American chemists have synthesized and tested for ability to protect against x-ray radiation, nanoparticles of selenometionina — pheomelanin with atoms of selenium instead of sulfur. The use of biocompatible suspensions of particles allowed to protect living cells from exposure to doses up to six grey, which is above the lethal dose for humans. The results of a study published in the Journal of the American Chemical Society.
People exposed to radiation from natural sources almost every day, as well as unwanted dose of radiation we receive during a medical diagnosis using x-rays, radiotherapy and even travel. People, as well as many plants, animals and fungi to protect from exposure to radiation melanin — a group of heterogeneous biopolymers. There are five types of melanin, one of which, pheomelanin, according to assumptions of scientists, is more effective than other studied melanin protects against exposure to ionizing radiation. The increasing interest in space flights raises the need for effective protection against ionising radiation dose of which in space are particularly large and destructive.
Taking into account the fact that with increasing atomic number, the absorption efficiency of x-ray radiation is significantly increased, Wei Cao (Cao Wei) with colleagues from northwestern University have synthesized nanoparticles of pheomelanin with selenium atoms is sulfur and tested the ability of the received material to protect from ionizing radiation. The researchers conducted the reaction of oxidation of l-DOPA (L-3,4-dihydroxyphenylalanine) in the presence of the natural amino acid selenocysteine, which was formed selenometionina particles with a diameter of about 160 nm. Scientists have also synthesized nanoparticles of pheomelanin and eumelanin to compare the ability to protect from x-rays.