Controlled Release, Disintegration, Antioxidant, and Antimicrobial Properties of Poly (Lactic Acid)/Thymol/Nanoclay Composites

Abstract

Nano-biocomposite films based on poly (lactic acid) (PLA) were prepared by adding thymol (8 wt.%) and a commercial montmorillonite (D43B) at different concentrations (2.5 and 5 wt.%). The antioxidant, antimicrobial, and disintegration properties of all films were determined. A kinetic study was carried out to evaluate the thymol release from the polymer matrix into ethanol 10% (v/v) as food simulant. The nanostructured networks formed in binary and ternary systems were of interest in controlling the release of thymol into the food simulant. The results indicated that the diffusion of thymol through the PLA matrix was influenced by the presence of the nanoclay. Disintegration tests demonstrated that the incorporation of both additives promoted the breakdown of the polymer matrix due to the presence of the reactive hydroxyl group in the thymol structure and ammonium groups in D43B. Active films containing thymol and D43B efficiently enhanced the antioxidant activity (inhibition values higher than 77%) of the nano-biocomposites. Finally, the addition of 8 wt.% thymol and 2.5 wt.% D43B significantly increased the antibacterial activity against Escherichia coli and Staphylococcus aureus 8325-4, resulting in a clear advantage to improve the shelf-life of perishable packaged food.

Embracing Additive Manufacturing Technology through Fused Filament Fabrication for Antimicrobial with Enhanced Formulated Materials

“…Moreover, the antibacterial property is added with the help of processing techniques such as co-extrusion with particles for instance using chitosan as studied by Mania et al [ 18 ] or using metallic nanoparticles as done by Rezić et al [ 47 ]. Biomedical applications such as dental resins as studied by Bayarsaikhan et al [ 48 ] and drug delivery as highlighted by Shaqour et al [ 49 , 50 ] highly promote a practical approach of using 3D Printing along with compatible antibacterial material. Bartolomé et al [ 51 ] and Navaruckiene et al [ 52 ] both emphasize the use of FFF as a promising approach for bio fabrication of antibacterial material and suggest that using metallic particles alongside biodegradable polymers show great compatibility to the human body and is expected to be considered as the more superior and dynamic approach of development in the field in the upcoming years.…”

Influence of plasticizers on the compostability of polylactic acid

“…This formulations were also loaded with cloisite nanoclay and the rate of disintegration under composting conditions was slightly longer for PLAessential oil loaded Cloisite formulations but still higher than meat PLA or PLA-Cloisite nanocomposite, being all formulations completelly disintegrated in less than two weeks (Villegas et al, 2019). Similarly, the addition of clay such as montmorillonite somewhat delay on the disintegration rate of PLA-thymol film formulations (Ramos et al, 2020). Nevertheless, it should be highlighted that all formulations were completely disintegrated in 35 days (Ramos et al, 2020).…”

“…Similarly, the addition of clay such as montmorillonite somewhat delay on the disintegration rate of PLA-thymol film formulations (Ramos et al, 2020). Nevertheless, it should be highlighted that all formulations were completely disintegrated in 35 days (Ramos et al, 2020).…”

Antimicrobial Food Packaging with Biodegradable Polymers and Bacteriocins

“…One of the newest solutions seen in the literature is the use of packaging employing “controlled release” technology based on biodegradable polymers, including biopolymers obtained from lactic acid. “Controlled release” is the release of active compounds contained on the surface of the packaging in a controlled manner to extend the shelf life [ 141 , 152 , 154 , 157 , 158 ]. Currently available systems are not sufficient to simultaneously release many active substances in a sustainable manner.…”