Low Bacterial Adhesion Research Articles

Graphene Surfaces Interaction with Proteins, Bacteria, Mammalian Cells, and Blood Constituents: The Impact of Graphene Platelet Oxidation and Thickness.

Graphene-based materials (GBMs) have been increasingly explored for biomedical applications. However, interaction between GBMs-integrating surfaces and bacteria, mammalian cells, and blood components, that is, the major biological systems in our body, is still poorly understood. In this study, we systematically explore the features of GBMs that most strongly impact the interactions of GBMs films with plasma proteins and biological systems. Films produced by vacuum filtration of GBMs with different oxidation degree and thickness depict different surface features: graphene oxide (GO) and few-layer GO (FLGO) films are more oxidized, smoother, and hydrophilic, while reduced GO (rGO) and few-layer graphene (FLG) are less or nonoxidized, rougher, and more hydrophobic. All films promote glutathione oxidation, although in a lower extent by rGO, indicating their potential to induce oxidative stress in biological systems. Human plasma proteins, which mediate most of the biological interactions, adsorb less to oxidized films than to rGO and FLG. Similarly, clinically relevant bacteria, Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, adhere less to GO and FLGO films, while rGO and FLG favor bacterial adhesion and viability. Surface features caused by the oxidation degree and thickness of the GBMs powders within the films have less influence toward human foreskin fibroblasts; all materials allow cell adhesion, proliferation and viability up to 14 days, despite less on rGO surfaces. Blood cells adhere to all films, with higher numbers in less or nonoxidized surfaces, despite none having caused hemolysis (<5%). Unlike thickness, oxidation degree of GBMs platelets strongly impact surface morphology/topography/chemistry of the films, consequently affecting protein adsorption and thus bacteria, fibroblasts and blood cells response. Overall, this study provides useful guidelines regarding the choice of the GBMs to use in the development of surfaces for an envisioned application. Oxidized materials appear as the most promising for biomedical applications that require low bacterial adhesion without being cytotoxic to mammalian cells.

Osteogenic and antibacterial dual functions of a novel levofloxacin loaded mesoporous silica microspheres/nano-hydroxyapatite/polyurethane composite scaffold

Lev/MSNs/n-HA/PU has been proved to be a novel scaffold material to treat bone defect caused by chronic osteomyelitis. We have previously identified that this material can effectively treat chronic osteomyelitis caused by Staphylococcus aureusin vivo. However, the potential mechanisms of antibacterial and osteogenic induction properties remain unclear. Thus, for osteogenesis property, immunohistochemistry, PCR, and Western blot were performed to detect the expression of osteogenic markers. Furthermore, flow cytometry and TUNEL were applied to analyze MC3T3-E1 proliferation and apoptosis. For antibacterial property, the material was co-cultivated with bacteria, bacterial colony forming units was counted and the release time of the effective levofloxacin was assayed by agar disc-diffusion test. Moreover, scanning electron microscope was applied to observe adhesion of bacteria. In terms of osteogenic induction, we found BMSCs adherently grew more prominently on Lev/MSNs/n-HA/PU. Lev/MSNs/n-HA/PU also enhanced the expression of osteogenic markers including OCN and COL1α1, as well as effectively promoted the transition from G1 phase to G2 phase. Furthermore, Lev/MSNs/n-HA/PU could reduce apoptosis of MC3T3-E1. Besides, both Lev/MSNs/n-HA/PU and n-HA/PU materials could inhibit bacterial colonies, while Lev/MSNs/n-HA/PU possessed a stronger antibacterial activities, and lower bacterial adhesion than n-HA/PU. These results illustrated that Lev/MSNs/n-HA/PU composite scaffold possess favorable compatibility in vitro, which induce osteogenic differentiation of MSCs, promote proliferation and differentiation of MC3T3-E1, and inhibit apoptosis. Moreover, clear in vitro antibacterial effect of Lev/MSNs/n-HA/PU was also observed. In summary, this study replenishes the potential of Lev/MSNs/n-HA/PU composite scaffold possess dual functions of anti-infection and enhanced osteogenesis for future clinical application.

Effects of surface pretreatments and coating period on hydroxyapatite coating of Ti6Al4V alloy

In this study, Ti6Al4V plates were gone through three steps of pretreatment process (sandblasting + acid etching + preheating) followed by biomimetic coating of pure hydroxyapatites (HAp) on pretreated substrate. Pretreated substrates were examined by SEM, EDS, AFM, FTIR, and XRD; meanwhile, prepared coatings were examined by SEM, EDS, FTIR, XRD, XPS, scratch test, and in vitro cell studies (SaOS-2 cell line). Prepared coatings were also investigated in terms of antibacterial property by determining the survival of the Staphylococcus epidermidis on the surface. Structural analysis results of pretreated substrates proved that surface roughness increased proportionally as sandblasting, acid etching, and preheating process were performed. Successively, surface became more porous according to SEM images which were also supported by AFM results that indicate that Ra increased up to 953 nm values. EDS and FTIR spectra showed that functional groups were formed with the pretreatment procedure. Especially titanium salts were formed during acid etching process while preheating caused oxidation. XRD spectra revealed that as-received substrates mostly consisted of α-Ti, acid etching resulted in formation of TiH2 structure and oxidation resulted to form rutile and anatase structure patterns. Pretreatment procedure had positive effect on biomimetic coatings according to the evaluation of structural, mechanical, and biological properties. SEM analysis revealed that HAp nucleation started 4 days after immersion and nucleation increased with the incubation time. EDS results indicated that maximum Ca/P ratio (1.48) was achieved by P14. FTIR, XRD, and XPS analysis proved the presence of hydroxyapatite on the substrate surface. The pretreatment procedure had significant influence on mechanical properties of the coatings resulting in increase of critical loads. P14 sample had the highest critical load. In terms of biological evaluation, P14 exhibited the highest cell proliferation and lowest bacterial adhesion. The highest stability and coherence of P14 coating was also confirmed by mechanical test results. Eventually, it was observed that pretreatment technique has great effect on surface properties. In addition, 14 days immersion period was found to be optimum along the investigated immersion times.

Biocorrosion and biological properties of sputtered ceramic carbide coatings for biomedical applications

Surface coating with superior corrosion resistance properties is indispensable for biomedical implant industries to reduce the cytotoxicity related problems. In this work, microstructure, biocorrosion and biological properties of magnetron sputtered TiC and ZrC coatings on type 316L stainless steel (SS) substrates are studied for biomedical applications. Biocorrosion properties have been examined in the Artificial Blood Plasma (ABP) solution with 1% and 10% of H2O2 to study the corrosion behavior of carbides coated 316L SS. The formation of strong oxide passive layers on ceramic carbide coated substrates could enhance the corrosion resistance properties than uncoated SS substrates. The whole blood protein adsorption behavior of carbides coated and uncoated SS substrates are studied and the bacterial adhesion behavior is measured with Pseudomonas aeruginosa (P.aeruginosa) pathogen. The results revealed that the coatings possess higher protein adsorption and lower bacterial adhesion than that of bare steel substrates. In addition, Alizarin red based assay is done to confirm the biomineralization (calcium precipitation) of osteoblast like cells onto test samples and the results showed that TiC and ZrC coatings could enhance the biomineralization process.

In-situ doping of a conductive hydrogel with low protein absorption and bacterial adhesion for electrical stimulation of chronic wounds

Electrical stimulation (ES) via electrodes is promising for treating chronic wounds, but this electrode-based strategy is unable to stimulate the whole wound area and the therapeutic outcome may be compromised. In this study, a conductive poly(2-hydroxyethyl methacrylate) (polyHEMA)/polypyrrole (PPY) hydrogel was developed, and 3-sulfopropyl methacrylate was covalently incorporated in the hydrogel’s network to in-situ dope the PPY and maintain the hydrogel’s conductivity in the weak alkaline physiological environment. The obtained hydrogel was superior to the commercial Hydrosorb® dressing for preventing bacterial adhesion and protein absorption, and this is helpful to reduce the possibilities of infection and secondary damage during dressing replacement. The in vitro scratch assay demonstrates that ES through the hydrogel enhanced fibroblast migration, and this enhancement effect remained even after the ES was ended. The in vivo assay using diabetic rats shows that when ES was conducted with this polyHEMA/PPY hydrogel, the healing rate was faster than that achieved by the electrode-based ES strategy. Therefore, this polyHEMA/PPY hydrogel shows a great potential for developing the next generation of ES treatment for chronic wounds. Statement of SignificanceElectrical stimulation (ES) via separated electrodes is promising for treating chronic wounds, but this electrode-based strategy is unable to stimulate the whole wound area, compromising the therapeutic outcome. Herein, a hydrogel was developed with stable electrical conductivity in the physiological environment and strong resistance to protein absorption and bacterial adhesion. The in vitro and in vivo tests proved that ES applied through the flexible and conductive hydrogel that covered the wound was superior to ES through electrodes for promoting the healing of the chronic wound. This hydrogel-based ES strategy combines the advantages of ES and hydrogel dressing and will pave the way for the next generation of ES treatment for chronic wounds.

Do graphene oxide nanostructured coatings mitigate bacterial adhesion?

Graphene oxide (GO) is a biocidal nanomaterial, but is it also anti-adhesive? Here we show that GO-based coatings exhibiting low bacterial adhesion properties can be formed by edge-tethering GO nanosheets to hydrophilic polymer brushes.

Polytetrafluoroethylene (PTFE): A resin material for possible use in dental prostheses and devices.

Polytetrafluoroethylene (PTFE) is chemically stable, non-toxic to humans, highly resistant to heat and chemicals, and has an extremely low coefficient of friction. Therefore, PTFE is used in medical applications. We focused on the physical properties of PTFE in relation to its application as a material for use in prostheses and dental devices/instruments. PTFE exhibited low wear (approximately 1/3 that of bovine tooth, and 1/2 that of type III gold alloy), low dynamic friction (approximately 1/5 that of the other specimens), low hardness (4.8HV1.0), low coloration, and low bacterial adhesion, compared to other specimens except porcelain in wear and coloration test (p<0.01). These results suggest that PTFE could have applications in some prostheses for provisional and/or permanent use, and dental instruments/devices by providing excellent impact absorption, high wear resistance for maintenance of occlusal vertical dimension and original function, and ease of cleaning.

CuO Nanoparticles-Containing Highly Transparent and Superhydrophobic Coatings with Extremely Low Bacterial Adhesion and Excellent Bactericidal Property.

Human health and industrial instruments have been suffering from bacterial colonization on the surface of materials for a long time. Recently, antibacterial coatings are regarded as the new strategy to resist bacterial pathogens. In this work, novel highly transparent and superhydrophobic coatings with extremely low bacterial adhesion and bactericidal performance were prepared by spray-coating hydrophobic silica sol and CuO nanoparticles. The coated glass showed high transmittance in 300-2500 nm with a maximum value of 96.6%. Compared with bare glass, its superhydrophobic characteristics resulted in a reduction in adhesion of bacteria ( Escherichia coli, E. coli) by up to 3.2 log cells/cm2. Additionally, the live/dead staining test indicated that the as-prepared coating exhibited excellent bactericidal performance against E. coli. Moreover, the as-prepared coating could maintain their superhydrophobicity after the sand impact test. The proposed method to fabricate such coatings could be applied on various substrates. Therefore, this novel hybrid surface with the abilities to reduce bacterial adhesion and kill attached bacteria make it a promising candidate for biosensors, microfluidics, bio-optical devices, household facilities, lab-on-chips, and touchscreen devices.

L’adhésion bactérienne n’est pas plus faible sur les céramiques que sur les autres biomatériels. Analyse in vitro

BackgroundAlthough there is some clinical evidence of ceramic bearings being associated with a lower infection rate after total hip arthroplasty (THA), available data remains controversial since this surface is usually reserved for young, healthy patients. Therefore, we investigated the influence of five commonly used biomaterials on the adhesion potential of four biofilm-producing bacteria usually detected in infected THAs. HypothesisCeramic biomaterials exhibit less bacterial adherence than other biomaterials. Material and methodsIn this in-vitro research, we evaluated the ability of Staphylococcus. aureus, Staphylococcus. epidermidis ATCC 35984, Escherichia. coli ATCC 25922 and Pseudomonas. aeruginosa to adhere to the surface of a cobalt-chromium metal head, a fourth-generation ceramic head, a fourth-generation ceramic insert, a highly-crossed linked polyethylene insert and a titanium porous-coated acetabular component. After an initial washing step, bacterial separation from the surface of each specimen was done with a vortex agitator. The colony-forming units were counted to determine the number of viable adherent bacteria. ResultsWe found no differences on global bacterial adhesion between the different surfaces (p=0.5). E. coli presented the least adherence potential among the analysed pathogens (p<0.001). The combination of E. coli and S. epidermidis generated an antagonist effect over the adherence potential of S. epidermidis individually (58±4% vs. 48±5%; p=0.007). The combination of P. aeruginosa and S. aureus presented a trend to an increased adherence of P. aeruginosa independently, suggesting an agonist effect (71% vs. 62%; p=0.07). DiscussionCeramic bearings appeared not to be related to a lower bacterial adhesion than other biomaterials. However, different adhesive potentials among bacteria may play a major role on infection's inception. Level of evidenceIV, in-vitro study.

No lower bacterial adhesion for ceramics compared to other biomaterials: An in vitro analysis.

Although there is some clinical evidence of ceramic bearings being associated with a lower infection rate after total hip arthroplasty (THA), available data remains controversial since this surface is usually reserved for young, healthy patients. Therefore, we investigated the influence of five commonly used biomaterials on the adhesion potential of four biofilm-producing bacteria usually detected in infected THAs. Ceramic biomaterials exhibit less bacterial adherence than other biomaterials. In this in vitro research, we evaluated the ability of Staphylococcus aureus, Staphylococcus epidermidis ATCC 35984, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa to adhere to the surface of a cobalt-chromium metal head, a fourth-generation ceramic head, a fourth-generation ceramic insert, a highly-crossed linked polyethylene insert and a titanium porous-coated acetabular component. After an initial washing step, bacterial separation from the surface of each specimen was done with a vortex agitator. The colony-forming units were counted to determine the number of viable adherent bacteria. We found no differences on global bacterial adhesion between the different surfaces (p=0.5). E.coli presented the least adherence potential among the analysed pathogens (p<0.001). The combination of E.coli and S.epidermidis generated an antagonist effect over the adherence potential of S.epidermidis individually (58±4% vs. 48±5%; p=0.007). The combination of P.aeruginosa and S.aureus presented a trend to an increased adherence of P.aeruginosa independently, suggesting an agonist effect (71% vs. 62%; p=0.07). Ceramic bearings appeared not to be related to a lower bacterial adhesion than other biomaterials. However, different adhesive potentials among bacteria may play a major role on infection's inception. IV, in vitro study.

Preparation, characterization, and properties of fluorine-free superhydrophobic paper based on layer-by-layer assembly

A fluorine-free superhydrophobic paper was prepared by a facile method involving layer-by-layer deposition of cationic starch and sodium alginate together with subsequent modification of trichloromethylsilane has been reported in this article. The surface chemical compositions, potentials and surface morphologies of the modified papers were characterized, respectively. The wetting abilities and physical strength properties of the modified papers were investigated. After 4-time deposition of cationic starch/sodium alginate bilayer followed by trichloromethylsilane treatment, the water contact angle of modified paper reached up to 161.7°, and the tensile strength increased by 6.8% in comparison to that of pristine paper. This as-prepared superhydrophobic paper not only showed low bacterial adhesion property, self-cleaning behavior, water repellency, as well as high durability against deformation, chemical and time, but also kept a high strength property under high relative humidity condition, which might has a great application potential in the liquid paper packaging industry.

Nanostructured mesoporous carbon polyethersulfone composite ultrafiltration membrane with significantly low protein adsorption and bacterial adhesion

A novel polyethersulfone (PES) ultrafiltration membrane containing 0.05–2.00 wt% of synthesized mesoporous carbon nanoparticles (MCNs) was prepared via the phase inversion technique. The structures and properties of MCNs were characterized using a variety of analytic techniques. The MCNs showed the surface area of 1396.8 m2/g and the highest pore size of around 1 nm. The effect of incorporation of MCNs on the composite membrane morphology and performance was investigated through pure water flux, protein adsorption, and bacterial adhesion resistance tests. The membrane's anti-fouling performances were determined under constant-pressure operation at 100 kPa in a dead-end module. The as-prepared nanocomposite membranes were also studied in terms of morphology, structure and surface chemistry. Generally, the incorporation of MCNs into the polymeric membrane improved the pure water flux. The composite membrane containing 0.20 wt% MCNs exhibited the highest antifouling, protein adsorption resistance, and bacterial attachment inhibition property. The incorporation of the MCNs into the membranes introduces a different strategy of inhibiting biomolecule adsorption and bacterial attachment to the membrane surface, instead of killing the bacteria which may lead to more severe membrane fouling by the intracellular substances.

High‐Performance Carbon Anode Derived from Sugarcane for Packed Microbial Fuel Cells

AbstractMicrobial fuel cells (MFCs) provide a new opportunity to produce sustainable energy from the treatment of the organic matter in wastewater. However, the power density of MFCs for large‐scale application is limited by the performance of anode, with one of the major factors being low bacterial adhesion capacity. In this work, a novel macroporous sugarcane carbon (SC) is prepared by a direct carbonization process, and is used as anode material in a packed MFC. A maximum power density of 59.94±2.81 W m−3 is achieved in an MFC equipped with the SC anode, which is 2.62 times higher than that of the granular activated carbon (GAC) anode. A microbial analysis shows that the SC anode has a higher amount of biomass and the abundance of Geobacter is 6.6 times higher than that of the GAC anode, which indicates that the SC anode has higher biocompatibility. Further studies show that the macroporous structure, high surface roughness, large surface hydrophobicity and low absolute value of zeta potential favor bacterial adhesion to the SC anode surface. Therefore, this study provides an excellent anode material for high‐performance MFCs, and reveals the impact of physicochemical properties on power generation.

&lt;i&gt;In Vitro&lt;/i&gt; Bioactivity and Bacteriostasis Effect of Thermally Treated and UV-Light Irradiated TiO&lt;sub&gt;2&lt;/sub&gt; Ceramics

Biomaterials used in bone repair must satisfy certain criteria in order to perform without undesirable immunological response. They must be biocompatible and should inhibit bacteria adhesion on the surface, that could led to strong inflammatory process and implant failure. Our study reveals a synergistic effect on bioactivity and bacteriostasis effect of the TiO2 ceramics with different surface properties and provides insight into the design of better biomedical implant surfaces. The results show that UV light irradiation has great impact on hidrophilicity of TiO2 ceramics, but little effect on the sample bacteriostatic effect and bioactivity. TiO2 ceramic samples showed no or very low bacterial adhesion. Nevertheless, in vitro bioactivity showed TiO2 ceramic that was thermally treated at lower temperature. Thus for bone repair it’s suggested to use TiO2 ceramic sintered at lower temperature in order to provide bioactivity with bacterostatic effect and use UV-light irradiation to improve hidrophilicity.

Influence of Oxynitrided Surface in the Production of a Less Susceptible Titanium Surface to Skin-Borne Bacterial Adhesion.

There is a growing quest for an ideal biomaterial that shows appropriate cellular response and is not susceptible to microbial adhesion. In this study, commercial grade II titanium was submitted to RF/DC plasma surface modification at 2.2 mbar, using gas mixtures of argon, nitrogen, and oxygen at proportions 4:1:2 and 4:1:3. The surfaces were physically and chemically characterized. In order to evaluate bacterial response, the surfaces were exposed to Staphylococcus epidermidis. Oxynitrided samples, although having a higher roughness as compared with untreated samples, exhibited lower bacterial growth. This observation is probably due to the formation of different crystalline phases of nitrides and oxides caused by plasma treatment. The surface with highest contact angle and highest surface tension showed lower bacterial adhesion. These results were confirmed by scanning electron microscopy. The role of nitrogen in reducing bacterial adhesion is clear when this material is compared with untreated titanium, on which only an oxide film is present.

Bacterial adhesion on biomedical surfaces covered by yttria stabilized zirconia.

The aim of this study was to compare the bacterial adhesion of Staphylococcus spp. on Ti-6Al-4V with respect to Ti-6Al-V modified alloys with a set of Cubic yttria stabilized zirconia (YSZ) and Ag-YSZ nanocomposite films. Silver is well known to have a natural biocidal character and its presence in the surface predicted to enhance the antimicrobial properties of biomedical surfaces. Microbial adhesion tests were performed using collection strains and twelve clinical strains of Staphylococcus aureus and Staphylococcus epidermidis. The adherence study was performed using a previously published protocol by Kinnari et al. Both collection strains and clinical isolates have shown lower bacterial adhesion to materials modified with respect to the alloy Ti-6Al-4V and the modification with silver reduced the bacterial adhesion for most of all the strains studied. Moreover the percentage of dead bacteria have been evaluated, demonstrating increased proportion of dead bacteria for the modified surfaces. Nanocrystalline silver dissolves releasing both Ag(+) and Ag(0) whereas other silver sources release only Ag(+). We can conclude that YSZ with nanocrystalline silver coating may lead to diminished postoperative infections and to increased corrosion and scratch resistance of YSZ incorporating alloys Ti-6Al-4V.

Impact of 3D Hierarchical Nanostructures on the Antibacterial Efficacy of a Bacteria-Triggered Self-Defensive Antibiotic Coating.

Titanium is often applied in implant surgery, but frequently implicated in infections associated with bacterial adhesion and growth on the implant surface. Here, we show that hierarchical nanostructuring of titanium and the subsequent coating of resulting topographical features with a self-defensive, antibacterial layer-by-layer (LbL) film enables a synergistic action of hierarchical nanotopography and localized, bacteria-triggered antibiotic release to dramatically enhance the antibacterial efficiency of surfaces. Although sole nanostructuring of titanium substrates did not significantly affect adhesion and growth of Staphylococcus aureus, the coating of 3D-nanopillared substrates with an ultrathin tannic acid/gentamicin (TA/G) LbL film resulted in a 10-fold reduction of the number of surface-attached bacteria. This effect is attributed to the enlarged surface area of the nanostructured coating available for localized bacteria-triggered release of antibiotics, as well as to the lower bacterial adhesion forces resulting in subsided activation of bacterial antibiotic-defense mechanisms when bacteria land on nanopillar tips. The result shows that a combination of 3D nanostructuring with a bacteria-triggered antibiotic-releasing coating presents a unique way to dramatically enhance antibacterial efficacy of biomaterial implants.

Antifouling coatings for dental implants: Polyethylene glycol-like coatings on titanium by plasma polymerization.

Titanium dental implants are commonly used for the replacement of lost teeth, but they present a considerable number of failures due to the infection on surrounding tissues. The aim of this paper is the development of a polyethylene glycol-like (PEG-like) coating on the titanium surface by plasma polymerization to obtain a novel improved surface with suitable low bacterial adhesion and adequate cell response. Surface analysis data of these coatings are presented, in particular, water contact angle, surface roughness, and film chemistry, demonstrating the presence of a PEG-like coating. Streptococcus sanguinis and Lactobacillus salivarius bacterial adhesion assays showed a decreased adhesion on the plasma polymerized samples, while cell adhesion of fibroblasts and osteoblasts on the treated surfaces was similar to control surfaces. Thus, the PEG-like antifouling coating obtained by plasma polymerization on Ti confers this biomaterial's highly suitable properties for dental applications, as they reduce the possibility of infection while allowing the tissue integration around the implant.

The influence of surface modification on bacterial adhesion to titanium-based substrates.

This study examines bacterial adhesion on titanium-substrates used for bone implants. Adhesion is the most critical phase of bacterial colonization on medical devices. The surface of titanium was modified by hydrothermal treatment (HT) to synthesize nanostructured TiO2-anatase coatings, which were previously proven to improve corrosion resistance, affect the plasma protein adsorption, and enhance osteogenesis. The affinity of the anatase coatings toward bacterial attachment was studied by using a green fluorescent protein-expressing Escherichia coli (gfp-E. coli) strain in connection with surface photoactivation by UV irradiation. We also analyzed the effects of surface topography, roughness, charge, and wettability. The results suggested the dominant effects of the macroscopic surface topography, as well as microasperity at the surface roughness scale, which were produced during titanium machining, HT treatment, or both. Macroscopic grooves provided a preferential site for bacteria deposit within the valleys, while the microscopic roughness of the valleys determined the actual interaction surface between bacterium and substrate, resulting in an "interlocking" effect and undesired high bacterial adhesion on nontreated titanium. In the case of TiO2-coated samples, the nanocrystals reduced the width between the microasperities and thus added nanoroughness features. These factors decreased the contact area between the bacterium and the coating, with consequent lower bacterial adhesion (up to 50% less) in comparison to the nontreated titanium. On the other hand, the pronounced hydrophilicity of one of the HT-coated discs after pre-irradiation seemed to enhance the attachment of bacteria, although the increase was not statistically significant (p > 0.05). This observation may be explained by the acquired similar degree of wetting between gfp-E. coli and the coating. No correlation was found between the bacterial adhesion and the ζ-values of the samples in PBS, so the effect of surface charge was considered negligible in this study.

The Promotion of Antibacterial Effects of Ti6Al4V Alloy Modified with TiO2 Nanotubes Using a Superoxidized Solution

The purpose of the present study was to synthetize 80 nm diameter TiO2 nanotubes (NTs) on Ti6Al4V alloy using a commercially superoxidized water (SOW) enriched with fluoride to reduce anodization time and promote the antibacterial efficacy against Staphylococcus aureus (S. aureus). The alloy discs were anodized for 5 min and as a result, NTs of approximately 80 nm diameters were obtained with similar morphology as reported in previous studies using longer anodization times (1‐2 h). Filed emission‐scanning electron microscopy (FE‐SEM) and energy dispersive X‐ray spectroscopy (EDX) were used to characterize the materials surfaces. The NTs showed significantly decreased S. aureus viability after 1, 3, and 5 days of culture in comparison to nonanodized alloy. Likewise, SEM analysis also suggested lower bacterial adhesion on the NTs surface. No differences in bacterial morphology and topography were observed on both materials, as analyzed by SEM and atomic force microscopy (AFM). In conclusion, 80 nm diameter NTs were grown on Ti6Al4V alloy in 5 min by using a SOW solution enriched with fluoride, which resulted in a material with promoted antibacterial efficacy against S. aureus for up to 5 days of in vitro culture when compared to nonanodized alloy.