Selenomelanin-- Resistant to X-ray Radiation

wallpapers Innovation 2020-07-16

Absorption of X-ray By Pheomelanin

Melanin is widely found in the body and is part of the body's defense mechanism. When summer arrives and the sun becomes more toxic, melanin in the skin protects us from mild uv damage. The shorter the wavelength of light, the more penetrating. UVB rays (320-280 nm) only reach the surface of the skin, but prolonged exposure is sufficient to cause cancer, while shorter X-ray wavelengths (0.01 to 10 nm) can penetrate soft tissue and image bone directly. High doses of X-ray radiation can cause cancer. Although more and more people are aware of sun protection, how to protect themselves from X-ray radiation is also an important topic.
The study found that many melanin organisms survived in places exposed to high levels of radiation, such as the Chernobyl nuclear power plant and orbiting spacecraft. Melanin may protect these organisms by directly attenuating radiation or quenching free radicals. The study also found that among many types of melanin, Pheomelanin, which contains a benzothiazide structure, seems to absorb X-rays more efficiently.

The Preparation of Selenomelanin

In the selenium title "Selenomelanin: In this paper, An Abiotic Selenium Analogue of Pheomelanin "was used to replace the sulfur in the structure of benzodiazepine with Selenium of the same family, the fourth cycle Selenium was used to prepare Selenomelanin nanoparticles with similar structure, and it was found that it can efficiently protect NHEK cells from high-dose X-ray damage.
Selenomelanin has not been found in nature. If it is found to exist in the future, the melanin must be more resistant to radiation because the X-ray absorption coefficient is proportional to the fourth power of the atomic number of the element. For this reason, it makes sense to develop a synthetic route to be the first to obtain melanin in the laboratory and to evaluate its properties. The selenium-containing melanin nanoparticles were prepared by using selenium cysteine and L-dopamine as raw materials through chemical synthesis and live bacteria in situ biosynthesis respectively. Chemical synthesis and Characterization of Selenomelanin Solid magnetic studies have shown that Selenomelanin has a similar structure to natural brown melanin, the pigment found in red hair. This material can well protect the cell cycle changes caused by X-ray (especially the stagnation in the late stage of cell DNA synthesis), and the maximum protective dose reaches 6Gy, which is much higher than the clinical radiotherapy dose. The protection mechanism was also discussed and it was found that Selenomelanin was superior to other melanin in physical protection, antioxidant and gene expression regulation. Professor Gianneschi believes that selenium-containing melanin should or already exists in nature and has not been discovered.

Selenomelanin Has a Promising Future

Whether from the treatment of skin diseases or cancer prevention, the preparation of Selenomelanin has a pioneering significance. In the future, it may play a key role in the treatment of psoriasis, vitiligo and planus. In addition, due to selenium's scavenging effect on free radicals, it can be predicted that this invention will lead to another wave of skin care products to delay aging in the near future.