Antioxidant/Antibacterial Electrospun Nanocoatings Applied onto PLA Films

Abstract

Polylactic acid (PLA) films were coated by coaxial electrospinning with essential and vegetable oils (clove and argan oils) and encapsulated into chitosan, in order to combine the biodegradability and mechanical properties of PLA substrates with the antimicrobial and antioxidant properties of the chitosan–oil nanocoatings. It has been established that the morphology of the electrospun nanocoatings mainly depend on the average molecular weight (MW) of chitosan. Oil beads, encapsulated into the main chitosan nanofibers, were obtained using high-MW chitosan (Chit-H). Oil encapsulated in chitosan naoparticles resulted when low-MW chitosan (Chit-L) was used. The coating layer, with a thickness of 100 ± 20 nm, had greater roughness for the samples containing Chit-H compared with the samples containing Chit-L. The coated PLA films had higher antibacterial activity when the nanocoating contained clove oil rather than when argan oil was used, for both types of chitosan. Nanocoatings containing Chit-H had higher antibacterial activity compared with those containing Chit-L, for both types of oil tested, due to the larger surface area of the rougher nanoscaled morphology of the coating layer that contained Chit-L. The chitosan–clove oil combination had higher antioxidant activity compared to the simple chitosan nanocoating, which confirmed their synergistic activities. The low activity of systems containing argan oil was explained by big differences between their chemical composition and viscosity.

Essential Oils-Loaded Electrospun Biopolymers: A Future Perspective for Active Food Packaging

“…Munteanu et al investigated the biodegradation and tensile properties of PLA membranes coated with antimicrobial and antioxidant CS-EO complexes [136]. Chitosan has exhibited significant antibacterial action against various pathogens such as Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa [137]; therefore, it has been a popular subject of studies in antibacterial coatings [138].…”

Bioactive Properties of Nanofibres Based on Concentrated Collagen Hydrolysate Loaded with Thyme and Oregano Essential Oils

“…The antimicrobial activity of plant essential oils is attributed to their chemical structure, in particular the presence of hydrophilic functional groups, such as hydroxyl groups of phenolic components and/or lipophilicity of some essential oil components [20]. To overcome the essential oils volatility, different formulation techniques and methods have been developed, such as casting [21], emulsion ionic gelation [22] or encapsulation by electrospinning [23].…”

Bio-Based Polymers with Antimicrobial Properties towards Sustainable Development

“…Munteanu et al [ 259 ] prepared a nanocoating by encapsulating argan and clove oils into chitosan by coaxial electrospinning and then used it to functionalize electrospun PLA materials previously treated with CPT. The authors concluded that the electrospun coaxial encapsulation of clove and argan oils into chitosan led to enhanced antimicrobial activity against E. coli , S. typhymurium , and L. monocytogenes .…”