Zein-based sponges functionalized with glucose and loaded with ellagic acid for wound treatment

This study aimed to design and characterize zein sponges functionalized with glucose and loaded with ellagic acid for wound treatment. The sponges were obtained by an easy two-step’ procedure, consisting of homogenization and freeze-drying of zein-ellagic acid mixtures. Subsequently, glucose solutions were added to the surface of the pre-lyophilized sponges, which were then incubated in an oven at 120 °C for 2 h to induce the Maillard reaction. The formulations were characterized in terms of thickness, contact angle, water sorption, solubility, scanning electron microscopy (SEM), release kinetics, docking molecular, biodegradability, irritative potential using the HET-CAM assay and ex-vivo antibiofilm activity against S. aureus. The sponges obtained presented a homogeneous aspect, appropriate mechanical resistance with highly hydrophilic (contact angles <44°) and porous surfaces. All formulations presented a high sorption capacity, together with a limited solubility, vital aspects for the clinical applicability of wound dressing materials. The functionalization with glucose enhanced their solubility and also the ellagic acid release. The formulation with glucose exhibited a sustained release pattern, reaching 47 % after 240 h. Molecular docking revealed a transient affinity between glucose and ellagic acid, which may have contributed to the increased release observed. Also, ellagic acid contributed to increase the biodegradation rate of the sponges, reaching 40 % after 35 days. The HET-CAM assay showed minimal irritant effects, supporting their topical application. Accordingly, the zein-based sponges containing ellagic acid represent a promising alternative as bioactive wound dressings. They combine suitable morphological properties, controlled release of ellagic acid, high exudate absorption capacity, low solubility, minimal irritancy potential and fast biodegradability, highlighting their potential in advanced wound care applications.