Oster Christine G, Wittmar Matthias, Unger Florian, Barbu-Tudoran Lucian, Schaper Andreas K, Kissel Thomas
Department of Pharmaceutics and Biopharmacy, Philipps-University, D-35032 Marburg, Germany.
Pharm Res. 2004 Jun;21(6):927-31. doi: 10.1023/b:pham.0000029279.50733.55.
The purpose of this study was the design of a polymeric platform for effective gene delivery using DNA-loaded nanoparticles.
The polymers were synthesized by carbonyldiimidazole (CDI)-mediated coupling of diamines diethylaminopropylamine (DEAPA), dimethylaminopropylamine (DMAPA) or diethylaminoethylamine (DEAEA) to poly(vinyl alcohol) (PVA) with subsequent grafting of D,L-lactide and glycolide (1:1) in the stoichiometric ratios of 1:10 and 1:20 (free hydroxyl groups/monomer units). The polymers were characterized by 1H-NMR, gel permeation chromatography-multiple-angle laser-light-scattering, and differential scanning calorimetry. DNA-loaded nanoparticles prepared by a modified solvent displacement method were characterized with regard to their zeta (zeta)-potential and size. The transfection efficiency was assessed with the plasmid DNA pCMV-luc in L929 mouse fibroblasts.
The polymers were composed of highly branched, biodegradable cationic polyesters exhibiting amphiphilic properties. The amine modification enhanced the rapid polymer degradation and resulted in the interaction with DNA during particle preparation. The nanoparticles exhibited positive zeta-potentials up to +42 mV and high transfection efficiencies, comparable to polyethylenimine (PEI) 25 kDa/DNA complexes at a nitrogen to phosphate ratio of 5.
The polymers combined amine-functions and short poly(D,L-lactic-co-glycolic acid) (PLGA) chains resulting in water-insoluble polymers capable of forming biodegradable DNA nanoparticles through coulombic interactions and polyester precipitation in aqueous medium. The high transfection efficiency was based on fast polymer degradation and the conservation of DNA bioactivity.
本研究旨在设计一种使用负载DNA的纳米颗粒进行有效基因递送的聚合物平台。
通过羰基二咪唑（CDI）介导的二乙氨基丙胺（DEAPA）、二甲基氨基丙胺（DMAPA）或二乙氨基乙胺（DEAEA）与聚乙烯醇（PVA）的偶联，随后以化学计量比1:10和1:20（游离羟基/单体单元）接枝D，L-丙交酯和乙交酯（1:1）来合成聚合物。通过1H-NMR、凝胶渗透色谱-多角度激光光散射和差示扫描量热法对聚合物进行表征。采用改进的溶剂置换法制备的负载DNA的纳米颗粒，对其zeta电位和尺寸进行了表征。用质粒DNA pCMV-luc在L929小鼠成纤维细胞中评估转染效率。
这些聚合物由具有两亲性的高度支化、可生物降解的阳离子聚酯组成。胺修饰增强了聚合物的快速降解，并导致在颗粒制备过程中与DNA相互作用。纳米颗粒表现出高达+42 mV的正zeta电位和高转染效率，在氮磷比为5时与25 kDa聚乙烯亚胺（PEI）/DNA复合物相当。
这些聚合物结合了胺功能和短聚（D，L-乳酸-乙醇酸）（PLGA）链，形成了水不溶性聚合物，能够通过库仑相互作用和聚酯在水性介质中的沉淀形成可生物降解的DNA纳米颗粒。高转染效率基于聚合物的快速降解和DNA生物活性的保留。
