Junbo Bao, Cunxian Song
Key Laboratory of Biomedical Materials of Tianjin, Institute of Biomedical Engineering, Peking Union Med College, Chinese Academy of Medical Sciences, Tianjin 300192, People's Republic of China.
Biomed Mater. 2009 Feb;4(1):011002. doi: 10.1088/1748-6041/4/1/011002. Epub 2008 Dec 12.
The plasmid DNA (pDNA) loading by cationic polymers or/and cationic lipids is essential for gene therapy, especially for metal implants such as stents and artificial joints. Polycations can condense with pDNA by self-assembly, forming polyplexes spontaneously as a result of electrostatic interactions to carry and transfer pDNA in vivo. Cationic polymers, such as chitosan, can also protect pDNA from degradation by DNase. In this study, a chitosan chip was prepared and loaded with pDNA layer-by-layer with polycation/cationic lipids. By real-time surface plasmon resonance (SPR) sensorgram, pDNA loading ability, layer stability and protective effect on pDNA from DNase degradation have been detected. Chitosan can increase the pDNA loading amount of N-(1-(2,3-dioleoyloxy)propyl)-N, N, N-trimethylammonium methyl sulphate (DOTAP) and Lipofectmine 2000 (Lipo) on the chip surface. Different flow rates can affect the pDNA loading on the chitosan chip, and it is not significant at a lower flow rate. The pDNA protection by chitosan with different molecular weights from DNase degradation was also tested. Polycationic chitosan with higher molecular weight (> or =200 kDa) can fulfil the requirements for effective gene protection from DNase degradation. The results of this study present a platform for further optimization studies of polycation-based gene delivery systems.
通过阳离子聚合物或/和阳离子脂质加载质粒DNA（pDNA）对于基因治疗至关重要，尤其是对于诸如支架和人工关节等金属植入物。聚阳离子可以通过自组装与pDNA凝聚，由于静电相互作用自发形成多聚体，以便在体内携带和转移pDNA。阳离子聚合物，如壳聚糖，还可以保护pDNA不被脱氧核糖核酸酶降解。在本研究中，制备了壳聚糖芯片，并与聚阳离子/阳离子脂质逐层加载pDNA。通过实时表面等离子体共振（SPR）传感图，检测了pDNA加载能力、层稳定性以及对pDNA免受脱氧核糖核酸酶降解的保护作用。壳聚糖可以增加芯片表面上N-（1-（2,3-二油酰氧基）丙基）-N，N，N-三甲基硫酸甲酯铵（DOTAP）和脂质体2000（Lipo）的pDNA加载量。不同流速会影响壳聚糖芯片上的pDNA加载，在较低流速下不显著。还测试了不同分子量的壳聚糖对pDNA免受脱氧核糖核酸酶降解的保护作用。较高分子量（>或=200 kDa）的聚阳离子壳聚糖可以满足有效保护基因免受脱氧核糖核酸酶降解的要求。本研究结果为基于聚阳离子的基因递送系统的进一步优化研究提供了一个平台。
