Rosemary resin-oil incorporation into chitosan films: development of natural antimicrobial bioactive dressings

<i>Salvia rosmarinus</i> Spenn., known as rosemary, is an aromatic plant with remarkable biological properties. This study developed bioactive dressings based on chitosan and rosemary resin oil (RR) to evaluate their efficacy in inhibiting common pathogens in skin lesions, such as <i>Staphylococcus aureus</i>, <i>Acinetobacter baumannii</i> and <i>Pseudomonas aeruginosa</i>. The films were formulated with 2% chitosan and different concentrations of RR, presenting colloidal stability, uniform weight and thickness. The physicochemical properties demonstrated that the higher concentration of RR increased the swelling and wetting capacity, while decreasing the solubility, due to its nonpolar nature. Antimicrobial assays demonstrated a synergistic effect between chitosan and RR, and FT-IR and RAMAN analyses confirmed interactions between the components in the formulation, suggesting the sustainable and innovative potential of chitosan and RR films as antimicrobial dressings for the management of wound infections.