Control of bacterial attachment by fracture topography

Amar Velic; Asha Mathew; Peter Hines; Prasad K D V Yarlagadda

doi:10.1016/j.jmbbm.2018.10.020

Control of bacterial attachment by fracture topography

J Mech Behav Biomed Mater. 2019 Mar:91:416-424. doi: 10.1016/j.jmbbm.2018.10.020. Epub 2018 Oct 21.

Authors

Amar Velic¹, Asha Mathew¹, Peter Hines², Prasad K D V Yarlagadda³

Affiliations

¹ School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia.
² Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, Australia.
³ School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia. Electronic address: y.prasad@qut.edu.au.

PMID: 30424978
DOI: 10.1016/j.jmbbm.2018.10.020

Abstract

In the biomedical arena, bacterial fouling is a precursor to complications such as implant infection and nosocomial infection. These complications are further compounded by biochemical mechanisms of resistance that threaten the action of traditional antibacterial strategies. Accordingly, antibacterial property by physical, not biochemical, mechanisms of action is becoming increasingly popular and promising. The present work falls in line with this paradigm shift. Here, microtextured Ti-6Al-4V surfaces were manufactured by destructive tension at three different cross-head speeds, probed with scanning electron microscopy (SEM) and multifocus optical microscopy, and treated with Staphylococcus aureus to study bacterial attachment. The fractographic study revealed the presence of dual-mode fracture, typical of Ti-6Al-4V, comprising regions of both ductile, microvoid coalescence and brittle, cleavage faceting. Based on load-extension curves, quantitative roughness data, and qualitative SEM visualisation, it was evident that cross-head speed modulated fracture behaviour such that increased speed produced more brittle fracture whilst lower speeds produced more ductile fracture. The topography associated with ductile fracture was found to possess notable antibiofouling property due to geometric constrains imposed by the coalesced microvoids. Accordingly, fracture at low cross-head speeds (1 mm/min and 10 mm/min) yielded significant reduction in bacterial attachment, whilst fracture at high cross-head speeds (100 mm/min) did not. The greatest reduction (~72%) was achieved at a cross-head speed of 1 mm/min. These findings suggest that antibiofouling property can be elicited by fracture and further 'tuned' by fracture speed. Discovery of this novel, albeit simple, avenue for topography-mediated antibacterial property calls for further research into alternate techniques for the manufacture of 'physical antibacterial surfaces'.

Keywords: Antibiofouling; Bacterial adhesion; Fractography; Staphylococcus aureus; Titanium alloy; Topography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alloys
Bacterial Adhesion / drug effects*
Mechanical Phenomena
Staphylococcus aureus / drug effects*
Staphylococcus aureus / physiology*
Surface Properties
Titanium / pharmacology

Substances

Alloys
titanium alloy (TiAl6V4)
Titanium