PVA/casein/chitosan-based hydrogels with antioxidant bioactive agents for diabetic wound treatment

Wound healing is a complex process, especially in chronic conditions such as diabetes mellitus, often hindered by a prolonged inflammatory stage. Modern wound dressings aim to protect wound beds and accelerate the healing process. Hydrogel dressings have raised special interest due to their ability to retain moisture. This work focused on developing innovative wound dressings with antioxidant properties to improve the healing of chronic wounds, namely through the regulation of the oxidative environment in diabetic wounds. A base hydrogel composed of polyvinyl alcohol (PVA)/casein/chitosan was produced by freeze-thawing method. Astaxanthin and ozonized oils were incorporated in the formulation in different amounts. In general, all hydrogels presented adequate physical, chemical and biological properties to be used as dressing materials, but the ozonized oil containing hydrogel BOz12_2 stood out as the most promising one. Its porous and hydrophilic network provided high water retention and an adequate water vapor transmission rate, while maintaining structural integrity with a slow degradation profile and suitable mechanical strength. The material also exhibited moderate mucoadhesion, ensuring sufficient adherence without compromising wound removal. Importantly, it proved to be non-toxic, non-irritant, and hemocompatible, while simultaneously showing strong antioxidant activity and selective antimicrobial efficacy, including inhibition of vancomycin-resistant Enterococcus faecium strains. • Hydrogel-based dressings were developed to aid healing of diabetic chronic wounds. •Formulation combines polyvinyl alcohol (PVA), casein and chitosan for multifunctionality. •Astaxanthin and ozonized oil were incorporated to get antioxidant and antimicrobial effects. •BOz12_2 hydrogel showed top performance in hydration, mechanical behaviour and biocompatibility. •It was highly antioxidant and inhibited vancomycin-resistant Enterococcus faecium growth.