Effect of gamma irradiation on biophysical and protection properties of Melanin.
Mady, Magdy M. Ghannam and Mohsen M. . 2012
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.
The in vitro release studies showed an initial rapid 5-FUrelease followed by a sustained release profile. The in vitro cytotoxicity of C-5-FU PLGA NPs showedsignificant inhibition of colon cancer…
Abstract: Due to widespread of human exposure to electromagnetic fields, there has been increasing public concern
about the potential health risks from low-frequency electromagnetic fields;…
Polymeric films based on polyvinyl alcohol (PVA) doped with titanium chloride (TiCl3) at different
weight percent ratios were prepared using the solvent cast technique. The structural…