叶酸修饰壳聚糖季铵盐载基因纳米复合物的制备及体外转染效果的研究

CSTM-g-PEG-FA Nanoparticles for Gene Delivery

目的合成水溶性阳离子聚合物壳聚糖季铵盐,通过叶酸修饰使其具备主动靶向性,并以此作为基因载体进行研究。方法利用双功能聚乙二醇将叶酸连接到壳聚糖季铵盐(CSTM)上,以自组装法制备壳聚糖季铵盐-g-聚乙二醇-叶酸(CSTM-g-PEG-FA)/pDNA纳米复合物,并考察其在293T细胞中的转染效率。结果当壳聚糖季铵盐-g-聚乙二醇-叶酸/pDNA纳米复合物质量比大于等于5时,pDNA能被完全包裹;细胞转染实验中,壳聚糖季铵盐-g-聚乙二醇-叶酸/pDNA纳米复合物的转染效率要明显高于壳聚糖季铵盐/pDNA纳米复合物。结论带正电荷的壳聚糖季铵盐-g-聚乙二醇-叶酸能够通过静电作用包裹pDNA,叶酸修饰使其具备了一定的主动靶向性。

OBJECTIVE To synthesize a water-soluble cationic polymer of quaternized chitosan modified by folic-acid for active targeting and to study its role as a gene vector. METHODS Folic-acid was connected to quaternized chitosan by bi-functional PEG, CSTM-g-PEG-FA/pDNA nanoparticles were prepared by self -assembly, and the gene transfection efficiency mediated by the nanoparti- cles into 293T cells in vitro was observed. RESULTS When weight ratio of CSTM-g-PEG-FA/pDNA was 5 or greater than 5, pDNA was completely wrapped. And the transfection efficiency of CSTM-g-PEG-FA/pDNA nanoparticles was significantly higher than CSTM/ pDNA nanoparticles. CONCLUSION Cationic polymer CSTM-g-PEG-FA can electrostatically bind and condense anionic DNA into nanometersized particles and has the function of active targeting.