叶酸偶联率对叶酸-壳聚糖纳米粒靶向抗瘤性的影响

Effects of Folic Acid Coupling Rate on Targeted Resistance to Cancer Cells of Folic Acid-Chitosan Nanoparticles

目的研究在不同叶酸偶联率下,叶酸-壳聚糖纳米粒对宫颈癌细胞系HeLa凋亡的影响。方法还原胺法合成不同叶酸偶联率的叶酸-壳聚糖复合物,紫外分光光度仪测定叶酸偶联率。将复合物包裹绿色荧光蛋白表达基因,电子显微镜观察纳米粒形态及大小。转染HeLa细胞7d后流式细胞仪测定转染效率及凋亡率。结果通过改变叶酸及壳聚糖不同的反应比,共合成四种不同偶联率的叶酸-壳聚糖复合物,偶联率依次是3%、7.5%、11.2%和17%。透射电子显微镜显示叶酸-壳聚糖-DNA纳米粒为近似球型,表面光滑、均质的纳米粒。上述纳米粒粒径分别为(289.6±0.7)nm、(78.1±0.3)nm、(186.6±0.6)nm和(212.2±0.5)nm。转染7d后叶酸偶联率为7.5%的纳米粒转染效率最高,与未偶联纳米粒相比,差异具有统计学意义(P<0.01)。凋亡率与未偶联纳米粒相比,差异具有统计学意义(P<0.01)。结论经叶酸偶联后,可以提高叶酸-壳聚糖纳米粒的HeLa细胞摄取量,增强其促肿瘤细胞凋亡作用,叶酸偶联率对纳米粒粒径、转染效率及细胞凋亡有一定影响。

Objective To study the effect of folic acid coupling rate on anti-tumor property of folic acid-chitosan nanoparticles.Methods Folate-chitosan complexes at different folic acid coupling rate were synthesized by using a reductive amidation reaction.The green fluorescent protein expression gene was encapsulated with complexes.The shape and size of nanoparticles were detected by electron microscope.The transfection efficiency and cell apoptosis rate were evaluated through the flow cytometer.Results The nanoparticles presented the different sizes of（289.6±0.7）nm,（78.1±0.3）nm,（186.6±0.6）nm and（212.2±0.5）nm at different coupling ratio with 3%、 7.5%、11.2% and 17% with smooth and round shape.The transfection efficiency of nanoprticles at 7.5% coupling ratio was higher than unmodified nanoparticles（P0.01）.Compared with the unmodified nanoparticles,the apoptosis rate of cells treaded by nanoprticles at 7.5% coupling ratio was higher and difference has statistical significance（P0.01）.Conclusion After modified by folic acid,the drug intake and apoptosis rate of HeLa cells are both enhanced.The folic acid coupling rate can influence the nanoparticles size,transfection efficiency and cell apoptosis.