Novel design of highly biocompatible and dual-network hydrogel films containing apple polyphenol and its potential application in functional package

Biocompatible hydrogel as environmentally friendly materials have been applied in food packaging, pharmaceuticals, and biosensors. However, single-function and relatively poor comprehensive performance for most of biocompatible hydrogel films seriously restricted its practical application in modern food packaging. In the light of these factors, novel biocompatible hydrogel films with highly antimicrobial activity and oxidation resistance were prepared by incorporating apple polyphenols (APP) into polyvinyl alcohol (PVA) and polyacrylamide (PAM) in this work. PAM formed a covalent crosslinked network due to the copolymerization of AM monomers. Furthermore, hydrogen bonds between the hydroxyl groups in APP and the hydroxyl groups in both PVA and PAM contributed to a dual interpenetrating network of PVA/PAM/APP, resulting in a hydrogel composite film with good elongation (301 %) and tensile strength (12.83 MPa). Moreover, the prepared PVA/PAM/APP hydrogel films exhibited excellent antimicrobial properties with antimicrobial diameters of 12 mm and 20 mm against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. Interestingly, the films also possessed good antioxidant and ultraviolet resistance properties. This dual-network hydrogel film addressed the problems of single function and poor comprehensive performance for traditional biocompatible hydrogel films. Therefore, as-prepared multifunctional and biocompatible hydrogel films in this work have great potential application in the food packaging filed.