Ultrascalable Multifunctional Nanoengineered Copper and Aluminum for Antiadhesion and Bactericidal Applications

Abstract

Biofouling disrupts the surface functionality and integrity of engineered substrates. A variety of natural materials such as plant leaves and insect wings have evolved sophisticated physical mechanisms capable of preventing biofouling. Over the past decade, several reports have pinpointed nanoscale surface topography as an important regulator of surface adhesion and growth of bacteria. Although artificial nanoengineered features have been used to create bactericidal materials that kill adhered bacteria, functional surfaces capable of synergistically providing antiadhesion and bactericidal properties remain to be developed. Furthermore, fundamental questions pertaining to the need for intrinsic hydrophobicity to achieve bactericidal performance and the role of structure length scale (nano vs micro) are still being explored. Here, we demonstrate highly scalable, cost-effective, and efficient nanoengineered multifunctional surfaces that possess both antiadhesion and bactericidal properties on industrially relevant copper (Cu) and aluminum (Al) substrates. We characterize antiadhesion and bactericidal performance using a combination of scanning electron microscopy (SEM), atomic force microscopy (AFM), live/dead bacterial staining and imaging, as well as solution-phase and Petrifilm measurements of bacterial viability. Our results showed that nanostructures created on both Cu and Al were capable of physical deformation of adhered Escherichia coli bacteria. Bacterial viability measurements on both Cu and Al indicated a complex interaction between the antiadhesion and bactericidal nature of these materials and their surface topography, chemistry, and structure. Increased superhydrophobicity greatly decreased bacterial adhesion while not significantly influencing surface bactericidal performance. Furthermore, we observed that more densely packed nanoscale structures improved antiadhesion properties when compared to larger features, even over extended time scales of up to 24 h. Our data suggests that the superhydrophobic Al substrate possesses superior antiadhesion and bactericidal effects, even over long time courses. The techniques and insights presented here will inform future work on antiadhesion and bactericidal multifunctional surfaces and enable their rational design.

Implication of Surface Properties, Bacterial Motility, and Hydrodynamic Conditions on Bacterial Surface Sensing and Their Initial Adhesion

“…Also, it may affect the longterm efficiency of these surfaces (Nino-Martinez et al, 2019). To overcome this issue, alternative approaches have been proceeded; developing a surface that (i) can hinder bacterial adhesion at its early stages that eventually alter biofilm formation (Zhang et al, 2018;Chi et al, 2019), (ii) physically disrupt membrane of adhered bacteria (Reed et al, 2019;Wandiyanto et al, 2019), or (iii) exhibits multifunctional antiadhesion/antibacterial properties (Balaure et al, 2016;Borcherding et al, 2019). Laser-based techniques used to modify surface topography can be a powerful technique for controlling bacterial colonization.…”

Anti-Biofouling Properties of Femtosecond Laser-Induced Submicron Topographies on Elastomeric Surfaces

“…Bacterial adhesion tests were performed on all investigated substrates with a rod-shaped gramnegative bacteria. The Escherichia coli BL21 (DE3) strain (Thermofisher Scientific, USA) was selected as an example bacteria in this research because of its wide use in investigations on antimicrobial efficacy of textured surfaces [40][41]. In particular, this motile strain was prepared by first cloning the hplA gene with Green Fluorescent Protein (GFP) in pBSK cloning vector.…”

Molecular and Topographical Organization: Influence on Cicada Wing Wettability and Bactericidal Properties

“…Identifying the modes in which insects enact these remarkable properties would act as a guide to the consideration of both chemistry and topography during the fabrication of engineered materials with combined superhydrophobic and antimicrobial purposes. [ 28 ]…”