Bioengineered nanocomposite bacitracin zinc-loaded chitosan microspheres containing keratin/gelatine films for wound healing

This study sought to create and characterize a novel antibiotic-loaded keratin-based film bandage for enhanced wound healing. Using the solvent casting method, keratin from chicken feathers was combined with gelatin (KG) in varying ratios to form films. Chitosan microspheres (Mc) were incorporated to achieve sustained release of bacitracin zinc (BZ). The microspheres were evaluated for particle size distribution, encapsulation efficiency, and in vitro drug release kinetics. The optimized film showed a controlled release profile with nearly 76% cumulative drug release over time. Embedding antibiotic-loaded microspheres within the keratin-gelatin matrix enabled prolonged delivery at the wound site, preventing infection and accelerating healing. In vivo excision wound studies demonstrated that the BZ-Mc-KG film achieved complete wound closure by day 20, significantly outperforming the disease control (<i>p</i> < .05). Comparative results indicated that microsphere-loaded gelatin films achieved 90% closure (<i>p</i> < .05), while free drug-loaded keratin-gelatin films reached 98% closure (<i>p</i> < .05). Slower healing was observed with drug-free keratin-gelatin films and standard mupirocin ointment (2.0% w/w). These findings highlight the synergistic potential of chicken feather keratin with BZ, supporting its application as a sustainable biomaterial for advanced wound dressings and effective therapeutic wound care strategies.