Natural Biopolymer–Hydrogel Nanofibers for Antibacterial Applications

This study used a suitable solvent such as deionized water and aqueous acetic acid to dissolve completely polymer blends such as gelatin: chitosan: pullulan (G: CS: PUL) with mixing ratios of 80:10:10, 60:20:20, 40:30:30, and 20:40:40, respectively. The properties of natural polymer mixtures, viscosity, surface tension, and electrical conductivity were examined, and the fiber diameter and nanofiber diameter distribution were measured. Increasing the gelatin content from 20% to 80% in the G: CS: PUL increases the properties of biopolymer solutions, such as viscosity, surface tension, and electrical conductivity of 157%, 14%, and 37%, respectively. In addition, increasing the gelatin content reduces the contact angle by 55%. In other words, the average diameter of the nanofibers increased from 91.177 ± 27.162 to 212.46 ± 67.91 nm with the increase of the gelatin content by 40–100% in the blends and obtaining uniform fibers without beads, which enhanced the ability of nanofibers for releasing into the aqueous media and enhancing their use in packaging food such as (80:10:10 and 60:20:20). Moreover, the blend ratio 60:30:30 (G:CS: PUL) had better resistance to bacterial growth; the inhibition zone diameters were 26 and 23 mm for E. coli and S. aureus and had better average crystalline size and crystallinity.