A Biodegradable Low Molecular Weight Polyethylenimine Derivative as Low Toxicity and Efficient Gene Vector
A Biodegradable Low Molecular Weight Polyethylenimine Derivative as Low Toxicity and Efficient Gene Vector
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DOI：
10.1021/bc800428y
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发表时间：
2009-02-01
影响因子：
4.7
通讯作者：
Feng, Min
中科院分区：
文献类型：
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作者：
Wen, Yuting;Pan, Shirong;Feng, Min
聚乙烯亚胺（PEI）是一类阳离子聚合物，已被证明可有效用于基因递送。然而，PEI是不可降解的，并且PEI的分子量影响细胞毒性和基因转移活性。为了制备高转染效率、低细胞毒性的可生物降解基因载体，我们将低分子量（LMW）聚乙烯（PEI）通过氨解偶联到可生物降解的主链聚谷氨酸衍生物（PEG-b-PBLG）上，形成PEN结合的PEG-b-PLG-g-PEI（GGI）。合成了两种共聚物，GGI 30和GGI 40。采用IR、1H-1 NMR和13 C NMR、GPC和CD对GGI的化学结构进行了表征。研究了共聚物GGI在木瓜蛋白酶溶液中的降解行为。GGIs显示出良好的DNA缩合能力和对DNA的高度保护以免受核酸酶降解。GGI/pDNA聚合复合物的ζ电位类似于15 mV，并且在10和30之间的N/P比下，粒度在102-138 nm的范围内。通过透射电子显微镜（TEM）进一步证实了聚合物的粒径和形态。在细胞毒性测定中，GGIs的毒性显著低于PEI 25 k。即使在高共聚物浓度下，GGI的降解产物对细胞的影响也可以忽略不计。GFP流式细胞术和荧光成像结果显示，GGIs在Hela、HcpG 2、Bel 7402和293细胞系中的转染效率均显著高于PEI 25 k。重要的是，与PEI 25 k和Lipofectamine 2000相比，血清的存在对GGI的转染活性具有较低的抑制作用。因此，PEGb-PLG-g-PEI共聚物可能是用于非病毒基因治疗的有吸引力的阳离子聚合物。
Polyethylenimine (PEI) is a class of cationic polymers proven to be effective for gene delivery. However, PEI is nondegradable and the molecular weight of PEI affects the cytotoxicity and gene transfer activity. Aiming to prepare a biodegradable gene vector with high transfection efficiency and low cytotoxicity, we conjugated low molecular weight (LMW) PEIs to the biodegradable backbone polyglutamic acids derivative (PEG-b-PBLG) by aminolysis to form PEN combined PEG-b-PLG-g-PEIs (GGI). Two copolymers, GGI 30 and GGI 40, were synthesized. The chemistry of GGI was characterized using IR, H-1 NMR and C-13 NMR, GPC, and CD, respectively. The degradation behaviors of copolymer GGI in papain solution were investigated. GGIs showed good DNA condensation ability and high protection of DNA from nuclease degradation. The zeta potential of the GGI/pDNA polyplexes was similar to 15 mV, and the particle size was in the range 102-138 nm at N/P ratios between 10 and 30. The particle size and the morphology of the polyplex was further confirmed by transmission electron microscope (TEM). In cytotoxicity assay, GGIs were significantly less toxic than PEI 25k. The degradation product of GGI exhibited negligible effects on cells even at high copolymer concentration. The results of GFP flow cytometry and fluorescence imaging showed that the trasnfection efficiencies of GGIs were all markedly higher than PEI 25k in Hela, HcpG2, Bel 7402, and 293 cell lines. Importantly, the presence of serum had a lower inhibitive effect on the transfection activity of GGI in comparison to PEI 25k and Lipofectamine 2000. Therefore, PEGb-PLG-g-PEI copolymers may be attractive cationic polymers for nonviral gene therapy.