基于量子点CdSe两次给药PDT体外灭活HL60的最佳参数实验研究

光漂白是光动力疗法（Photodynamic therapy,PDT）中的一个伴随过程,其存在会影响光敏剂的光敏性能并消耗光敏剂.初步探讨了基于量子点CdSe的光动力疗法中两次给药的问题、给药最佳时间间隔、二次给药的最佳作用参数及正常的与药物处理过的白血病HL60细胞表面的超微结构变化.实验表明,一次给药在量子点浓度为1.0 μmol/L且18 J/cm2的光剂量作用下,PDT效率达到61.0％;经过48 h后,进行二次给药,在量子点浓度为0.75 μmol/L,18 J/cm2光剂量作用下,PDT效率达到了72.1％,较一次给药有了较大幅度提升;扫描电子显微镜（SEM）观察药物作用前后的白血病HL60细胞表面超微结构,结果显示,细胞表面发生了一些显著的变化,由此推测细胞膜可能是量子点CdSe介导的光动力疗法（CdSe-PDT）灭活白血病HL60细胞的一个重要突破口;最后对量子点CdSe光致毒性的机制进行了初步探讨.

The Optimal Parameter of vitro Inactivation on Leukemic HL60 Cells by Double Drug Delivery of CdSe Quantum Dots Based on Photodynamic Therapy

The concentration of photosensitizer may be reduced and the photosensitive properties could be affected during the photodynamic therapy with a coinstantaneous process which is known as photobleaching.The optimal parameter of vitro inactivation on Leukemic HL60 by double drug delivery,the best time interval between the first and second drug delivery and the ultrastructural morphology of treated and untreated HL60 cells,based on Photodynamic Therapy（PDT） are investigated.The results show that the PDT efficiency could achieve 61.0％ for the first drug delivery with the concentration of 1.0 μmol/L and irradiation dosage of 18 J/cm2.After 48 hours,the second drug deliver is carried out.When the final concentration of CdSe is at 0.75 μmol/L,the PDT efficiency is up to 72.1 ％ with the irradiation dosage of 18 J/cm2.The ultrastructural morphology of the treated and untreated HL60 cells are observed by scanning electron microscope（SEM）.The experimental results indicate that significant change occurred,which may be a convincing evidence that cytomembrane is a probable target in Leukemic HL60 cells destruction using CdSe-PDT.A possible mechanism of photoinduced toxicity of CdSe quantum dots is proposed.