TiO_2 光化自由基对 U937 细胞氧化压迫凋亡研究

Radicals Produced by Photoexcited TiO 2 Particles to Oxidatively Stress U937 Cell to Apoptosis

ＴｉＯ２纳米超微粒在３００～４００ｎｍ紫外光照激发下所产生的光生电子空穴对具有极强的光催化反应性能，受其光催化作用，大量活性氧类自由基在细胞内累积，形成细胞内氧化压迫并最终导致细胞凋亡．本研究观察分析了ＴｉＯ２超微粒光激发自由基与氧化压迫性细胞凋亡的关系。

The electron hole pairs generated upon photoexcited nanometer material TiO 2 can effectively induce the monocytic leukemia cells to apoptosis. The average diameter of ultrafine TiO 2 particles prepared by nanometer technology in this study was about 15 nm, and the U937 cell line was used as a subject. TiO 2 particles were proved to be able to oxidatively stress the malignant cells to apoptosis. The mechanism for oxidative stress induced apoptosis by TiO 2 was discussed. The results revealed that photoexcited TiO 2 can catalyze water attached on TiO 2 to produce reactive oxygen species, which are the main reason for stressing cell programmed death.