Bacteria are known to adhere to surfaces, which allows for the formation of
biofilms, possibly causing a surge in hospital-offset infections, perilous
diseases, and in some cases, death. Although certain bacteria are present in
the natural flora of the human skin, some present extreme clinical
significance due to the ability to transmit and adhere, and can be resistant to
antibiotics. They also evolve over time to survive in harsh environmental
conditions.
Current research reveals that design of plastic surfaces containing
submicron structures, is becoming a popular approach to tackle issues
concerning infection transmission, with inspiration being derived from
biomimetics and self-cleaning surfaces, such as the surface of a gecko skin,
and the hydrophobic wax layer of forest leaves. Main barriers to adoption
include that these surfaces alone are difficult to manufacture on 3D products,
expensive to fabricate on a large scale and do not last long when subjected
to environmental wear.
Replication of nano-scale ridges was carried out using micro-injection, and
the various samples were characterised using a range of tools to determine
physical and biomechanical parameters. The sample surfaces were then
cultured with the pathogenic bacterium Staphylococcus aureus under several
environmental conditions, and the results were statistically analysed to reveal
that anti-fouling LIPSS (laser induced periodic surface structures) ridges
perform better to reduce bacteria cell-substrate adhesion, when compared to
flat surfaces, or surfaces containing dual structures (anti-fouling ridges
combined with anti-wear walls). It was therefore demonstrated that nanotextured
polymeric surfaces with hydrophobic characteristics have
exceptional non-fouling properties, preventing S. aureus, a very significant bacterial strain, from initial adhesion, a critical primary mechanism in its
ability to proliferate.
Collectively, the findings of this study strongly support the literature,
suggesting that the bacteria struggle to adhere onto polymeric topography
with increased water contact angles and simple nanostructures. However,
the addition of certain anti-wear micro-features increased bacterial adhesion,
reducing the efficacy of the non-fouling nanostructures from preventing
biofilm formation.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/19763 |
| Date | January 2021 |
| Creators | Israr Raja, Tehmeena |
| Contributors | Whiteside, Benjamin R., Katsikogianni, Maria G., Sefat, Farshid, Snelling, Anna M. |
| Publisher | University of Bradford, Faculty of Engineering and Informatics |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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