Martien Ronny, Loretz Brigitta, Thaler Marlene, Majzoob Sayeh, Bernkop-Schnürch Andreas
Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
J Biomed Mater Res A. 2007 Jul;82(1):1-9. doi: 10.1002/jbm.a.31135.
Regarding safety concerns, nonviral gene delivery vehicles that have the required efficiency and safety for use in human gene therapy are being widely investigated. The aim of this study was to synthesize and evaluate a thiolated chitosan to improve the efficacy of oral gene delivery systems. Thiolated chitosan was synthesized by introducing thioglycolic acid (TGA) to chitosan via amide bond formation mediated by a carbodiimide. Based on this conjugate, nanoparticles with pDNA were generated at pH 4.0 and 5.0. Cytotoxicity of the thiolated chitosan/pDNA nanoparticles on Caco-2 cells was evaluated. The diameter of thiolated chitosan/pDNA nanoparticles was in the range of 100-200 nm. The zeta potential was determined to be 5-6 mV. Due to stability toward nucleases, the transfection rate of thiolated chitosan/pDNA nanoparticles was fivefold higher than that of unmodified chitosan/pDNA nanoparticles. Lactate dehydrogenase tests for thiolated chitosan/pDNA (pH 4.0 and 5.0) showed that (3.79 +/- 0.23)% and (2.9 +/- 0.13)% cell damage. According to these results, thiolated chitosan represents promising excipients for preparation DNA nanoparticles in nonviral gene delivery system.
关于安全性问题，具有用于人类基因治疗所需效率和安全性的非病毒基因递送载体正在被广泛研究。本研究的目的是合成并评估一种巯基化壳聚糖，以提高口服基因递送系统的功效。通过由碳二亚胺介导的酰胺键形成将巯基乙酸（TGA）引入壳聚糖来合成巯基化壳聚糖。基于这种共轭物，在pH 4.0和5.0下生成了含有质粒DNA（pDNA）的纳米颗粒。评估了巯基化壳聚糖/pDNA纳米颗粒对Caco-2细胞的细胞毒性。巯基化壳聚糖/pDNA纳米颗粒的直径在100-200nm范围内。zeta电位测定为5-6mV。由于对核酸酶具有稳定性，巯基化壳聚糖/pDNA纳米颗粒的转染率比未修饰的壳聚糖/pDNA纳米颗粒高五倍。对巯基化壳聚糖/pDNA（pH 4.0和5.0）的乳酸脱氢酶测试表明细胞损伤分别为（3.79±0.23）%和（2.9±0.13）%。根据这些结果，巯基化壳聚糖是在非病毒基因递送系统中制备DNA纳米颗粒的有前景的赋形剂。
