Multiple Dynamic Covalent Bond Crosslinked Ionic Liquids-Based Hydrogel with Stretchable, Rapid Self-Healing and Antibacterial Activity Properties

The development of antibacterial hydrogel with stretchable and self-healing properties is an urgent problem in the field of biomedical engineering. Herein, a series of hydrogels with antibacterial activity was successfully fabricated using polyvinyl alcohol (PVA), borax, 4-formylphenyl-β-D-allopyranoside (HLC), 3,3′-dithiobis (propionohydrazide) (DPH) and ionic liquid, 1-aminopropyl-3-methylimidazolium bromide (C3MimNBr). The hydrogels were formed via in situ crosslinking through multiple dynamic covalent bonds, primarily including borate ester bonds, imine bonds and acylhydrazone bonds. A Field Emission Scanning Electron Microscope (FE-SEM) revealed that the formed hydrogels possessed a typical three-dimensional network structure. Notably, the interpenetrating network structure endowed the hydrogels with excellent stretchability and self-healing capability, as demonstrated by their ability to be molded into various shapes and stretched up to five times their original length. Furthermore, the mechanical properties of the hydrogel were affected by the amount of the ionic liquid added. Antibacterial evaluation using the colony counting method showed that the hydrogels exhibited outstanding antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In summary, the multifunctional hydrogels, with favorable stretchability and antibacterial activity, represent promising alternative materials for biomedical engineering applications.