Key Laboratory on Assisted Circulation, Ministry of Health, First Affiliated Hospital, Sun Yat-sen University, Guangdong 510089, P. R. China.
J Biomater Sci Polym Ed. 2012;23(1-4):315-31. doi: 10.1163/092050610X550359. Epub 2011 Jan 18.
To overcome the efficiency-cytotoxicity dilemma of native PEI and incorporate the advantages of alginate, we designed a novel gene vector by grafting PEI 2000 onto alginate, an anionic polysaccharide with excellent biocompatibility. The alginate-graft-PEI (Alg-g-PEI) was successfully synthesized and then characterized by elemental analysis, (1)H-NMR and (13)C-NMR. The M(w) of Alg-g-PEI is ca. 17 000. Acid-base titration confirmed that Alg-g-PEI retained the buffering capacity of native PEI. The DNA binding ability of the polymer was confirmed by gel retardation assay. DSL analysis showed that Alg-g-PEI had a particle size and zeta-potential similar to PEI 25K. AFM detected a clear and well-shaped morphology of the complexes. Additionally, Alg-g-PEI exhibited lower cytotoxicity than PEI 25K in BEL7402, MSC and RVMSC cells. Compared with PEI 25K, Alg-g-PEI had comparable or even higher transfection efficiency. Similarly, Alg-g-PEI-mediated VEGF expression was significantly higher compared with PEI 25K-mediated VEGF expression. All together, our results suggest that Alg-g-PEI has a potential to be a safe and efficient agent for gene therapy.
为了克服天然 PEI 的效率-细胞毒性困境，并结合海藻酸钠的优势，我们设计了一种新型基因载体，通过将 PEI 2000 接枝到海藻酸钠上来实现，海藻酸钠是一种具有优异生物相容性的阴离子多糖。成功合成了海藻酸钠接枝聚醚亚胺（Alg-g-PEI），并通过元素分析、（1）H-NMR 和（13）C-NMR 进行了表征。Alg-g-PEI 的 M(w)约为 17000。酸碱滴定证实了 Alg-g-PEI 保留了天然 PEI 的缓冲能力。聚合物的 DNA 结合能力通过凝胶阻滞实验得到证实。DSL 分析表明，Alg-g-PEI 的粒径和 ζ 电位与 PEI 25K 相似。AFM 检测到复合物具有清晰且形状良好的形态。此外，Alg-g-PEI 在 BEL7402、MSC 和 RVMSC 细胞中的细胞毒性低于 PEI 25K。与 PEI 25K 相比，Alg-g-PEI 的转染效率相当或更高。同样，Alg-g-PEI 介导的 VEGF 表达明显高于 PEI 25K 介导的 VEGF 表达。总的来说，我们的结果表明，Alg-g-PEI 有潜力成为一种安全有效的基因治疗试剂。
