CNS gene transfer mediated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes
CNS gene transfer mediated by a novel controlled release system based on DNA complexes of degradable polycation PPE-EA: a comparison with polyethylenimine/DNA complexes
复制标题
DOI：
10.1038/sj.gt.3302135
复制
发表时间：
2004-01-01
期刊：
影响因子：
5.1
通讯作者：
Wang, S
中科院分区：
文献类型：
--
作者：
Li, Y;Wang, J;Wang, S
基于聚阳离子/质粒DNA复合体的非病毒基因递送系统因其在避免病毒系统固有的免疫原性和毒性问题方面的潜力而迅速被认为是病毒基因载体的替代品。在本研究中，我们研究了利用基于DNA的控释系统与新近开发的聚合物基因载体聚氨基乙基丙二酸丙酯(PPE-EA)复合来实现脑内基因转移的可行性。这种基因传递系统的一个独特特征是PPE-EA的生物降解性，它可以根据聚合物与DNA的电荷比以不同的速度提供DNA的持续释放。将PPE-EA/DNA复合体、裸DNA以及与聚乙烯亚胺(PEI)复合的DNA注入小鼠脑脊液，PEI是一种不可降解的阳离子聚合物，是一种有效的基因载体。裸露DNA介导的转基因表达主要在靠近注射部位的脑干区域检测到。以PPE-EA或PEI为载体，可在大脑皮层、基底节和间脑检测到较高水平的基因表达。在N/P比为2时，PPE-EA/DNA复合体介导的转基因在脑内的表达持续了至少4周，在4周的时间点上显著高于裸质粒DNA或PEI/DNA。此外，与PEI相比，PPE-EA在培养的神经细胞中的毒性要低得多，并且不会在中枢神经系统(CNS)引起可检测到的病理变化。这些结果为PPE-EA作为一种新型的、生物相容的基因载体在中枢神经系统实现持续基因表达奠定了基础。
Nonviral gene delivery systems based upon polycation/ plasmid DNA complexes are quickly gaining recognition as an alternative to viral gene vectors for their potential in avoiding immunogenicity and toxicity problems inherent in viral systems. We investigated in this study the feasibility of using a controlled release system based on DNA complexed with a recently developed polymeric gene carrier, polyaminoethyl propylene phosphate (PPE-EA), to achieve gene transfer in the brain. A unique feature of this gene delivery system is the biodegradability of PPE-EA, which can provide a sustained release of DNA at different rates depending on the charge ratio of the polymer to DNA. PPE-EA/DNA complexes, naked DNA, and DNA complexed with polyethylenimine (PEI), a nondegradable cationic polymer known to be an effective gene carrier, were injected intracisternally into the mouse cerebrospinal fluid. Transgene expression mediated by naked DNA was mainly detected in the brain stem, a region close to the injection site. With either PPE-EA or PEI as a carrier, higher levels of gene expression could be detected in the cerebral cortex, basal ganglia, and diencephalons. Transgene expression in the brain mediated by PPE-EA/DNA complexes at an N/P ratio of 2 persisted for at least 4 weeks, with a significant higher level than that produced by either naked plasmid DNA or PEI/DNA at the 4-week time point. Furthermore, PPE-EA displayed much lower toxicity in cultured neural cells as compared to PEI and did not cause detectable pathological changes in the central nervous system (CNS). The results established the potential of PPE-EA as a new and biocompatible gene carrier to achieve sustained gene expression in the CNS.