cientists think that new nanoparticles called nanoceria, made out of cerium oxide, are strong antioxidants. So to test the possibility that nanoceria might be used to fight cellular damage from reactive oxygen species (ROS), a team from University of Central Florida treated mice with retinal defects, similar to those in people with age related macular degeneration, and found positive results.
The National Science Foundation reports:
In a nanocrystalline form, cerium oxide is a powerful antioxidant because its latticework crystal structure has many vacancies that can capture oxygen, and the material has a large surface area. Self showed that nanoceria mimic the activity of superoxide dismutases (SOD), an antioxidant that can stop the deadly chain reactions caused by ROS.Nanoceria are also able to regenerate their antioxidant abilities. “Due to this catalytic property,” explains Seal, “repeated dosing with nanoceria may not be needed, as it is with certain antioxidant vitamins.”
In a biological paradox, ROS are actually required for some beneficial cellular reactions. Fortunately, nanoceria do not deactivate all ROS. Rather, says Seal, “they reduce the amount of ROS to a certain low level, thus striking a perfect balance.”
Because they are bombarded by light and have a very high rate of oxygen metabolism, cells in the retina encounter relatively high numbers of ROS. Seal and his colleagues hypothesized that ROS may represent an “Achilles’ heel” of blinding diseases, which can be specifically targeted using cerium oxide nanoparticles.
To test their hypothesis, the researchers used mice whose eyes have retinal defects similar to those found in patients with age-related macular degeneration. They treated some of the mice with nanoceria and then compared the number of lesions that occurred in their retinas. The researchers’ results, published in Nature Nanotechnology, indicate that the nanoceria prevented about 85 percent of the damage to the retina.