二氧化钛纳米颗粒对人角质形成细胞超微结构的影响及毒性效应

TiO_2 nanoparticles on cellular ultrastructure and toxic effect of HaCaT cells

目的:观察无机二氧化钛(TiO2,20～35nm)纳米颗粒进入人角质形成细胞(HaCaT)后的超微结构变化及毒性效应的影响。方法:将TiO2纳米颗粒与HaCaT细胞共孵育4h后,收集细胞。采用透射电镜观察TiO2纳米颗粒引起细胞超微结构变化及在细胞内的分布;采用激光共聚焦扫描显微镜观察TiO2纳米颗粒进入细胞后引起的细胞凋亡和坏死;采用噻唑蓝比色法测定TiO2纳米颗粒对细胞存活的影响。结果:TiO2纳米颗粒通过吞噬方式进入细胞。实验组里TiO2纳米颗粒呈簇状存在于HaCaT细胞内,并使细胞有较大损伤;细胞质有溶解现象,内质网肿胀,线粒体嵴结构紊乱,并肿胀崩解;核周间隙扩大、核固缩。结论:TiO2纳米颗粒具有的毒性效应能够损伤HaCaT细胞超微结构并且抑制细胞的生长。

Objective： To observe the cellular ultrastructure changes and the toxic effects after TiO2 （20-35 nm） nanoparticles invading the human keratinocytes （HaCaT）. Methods： Inorganic TiO2 nanoparticles and HaCaT cells were incubated together for 4 h, and then collected. Under a transmission electron microscopy, the cellular ultrastructure changes caused by TiO2 nanoparticles and its distribution in the cells were observed. A laser scanning confocal microscope was used to observe the apoptosis and necrosis after TiO2 nanoparticles entering the ceils. Methylthiazoletetrazolium colorimetric assay was used to detect the survival rate of cells after TiO2 nanoparticles entering HaCaT cells. Results ： TiO2 nanoparticle entered HaCaT cell through phagocytosis and distributed in cluster. After treated with TiO2 nanoparticles, dissolved cytoplasm and swelled endoplasmic reticulum were observed. The mitochondria were found with disorder mitochondrial crista, and then swelled and disintegrated. Additionly, the perinuclear space was expanded and karyopyknosis was exhibited in the experimental cells. Conclusion： TiO2 nanoparticles damage the HaCaT cells structure and inhibit cell growth.