Chitosan-poly (vinyl alcohol) films enriched with Marrubium peregrinum extract: a promising biomaterial for wound healing applications

Abstract

Bioactive wound dressings based on natural polymers and plant-derived compounds are of great interest due to their biocompatibility, biodegradability, and therapeutic potential. The incorporation of plant extracts with antioxidant and antimicrobial properties into polymeric matrices is a promising approach for enhancing the functionality of wound healing materials. In this study, multicomponent films from polyvinyl alcohol (PVA) and chitosan (Ch) incorporating a methanol extract from Marrubium peregrinum were prepared and characterized. The plant extract was prepared using 70% methanol combined with ultrasound-assisted extraction, followed by centrifugation, filtration, and solvent evaporation. The dry extract was incorporated into 1% polymer solutions, and films were prepared by the solvent-casting method using glycerol as a plasticizer. Two extract concentrations (4 and 8 mg/cm2) were investigated. Pure PVA/chitosan films were used as a control. Scanning electron microscopy revealed a homogeneous structure in the control films, whereas films containing the extract exhibited a heterogeneous morphology with micron-sized structural units. Mechanical testing indicated that the incorporation of the extract decreased tensile strength, elongation at break, and Young’s modulus, particularly at higher extract concentration. The presence of the extract increased water vapour permeability and moisture sorption, suggesting enhanced hydrophilicity of the film matrix. Release studies in phosphate-buffered saline demonstrated complete release of the extract within 24 h. The effect of glycerol concentration on release kinetics was also examined and an optimal concentration of 0.2% was identified. These results indicate that PVA–chitosan films loaded with Marrubium peregrinum extract are promising candidates for the development of bioactive wound dressing materials.