Enhanced and Stem-Cell-Compatible Effects of Nature-Inspired Antimicrobial Nanotopography and Antimicrobial Peptides to Combat Implant-Associated Infection

Abstract

Nature-inspired antimicrobial surfaces and antimicrobial peptides (AMPs) have emerged as promising strategies to combat implant-associated infections. In this study, a bioinspired antimicrobial peptide was functionalized onto a nanospike (NS) surface by physical adsorption with the aim that its gradual release into the local environment would enhance inhibition of bacterial growth. Peptide adsorbed on a control flat surface exhibited different release kinetics compared to the nanotopography, but both surfaces showed excellent antibacterial properties. Functionalization with peptide at micromolar concentrations inhibited Escherichia coli growth on the flat surface, Staphylococcus aureus growth on the NS surface, and Staphylococcus epidermidis growth on both the flat and NS surfaces. Based on these data, we propose an enhanced antibacterial mechanism whereby AMPs can render bacterial cell membranes more susceptible to nanospikes, and the membrane deformation induced by nanospikes can increase the surface area for AMPs membrane insertion. Combined, these effects enhance bactericidal activity. Since functionalized nanostructures are highly biocompatible with stem cells, they make promising candidates for next generation antibacterial implant surfaces.

Bioinspired Nanotopography for Combinatory Osseointegration and Antibacterial Therapy

“…aureus quantified from images in Figure C,D (* p < 0.05 and ** p < 0.005 compared with control, # p < 0.05 and ## p < 0.005 compared with nanoripple). (C, D) Comparison of antibacterial effect with previous papers; PLA, silk, DGEBA nanopatterns, ZnO, PC, PEEK nanopillars, black Ti, and TiO 2 nanospikes. ,,, (E) Schematic illustration of the mechanism of multifunctional nanopillar surface.…”

“…Figure C,D illustrates previous efforts to improve the antibacterial properties and cytocompatibility on various surfaces. ,,,− ,− These studies evaluate the antibacterial properties of Gram-negative (E. coli and P.…”

“…The surface coverage rates of preosteoblasts cocultured with E. coli and S. aureus on nanopillars were 33 and 29%, respectively, the highest values of 33 DGEBA nanopatterns, 34 ZnO, 37 PC, 52 PEEK nanopillars, 53 black Ti, 36 and TiO 2 nanospikes. 18,38,54,55 all groups. Colonization of bacteria predominates over preosteoblast cell proliferation on other surfaces because of the lack of antibacterial properties.…”

Antimicrobial Activity of Anodic Porous Alumina with Controlled Surface Structures

“…Surfaces with nanometer-scale concavo–convex structures, such as nanopillar arrays, exhibit antimicrobial properties and are expected to have various applications as drug-free antimicrobial surfaces. − Several methods, including reactive-ion etching, nanoimprinting, and chemical vapor deposition, have been used to fabricate microstructure-based antimicrobial surfaces. − However, the relationship between the antimicrobial properties and surface structures has not yet been clarified. To realize the fabrication of surfaces with higher antimicrobial properties, it is important to elucidate the effects of surface structures on antimicrobial properties.…”

Nanotopography Influences Host–Pathogen Quorum Sensing and Facilitates Selection of Bioactive Metabolites in Mesenchymal Stromal Cells and Pseudomonas aeruginosa Co-Cultures

“…Previous work has shown that introducing high aspect ratio nanoscale topographies on Ti can confer antibacterial properties in vivo and in vitro while allowing mesenchymal stromal cell (human, hMSC) growth. 7,8 Additionally, studies have shown that bacteria are less likely to adhere to high aspect ratio nanostructured Ti compared to smooth surfaces. 9−11 First, this is because increased high aspect ratio features provide fewer contact points for bacterial adhesion as they rely on the physical interactions between their outer structures and the surfaces they colonize.…”