Cu Nanoparticles Have Different Impacts in Escherichia coli and Lactobacillus brevis than Their Microsized and Ionic Analogues

详细信息    查看全文

• 作者：Chitrada Kaweeteerawat ; Chong Hyun Chang ; Kevin R. Roy ; Rong Liu ; Ruibin Li ; Daniel Toso ; Heidi Fischer ; Angela Ivask ; Zhaoxia Ji ; Jeffrey I. Zink ; Z. Hong Zhou ; Guillaume Francois Chanfreau ; Donatello Telesca ; Yoram Cohen ; Patricia Ann Holden ; Andre E. Nel ; Hilary A. Godwin
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：July 28, 2015
• 年：2015
• 卷：9
• 期：7
• 页码：7215-7225
• 全文大小：557K
• ISSN：1936-086X

文摘

Copper formulations have been used for decades for antimicrobial and antifouling applications. With the development of nanoformulations of copper that are more effective than their ionic and microsized analogues, a key regulatory question is whether these materials should be treated as new or existing materials. To address this issue, here we compare the magnitude and mechanisms of toxicity of a series of Cu species (at concentration ranging from 2 to 250 渭g/mL), including nano Cu, nano CuO, nano Cu(OH)₂ (CuPro and Kocide), micro Cu, micro CuO, ionic Cu²⁺ (CuCl₂ and CuSO₄) in two species of bacteria (Escherichia coli and Lactobacillus brevis). The primary size of the particles studied ranged from 10 nm to 10 渭m. Our results reveal that Cu and CuO nanoparticles (NPs) are more toxic than their microsized counterparts at the same Cu concentration, with toxicities approaching those of the ionic Cu species. Strikingly, these NPs showed distinct differences in their mode of toxicity when compared to the ionic and microsized Cu, highlighting the unique toxicity properties of materials at the nanoscale. In vitro DNA damage assays reveal that both nano Cu and microsized Cu are capable of causing complete degradation of plasmid DNA, but electron tomography results show that only nanoformulations of Cu are internalized as intact intracellular particles. These studies suggest that nano Cu at the concentration of 50 渭g/mL may have unique genotoxicity in bacteria compared to ionic and microsized Cu.