Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Antioxidants (Basel). 2016 Jul 11;5(3):23. doi: 10.3390/antiox5030023.
Oxidative stress in a biological system is often defined as a redox imbalance within cells or groups of cells within an organism. Reductive-oxidative (redox) imbalances in cellular systems have been implicated in several diseases, such as cancer. To better understand the redox environment within cellular systems, it is important to be able to characterize the relationship between the intensity of the oxidative environment, characterized by redox potential, and the biomolecular consequences of oxidative damage. In this study, we show that an in situ electrochemical potential gradient can serve as a tool to simulate exogenous oxidative stress in surface-attached mammalian cells. A culture plate design, which permits direct imaging and analysis of the cell viability, following exposure to a range of solution redox potentials, was developed. The in vitro oxidative stress test vessel consists of a cell growth flask fitted with two platinum electrodes that support a direct current along the flask bottom. The applied potential span and gradient slope can be controlled by adjusting the constant current magnitude across the vessel with spatially localized media potentials measured with a sliding reference electrode. For example, the viability of Chinese Hamster Ovary cells under a gradient of redox potentials indicated that cell death was initiated at approximately 0.4 V vs. standard hydrogen electrode (SHE) media potential and this potential could be modified with antioxidants. This experimental platform may facilitate studies of oxidative stress characteristics on different types of cells by enabling imaging live cell cultures that have been exposed to a gradient of exogenous redox potentials.
在生物系统中，氧化应激通常被定义为细胞内或生物体中细胞群内的氧化还原失衡。细胞系统中的还原性-氧化性（氧化还原）失衡与几种疾病有关，如癌症。为了更好地了解细胞系统中的氧化还原环境，能够描述氧化环境的强度与氧化损伤的生物分子后果之间的关系非常重要。在这项研究中，我们表明，原位电化学电势梯度可以作为一种工具，模拟表面附着的哺乳动物细胞中外源性氧化应激。设计了一种培养板，可在暴露于一系列溶液氧化还原电势后直接对细胞活力进行成像和分析。体外氧化应激测试容器由一个细胞生长瓶组成，瓶内装有两个支持沿瓶底的直流电的铂电极。通过调整容器内的恒流大小来控制施加的电势范围和梯度斜率，并用滑动参考电极测量空间局部介质电势进行测量。例如，在氧化还原电势梯度下的中国仓鼠卵巢细胞的活力表明，细胞死亡大约在相对于标准氢电极（SHE）介质电势的 0.4 V 时开始，并且可以用抗氧化剂来修饰该电势。这个实验平台可以通过使已经暴露于外源性氧化还原电势梯度的活细胞培养物成像，从而促进对不同类型细胞的氧化应激特征的研究。
