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

This work sought to create and describe a new antibiotic-loaded keratin-based film bandage to accelerate wound healing. Using the solvent casting technique, keratin—derived from chicken feathers, was used in different ratios to create films combining keratin to gelatin (KG). The films were coupled with chitosan-based microspheres (Mc) for bacitracin zinc (BZ) release over time. In vitro drug release kinetics, particle size distribution, and encapsulation efficiency were assessed among the chitosan microspheres. With a regulated antibiotic release profile, the best film achieved almost 76% cumulative release over time. Antibiotic-loaded microspheres integrated within a keratin-gelatin matrix facilitated prolonged drug delivery to the wound site, hence preventing infection and improving the healing process. Significantly outperforming the disease control group (p < 0.05), in vivo excision wound investigations found that the antibiotic-loaded microsphere-embedded keratin-gelatin film (BZ-Mc-KG) achieved 100% wound closure by the 20th day. Comparative research revealed that although the drug-loaded microsphere-embedded gelatin film demonstrated 90% wound contraction (p < 0.05), the free drug-loaded keratin-gelatin film reached 98% wound closure (p< 0.05, slower wound closure rates were shown by the drug-free keratin-gelatin film and the conventional therapy (2.0% w/w mupirocin ointment). These findings underscore the synergistic effect of combining chicken feather keratin with bacitracin zinc, highlighting the potential of this novel film dressing as an effective therapeutic strategy for enhanced wound healing. The study demonstrates the utility of sustainable keratin-based biomaterials in advanced wound care applications.