Antioxidant nanoparticles could treat sepsis | July 17, 2017 Issue - Vol. 95 Issue 29 | Chemical & Engineering News
Volume 95 Issue 29 | p. 11 | Concentrates
Issue Date: July 17, 2017

Antioxidant nanoparticles could treat sepsis

Ceria-zirconia nanoparticles combat reactive oxygen species and reduce inflammation
By Emma Hiolski
Department: Science & Technology
News Channels: Materials SCENE, Nano SCENE, Biological SCENE, Materials SCENE, Nano SCENE, Biological SCENE
Keywords: nanomedicines, sepsis, ceria-zirconia nanoparticles, inflammation
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Ceria-zirconia nanoparticles (red) target inflammation in the intestine of a mouse with sepsis (right), but do not enter healthy tissue (left, blue).
Credit: Angew. Chem. Int. Ed.
A two-panel figure shows fluorescent microscopic images of healthy mouse intestine tissue (in blue, on left) and intestine tissue from a mouse with sepsis (right). Ceria-zirconia nanoparticles (red) target inflammation in the septic tissue.
 
Ceria-zirconia nanoparticles (red) target inflammation in the intestine of a mouse with sepsis (right), but do not enter healthy tissue (left, blue).
Credit: Angew. Chem. Int. Ed.

Sepsis occurs when the body’s immune response to an infection spirals out of control. The inflammatory signals designed to kill bacteria and other invaders spread beyond the infection site and in the worst cases lead to organ failure and death. The only effective treatment for sepsis is antibiotics, but they target only the source of the infection, not its symptoms. To combat that inflammation, scientists at Seoul National University, led by Seung-Hoon Lee and Taeghwan Hyeon, synthesized ceria-zirconia nanoparticles to scavenge reactive oxygen species (ROS) that damage and kill cells. The cerium ion Ce3+ mimics natural catalysts that remove superoxide and hydroxyl radicals, so a high Ce3+:Ce4+ ratio in the particles is important for treating inflammation. Shifting to the +3 oxidation state is energetically unfavorable, however, so the researchers added Zr4+ ions to the nanoparticles to stabilize the Ce3+:Ce4+ ratio and improve their antioxidant capabilities over ceria-only nanoparticles (Angew. Chem. Int. Ed. 2017, DOI: 10.1002/anie.201704904). The team tested the ceria-zirconia nanoparticles in cell and animal models of inflammation and sepsis and discovered that the nanoparticles targeted inflammation, reduced ROS, and prolonged the survival of mice with sepsis with only a single, low dose. The authors note that the nanoparticles “have the potential as a therapeutic nanomedicine for treating ROS-related inflammatory diseases.”

 
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