Antibacterial Capability of MXene (Ti3C2Tx) to Produce PLA Active Contact Surfaces for Food Packaging Applications

Abstract

The globalization of the market and the increase of the global population that requires a higher demand of food products superimposes a big challenge to ensure food safety. In this sense, a common strategy to extend the shelf life and save life of food products is by avoiding bacterial contamination. For this, the development of antibacterial contact surfaces is an urgent need to fulfil the above-mentioned strategy. In this work, the role of MXene (Ti3C2Tx) in providing antibacterial contact surfaces was studied through the creation of composite films from polylactic acid (PLA), as the chosen polymeric matrix. The developed PLA/MXene films maintained the thermal and mechanical properties of PLA and also presented the attractive antibacterial properties of MXene. The composites’ behaviour against two representative foodborne bacteria was studied: Listeria mono-cytogenes and Salmonella enterica (representing Gram-positive and Gram-negative bacteria, respectively). The composites prevented bacterial growth, and in the case of Listeria only 0.5 wt.% of MXene was necessary to reach 99.9999% bactericidal activity (six log reductions), while against Salmonella, 5 wt.% was necessary to achieve 99.999% bactericidal activity (five log reductions). Cy-totoxicity tests with fHDF/TER166 cell line showed that none of the obtained materials were cytotoxic. These results make MXene particles promising candidates for their use as additives into a polymeric matrix, useful to fabricate antibacterial contact surfaces that could prove useful for the food packaging industry.

MXenes Antibacterial Properties and Applications: A Review and Perspective

“…As can be seen, a higher activity against Grampositive bacteria was observed for Ti 3 C 2 T X com pared to Grampositive bacteria and it agrees well with pre vious studies. [141,144] The difference in antibacterial activity of MXene toward both bacteria species might be related to dissimilarities in the structure and surface charge of the bacteria. The outer protective lipid membrane in the cell wall of Gramnegative bacteria can prevent direct damage of MXene nanoknives.…”

Capability of Copper Hydroxy Nitrate (Cu2(OH)3NO3) as an Additive to Develop Antibacterial Polymer Contact Surfaces: Potential for Food Packaging Applications

“…To achieve homogeneity in film thickness, a 1000 μm thick Doctor Blade was used on a glass support. The composite films were dried at room temperature for 24 h and then placed in an oven at 40 °C for 5 days to achieve complete solvent removal [ 6 , 32 ].…”

“…Among the microorganisms responsible, norovirus, Salmonella , Campylobacter spp., Listeria monocytogenes , Staphylococcus aureus and Escherichia coli O157:H7 were identified as the main agents [ 4 , 5 ]. Specifically, Salmonella and Listeria are two of the pathogens with the greatest impact on health and the economy worldwide [ 5 , 6 , 7 , 8 , 9 ]. Apart from the health aspect, these diseases also affect socio-economic development [ 3 ].…”

“…This can be achieved by inhibiting the microbial growth responsible for food spoilage and, at the same time, inhibiting the growth of the pathogenic microorganisms associated with the occurrence of foodborne diseases. To this end, the development of antimicrobial active packaging systems constitutes an important alternative for prolonging the freshness and quality of food, which translates into an increase in shelf life and food safety for consumers [ 6 , 12 , 13 ].…”

“…Given these proprieties, this study will be focused on the application of a BS, more specifically CuHS, as a direct antibacterial filler to develop active contact surfaces. Two strategies were planned to produce the active materials via direct incorporation of the CuHS: (i) using melt-extrusion with an LDPE matrix, which is one of the most used polymers in the food packaging industry due to its high chemical and thermal stability, which favors its thermal processability and heat-sealing capabilities [ 31 ]; and (ii) using solution casting with PLA, which is a polyester that, due to its biodegradability under composting conditions, biocompatibility, and good mechanical properties, is gaining importance in the food packaging industry [ 6 ].…”