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.