A green strategy for resveratrol nanodelivery. A multidisciplinary approach for the physicochemical characterization of Thymus-based liposomes with anti-biofilm activity against Listeria monocytogenes

Nanocarrier-based drug delivery systems (DDS) offer promising strategies to enhance therapeutic efficacy, stability, and targeted delivery of bioactive compounds while reducing side effects. In this study, a multidisciplinary approach was employed to develop and characterize bioactive liposomes incorporating resveratrol (RV), a polyphenol with known therapeutic potential but limited bioavailability, and Thymus vulgaris essential oil (TEO), recognized for its antimicrobial and antioxidant properties. To obtain stable nanocarriers, liposomes were formulated using soy lecithin and prepared by thin layer evaporation technique followed by sonication process. To assess the preservation of TEO's chemical profile during formulation, Headspace Solid Phase Microextraction coupled with Gas Chromatography–Mass Spectrometry (HS-SPME/GC-MS) was performed. Quantitative analysis of thymol and carvacrol, the two main active components, was performed by HPLC-UV experiments. Physicochemical characterization of DDS was carried out employing Dynamic Light Scattering (DLS), UV–Vis spectrophotometer and Transmission electron microscopy. Antimicrobial activity was assessed by broth microdilution method, while biofilm inhibition ability was evaluated using crystal violet staining. The obtained nanocarriers exhibited appropriate physicochemical characteristics, including optimal particle size and stability. They can efficiently load both oil and RV. These features enhanced the antibacterial activity of LT-RV compared to free RV, and improved its inhibitory effect, at sub-MIC concentrations, against the sessile form of Listeria monocytogenes strains. This study highlights the importance of integrating chemical, physical, and biological evaluations to develop effective nanocarrier-based formulations with the aim to identify a suitable strategy to combat infections associated with resistant, biofilm-producing pathogens, and offer a versatile and effective delivery platform.