Atmospheric pressure cold plasma anti-biofilm coatings for 3D printed food tools

Abstract

Increasing adoption of 3D printing in the daily life and, specifically, the food field (kitchen tools and food contact containers) is associated with potential health risks when printed tools are made by specialized centers and designed for disabled patients, who cannot re-print them with the necessary periodicity. The characteristic pattern of 3D printing promotes bacterial adhesion and biofilm formation. In this work acrylic acid (AcAc) and tetraethyl orthosilicate (TEOS) coatings applied by plasma-polymerization have been developed to reduce biofilm formation by Pseudomonas aeruginosa, Escherichia coli and Listeria monocytogenes on 3D printed PLA materials. Chemical (generation of a hydration layer) and morphological (a decrease in distance between peaks) modifications provoked by plasma-polymerized treatments could explain the reduction in bacterial attachment and biofilm formation. AcAc coatings were more effective than TEOS coatings, and showed up to a 47.7% (L. monocytogenes), 50.4% (P. aeruginosa) and 64.1% (E. coli) relative biofilm production, when compared with untreated samples. Industrial relevance textNowadays, products manufactured by 3D printing technologies are constantly growing; resulting in a greater flexibility and customization in the designs and a reduction of production costs. One of the main applications of 3D printed tools is the food industry, specifically, kitchen tools and containers for disabled people. There are great difficulties when it comes to disinfecting these types of parts. So, the health risks associated with the use of 3D printed tools for food contact applications should be attended. Our study demonstrated that acrylic acid plasma coatings are suitable for decreasing the amount of biofilm generated by different bacteria over 3D printed poly-lactic acid (PLA) substrates. Plasma coatings make it possible to address food-related health issues through the generation of safe tools manufactured by 3D printing. The mitigation of those issues will allow the food industry to safely employ a technology as versatile as 3D printing.