TiAl6V4 Alloy Surface Modifications and Their Impact on Biofilm Development of S. aureus and S. epidermidis

Abstract

One of the most serious complications following joint replacement surgeries are periprosthetic infections (PIs) arising from the adhesion of bacteria to the artificial joint. Various types of titanium–aluminum–vanadium (TiAl6V4) alloy surface modifications (coatings with silver (Ag), titanium nitride (TiN), pure titanium (cpTi), combinations of cpTi and hydroxyapatite (HA), combinations of cpTi and tricalcium phosphate (TCP), and a rough-blasted surface of TiAl6V4) have been investigated to assess their effects on biofilm development. Biofilms were grown, collected, and analyzed after 48 h to measure their protein and glucose content and the cell viability. Biofilm-associated genes were also monitored after 48 h of development. There was a distinct difference in the development of staphylococcal biofilms on the surfaces of the different types of alloy. According to the findings of this study, the base alloy TiAl6V4 and the TiN-coated surface are the most promising materials for biofilm reduction. Rough surfaces are most favorable when it comes to bacterial infections because they allow an easy attachment of pathogenic organisms. Of all rough surfaces tested, rough-blasted TiAl6V4 was the most favorable as an implantation material; all the other rough surfaces showed more distinct signs of inducing the development of biofilms which displayed higher protein and polysaccharide contents. These results are supported by RT-qPCR measurements of biofilm associated genes for Staphylococcus aureus (icaA, icaC, fnbA, fnbB, clfB, atl) and Staphylococcus epidermidis (atle, aap).

Effect of Cobalt–Chromium–Molybdenum Implant Surface Modifications on Biofilm Development of S. aureus and S. epidermidis

“…In most cases this is a statistically significant difference and holds for most of the comparisons of the alloys to each other as well (see Table 3). Those results are in accordance with earlier studies on the topic (Öztürk et al, 2007;Yoda et al, 2014;Kunrath et al, 2020;Palka et al, 2020;Paulitsch-Fuchs et al, 2021), supporting the conclusion that the higher surface roughness is beneficial for protein and polysaccharide rich biofilms on the surfaces studied here. However, in a review by Zheng et al (2021), the influence of surface structures has been recently summarized showing that generally, bacteria tend to attach to surfaces more easily when they have a certain roughness, however there are also some rough surfaces achieving the opposite and also different bacterial species can react in different ways to the same surface.…”

“…But also, within the S. aureus and S. epidermidis isolates, differences in biofilm forming abilities exist, making it difficult to generalize results. S. aureus Newman has already been used for many studies on biofilm formation (e.g., Johnson et al, 2008 ; Abraham and Jefferson, 2012 ; Forson et al, 2020 ; Inés Molina et al, 2020 ; Pinto et al, 2020 ) although it is not considered a very good biofilm forming strain and the same is true for the ica negative S. epidermidis strain (e.g., Stepanovic et al, 2000 ; Lee et al, 2016 ; Paduszynska et al, 2019 ; Di Pilato et al, 2020 ; Paulitsch-Fuchs et al, 2021 ). However, the variant of the S. aureus strain used in this study S. aureus Newman D2C is considered to be a relatively good biofilm forming strain ( Grundmeier et al, 2004 ; Tsompanidou et al, 2010 ; Abraham and Jefferson, 2012 ; Dauros-Singorenko et al, 2020 ; Paulitsch-Fuchs et al, 2021 ).…”

“…S. aureus Newman has already been used for many studies on biofilm formation (e.g., Johnson et al, 2008 ; Abraham and Jefferson, 2012 ; Forson et al, 2020 ; Inés Molina et al, 2020 ; Pinto et al, 2020 ) although it is not considered a very good biofilm forming strain and the same is true for the ica negative S. epidermidis strain (e.g., Stepanovic et al, 2000 ; Lee et al, 2016 ; Paduszynska et al, 2019 ; Di Pilato et al, 2020 ; Paulitsch-Fuchs et al, 2021 ). However, the variant of the S. aureus strain used in this study S. aureus Newman D2C is considered to be a relatively good biofilm forming strain ( Grundmeier et al, 2004 ; Tsompanidou et al, 2010 ; Abraham and Jefferson, 2012 ; Dauros-Singorenko et al, 2020 ; Paulitsch-Fuchs et al, 2021 ). Abraham and Jefferson (2012) showed that the autolysin activity in the Newman D2C variant was low enough to allow the expression of ClfB on the cell surface, which seems to be (at least partly) responsible for the difference in biofilm forming abilities between the two strains.…”

Infections @ Trauma/Orthopedic Implants: Recent Advances on Materials, Methods, and Microbes—A Mini-Review

“…More complex approaches use coatings or the addition of other substances. In one study, the effect of surface modifications on the formation of a difficult to eradicate biofilm was investigated [ 18 ]. The coating of Ti alloy with pure Ti, silver (Ag), hydroxyapatite (HA), or tricalcium phosphate (TCP) as well as the effect of rough blasting (rb) were analyzed.…”

Wear Resistance of Ti–6Al–4V Alloy Ball Heads for Use in Implants

“…To increase the wear resistance of titanium alloys, nitrogen is most often used, both in the creation of nitrogen-containing “alpha” layers on the surface and in its application as nitride coatings. This is achieved by using thermal diffusion saturation with nitrogen from the gaseous environment, by ion implantation, or by applying PVD coatings [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. The disadvantages of these technologies include: A change in the volume structure of a device during thermal diffusion saturation at elevated temperatures, which leads to a significant deterioration in the mechanical properties [ 18 , 19 , 20 ]; A change in the surface microgeometry after nitriding at elevated temperatures, which excludes the use of such processing as a way of applying a finish to the completed product because one of the main conditions for the operation of friction components is a high level of surface cleanliness [ 21 , 23 , 24 ]; The low adhesion strength of nitride coatings, which quite often leads to their peeling off during use [ 22 ].…”