Microbial Adhesion to Poly(ethylene oxide) Brushes:  Influence of Polymer Chain Length and Temperature

Abstract

Glass surfaces were modified by end-grafting poly(ethylene oxide) (PEO) chains having molecular weights of 526, 2000, or 9800 Da. Characterization using water contact angles, ellipsometry, and X-ray photoelectron spectroscopy confirmed the presence of the PEO brushes on the surface with estimated lengths in water of 2.8-, 7.5-, and 23.7-nm, respectively. Adhesion of two bacterial (Staphylococcus epidermidis and Pseudomonas aeruginosa) and two yeast (Candida albicans and Candida tropicalis) strains to these brushes was studied and compared to their adhesion to bare glass. For the bacterium P. aeruginosa and the yeast C. tropicalis, adhesion to the 2.8-nm brush was comparable to their adhesion on bare glass, whereas adhesion to the 7.5- and 23.7-nm brushes was greatly reduced. For S. epidermidis, adhesion was only slightly higher to the 2.8-nm brush than that to the longer brushes. Adhesion of the yeast C. albicans to the PEO brushes was lower than that to glass, but no differences in adhesion were found between the three brush lengths. After passage of an air bubble, nearly all microorganisms adhering to a brush were removed, irrespective of brush length, whereas retention of the adhering organisms on glass was much higher. No significant differences were found in adhesion nor retention between experiments conducted at 20 and those conducted at 37 degrees C.

New Strategies in the Development of Antimicrobial Coatings: The Example of Increasing Usage of Silver and Silver Nanoparticles

“…The higher the surface density of the polymer chains on the surface, the better the anti-adhesive characteristics will be. Also the chain length of the polymers is of importance; longer chains are more effective in prevention of bacterial adhesion [42][43][44]. Because most of the polymers used for brushes are hydrophilic, water will be attracted into the brush layer and form a repellent layer close to the surface.…”

Bacterial factors influencing adhesion of Pseudomonas aeruginosa strains to a poly(ethylene oxide) brush

“…However, the density of acid-base interacting groups is lower in a swollen state than during contact-angle measurements, and this can be accounted for by calculating the volume density of PEO in the swollen brush. Based on the volume taken up by a PEO chain of 220 ethylene oxide monomers in the swollen brush (118 nm 3 ; Roosjen et al, 2004), and the dry volume of a PEO chain (16 nm 3 ; Van Krevelen, 1976), it can be calculated that 14 % of the total brush volume is taken up by PEO chains. Consequently, the acid-base interaction energies calculated from equation (10) The mean distance dependence of the interaction energies between non-adhesive or adhesive strains and glass or Table 2.…”

Inhibition of bacterial adhesion and biofilm formation on zwitterionic surfaces

“…It has been shown in several previous studies that PEG-coated surfaces can reduce bacterial adhesion as compared to their control samples over a short period of time (e.g., 3 hours), such as Streptococcus mutans on PEG-coated polystyrene by Harris et al [2], P. aeruginosa on a set of plasma deposited PEG-like film by Johnston et al [3], S. epidermidis, S. aureus, S. salivarius, E. coli, and P. aeruginosa on PEG-brush coated glass by Roosjen et al [4], Pseudomonas sp. on PEG-grafted surfaces by Kingshott et al [5], S. aureus on oligo(ethylene glycol) (OEG) self-assembled monolayers (SAMs) by Cooper and Tegoulia [6], and for S. aureus and S. epidermidis on OEG SAMs by Ostuni et al [7].…”