Oxygen‐Vacancy‐Mediated ROS Generation Mechanism of MgO Nanoparticles against Escherichia coli

Abstract

The antibacterial property of MgO nanomaterials was strongly dependent on the surface defect-mediated reactive oxygen species (ROS, such as * O 2 À , * OH and H 2 O 2 ) generation, which makes the construction of surface defects become very significant. This work demonstrated that the anti-Escherichia coli (E. coli) activity of MgO nanoparticles was obviously enhanced via N 2 calcination processes, with the antibacterial ratio of 95.7 % for MgO nanoparticles calcined in N 2 at 650 °C. The electron spin resonance (ESR) and X-ray photoelectron spectroscopy (XPS) results indicated that rich oxygen vacancies on the surface of designed MgO nanoparticles could increase adsorbed oxygen content and further promote the activation of O 2 and generation of ROS. The fluorescence probe results also verified that high-level ROS could accumulate in E. coli exposed to MgO nanomaterials. Besides, * O 2 À played a dominant role in the antibacterial property of MgO nanoparticles compared with * OH and H 2 O 2 . The above findings illustrated the correlation between oxygen vacancy-mediated ROS generation and enhanced antibacterial activity in MgO nanoparticles calcined under N 2 atmosphere.

Intestinal Absorption of Nanoparticles to Reduce Oxidative Stress and Vasoconstriction for Treating Diabetic Nephropathy

“…High glucose induced the HK-2 cells to produce a large amount of ROS. The DCFH-DA probe was oxidized by ROS to generate green fluorescence for quantitative analysis of intracellular ROS levels Figure A,B shows that free Tel and free CAN reduced the ROS level to a certain extent.…”

“…The DCFH-DA probe was oxidized by ROS to generate green fluorescence for quantitative analysis of intracellular ROS levels. 51 Figure 4A,B shows that free Tel and free CAN reduced the ROS level to a certain extent. However, the green fluorescence intensity of the Tel/CAN@CS-DA group was much lower than that of free Tel, CAN, and Tel/CAN@CS groups, which was closer to that of the control group.…”