Functionalization of Dual‐Stimuli Responsive Double‐Network Hydrogels With Silver Nanoparticles for Antibacterial Performance

ABSTRACT

In this report, hydrogels were combined with silver nanoparticles to impart antibacterial properties, yielding robust materials that prevent bacterial infections while maintaining stimulus responsiveness. The antibacterial hydrogel was based on double‐network (DN) hydrogels and prepared via in situ reduction of silver nitrate to silver nanoparticles (AgNPs). The DN hydrogel consists of polyvinyl alcohol‐ co ‐glutaraldehyde and poly(acrylamide‐ co ‐sodium acrylate‐ co ‐N‐isopropylacrylamide), serving as the first and second networks, respectively. The FT‐IR, x‐ray diffraction, and TEM analysis revealed the successful incorporation of silver nanoparticles within the DN hydrogel. The stimulus responsiveness of these hydrogels was assessed through temperature‐ and pH‐dependent swelling, and their thermal properties were also evaluated. The antibacterial efficacy of AgNPs embedded in DN hydrogels was validated by optical density (OD ₆₀₀ ) measurements in suspension culture, which confirmed significant growth inhibition of both Escherichia coli (Gram‐negative) and Staphylococcus aureus (Gram‐positive) bacteria. Interestingly, the assessment of antibacterial activity using an agar diffusion assay with silver nanoparticle‐loaded hydrogels also revealed excellent bacterial growth inhibition against both Escherichia coli and Staphylococcus aureus (p < 0.0001). Hydrogels also showed notable cytocompatibility. These findings highlight the potential of AgNPs‐embedded stimuli‐responsive DN nanocomposite hydrogels, which may serve as promising materials for various biomedical products that require an antibacterial microenvironment.