Chitosan and Solid Lipid Nanoparticles as Nano-carriers of Chamomile oil Against S. aureus and P. aeruginosa for Wound Healing.

Burn wound infections represent a significant clinical challenge, frequently involving antibiotic-resistant pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus. The escalating concern over antimicrobial resistance has intensified the search for alternative therapeutic strategies. Natural bioactive compounds, including chamomile essential oil, have attracted considerable interest due to their broad-spectrum antimicrobial properties; however, their clinical application is limited by poor stability, rapid volatility, and low bioavailability. Nanoencapsulation offers a promising approach to overcome these limitations. This study investigated whether nanoencapsulation of chamomile essential oil (ChEO) in chitosan (CH) and solid lipid (SLN) nanoparticles could enhance its antimicrobial efficacy. Nanoparticles were prepared using probe sonication and characterized for size, morphology, and encapsulation efficiency. Cytotoxicity assessments were also conducted. The results demonstrated that nanoencapsulation substantially improved the antibacterial activity of chamomile essential oil. Chitosan-based nanoparticles achieved minimum inhibitory concentrations of 80 and 85 µg/mL against S. aureus and P. aeruginosa, respectively, compared with 520 and 530 µg/mL for solid lipid nanoparticles, and 970 and 985 µg/mL for the pure essential oil. Both nanoparticle formulations proved considerably more effective than the pure oil alone, with chitosan carriers demonstrating superior performance. These findings suggest that chitosan-based nano-formulations of chamomile essential oil hold significant promise as a complementary strategy for managing burn wound infections.