the effect of gamma rays on gelatin / chitosan wound dressing physico-chemical and biological properties

In this research, gelatine (gel)/ chitosan (ch) wound dressing was prepared and irradiated with gamma rays from 60co source for wound healing applications. gel-ch composite characterization and functional properties were determined. the structural changes occurring after γ-irradiation at doses from 5 to 25 kgy were studied by using physico-chemical techniques such as electron paramagnetic resonance (epr), fourier transform infrared spectroscopy (ftir), x-ray diffraction (xrd) and electrochemical impedance spectroscopy (eis) studies. the antioxidant capacity was studied using dpph (1, 1-diphenyl-2-picrylhydrazyl free radical) scavenging and the antibacterial activities of staphylococcus aureus and escherichia coli were measured using liquid medium. results revealed that epr spectroscopy of un-irradiated gel-ch showed 2 paramagnetic centers associated with g= 2.077 and g= 2.079. after irradiation, no active centre was appeared. a dose-dependent decrease in the central signal intensity was detected, and the epr signal intensity almost disappeared at 20 kgy. gamma rays caused a slight increase in ionic conductivity. ftir suggested a slight crosslinking phenomenon at 20 kgy. the xrd analysis did not show peaks indicating crystallinity in the 2θ range of 15– 30°. moreover, γ-irradiation elevated the scavenging dpph radical activity (0.75 ± 0.07%). gamma rays did not affect the antibacterial activity of gel-ch wound dressing against pathogenic bacteria. the results showed that the required γ-radiation for sterilization ranged from 5 to 25 kgy. the radiation improved the physico-chemical and biological properties while maintaining the native structural integrity of the gel/ col wound dressing.