Polymeric blends enabling controlled delivery of Lippia graveolens bioactives for wound repair: in vitro and in vivo evaluation.

Chronic wounds are characterized by an increased susceptibility to microbial colonization, which results in prolonged inflammation and the development of microbial biofilms. The inadequate use of systemic antibiotics has led to the emergence of antibiotic-resistant microorganisms. Therefore, the use of essential oils has gained significant importance. Lippia graveolens Kunth essential oil (OR) presents antioxidant, anti-inflammatory, antimicrobial and antifungal properties, which could enhance the wound healing process. In this study, we prepared PCL microfiber mats (MFs) loaded with either OR (PCL-OR) or carvacrol (CV) and characterized them for their physicochemical properties. Their antimicrobial and antioxidant and properties were also assessed. In vitro and in vivo models were used to verify the suitability of the materials. The results revealed that the addition of OR and CV enhanced the surface roughness of the MFs, which may influence protein-material interactions and contribute to favorable biological responses at the wound interface. The proposed MFs demonstrated suitable mechanical properties, rendering them appropriate as wound dressings. The incorporation of OR and CV enhanced antioxidant and antimicrobial properties, against both Gram-positive and Gram-negative bacteria. In vitro assays demonstrated promising cell viability and non-cytotoxic effects of PCL-OR MFs. In vivo evaluations showed adequate wound closure rates, thus rendering PCL-OR as a feasible bioactive wound dressing platform.