Wei Ji-Zheng, Lin Lei, Xiong Wei, Zhu Qing-Yu
State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China.
Sheng Wu Gong Cheng Xue Bao. 2007 Mar;23(2):229-34.
This study mainly deals with cell transfection and cytotoxicity for PEI(10kD)-PBLG, a novel cationic copolymer, to observe its potential as a gene carrier. Size measurement and SEM were used to show the modality of the PEI-PBLG/pDNA complexes. Cytotoxicity of PEI (10kD)-PBLG was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and compared with PEI(25kD)-PBLG, PEI(10kD), and PEI(25kD). Furthermore, pEGFP that can express the enhanced green fluorescent protein was chosen as a reporter to observe the transfection efficiency directly. Then, PEI (10kD)-PBLG/pEGFP complexes were transfected into several cell lines, such as Hela, COS-7, Vero-E6, and ECV-304, and effects of the transfection conditions were evaluated. The efficiencies were measured by FACS. Size measurement of complex particles indicated that PEI-PBLG/pDNA tended to form smaller nanoparticles compared with PEI/pDNA. The representative size of the PEI(10kD)-PBLG/pDNA complex was approximately 100 - 200 nm. SEM images showed that the particles were condense and compact. This can be suitable for their entry into cells. Cytotoxicity studies suggested that PEI (10kD)-PBLG had considerably lower toxicity than the other three materials. In the transfection tests, PEI (10kD)-PBLG/pDNA complexes could be transfected into all the cell lines that were tested. These provided the highest level of EGFP expression (45.02%) in Hela cells, which was considerably higher than that of PEI(10kD)/pEGFP (29.16%). Being less affected by the serum during transfection, PEI-PBLG/pDNA complexes offered greater biocompatibility than PEI. PEI-PBLG copolymer reduces the cytotoxicity of PEI, improves the transfection efficiency, and offers greater biocompatibility than PEI. It shows considerable potential as an efficient nonviral carrier for gene delivery.
本研究主要探讨新型阳离子共聚物PEI(10kD)-PBLG的细胞转染及细胞毒性，以观察其作为基因载体的潜力。通过尺寸测量和扫描电子显微镜（SEM）来展示PEI-PBLG/pDNA复合物的形态。采用3-(4,5-二甲基噻唑-2)-2,5-二苯基溴化四氮唑（MTT）比色法评估PEI(10kD)-PBLG的细胞毒性，并与PEI(25kD)-PBLG、PEI(10kD)和PEI(25kD)进行比较。此外，选择可表达增强型绿色荧光蛋白的pEGFP作为报告基因，直接观察转染效率。然后，将PEI(10kD)-PBLG/pEGFP复合物转染至多种细胞系，如Hela、COS-7、Vero-E6和ECV-304，并评估转染条件的影响。通过流式细胞仪（FACS）测定效率。复合物颗粒的尺寸测量表明，与PEI/pDNA相比，PEI-PBLG/pDNA倾向于形成更小的纳米颗粒。PEI(10kD)-PBLG/pDNA复合物的典型尺寸约为100 - 200 nm。SEM图像显示颗粒凝聚且致密。这有利于它们进入细胞。细胞毒性研究表明，PEI(10kD)-PBLG的毒性远低于其他三种材料。在转染试验中，PEI(10kD)-PBLG/pDNA复合物可转染至所有测试的细胞系。这些复合物在Hela细胞中提供了最高水平的EGFP表达（45.02%），显著高于PEI(10kD)/pEGFP（29.16%）。在转染过程中受血清影响较小，PEI-PBLG/pDNA复合物比PEI具有更高的生物相容性。PEI-PBLG共聚物降低了PEI的细胞毒性，提高了转染效率，并且比PEI具有更高的生物相容性。它作为一种高效的非病毒基因递送载体显示出相当大的潜力。
