Superior physicochemical and biological properties of poly(vinyl alcohol)/sericin hydrogels fabricated by a non-toxic gamma-irradiation technique

Gamma irradiation was used to fabricate crosslinked poly(vinyl alcohol)/sericin hydrogels with different sericin concentrations, and the physicochemical and biological properties of the gamma-irradiated poly(vinyl alcohol)/sericin hydrogels were characterized. Following gamma irradiation, the hydrogels had a high gel fraction (80%-95%), implying a high degree of crosslinking. Fourier transform infrared spectra confirmed the crosslinking bonds within the hydrogels, as seen by the characteristic shift in the peak. Furthermore, a low tensile modulus together with a high elongation percentage indicated that the hydrogels were easy to handle. We also showed that all hydrogels released sericin simultaneously. The poly(vinyl alcohol)/sericin hydrogels with high sericin content released more sericin, possibly due to less crosslinking of the hydrogels. When L929 cells were cultured with the hydrogel extracts, the cells were viable and could proliferate, particularly for the cells cultured with the hydrogels containing a high sericin content, which released more sericin. Migration assays also demonstrated that the cells migrated toward the medium extract of hydrogels containing high sericin. We suggest that sterile gamma-irradiated poly(vinyl alcohol)/sericin hydrogels could be used as a wound dressing for the treatment of dry and low-exudate wounds.