12-crown-4-ether and tri(ethylene glycol) dimethyl-ether plasma-coated stainless steel surfaces and their ability to reduce bacterial biofilm deposition

It has been demonstrated that surfaces coated with poly(ethylene glycol) (P EG) are capable of reducing protein adsorption, bacterial attachment, and b iofilm formation. In this communication cold-plasma-enhanced processes were employed for the deposition of PEG-like structures onto stainless steel su rfaces. Stainless steel samples were coated under 1,4,7,10-tetraoxacyclodod ecane (12-crown-4)-ether and tri(ethylene glycol) dimethyl ether (triglyme) -radio frequency (RF)-plasma conditions. The chemistry and characteristics of plasma-coated samples and biofilms were investigated using electron spec troscopy for chemical analysis (ESCA), atomic force microscopy (AFM), and w ater contact angle analysis. ESCA analysis indicated that the plasma modifi cation resulted in the deposition of PEG-like structures, built up mainly o f -CH2-CH2-O- linkages. Plasma-coated stainless steel surfaces were more hy drophilic and had lower surface roughness values compared to those of unmod ified substrates. Compared to the unmodified surfaces, they not only signif icantly reduced bacterial attachment and biofilm formation in the presence of a mixed culture of Salmonella typhimurium, Staphylococcus epidermidis, a nd Pseudomonas fluorescens but also influenced the chemical characteristics of the biofilm. Thus, plasma deposition of PEG-like structures will be of use to the food-processing and medical industries searching for new technol ogies to reduce bacterial contamination. (C) 2001 John Wiley & Sons, Inc.