Martien Ronny, Loretz Brigitta, Schnürch A B
Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
Biopolymers. 2006 Nov;83(4):327-36. doi: 10.1002/bip.20521.
The gastrointestinal tract poses a variety of morphological and physiological barriers to the expression of target genes. The aim of this study was to evaluate the stability of cationic polymer/pDNA nanoparticles toward salts and enzymes of the intestinal fluid. Within this study, a chitosan-enzyme inhibitor conjugate has been generated and characterized. Based on this conjugate, nanoparticles with pDNA were generated to enhance transfection rate in oral gene delivery. The enzyme inhibitor aurintricarboxylic acid (ATA) was covalently bound to chitosan to improve the enzymatic stability of nanoparticles formed with this polymer and pDNA. Chitosan-ATA/pDNA nanoparticles showed a size of 98.5 +/- 26 nm and a zeta potential of -13.26 +/- 0.24 mV (n = 3-4). Stability studies with salt solution, lysozyme, DNase, and freshly collected porcine intestinal fluid showed that chitosan-ATA/pDNA nanoparticles are significantly (p < 0.05) more stable than unmodified chitosan/pDNA nanoparticles. Apart from improved stability, chitosan-ATA/pDNA nanoparticles showed a 2.6-fold higher transfection rate than chitosan/pDNA nanoparticles in the Caco-2 cell line, thus creating a promising carrier for orally administered therapeutic genes.
胃肠道对靶基因的表达构成了多种形态学和生理学屏障。本研究的目的是评估阳离子聚合物/pDNA纳米颗粒对肠液中盐类和酶的稳定性。在本研究中，制备并表征了壳聚糖-酶抑制剂缀合物。基于该缀合物，制备了含pDNA的纳米颗粒，以提高口服基因递送中的转染率。将酶抑制剂金精三羧酸（ATA）共价结合到壳聚糖上，以提高用该聚合物和pDNA形成的纳米颗粒的酶稳定性。壳聚糖-ATA/pDNA纳米颗粒的尺寸为98.5±26nm，ζ电位为-13.26±0.24mV（n=3-4）。用盐溶液、溶菌酶、DNase和新鲜采集的猪肠液进行的稳定性研究表明，壳聚糖-ATA/pDNA纳米颗粒比未修饰的壳聚糖/pDNA纳米颗粒显著更稳定（p<0.05）。除了稳定性提高外，壳聚糖-ATA/pDNA纳米颗粒在Caco-2细胞系中的转染率比壳聚糖/pDNA纳米颗粒高2.6倍，从而为口服治疗性基因创造了一种有前景的载体。
