Bio-Inspired Nanostructured Ti-6Al-4V Alloy: The Role of Two Alkaline Etchants and the Hydrothermal Processing Duration on Antibacterial Activity

Bright, Richard, Hayles, Andrew, Wood, Jonathan, Ninan, Neethu, Palms, Dennis, Visalakshan, Rahul M., Burzava, Anouck, Brown, Toby, Barker, Dan, and Vasilev, Krasimir (2022) Bio-Inspired Nanostructured Ti-6Al-4V Alloy: The Role of Two Alkaline Etchants and the Hydrothermal Processing Duration on Antibacterial Activity. Nanomaterials, 12. 1140.

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Inspired by observations that the natural topography observed on cicada and dragonfly wings may be lethal to bacteria, researchers have sought to reproduce these nanostructures on biomaterials with the goal of reducing implant-associated infections. Titanium and its alloys are widely employed biomaterials with excellent properties but are susceptible to bacterial colonisation. Hydrothermal etching is a simple, cost-effective procedure which fabricates nanoscale protrusions of various dimensions upon titanium, depending on the etching parameters used. We investigated the role of etching time and the choice of cation (sodium and potassium) in the alkaline heat treatment on the topographical, physical, and bactericidal properties of the resulting modified titanium surfaces. Optimal etching times were 4 h for sodium hydroxide (NaOH) and 5 h for potassium hydroxide (KOH). NaOH etching for 4 h produced dense, but somewhat ordered, surface nanofeatures with 75 nanospikes per µm2. In comparison, KOH etching for 5 h resulted sparser but nonetheless disordered surface morphology with only 8 spikes per µm2. The NaOH surface was more effective at eliminating Gram-negative pathogens, while the KOH surface was more effective against the Gram-positive strains. These findings may guide further research and development of bactericidal titanium surfaces which are optimised for the predominant pathogens associated with the intended application.

Item ID: 77006
Item Type: Article (Research - C1)
ISSN: 2079-4991
Keywords: antibacterial, biofilm, biomimetic, implant associated infection, nanostructure, titanium alloy
Copyright Information: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (
Projects and Grants: NHMRC GNT1194466, ARC DP180101254
Date Deposited: 23 Mar 2023 04:00
FoR Codes: 32 BIOMEDICAL AND CLINICAL SCIENCES > 3206 Medical biotechnology > 320699 Medical biotechnology not elsewhere classified @ 50%
40 ENGINEERING > 4018 Nanotechnology > 401807 Nanomaterials @ 50%
SEO Codes: 20 HEALTH > 2001 Clinical health > 200104 Prevention of human diseases and conditions @ 100%
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