Novel polyvinyl alcohol-borax hydrogel with potential to accelerate skin wound healing in aquatic models: zebrafish and tilapia.

Skin integrity is vital for fish survival, as injuries compromise the protective barrier and increase infection risk. This study introduces a simple and eco-friendly strategy to enhance skin wound healing in aquatic species using a PVA+borax hydrogel. The hydrogel, characterized by tunable cross-linking and biodegradability, was applied to zebrafish and tilapia via water immersion to evaluate its therapeutic efficacy. Full-thickness wounds were created in zebrafish via laser ablation for precise assessment of closure kinetics. Among tested conditions, the PVA+borax formulation significantly accelerated wound closure compared with individual components and untreated controls. Acute toxicity and behavioural analyses confirmed high biocompatibility and no developmental or neurological abnormalities up to higher concentration use (0.01-100 ppm). qRT-PCR analysis showed that treatment reduced injury-induced inflammatory and macrophage markers, suggesting modulation of inflammatory responses during wound healing. Concurrent changes in basement membrane-related genes indicate coordinated extracellular matrix remodelling, consistent with progression towards tissue repair and balanced regeneration. Both zebrafish and tilapia exhibited faster re-epithelialization and collagen deposition under hydrogel treatment. These findings suggest that PVA+borax hydrogel is a safe, cost-effective and promising platform for accelerating wound healing in aquatic models, with translational potential in both biomedical research and aquaculture health management.