Model Organic Surfaces to Probe Marine Bacterial Adhesion Kinetics by Surface Plasmon Resonance

Abstract

Understanding how bacteria adhere to a surface is a critical step in the development of novel materials and coatings to prevent bacteria forming biofilms. Here, surface plasmon resonance (SPR) spectroscopy, in combination with self‐assembled monolayers (SAMs) that have different backbone structures and/or functional groups, is used for the first time to study the initial stages of bacterial adhesion to surfaces (i.e., initial interaction of cells with a surface, a process governed by van der Waals, electrostatic, and hydrophobic interactions). The work highlights SPR spectroscopy as a powerful and unique approach to probe bacterial adhesion in real time. SPR spectral data reveal different kinetics of adhesion for the interaction of two marine bacterial species (Marinobacter hydrocarbonoclasticus and Cobetia marina) to a range of organosulfur SAMs. Furthermore, the extent of adhesion is dependent on the backbone structures and functional groups of the SAMs. The role of extracellular polymeric substances (EPS) in bacterial adhesion is also investigated. Pre‐conditioning experiments with cell‐free culture supernatants, containing planktonic EPS, allow quantification of the amount adsorbed onto surfaces and directly account for the impact of EPS adsorption on bacterial adhesion in the assay. While the physicochemical characteristics of the surfaces play a significant role in determining bacterial cell adhesion for low levels of conditioning by planktonic EPS, greater levels of conditioning by EPS reduce the difference between surfaces.

Charged hydrophilic polymer brushes and their relevance for understanding marine biofouling

“…Although no comprehensive studies on the influence of polymer charge on the attachment of cells of C. marina have been reported yet, Pranzetti et al (Pranzetti et al 2012) demonstrated higher attachment of cells of C. marina (1 h exposure) on positively charged amine-terminated SAMs than on neutral (methyl-, EG6-or hydroxyl-terminated) SAMs, which is in accordance with our current results. It has also been reported (Ista et al 1996, Ista et al 1999) that cells of C. marina have a higher affinity for hydrophobic surfaces (2 h exposure).…”

Hydration and Chain Entanglement Determines the Optimum Thickness of Poly(HEMA-co-PEG10MA) Brushes for Effective Resistance to Settlement and Adhesion of Marine Fouling Organisms

“…41 The final stage of the protocol involved two washes of the cells in filtered ASW to remove excess extracellular polymeric substances that interfere with cell attachment. 42 The final bacterial suspension had an OD600nm = 0.1 (4 x 10 7 cells/ml). The slides were placed in polystyrene Quadriperm dishes (Greiner Bio-One Ltd.) and 10 mL of bacterial suspension were added to each well.…”

Stimuli‐Responsive Surfaces in Biomedical Applications

“…These switchable surfaces are playing an increasingly important part in the development of highly sensitive biosensors [85], novel drug delivery systems [148] and highly functional microfluidic [277], bioanalysis [278], and bioseparation [279] systems. Additionally, dynamic, synthetic surfaces that can control the presentation of regulatory signals [220,280] to a cell are expected to have a significant impact in tissue engineering [176] and regenerative medicine [208], and to provide unprecedented opportunities in fundamental studies of cell biology.…”