Preparation of sponge-like macroporous PVA hydrogels via n-HA enhanced phase separation and their potential as wound dressing

Polyvinyl alcohol (PVA) hydrogels have been widely studied for biomedical applications due to their water solubility, non-toxicity, non-carcinogenicity, and biocompatibility. However, PVA hydrogels prepared by the physical crosslinking method usually do not exhibit a macroporous structure, which limits their application when PVA hydrogels are used alone as a wound dressing. Here, we reported a sponge-like macroporous PVA hydrogel (SPH) prepared by employing polyethylene glycol and nano-hydroxyapatite (n-HA) to enhance phase separation. After being fabricated through cyclic freezing/thawing, the resulting PVA hydrogels possessed macroporous structures. The swelling ratio could reach nearly 1500%, resulting from the excellent water absorption capacity, and the sample could rapidly restore to the original state after being pressed, suggesting a sponge-like characteristic. Furthermore, cell experiments showed that macroporous PVA hydrogels exhibited good biocompatibility and the results of wound closure and H&E analysis consistently indicated that SPHs could significantly promote the wound healing process.