This study aimed to develop
hydrogels for
tissue adhesion that are biocompatible,
antioxidant, and antibacterial. We achieved this by using
tannic acid (TA) and fungal-derived
carboxymethyl chitosan (FCMCS) incorporated in a
polyacrylamide (PAM) network using
free-radical polymerization. The concentration of TA greatly influenced the physicochemical and
biological properties of the
hydrogels. Scanning electron microscopy showed that the nanoporous structure of the FCMCS
hydrogel was retained with the addition of TA, resulting in a nanoporous surface structure. Equilibrium-swelling experiments revealed that increasing the concentration of TA significantly improved water uptake capacity.
Antioxidant radical-scavenging assays and porcine skin adhesion tests confirmed the excellent adhesive properties of the
hydrogels, with adhesion strengths of up to 39.8 ± 1.2 kPa for 1.0TA-FCMCS due to the presence of abundant phenolic groups on TA. The
hydrogels were also found to be biocompatible with skin fibroblast cells. Furthermore, the presence of TA significantly enhanced the antibacterial properties of the
hydrogels against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Therefore, the developed
drug-free antibacterial and
tissue-adhesive hydrogels can potentially be used as
wound dressings for infected
wounds.