysine) (PLL) was used to form pDNA/PLL complexes with complexation ratio of 1:0.125 and 1:0.333 w/w to enhance the stability of pDNA during microsphere preparation and protect pDNA from nuclease attack. pDNA structure, particle size, zeta potential, drug loading, in vitro release properties, and protection from DNase I were studied.Results. The microspheres were found to be spherical with average particle size of 3.1-3.5 mu m Drug loading of 0.6% was targeted. Incorporation efficiencies of 35.1% and 29.4-30.6% were obtained for pDNA and pDNA/PLL loaded microspheres respectively. Overall, pDNA release kinetics following the initial burst did not correlate with blank microsphere polymer degradation profile suggesting that pDNA release is convective diffusion controlled. The percentage of supercoiled pDNA in the pDNA and pDNA/PLL loaded microspheres was 16.6% and 76.7-85.6% respectively. Unencapsulated pDNA and pDNA/PLL degraded completely within 30 minutes upon the addition of DNase I. Encapsulation of DNA/PLL in PLGA microspheres protected pDNA from enzymatic degradation.Conclusions. The results show that using a novel process, pDNA can be stabilized and encapsulated in PLGA microspheres to protect pDNA from enzymatic degradation.