Fe ₃ O ₄ –chitosan nanocomposite hydrogel films for wound healing, swelling behavior, and antibacterial performance

Chitosan hydrogels are promising wound dressing materials despite the potential limitations in their functional performance concerning hydration property and antimicrobial property. In this study, an Fe ₃ O ₄ –chitosan nanocomposite hydrogel film containing CaCl ₂ as an ionic formulation additive was prepared using a physically associated chitosan matrix. The incorporation of Fe ₃ O ₄ nanoparticles increased the gel fraction from 78% to 86% and the equilibrium swelling ratio from 383% to 420%. Moisture retention after 12 h increased from 38% to 58%. The nanocomposite also showed greater antibacterial activity, with inhibition zones of 20 ± 1.2 mm against E. coli and 18 ± 1.0 mm against P. aeruginosa . In vivo evaluation showed 95% wound closure on Day 10, compared with 70% for the pure chitosan hydrogel and 40% for the untreated control. These findings indicate that Fe ₃ O ₄ incorporation improves the hydration-related, antibacterial, and wound-healing performance of chitosan hydrogel films for potential wound-dressing applications.