糖原作为新型基因载体的研究

Glycogen as Novel Gene Vector

摘要:

为探索功能化糖原作为基因载体的可行性和有效性，利用二乙烯三胺修饰糖原合成了氨基化的糖原衍生物（NH₂-Gly），利用红外光谱对其结构进行了表征；采用凝胶电泳阻滞实验考察了NH₂-Gly对pEGFP的负载能力和保护能力；通过MTT和溶血实验考察了NH₂-Gly的生物相容性；利用激光共聚焦显微镜和流式细胞术分析了NH₂-Gly/pEGFP在NIH 3T3细胞内的转染效果。结果表明，制备的NH₂-Gly为均匀分散的纳米粒子，粒径约为80 nm，带有显著的正电荷。与相对分子质量为25 000的聚乙烯亚胺（PEI 25k）相比，NH₂-Gly具有良好的生物相容性。NH₂-Gly可有效络合pEGFP并保护其免受核酸酶的降解，且大幅提高了pEGFP在NIH 3T3细胞中的转染效率，几乎与PEI 25k相当。因此，糖原有望作为安全高效的基因载体。

Abstract:

This study aims to explore the feasibility and effectiveness of functionalized glycogen as a gene vector. Aminated glycogen (NH₂-Gly) was synthesized through functionalization of glycogen with diethylenetriamine. The structure of NH₂-Gly was characterized by infrared spectra. The encapsulation and protection of pEGFP by NH₂-Gly was studied by gel retardation assay. The biocompatibility of NH₂-Gly was investigated by MTT and hemolysis assay. The transfection efficiency of NH₂-Gly/pEGFP in NIH 3T3 cells was analyzed by confocal laser scanning microscope and flow cytometry. The results showed that the prepared NH₂-Gly was uniformly dispersed with a particle size of about 80 nm and a significant positive charge. Compared with PEI 25 k, NH₂-Gly had good biocompatibility. NH₂-Gly could effectively encapsulate pEGFP and protect it from degradation by nuclease. NH₂-Gly significantly increased the transfection efficiency of pEGFP in NIH 3T3 cells, which was almost equivalent to that of PEI 25 k. Therefore, glycogen is expected to be a safe and efficient gene vector.