Effect of gamma irradiation on biophysical and protection properties of Melanin.

Journal Article

Mady, Magdy M. Ghannam and Mohsen M. . 2012

• Publication Work Type: Research Work
• Magazine \ Newspaper: International Journal of Physical Sciences
• Issue Number: 23
• Volume Number: 7(23)
• Pages: 2952-2959.

Publication Abstract

Melanins are natural pigments distributed in living organisms and they are responsible for pigmentation
of surface structure. In the present work, gel exclusion chromatography, spectrophotometric, and
dielectric relaxation techniques were used to characterize DOPA melanin before and after irradiation
with 60Co gamma rays in the range of 5 to 50 Gy. The results show that the studied melanin is
composed of two structural groups. The extinction absorption coefficient and relative permittivity and
conductivity of melanin sample increased after irradiation with gamma rays and were dose dependent
in manner. These increases were attributed to the formation of melanin aggregation and crosslinks
which result from the growing number of the formed free radicals by radiation. It was concluded from
the results that melanin goes through some structural changes after irradiation with the gamma doses
demonstrated. Further studies were recommended to investigate and evaluate whether these changes
could affect its efficiency as a radio protector against gamma radiation.