Department of Chemistry, Kanbar Laboratory for Nanomaterials, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.
Nanotechnology. 2011 Mar 11;22(10):105101. doi: 10.1088/0957-4484/22/10/105101. Epub 2011 Feb 2.
Metal oxide nanoparticles have marked antibacterial activity. The toxic effect of these nanoparticles, such as those comprised of ZnO, has been found to occur due to an interaction of the nanoparticle surface with water, and to increase with a decrease in particle size. In the present study, we tested the ability of ZnO nanoparticles to affect the viability of the pathogenic yeast, Candida albicans (C. albicans). A concentration-dependent effect of ZnO on the viability of C. albicans was observed. The minimal fungicidal concentration of ZnO was found to be 0.1 mg ml(-1) ZnO; this concentration caused an inhibition of over 95% in the growth of C. albicans. ZnO nanoparticles also inhibited the growth of C. albicans when it was added at the logarithmic phase of growth. Addition of histidine (a quencher of hydroxyl radicals and singlet oxygen) caused reduction in the effect of ZnO on C. albicans depending on its concentration. An almost complete elimination of the antimycotic effect was achieved following addition of 5 mM of histidine. Exciting the ZnO by visible light increased the yeast cell death. The effects of histidine suggest the involvement of reactive oxygen species, including hydroxyl radicals and singlet oxygen, in cell death. In light of the above results it appears that metal oxide nanoparticles may provide a novel family of fungicidal compounds.
金属氧化物纳米颗粒具有显著的抗菌活性。这些纳米颗粒（如 ZnO 纳米颗粒）的毒性作用被发现是由于纳米颗粒表面与水的相互作用引起的，并且随着颗粒尺寸的减小而增加。在本研究中，我们测试了 ZnO 纳米颗粒对致病性酵母白色念珠菌（C. albicans）活力的影响。观察到 ZnO 对 C. albicans 活力的浓度依赖性影响。发现 ZnO 的最小杀菌浓度为 0.1 mg ml(-1) ZnO；该浓度导致 C. albicans 的生长抑制超过 95%。当在生长对数期添加 ZnO 时，它也抑制了 C. albicans 的生长。添加组氨酸（羟基自由基和单线态氧的猝灭剂）会根据其浓度降低 ZnO 对 C. albicans 的作用。添加 5 mM 组氨酸后，几乎完全消除了抗真菌作用。用可见光激发 ZnO 会增加酵母细胞死亡。组氨酸的作用表明活性氧物种（包括羟基自由基和单线态氧）参与细胞死亡。鉴于上述结果，似乎金属氧化物纳米颗粒可能提供了一类新型的杀真菌化合物。
