DNA will protect against melanoma
DNA-based sunscreen taught to evolve
Denis Strigun, Naked Science
Ultraviolet radiation is considered one of the main risk factors for melanoma, the most aggressive form of skin cancer. At the molecular level, the negative effect is mediated by damage to mitochondrial and genomic DNA (deformation of chains that complicate transcription and replication), which weakens the barrier functions of the skin and leads to sunburn. Now special creams are often used to prevent such disorders – under certain conditions they can protect the p53 gene. The latter regulates the restoration of mutant cells or, if impossible, their death, and DNA repair. However, such products do not have high reliability, so scientists are looking for alternative ways to protect the skin.
As an alternative, the authors of the new work suggested using DNA films. According to past observations, such structures may have specific electrical and optical properties, but so far they have not been tested for exposure to ultraviolet radiation. As a basis for the films, American scientists took a solution with different concentrations of sodium salt DNA from salmon sperm, which was mixed with deionized water until homogeneity and dried. Then the substance was treated with electromagnetic radiation with different wavelengths. It is known that the strongest associations with melanoma have radiation in the medium–wave (280-315 nanometers) and long-wave (315-400 nanometers) ranges - UVB and UVA, respectively.
Examination of the obtained films using a scanning electron microscope (SEM) showed that, on a micrometer scale, the final biomaterial is a topographically inhomogeneous crystal structure. According to spectrophotometry data, only denser films – from 0.031 milligrams per square millimeter - cope well with the absorption of radiation in the desired range. Moreover, the efficiency of samples with a density of 0.0124 milligrams per square millimeter not only did not decrease, but increased with repeated exposure, especially with long-wave radiation (with a wavelength of 300 nanometers). At the same time, dense films slowed down the evaporation of water from the skin and even contributed to its hydration.
According to the authors, the proposed technology can find application in the perfume industry and medicine. Since DNA films, along with UV protection, stimulate hydration, they can potentially be applied to open wounds without the need for dressing. This will simplify the care of the damaged surface and accelerate healing.
Details of the study are presented in the journal Scientific Reports (Gasperini et al., Non-ionising UV light increases the optical density of hygroscopic self assembled DNA crystal films).
Previously, scientists described a non-invasive method that allows you to stimulate skin pigmentation, causing an artificial tan.
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28.07.2017