本文研究了叶酸修饰硫化镉掺杂二氧化钛(FA-CdS-TiO2)纳米颗粒体外光动力(PDT)灭活HL60细胞的作用效果, 探讨了叶酸修饰增强CdS-TiO2体外PDT效果的作用机理。采用表面修饰的方法制备FA-CdS-TiO2; 通过透射电镜(TEM)、傅里叶红外光谱(FTIR)、荧光激发光谱(FS)方法, 对纳米颗粒进行结构和光学性质的表征; 采用CCK-8法检测细胞活性; 利用荧光探针标记技术分析细胞内活性氧水平和细胞对纳米颗粒的摄取效率。实验结果表明: 叶酸修饰后, 纳米颗粒粒径大小和光学性质符合光敏剂要求, 且不会引起新的细胞毒性; 通过叶酸修饰, 细胞对纳米颗粒的摄取效率提升, 细胞内活性氧产量提高, FA-CdS-TiO2纳米颗粒的PDT效率明显增强, 在FA-CdS-TiO2浓度为20 μg/mL时, 暗室细胞存活率约为85%, 可见光下对HL60细胞的灭活率达78%, 实现了较低暗毒性下的较高PDT灭活效率。

The photocatalytic inactivation efficiency of HL60 cells in vitro based on cadmium sulfide-doped titanium dioxide modified folic acid (FA-CdS-TiO2 ) and the mechanism of folic acid enhancing the effect of CdS-TiO2 on PDT were researched in this paper. The FA-CdS-TiO2 nanoparticles were prepared by surface modification method.The nanoparticles were characterized using transmission electron microscopy (TEM), fourier transform infrared spectroscopy(FTIR), fluorescence excitation spectroscopy(FS).Cell viability was measured by CCK-8 method.The intracellular reactive oxygen species (ROS) and the uptake efficiency of nanoparticles were analyzed by fluorescence probe labeling technique. The results showed that the size and optical properties of nanoparticles after folic acid modification met the requirements of photosensitizer, and the naoparticles don’t cause new cytotoxicity. After folic acid modification, the uptake efficiency of nanoparticles by cells was enhanced, the production of ROS in cells increased, and the PDT efficiency of FA-CdS-TiO2 nanoparticles increased significantly.When the concentration of FA-CdS-TiO2 was 20 μg/mL, the cell survival rate is about 85% under darkroom conditions, the inactivation rate reached 78% under visible light,which indicates that the higher PDT inactivation efficiency under lower dark toxicity is achieved.