Li D, Tang G P, Li J Z, Kong Y, Huang H L, Min L J, Zhou J, Shen F P, Wang Q Q, Yu H
Institute of Immunology, Zhejiang University, 388 Yuhangtang Road, Hangzhou 310058, P. R. China.
J Biomater Sci Polym Ed. 2007;18(5):545-60. doi: 10.1163/156856207780852532.
Polyethylenimine (PEI) is the polymer most commonly used for transferring plasmids into eukaryotes, but its gene-transfer efficiency is lower compared to viral vectors. Receptors targeting PEI combined with ligands can enhance efficiency of gene transfer into the corresponding receptor-positive cells. Using the double-receptor-mediated pathway of viral infection, in this study we synthesized a novel non-viral vector based on PEI combined with two peptides recognizing FGF receptors (peptide YC25) and integrins (peptide CP9) on the cell surface. The dual targeting vector showed a physicochemical character similar to that of PEI, such as pDNA formation, particle size, zeta potential and lower toxicity. In vitro gene transfer showed that the dual-receptor targeted vector (YC25-PEI-CP9) exhibited a markedly higher transgene efficiency in cell lines with positive expression of FGF receptors and integrins, compared with single-peptide-modified PEI or unmodified PEI. In the cells with only integrin-positive expression, YC25-PEI-CP9 mediated a higher transgene expression than PEI but lower than CP9-PEI. The corresponding free peptides could inhibit the transgene efficiency of the peptide-coupled PEI. In vivo gene transfer in tumor-bearing nude mice also demonstrated that the dual-targeting vectors showed a significantly enhanced transfection efficiency in tumors with positive expression of FGF receptors and integrins. The synthesized polymer YC25-PEI-CP9 has the prospect to act as a novel kind of non-viral vector in gene therapy.
聚乙烯亚胺（PEI）是最常用于将质粒导入真核细胞的聚合物，但其基因转移效率与病毒载体相比更低。将靶向PEI与配体相结合可提高基因导入相应受体阳性细胞的效率。本研究利用病毒感染的双受体介导途径，合成了一种基于PEI的新型非病毒载体，该载体结合了两种能识别细胞表面成纤维细胞生长因子受体（肽YC25）和整合素（肽CP9）的肽。双靶向载体表现出与PEI相似的物理化学特性，如形成质粒DNA、粒径、zeta电位以及较低的毒性。体外基因转移实验表明，与单肽修饰的PEI或未修饰的PEI相比，双受体靶向载体（YC25-PEI-CP9）在成纤维细胞生长因子受体和整合素呈阳性表达的细胞系中表现出显著更高的转基因效率。在仅整合素呈阳性表达的细胞中，YC25-PEI-CP9介导的转基因表达高于PEI但低于CP9-PEI。相应的游离肽可抑制肽偶联PEI的转基因效率。在荷瘤裸鼠体内进行的基因转移实验也表明，双靶向载体在成纤维细胞生长因子受体和整合素呈阳性表达的肿瘤中表现出显著提高的转染效率。合成的聚合物YC25-PEI-CP9有望成为基因治疗中一种新型的非病毒载体。
