Abstract The effects of two prominent copper oxide nanoparticles (CuO-NP and Cu2O-NP), with the oxidation state of Cu++ (cupric) and Cu+ (cuprous), on Candida albicans were evaluated. CuO-NP and Cu2O-NP were synthesized and characterized by XRD, FESEM, HR-TEM and Zeta potential. At sub-MIC (50 µg ml−1), both cupric and cuprous oxide NPs prevented yeast-to-hyphae switching and wrinkling behaviour in C. albicans. The mechanism for the antifungal action of the two NPs differed; CuO-NP significantly elicited reactive oxygen species, whereas membrane damage was more pronounced with Cu2O-NP. Real time PCR analysis revealed that CuO-NP suppressed the morphological switching of yeast-to-hyphae by down-regulating cph1, hst7 and ras1 and by up-regulation of the negative regulator tup1. In comparison, Cu2O-NP resulted in down-regulation of ras1 and up-regulation of the negative regulators nrg1 and tup1. Between the two NPs, CuO exhibited increased antifungal activity due to its stable oxidation state (Cu++) and its smaller dimensions compared with Cu2O-NP. Graphical Abstract

中文翻译：

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氧化铜纳米颗粒对白色念珠菌生长和酵母菌向菌丝转变的阻碍

摘要 评估了两种主要氧化铜纳米粒子（CuO-NP 和 Cu2O-NP）对白色念珠菌的影响，其氧化态为 Cu++（铜）和 Cu+（亚铜）。合成了CuO-NP和Cu2O-NP，并通过XRD、FESEM、HR-TEM和Zeta电位对其进行了表征。在亚 MIC (50 µg ml-1) 下，铜和氧化亚铜 NPs 都阻止了酵母菌到菌丝的转换和白色念珠菌的起皱行为。两种纳米颗粒的抗真菌作用机制不同；CuO-NP 显着引发活性氧，而 Cu2O-NP 对膜的损伤更明显。实时 PCR 分析显示，CuO-NP 通过下调 cph1、hst7 和 ras1 以及上调负调节因子 tup1 来抑制酵母菌向菌丝的形态转换。相比下，Cu2O-NP 导致 ras1 的下调和负调节因子 nrg1 和 tup1 的上调。在两种纳米颗粒之间，与 Cu2O-NP 相比，CuO 由于其稳定的氧化态 (Cu++) 和更小的尺寸而表现出更高的抗真菌活性。图形概要