目的 合成可生物降解的基因载体，并分析其生物毒性及转染率。 方法 低分子量聚乙烯亚胺（PEI）通过双硫键交联合成可降解的高分子量PEI衍生物（SS-PEI），通过红外光谱和核磁波谱分析技术分析其化学结构，采用细胞活力实验和检测大鼠肝肾功能指标分析其细胞和体内毒性，并转染羟基荧光素修饰的siRNA（FAM-siRNA）分析细胞转染率。 结果 红外波谱和核磁波谱分析可见酰胺键的特征波谱，噻唑蓝法和肝肾功能指标显示SS-PEI不同剂量组与对照组的差异均无统计学意义（P＞0.05），SS-PEI/FAM-siRNA转染率为（76.0 ± 2.8）%。 结论 SS-PEI的合成可明显提高装载siRNA的效率，具有安全、高效等特点。
We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
In the present study, packaging system composed of pAAV-CMV-GFP, pAAV-RC and pHelper were transfected into human embryonic kidney 293 cells (HEK293 cells) mediated by polyethyleneimine (PEI) to explore an optimal transfection condition. Different total plasmid DNA dosages (1, 2, 3, 4, 5, 6μg) and different PEI/Plasmid ratios (1:1, 3:1, 5:1, 7:1) were tested with detection of green fluorescence protein (GFP) with ImagePro Plus6.0 Software. Then transfection efficiency of the optimized transfection system was further observed for different time periods(12, 24, 36, 48, 60, 72 h). The results showed that total plasmid dosage of 4μg/well with PEI/plasmid ratio of 3:1~5:1 was an efficient transfection condition. Transfection efficiency-time curve was an S-shaped curve. Transfection efficiency reached a plateau at 60 h after transfection. The optimized conditions for PEI-mediated transfection at the optimal time result in enhanced transfection efficiency of triple plasmid into HEK293 cells.
ObjectiveTo review the current status and advances of in vivo nucleic acid del ivery mediated by poly(ethylenimine) (PEI). MethodsThe related home and abroad literature about nucleic acid del ivery with applications in cancer treatments and tissue engineering was extensively reviewed and analyzed. ResultsA variety of in vivo study on the potential of PEI-mediated nucleic acid del ivery has been carried out and made certain effects in the animal model, ranging from cancer treatments to rectification of physiological defects (eg. cranial defect and corneal epithelium defect). Tail vein injection is the most commonly adopted route of administration in vivo, followed by pulmonary administration and intralesional injection. However, transfection and expression in vivo have some shortcomings, such as low transfection efficiency and short expression time, so there are some limitation in the cl inical application. ConclusionPEI mediated nucleic acid del ivery provides a good method for cancer treatments and rectification of physiological defects. For future research, not only should more in vivo animal testing be done, but the procedures of experimentation also need to be standardized.