A new form of selenium-enriched melanin, called selenomelanine , has been developed by researchers at Northwestern University in the United States.
This new biomaterial could be a shield for human tissue against harmful radiation, both in X-ray treatments and in space flights.
Melanin is found in most organisms in the plant and animal kingdoms, as well as in bacteria and fungi. Five types of melanin have been observed in nature, with pheomelanin (the pigment in red hair) absorbing X-rays more efficiently than the more common eumelanin (black and brown pigments in dark hair).
But the team of researchers hypothesized that a new type of melanin, enriched with selenium instead of sulfur, would provide better protection against X-rays. The team synthesized the new biomaterial, which they called "selenomelanin," and used it. to treat living cells . After receiving a radiation dose that would be lethal to a human, only cells treated with selenomelanine still exhibited a normal cell cycle.
Additional tests with bacteria showed that selenomelanine can be biosynthesized , meaning that living cells fed appropriate nutrients can produce selenomelanine on their own and retain its radioprotective properties.
Currently, melanin samples are currently in orbit on the International Space Station, and are being studied by another research team to determine the material’s response to radiation exposure .
Compared to the weight and volume of traditional radioprotective materials like lead, melanin is lighter and more flexible.
The research, which is published in the Journal of the American Chemical Society , has been led by Nathan Gianneschi , Professor of Chemistry at Northwestern’s Weinberg College of Arts and Sciences and associate director of the International Institute for Nanotechnology.