Synthesis, characterization, antioxidant and antimicrobial activities, and computational studies of chitosan nanoparticles loaded with vitamin E and clove essential oil

Efficient encapsulation of bioactive compounds in the food-grade delivery systems to improve their stability, efficiency, and bioavailability and to develop functional foods is a novel and interesting field of research in food industry. Here, two unstable and hydrophobic food ingredients including vitamin E (Vit E) and clove essential oil (CEO) were encapsulated in the chitosan nanoparticles (ChNPs) by the emulsion/ ionic gelation technique without using any toxic surfactant. The physicochemical characterization by DLS, FTIR, FE-SEM, and TEM, confirmed the synthesis of high colloidal and monodispersed ChNPs with narrow size distribution of less than 50 nm. MTT assay showed high biocompatibility of ChNPs after CEO loading, with the increased cellular viability of 72.84% for CEO loaded ChNPs. ABTS and DPPH assays also revealed high antioxidant activity of CEO loaded ChNPs with maximum activity of 75.66%. Co-loading of Vit E and CEO led to the antioxidant activity of 77.7% over 48 h, potent antibacterial effect on E. coli and S. aureus with the inhibition zone diameters of 14-17 mm, and complete growth inhibition of fungus A. niger. Molecular docking studies also showed strong binding of chitosan, eugenol, and α-tocopherol to different bacterial and fungal proteins. Overall results indicated that Vit E and CEO loaded ChNPs represent interesting physicochemical and biological properties and high potential for development of food preservatives and functional foods.