Fabrication of a platform to isolate the influences of surface nanotopography from chemistry on bacterial attachment and growth

Abstract

Billions of dollars are spent annually worldwide to combat the adverse effects of bacterial attachment and biofilm formation in industries as varied as maritime, food, and health. While advances in the fabrication of antifouling surfaces have been reported recently, a number of the essential aspects responsible for the formation of biofilms remain unresolved, including the important initial stages of bacterial attachment to a substrate surface. The reduction of bacterial attachment to surfaces is a key concept in the prevention or minimization of biofilm formation. The chemical and physical characteristics of both the substrate and bacteria are important in understanding the attachment process, but substrate modification is likely the most practical route to enable the extent of bacterial attachment taking place to be effectively controlled. The microtopography and chemistry of the surface are known to influence bacterial attachment. The role of surface chemistry versus nanotopography and their interplay, however, remain unclear. Most methods used for imparting nanotopographical patterns onto a surface also induce changes in the surface chemistry and vice versa. In this study, the authors combine colloidal lithography and plasma polymerization to fabricate homogeneous, reproducible, and periodic nanotopographies with a controllable surface chemistry. The attachment of Escherichia coli bacteria onto carboxyl (plasma polymerized acrylic acid, ppAAc) and hydrocarbon (plasma polymerized octadiene, ppOct) rich plasma polymer films on either flat or colloidal array surfaces revealed that the surface chemistry plays a critical role in bacterial attachment, whereas the effect of surface nanotopography on the bacterial attachment appears to be more difficult to define. This platform represents a promising approach to allow a greater understanding of the role that surface chemistry and nanotopography play on bacterial attachment and the subsequent biofouling of the surface.

Micro- and Nanotopography Sensitive Bacterial Attachment Mechanisms: A Review

“…While the introduction of nanoscale topography (random spherical protrusions, R ∼100 nm) enhanced biomass accumulation on substrates with either terminal group, the structure of the adhered biomass on nanorough substrates were clearly dependent on surface chemistry. On the contrary, Pegalajar-Jurado et al reported no statistically significant difference between E. coli biomass on a smooth control and nanostructured surfaces (colloidal crystals, radius ∼200 nm, height ∼30 nm), for both hydrophobic (WCA = 90°) and hydrophilic (WCA = 37°) surfaces (Pegalajar-Jurado et al, 2015).…”

Making Silicone Rubber Highly Resistant to Bacterial Attachment Using Thiol-ene Grafting

“…As the physical attributes of many devices are often optimal for their given application, much research directed toward reducing biofilm formation has been directed toward modification or adaptation of current device technology. For example, through modification via poly­(ethylene glycol), , topography, , zwitterions, − increased microbicidal activity, , or a combination of these a reduction in bacterial attachment has been observed . Recently, a novel class of nontoxic bacterial antiadhesive materials have emerged that significantly reduce bacterial attachment and biofilm formation both in vitro and in an in vivo foreign body mouse infection model. − These are polyacrylates, with monomers characterized by their weakly amphiphilic nature that reduce colonization of surfaces, and since they prevent biofilm formation rather than killing bacteria, minimize the selective pressure on bacteria to evolve antibiotic resistance.…”

Nanotechnology-Based Antimicrobial and Antiviral Surface Coating Strategies

“…In another work by Pegalajar-Juradoa et al, colloidal arrays and plasma polymerization technique were combined as a fabrication method to generate antibacterial surfaces without altering surface chemistry. This study suggests that bacteria prefer to adhere on the nanostructured hydrophilic regions [132].…”