Reactive oxygen species generation by copper(II) oxide nanoparticles determined by DNA damage assays and EPR spectroscopy.
Reactive oxygen species generation by copper(II) oxide nanoparticles determined by DNA damage assays and EPR spectroscopy.
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DOI：
10.1080/17435390.2017.1293750
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发表时间：
2017-03
期刊：
影响因子：
5
通讯作者：
Brumaghim JL
中科院分区：
文献类型：
--
作者：
Angelé-Martínez C;Nguyen KV;Ameer FS;Anker JN;Brumaghim JL
氧化铜（II）纳米颗粒（NPCuO）具有许多工业应用，但由于它们产生活性氧（ROS）而具有高度细胞毒性。目前尚不清楚破坏性的ROS是否主要由纳米颗粒中浸出的铜产生，或者纳米颗粒表面是否起着重要作用。为了解决这个问题，我们从含有溶解铜的上清液中分离出纳米颗粒，并测量了它们在加入过氧化氢、抗坏血酸盐或两者的情况下破坏质粒DNA的能力。虽然来自上清液的DNA损伤（使用电泳测定法测量）可以仅通过溶解的铜离子来解释，但是在抗坏血酸盐存在下由纳米颗粒造成的损伤比通过溶解的铜可以解释的高一个数量级，因此必须主要取决于纳米颗粒表面。DNA损伤是时间依赖性的，较短的孵育时间导致较高的EC 50值。羟基自由基是由NPCuO/过氧化氢产生的主要ROS，如通过EPR测量所确定的; NPCuO/过氧化氢/抗坏血酸条件产生抗坏血酸、羟基和超氧化物自由基。因此，NPCuO通过几种机制产生ROS，可能包括来自表面或溶解的铜离子的Fenton-like和Haber-Weiss反应。当NPCuO悬浮液用含有浸出的铜、洗涤的NPCuO或溶解的铜溶液的上清液替换时，观察到相同的自由基物质。总的来说，NPCuO在抗坏血酸存在下产生的ROS和DNA损伤比简单地从溶解的铜中解释的要多得多，并且NPCuO表面必须发挥很大的作用。
Copper(II) oxide nanoparticles (NPCuO) have many industrial applications, but are highly cytotoxic because they generate reactive oxygen species (ROS). It is unknown whether the damaging ROS are generated primarily from copper leached from the nanoparticles, or whether the nanoparticle surface plays a significant role. To address this question, we separated nanoparticles from the supernatant containing dissolved copper, and measured their ability to damage plasmid DNA with addition of hydrogen peroxide, ascorbate, or both. While DNA damage from the supernatant (measured using an electrophoresis assay) can be explained solely by dissolved copper ions, damage by the nanoparticles in the presence of ascorbate is an order of magnitude higher than can be explained by dissolved copper and must therefore depend primarily upon the nanoparticle surface. DNA damage is time-dependent, with shorter incubation times resulting in higher EC50 values. Hydroxyl radical is the main ROS generated by NPCuO/hydrogen peroxide as determined by EPR measurements; NPCuO/hydrogen peroxide/ascorbate conditions generate ascorbyl, hydroxyl, and superoxide radicals. Thus, NPCuO generate ROS through several mechanisms, likely including Fenton-like and Haber-Weiss reactions from the surface or dissolved copper ions. The same radical species were observed when NPCuO suspensions were replaced with the supernatant containing leached copper, washed NPCuO, or dissolved copper solutions. Overall, NPCuO generate significantly more ROS and DNA damage in the presence of ascorbate than can be explained simply from dissolved copper, and the NPCuO surface must play a large role.