Researchers at Northwestern University have developed a new biomaterial, selenomelanin, that can help protect people from radiation. The new substance, chemically synthesized and produced by bacteria, helps protect cells from radiation more effectively than other forms of melanin. One day, it may be used in sunscreens, medical treatments, or for long-term spaceflight as a radioprotective material.
In medical imaging, air travel, and space travel, there is often unwanted exposure to radiation. Traditional radioprotective materials such as lead are heavy, making transportation and use difficult and in many cases unfeasible. The researchers sought to address this challenge in a novel way.
They found selenomelanin protects skin cells from 6 gray (.06 rad) of radiation, a level that is greater than the lethal dose for a human. The cells maintained a normal cell cycle and overall did not die at a greater rate than controls that were not irradiated. The researchers were also able to produce selenomelanin with genetically engineered bacteria and observed radioprotective events.
“With an abundant source of selenium in the environment, some organisms may have been able to adapt to extreme circumstances such as radiation through the beneficial effects of selenomelanin,” said Nathan Gianneschi, a professor at Northwestern who led the research.
“Our work points to the possibility that melanin may act as a repository for selenium, helping ensure that organisms benefit from it,” said Wei Cao, lead author of the study. “Selenomelanin may play an important role in how selenium is metabolized and distributed biologically. It’s an area for further investigation.”
The researchers envision that selenomelanin could be used as a sunscreen or as a radioprotective material for air and space travel.
The article in the Journal of the American Chemical Society: Selenomelanin: An Abiotic Selenium Analogue of Pheomelanin