Photoactive antimicrobial PVA hydrogel prepared by freeze‐thawing process for wound dressing

A freeze‐thawing process was employed to produce both rose bengal (RB)/polyvinyl alcohol (PVA) and benzophenone (BP)/PVA hydrogels, respectively. Results indicated that only RB incorporated PVA (RB/PVA) could form hydrogel after undergoing three cycles of freeze‐thawing process; One of the cycles should be conducted by freezing at −15°C ± 3°C for 18 h followed by thawing at 25°C for 6 h. The structural features and functional properties of the RB/PVA hydrogel were investigated by FTIR, XRD, SEM evaluations, and photo‐induced antimicrobial functions were examined as well. Release of RB from the RB/PVA hydrogel was examined by UV‐Vis spectroscopy. The freeze‐thawed RB/PVA hydrogel showed antimicrobial abilities against both E. coli and S. aureus under the exposure to fluorescence light as well as UVA (365 nm) light.