Preparation and composition analysis of PVA/chitosan/PDA hybrid bioactive multifunctional hydrogel for wound dressing

An ideal wound dressing should possess self-healing, adhesion and adequate mechanical properties, as well as antioxidant, antimicrobial and biocompatible characteristics. In this study, we developed a self-healing highly adhesive, bioactive multifunctional composite hydrogel (PCP) with dual antimicrobial functions. The hydrogel was constructed using polyvinyl alcohol (PVA), chitosan (CS) and polydopamine nanoparticles (PDA) to achieve rapid wound healing. The one-pot method was utilized to blend these three raw materials at 95 °C, followed by the preparation of PCP with a dual physical network structure through a green freeze/thaw process. The incorporation of PDA nanoparticles not only endowed the hydrogel with excellent adhesion properties (46.7 kPa), photothermal properties (57.6 ℃, 0.6 W·cm⁻²), and DPPH scavenging ability (88.2 %), but also achieved more than 92 % inhibition against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in synergistic effect with the bioantimicrobial agent CS (PCP3). Scanning electron microscopy (SEM) revealed that the microstructures of P, PC, and PCP hydrogels exhibited a dense and permeable pore structure, which facilitates the absorption and removal of wound exudate. Furthermore, thermogravimetric (TGA) analysis demonstrated that PCP hydrogels displayed good thermal stability. In vitro cytotoxicity test on human fibroblasts (L929 cells) indicated that all the hydrogels possessed superior cytocompatibility, with a maximum survival of 101 % for L929 cells. Additionally, cell scratch test confirmed that the hydrogel promotes cell migration, thereby accelerating wound healing. These results suggest that the bioactive multifunctional hydrogel holds significant potential as a wound dressing.