Nanoimbibition of Essential Oils in Triblock Copolymeric Micelles as Effective Nanosanitizers against Food Pathogens Listeria monocytogenes and Escherichia coli O157:H7

Abstract

Herein, we report the development of novel antibacterial nanosanitizers involving nine different essential oils (EOs) and a food-grade triblock copolymer with polyethylene glycol and polypropylene glycol building blocks that demonstrate unique, versatile release profiles. Furthermore, this work also deals with the assessment and comparison of their inhibitory properties against food pathogens in conjunction with their release kinetics. The hydrodynamic diameter of EO nanosanitizers prepared by flash nanoimbibition method ranged from 27.4 ± 0.5 to 41.4 ± 0.1 nm. For these systems, three composite release kinetics trends were discovered: (i) a release rate having an exponential association behavior with time initially, which is followed by a linear decrease for basil, cinnamon cassia, and star anise EOs; (ii) a release rate having an exponential association behavior with time initially, which is followed by a plateau for citronella and clove bud EOs; and (iii) a release rate with a slow exponential association behavior with time for clove leaf, eucalyptus, peppermint, and tea tree EOs. For a given concentration, compared to bulk EOs, nanoimbibed EOs exhibited higher inhibitory effects against Listeria monocytogenes and Escherichia coli O157:H7. The order of antibacterial efficacy for bulk EOs was cinnamon cassia > peppermint ∼ clove leaf > clove bud > citronella > eucalyptus ∼ tea tree > star anise. On the contrary, the order of antibacterial potency for EO nanosanitizers was clove bud ∼ clove leaf ∼ cinnamon cassia > star anise ∼ citronella ∼ peppermint > tea tree > eucalyptus. These differences indicate that, aside from the chemistry of EO, the nanostructural details of their assembly and local distribution of EO constituents play a role in inhibiting bacterial growth.

Antibacterial Microfibrillated Cellulose as Stimuli-Responsive Carriers with Enhanced UV Stability for Sustained Release of Essential Oils and Pesticides

“…Nanoencapsulation and nanoimbibition are prominent research directions regarding the sustained and controlled release of essential oils by significantly enhancing physicochemical stability, solubility, and bioavailability of essential oils . For instance, encapsulation using multilayer liposomes, solid lipid nanoparticles (SLNs), and nanoemulsions has been explored. − Zhu et al employed polylactic acid (PLA) modified by octenyl succinic anhydride chitosan (OSA-CS) as shell materials to encapsulate TTO to form long-term antibacterial and pH-responsive microcapsules .…”