Thymol incorporation within chitosan/polyethylene oxide nanofibers by concurrent coaxial electrospinning and in-situ crosslinking from core-out for active antibacterial packaging

Abstract

Active packaging systems that are sustainable and capable of delivering antimicrobial agents are in demand in food industry. In this work, Thymol (Thy) was encapsulated into Polyethylene oxide (PEO)/Chitosan (CS) to form core-shell nanofibers via coaxial electrospinning. Various dose of the crosslinker-genipin (GP) were encapsulated into the core layer to achieve in-situ etching crosslink with the CS of shell layer during the electrospinning process. The core-shell structure of the nanofiber was confirmed by transmission electron microscopy. The microstructures, mechanical properties, water vapor permeability, swelling ratios, wettability, thermal stability, biocompatibility and antibacterial properties of the crosslinked films were characterized. The results showed that the crosslinked films had compact structures, strong water resistance, better mechanical property and thermal stability, the sustained release profiles and antioxidant activity were also improved. More importantly, the antibacterial assays indicated that the Thy loaded nanofiber films could effectively inhibit the growth of two common food spoilage bacteria-E. coli and S. aureus.

Keywords: Active packaging; Antibacterial; Coaxial electrospinning; Core-shell; In-situ crosslinking; Sustained release.