A Multifunctional Antibacterial Hydrogel with Injectable, Antifouling, and Conductive Properties

Zwitterionic hydrogels have shown promise as effective antifouling materials in wound dressing applications owing to their robust hydrate layer that offers protection against microbial infections. However, the traditional covalently crosslinked zwitterionic hydrogels may not be sufficient to adapt to irregular injury sites and fully address microbial infections within the wound. Herein, we propose an injectable zwitterionic hydrogel that utilizes dynamic hydrazone chemistry via aldehyde and hydrazide functional groups and contains N-halamine antibacterial agents. The dual dynamic exchangeable covalently and physically crosslinked structure resulting from the combination of hydrazone bonds and zwitterion interactions facilitates instantaneous gelation (within a few seconds) and extreme stability without any degradation (for over 2 months). The hydrogels exhibit remarkable fouling resistance against proteins and bacteria while demonstrating excellent antibacterial performance in vitro without compromising cytocompatibility. More importantly, we demonstrate their inherent conductivity properties and sensitivity to external pressure. The combination of the injectability, antifouling, antibacterial, cytocompatibility, and electrical conductivity properties achieved offers the potential to expand the utility of zwitterionic hydrogels in biological applications.