Preparation of poly (vinyl alcohol)/polydopamine/tannin acid composite hydrogels with dual adhesive, antioxidant and antibacterial properties

Sometimes traditional hydrogel dressings for wound repair were difficult to meet the needs of use due to insufficient adhesive, antibacterial and antioxidant properties, so a high-performance and multifunctional polyvinyl alcohol-based hydrogel dressing was prepared using poly (vinyl alcohol) (PVA), polydopamine (PDA), and tannic acid (TA) for dual adhesive, antibacterial, and antioxidant properties in this study. The structure and morphology of the hydrogel were analyzed by FTIR and SEM. The effects of the concentrations of PVA, TA and PDA on the swelling, antioxidation and adhesion of the hydrogel were investigated. The results showed that the maximum equilibrium swelling of the hydrogels were all below 6 %, and they had good anti-swelling effects in different solution environments. The maximum skin adhesive strength of the hydrogels was 75.7 kPa, and the scavenging efficiencies against free radicals were all above 90 %. Due to the inherent bacteriostatic ability of TA and the good photothermal conversion efficiency of PDA, the hydrogels could inhibit E. coli and S. aureus up to 99 %. The hydrogels possessed excellent dual antioxidant, antibacterial and adhesive properties, which greatly broadened the applications of PVA composite hydrogels.