The Effect of Chitosan Nanoparticle-Loaded Hydrogel and Lavandula angustifolia Extract on Staphylococcus aureus-Infected Wounds in a Rat Model: An Animal Study

Background: Chitosan and Lavandula angustifolia (lavender) exhibit antibacterial, antioxidant, and anti-inflammatory effects, making them potential candidates for managing infected wounds. This study investigated the therapeutic efficacy of a chitosan nanoparticle-loaded hydrogel, lavender extract, and their combination in treating Staphylococcus aureus-infected wounds in rats. Methods: Forty-eight male Sprague-Dawley rats (250–350 g, 8–10 weeks) were divided into six groups: healthy control, infected untreated, Fucidin, lavender extract, chitosan hydrogel, and chitosan–lavender combination. Wound healing was evaluated on days 3, 7, and 14 using clinical assessment, histopathology, and biochemical markers. Non-parametric statistical tests were applied, with significance set at p < 0.05. Results: The chitosan–lavender group showed the most pronounced healing response, with significantly reduced WBC counts, lower levels of TNF-α, IL-6, and MDA, and enhanced SOD activity (p < 0.05). Histological analysis confirmed superior re-epithelialization, granulation tissue development, collagen deposition, and wound contraction in chitosan-based treatments, particularly their combination, compared to lavender or Fucidin alone (p < 0.001). Inflammatory infiltrates, angiogenesis, necrosis, and hemorrhage were also notably reduced across treated groups. Conclusions: Combining chitosan hydrogel with lavender extract exerts synergistic antibacterial and wound healing effects, offering a promising alternative therapy for infected wounds.