Vanillin/fungal-derived carboxy methyl chitosan/polyvinyl alcohol hydrogels prepared by freeze-thawing for wound dressing applications

In this study, we developed hydrogels using polyvinyl alcohol (PVA), vanillin (V), and a fungus-derived carboxymethyl chitosan (FC) using a freeze-thaw-based method. These hydrogels were strengthened by bonding, including Schiff's base bonding between V and FC and hydrogen bonding between PVA, FC, and V. The physiological properties of these PFCV hydrogels were characterized by FTIR, TGA, compressive mechanical testing, and rheology and water contact angle measurements. FTIR spectra confirmed the effective integration of FC and V into the PVA network. TGA results showed that FC and V enhanced the thermal stability of PFCV hydrogels. Mechanical tests showed increasing the amount of V reduced mechanical properties but did not alter the elastic character of hydrogels. SEM images displayed a well-interconnected porous structure with excellent swelling capacity. In addition, we examined biological properties using cell-based in vitro studies and performed antibacterial assessments to assess suitability for potential wound dressing applications. Prestoblue™ and live/dead cell analysis strongly supported skin fibroblast attachment and viability, DPPH assays indicated substantial antioxidant activity, and PFCV hydrogels showed enhanced antibacterial effects against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In summary, incorporating V and FC into PVA hydrogels appears to be attractive for wound dressing applications.