Modeling Bacterial Attachment Mechanisms on Superhydrophobic and Superhydrophilic Substrates

Abstract

Superhydrophilic and superhydrophobic substrates are widely known to inhibit the attachment of a variety of motile and/or nonmotile bacteria. However, the thermodynamics of attachment are complex. Surface energy measurements alone do not address the complexities of colloidal (i.e., bacterial) dispersions but do affirm that polar (acid-base) interactions (ΔGAB) are often more significant than nonpolar (Lifshitz-van der Waals) interactions (ΔGLW). Classical DLVO theory alone also fails to address all colloidal interactions present in bacterial dispersions such as ΔGAB and Born repulsion (ΔGBorn) yet accounts for the significant electrostatic double layer repulsion (ΔGEL). We purpose to model both motile (e.g., P. aeruginosa and E. coli) and nonmotile (e.g., S. aureus and S. epidermidis) bacterial attachment to both superhydrophilic and superhydrophobic substrates via surface energies and extended DLVO theory corrected for bacterial geometries. We used extended DLVO theory and surface energy analyses to characterize the following Gibbs interaction energies for the bacteria with superhydrophobic and superhydrophilic substrates: ΔGLW, ΔGAB, ΔGEL, and ΔGBorn. The combination of the aforementioned interactions yields the total Gibbs interaction energy (ΔGtot) of each bacterium with each substrate. Analysis of the interaction energies with respect to the distance of approach yielded an equilibrium distance (deq) that seems to be independent of both bacterial species and substrate. Utilizing both deq and Gibbs interaction energies, substrates could be designed to inhibit bacterial attachment.

Adhesion of Oral Bacteria to Commercial d-PTFE Membranes: Polymer Microstructure Makes a Difference

“…A unified theory that would explain all aspects of bacterial adhesion still does not exist. Non-specific interactions can be viewed through the thermodynamic approach, classical DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory, or extended DLVO theory, the latter being the most accepted [ 2 , 10 , 11 , 12 ]. In this theory, the bacterial adhesion is described as a balance between attractive long-range Lifshitz–van der Waals forces (i.e., London, dipole-dipole and dipole-induced dipole forces), repulsive or attractive electrostatic forces, and short-range Lewis acid–base (AB) interactions.…”

Dry surface biofilms in the food processing industry: An overview on surface characteristics, adhesion and biofilm formation, detection of biofilms, and dry sanitization methods

“…The cost‐effectiveness of dry sanitation methods has not yet been fully elucidated, which limits large‐scale industrial application. Further studies on the bacteria–substrate interaction on dry surfaces are also essential to allow for the effective application of alternative sanitization methods (Cavitt & Pathak, 2021).…”

The Influence of Physical Characteristics of Wet Wipe Fabrics on the Microbial Biomass Accumulation

“…Multiple studies have shown that the physicochemical properties of fabrics and surfaces have a pronounced effect on microbial adhesion and proliferation, until reaching irreversible attachment and biofilm formation [7,8]. Surface charge and hydrophobicity level were shown to have an influence on microbial adhesion, with superhydrophobic (water contact angle >150°) having significantly reduced microbial adhesion [9][10][11][12][13]. Hemmatian et al examined the adhesion tendency of Escherichia coli and Staphylococcus aureus on polystyrene and poly lactic acid, both as films and fibers substrates, with modification of wettability by the plasma process using either O2 or C4F8 gas [10].…”