Influence of Surface Roughness, Nanostructure, and Wetting on Bacterial Adhesion

Abstract

Bacterial fouling is a persistent problem causing the deterioration and failure of functional surfaces for industrial equipment/components; numerous human, animal, and plant infections/diseases; and energy waste due to the inefficiencies at internal and external geometries of transport systems. This work gains new insights into the effect of surface roughness on bacterial fouling by systematically studying bacterial adhesion on model hydrophobic (methyl-terminated) surfaces with roughness scales spanning from ∼2 nm to ∼390 nm. Additionally, a surface energy integration framework is developed to elucidate the role of surface roughness on the energetics of bacteria and substrate interactions. For a given bacteria type and surface chemistry; the extent of bacterial fouling was found to demonstrate up to a 75-fold variation with surface roughness. For the cases showing hydrophobic wetting behavior, both increased effective surface area with increasing roughness and decreased activation energy with increased surface roughness was concluded to enhance the extent of bacterial adhesion. For the cases of superhydrophobic surfaces, the combination of factors including (i) the surpassing of Laplace pressure force of interstitial air over bacterial adhesive force, (ii) the reduced effective substrate area for bacteria wall due to air gaps to have direct/solid contact, and (iii) the reduction of attractive van der Waals force that holds adhering bacteria on the substrate were summarized to weaken the bacterial adhesion. Overall, this study is significant in the context of designing antifouling coatings and systems as well as explaining variations in bacterial contamination and biofilm formation processes on functional surfaces.

Mechanophysical and Anti-Adhesive Properties of a Nanoclay-Containing PMMA Denture Resin

“…Various surface properties of materials are known to influence microbial adhesion. Surface roughness, surface energy, and the resulting wettability of substrates have been found to have a significant impact on microbial adhesion. − Additionally, the cell surface hydrophobicity (CSH) and physicochemical interactions, such as van der Waals interactions, electrostatic interactions, and acid–base interactions, that occur on the microbial surface also have a substantial influence on the initial microbial adhesion. − After addition of NCs to PMMA, when DW and EG were dropped onto the specimen surface, both exhibited an increase in contact angle. Based on these results, it was confirmed that the addition of NCs to PMMA made the surface hydrophobic, particularly at 4 wt %, with a significantly increased antiadhesion activity of C.…”

Bacterial Patterning: A Promising Biofabrication Technique

“…Upon completion of the growth period, the stencil is removed, leaving the desired bacterial patterns on the surface. Elastomeric PDMS is commonly employed for stencil patterning due to its softness, cost-effectiveness, and flexible nature. , Taking advantage of the flexibility of PDMS stencils, it becomes feasible to pattern bacteria on various substrate surfaces, including those that are rough, corrugated, topographically textured, or even curved . However, nonspecific adhesion of bacterial cells may lead to pattern distortion.…”

Fundamentals and Applications of Surface Wetting

“…Accordingly, preparing substrates using biobased materials to achieve green and sustainable solutions is gaining attention . Furthermore, the fabrication of substrates with antimicrobial and antiviral characteristics is getting attention due to the modern-day problem of multidrug-resistant bacteria. − Furthermore, there is a need for methods that result in durable surface-engineered substrates. For instance, the durability and stability of widely used self-cleaning fluoropolymer TiO 2 superhydrophilic coatings are greatly influenced by time of ultraviolet exposure, followed by the amount of the polymer in the composition used .…”