The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, PR China.
Acta Biomater. 2010 Jul;6(7):2650-7. doi: 10.1016/j.actbio.2010.01.022. Epub 2010 Jan 28.
A novel class of non-viral gene vectors consisting of low molecular weight poly(ethylene imine) (PEI) (molecular weight 800 Da) grafted onto degradable linear poly(ethylene glycol) (PEG) analogs was synthesized. First, a Michael addition reaction between poly(ethylene glycol) diacrylates (PEGDA) (molecular weight 258 Da) and d,l-dithiothreitol (DTT) was carried out to generate a linear polymer (PEG-DTT) having a terminal thiol, methacrylate and pendant hydroxyl functional groups. Five PEG-DTT analogs were synthesized by varying the molar ratio of diacrylates to thiols from 1.2:1 to 1:1.2. Then PEI (800 Da) was grafted onto the main chain of the PEG-DTTs using 1,1'-carbonyldiimidazole as the linker. The above reaction gave rise to a new class of non-viral gene vectors, (PEG-DTT)-g-PEI copolymers, which can effectively complex DNA to form nanoparticles. The molecular weights and structures of the copolymers were characterized by gel permeation chromatography, (1)H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The size of the nanoparticles was<200 nm and the surface charge of the nanoparticles, expressed as the zeta potential, was between+20 and+40 mV. Cytotoxicity assays showed that the copolymers exhibited much lower cytotoxicities than high molecular weight PEI (25 kDa). Transfection was performed in cultured HeLa, HepG2, MCF-7 and COS-7 cells. The copolymers showed higher transfection efficiencies than PEI (25 kDa) tested in four cell lines. The presence of serum (up to 30%) had no inhibitory effect on the transfection efficiency. These results indicate that this new class of non-viral gene vectors may be a promising gene carrier that is worth further investigation.
合成了一类新型的非病毒基因载体，由低分子量的聚（亚乙基亚胺）（PEI）（分子量 800 Da）接枝到可降解的线性聚（乙二醇）（PEG）类似物上。首先，通过聚（乙二醇）二丙烯酸酯（PEGDA）（分子量 258 Da）和二硫苏糖醇（DTT）之间的迈克尔加成反应，生成具有末端巯基、甲基丙烯酰基和侧挂羟基官能团的线性聚合物（PEG-DTT）。通过改变二丙烯酸酯与硫醇的摩尔比从 1.2:1 到 1:1.2，合成了五种 PEG-DTT 类似物。然后，使用 1,1'-碳酰二咪唑作为连接剂，将 PEI（800 Da）接枝到 PEG-DTT 的主链上。上述反应产生了一类新型的非病毒基因载体，（PEG-DTT）-g-PEI 共聚物，它可以有效地将 DNA 复合形成纳米颗粒。通过凝胶渗透色谱、（1）H 核磁共振和傅里叶变换红外光谱对共聚物的分子量和结构进行了表征。纳米颗粒的粒径<200nm，纳米颗粒的表面电荷，用 zeta 电位表示，在+20 到+40 mV 之间。细胞毒性试验表明，与高分子量的 PEI（25 kDa）相比，共聚物的细胞毒性低得多。在培养的 HeLa、HepG2、MCF-7 和 COS-7 细胞中进行了转染实验。共聚物在四种细胞系中的转染效率均高于测试的 PEI（25 kDa）。血清（高达 30%）的存在对转染效率没有抑制作用。这些结果表明，这种新型的非病毒基因载体可能是一种有前途的基因载体，值得进一步研究。
