Duceppe Nicolas, Tabrizian Maryam
Department of Biomedical Engineering, Duff Medical Sciences Building, 3775 University Street, McGill University, Montreal H3A 2B4, Canada.
Biomaterials. 2009 May;30(13):2625-31. doi: 10.1016/j.biomaterials.2009.01.017. Epub 2009 Feb 6.
The present work describes nanoparticles made of ultra low molecular weight chitosan (ULMWCh)/hyaluronic acid (HA) as novel potential carriers for gene delivery. Small and monodispersed nanoparticles with high in vitro transfection capabilities have been obtained by the complexation of these two polyelectrolytes. ULMWCh (<10 kDa) presents more advantageous characteristics over the higher molecular weight chitosan for clinical applications, namely increased solubility at physiological pH and improved DNA release. The ULMWCh:HA ratio and the HA molecular weights were varied with the aim of obtaining particles in the 100 nm range. Using chitosan (Ch) with a molecular weight of 5 kDa, HA with a molecular weight of 64 kDa, and a weight ratio of 4:1, nanoparticles with a Z-average size of 146+/-1 nm and narrow size distribution (polydispersity index: 0.073+/-0.030) were obtained. Nanoparticle images taken in dry conditions by SEM and AFM showed spherical particles. The optimal pH for transfection ranged from 6.4 to 6.8 for 0.25 microg of EGFP plasmid per well, with an incubation time of 4 h. Using these optimized parameters, DNA/ULMWCh:HA nanoparticles successfully transfected 25+/-1% of the 293T cells with pEGFP, compared to 0.7% obtained for DNA/ULMWCh under the same conditions. This high transfection efficiency of our non-viral gene delivery system could be attributed to the synergic effect of ULMWCh and low charge density of the HA chain for easy release of DNA which makes the system suitable for targeted gene delivery.
本研究描述了由超低分子量壳聚糖（ULMWCh）/透明质酸（HA）制成的纳米颗粒，作为新型潜在的基因传递载体。通过这两种聚电解质的络合，获得了具有高体外转染能力的小尺寸且单分散的纳米颗粒。与较高分子量的壳聚糖相比，超低分子量壳聚糖（<10 kDa）在临床应用中具有更有利的特性，即在生理pH下溶解度增加以及DNA释放改善。改变ULMWCh:HA比例和HA分子量，旨在获得尺寸在100 nm范围内的颗粒。使用分子量为5 kDa的壳聚糖（Ch）、分子量为64 kDa的HA以及重量比为4:1，获得了Z平均尺寸为146±1 nm且尺寸分布窄（多分散指数：0.073±0.030）的纳米颗粒。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）在干燥条件下拍摄的纳米颗粒图像显示为球形颗粒。对于每孔0.25 μg的增强绿色荧光蛋白（EGFP）质粒，转染的最佳pH范围为6.4至6.8，孵育时间为4小时。使用这些优化参数，DNA/ULMWCh:HA纳米颗粒成功地用pEGFP转染了293T细胞的25±1%，而在相同条件下，DNA/ULMWCh的转染率为0.7%。我们的非病毒基因传递系统的这种高转染效率可归因于ULMWCh的协同作用以及HA链的低电荷密度，便于DNA释放，这使得该系统适用于靶向基因传递。
