Lysozyme amyloid fibrils /tannic acid antibacterial nanohydrogels with interpenetrating polymer network structure:...

In this study, the LAFs/TA antibacterial nanohydrogels with interpenetrating polymer network (IPN) structure were prepared by adding different TA concentrations (0, 10, 20, 30, 40 mM). The interaction mechanism, microstructure, physical properties, and antibacterial properties of the LAFs/TA antibacterial nanohydrogels with different TA concentrations were investigated. The results of zeta potential, FTIR analysis and SDS-PAGE demonstrated that both non-covalent interactions (including hydrogen bonds, hydrophobic interaction and electrostatic interaction) and covalent interactions served as the predominant driving forces governing the assembly of LAFs/TA nanohydrogels. Meanwhile, molecular docking was used to provide auxiliary evidence for the interaction mechanism between LAFs and TA. The SEM images confirmed that the LAFs/TA nanohydrogels with 30 mM TA displayed the strongest IPN structure. The rheological behaviors and mechanical properties suggested that the LAFs/TA nanohydrogels with 30 mM TA presented the best viscoelastic modulus and apparent viscosity, as well as outstanding water-holding capacity with a value of 66.12%. Furthermore, the LAFs/TA nanohydrogels with best IPN structure showed the highest antibacterial properties, where their minimum inhibitory concentration against S. aureus and E. coli was both 0.3125 mg/mL, with corresponding inhibition zone diameters of 16.90 mm and 16.38 mm and sterilizing rates of 96.74% and 94.86%, respectively. Overall, these findings provided a theoretical basis for future exploration of amyloid fibril-polyphenol complexes in food preservation.