Development and characterization of anti-biofilm coatings applied by Non-Equilibrium Atmospheric Plasma on stainless steel

Durability Assessment of a Plasma-Polymerized Coating with Anti-Biofilm Activity against L. monocytogenes Subjected to Repeated Sanitization

“…Relative biofilm productions of 14.6 ± 10% were obtained with the non-sanitized coating in comparison to the non-sanitized, uncoated SS. These relative biofilm production values were similar to those reported in our previous work [17] for a single-strain L. monocytogenes biofilm under the same incubation conditions, which confirms that this coating maintains its anti-biofilm effectiveness in a more realistic scenario using a multi-strain biofilm. On the other hand, after five sanitization cycles with peracetic acid, statistically significant greater relative biofilm production values than those of the non-sanitized coating were obtained, showing that the anti-biofilm effectiveness of the coating was diminished to some extent by this sanitization process.…”

“…These observations indicate that those grainy structures are sodium chloride (NaCl) crystals that originated from the sodium hypochlorite solution [23]. As concluded in our previous work [17], the morphology of the coating AP10 + AA6 contributed to its anti-biofilm effectiveness by reducing the occurrence of grooves on the SS substrate where bacteria would be prone to accumulate. According to the results of the morphological characterization tests of the current study, the sanitizing of the coating AP10 + AA6 with any of the two solutions resulted in smoother surfaces than those of the uncoated SS, with a reduced occurrence of grooves.…”

“…The plates were incubated for 6 days at 12 • C, which is a temperature that usually prevails in industrial environments and corresponds to the maximum recommended temperature for facilities processing products of animal origin according to the European Parliament and the Council of the European Union [20]. After incubation, biofilm formation was assessed by crystal violet (CV) staining, following the same procedure as in our previous work [17]. Briefly, the supernatant was discarded, and the plates were washed three times with Ringer solution (Merck, Darmstadt, Germany).…”

“…One of the initial steps in biofilm formation consists in the attachment of bacteria to a surface, which is influenced by its physicochemical properties, including functional groups, topography, wettability, and electrostatic charge [3,5]. Considering this, many efforts have been made for producing surfaces with physicochemical properties that prevent biofilm formation by hindering the initial attachment of bacteria, and therefore, reducing the possibility of resistance development [14][15][16][17][18]. In our previous work [17], anti-biofilm coatings that inhibited biofilm formation by L. monocytogenes were deposited by an atmospheric-pressure plasma jet (APPJ) system on AISI 316 stainless steel (SS) using different precursors and process parameters.…”

“…Considering this, many efforts have been made for producing surfaces with physicochemical properties that prevent biofilm formation by hindering the initial attachment of bacteria, and therefore, reducing the possibility of resistance development [14][15][16][17][18]. In our previous work [17], anti-biofilm coatings that inhibited biofilm formation by L. monocytogenes were deposited by an atmospheric-pressure plasma jet (APPJ) system on AISI 316 stainless steel (SS) using different precursors and process parameters. The most promising coating found in that previous study was composed of a base coating of (3-aminopropyl)triethoxysilane (APTES) and a functional coating of acrylic acid (AcAc) (coating AP10 + AA6).…”