Evaluation of Microbial Adhesion and Biofilm Formation on Nano-Structured and Nano-Coated Ortho-Prosthetic Materials by a Dynamic Model (original) (raw)
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Staphylococcal colonization of implants is a serious complication of orthopaedic surgery. Anti-infectious modification of implant surfaces may serve to prevent bacterial colonization. The authors set out to develop an in vitro test system for the analysis of prevention of biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus on implant materials. Biofilm growth was monitored over 10 days on titanium disks in order to develop appropriate test parameters. Bacterial cell counts following ultrasonic treatment of the colonized samples were compared with scanning electron microscope images of the specimens. Copper ion containing surfaces (ie copper [Cu] and inter-metallic Ti-Cu films) were used for growth inhibition assays: Copper ion releasing specimens led to reduced bacterial numbers in biofilms and decreased bacterial persistence in the model used. The assay used represents an inexpensive and quick in vitro screen for the antibacterial effects of novel implant surface materials.
ACS Biomaterials Science & Engineering, 2017
Additive manufacturing (AM) technologies enable greater geometrical design freedom compared with subtractive processes. This flexibility has been used to manufacture patient-matched implants. Although the advantages of AM are clear, the optimization at each process stage is often understated. Here we demonstrate that surface finishing of selective laser melted (SLM) implants significantly alters topography, which has implications for cellular and biofilm adhesion. Hot isostatic pressing of as-fabricated Ti-6Al-4V implants was shown to reduce porosity (1.04 to 0.02%) and surface roughness (34 ± 8 to 22 ± 3 μm). Despite these surface changes, preosteoblasts exhibited a similar viability and proliferation after 7 days of culture. Contrastingly, sandblasting and polishing significantly reduced cellular activity and increased cytotoxicity. Bacterial specimens (Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa) adhered more homogeneously to sandblasted implants compared with other treatments. This suggests that sandblasting may place the implant at risk of infection and reduce the strength of interaction with the surrounding soft tissues. The ability to tune the adhesion of cells to additively manufactured Ti-6Al-4V implants using postprocessing methods was demonstrated. Because the degree of tissue integration required of implants is application specific, these methods may be useful to tailor osseointegration. However, surface competition between mammalian and bacterial cells remains a challenge.
Antimicrobial activity of silver nanoparticles on biofilm – dental implant model (Atena Editora)
Antimicrobial activity of silver nanoparticles on biofilm – dental implant model (Atena Editora), 2024
Bacteria are capable of developing biofilms on various types of surfaces, and the bacterial adhesion process can be altered by the characteristics and micromorphology of these surfaces. This way, the properties of biomaterials can be targeted to inhibit bacterial adhesion and colonization. The use of silver is a promising strategy in an attempt to prevent biofilm formation, given its antimicrobial activity. Therefore, the objective of this study was to evaluate the antimicrobial effect of an experimental biomaterial, based on a photopolymerizable orthodontic adhesive (Orthocem UV Trace), modified by the addition of different concentrations of silver nanoparticles (NAg), on biofilm growth (S. mutans). Initially, the surface roughness of the titanium discs, the gap between implant/component and torque/untorque were evaluated. For the biofilm experiment, titanium discs (5 x 2mm) with treated surface (Ti oxide) were used, on which the experimental material was applied, being: G1: Control – biomaterial without addition of NAg; G2: 50ppm; G3: 100ppm; G4: 150ppm; G5: 200ppm; G6: 250ppm. In the end, 2 specimens/group were selected for SEM. The data were not normal, however they were homoscedastic. Thus, post-hoc Tukey (p<0.005) was applied for comparison between groups (Graph 3). The Control group, without the addition of NAg, showed less biofilm growth, while the T200ppm group showed greater growth. The T100 and 150ppm groups were similar to each other, as were the T50 and T250. Considering that the addition of NAg did not present the expected antimicrobial effect and that the reason may have been the unavailability of these on the surface, allowing direct contact with the bacterial biofilm, future research must be conducted, seeking to remedy these difficulties and seeking to highlight the antimicrobial effect of NAg.
Indian Journal of Orthopaedics, 2019
Prepared by dry and wet approaches, respectively, the surface properties and bacterial adhesion of conventional zirconia (CZ) and self-glazed zirconia (SGZ) were investigated. Each zirconia was divided into unpolished and polished groups. Our results revealed that SGZ showed significantly lower surface roughness than CZ (P < 0.05) and lower surface-free energy (P < 0.05) in both polished and unpolished groups. The number of bacteria attached to SGZ was less than CZ in vitro (P < 0.05), but no significant difference was found between two kinds of zirconia in vivo (P > 0.05). Our findings suggest that SGZ, due to its excellent surface characteristics, is superior to CZ in bacterial adhesion and zirconia polishing serves as an indispensable procedure in clinics.
Biofilm formation on titanium implants counteracted by grafting gallium and silver ions
Journal of Biomedical Materials Research Part A, 2014
Biofilm-associated infections remain the leading cause of implant failure. Thanks to its established biocompatibility and biomechanical properties, titanium has become one of the most widely used materials for bone implants. Engineered surface modifications of titanium able to thwart biofilm formation while endowing a safe anchorage to eukaryotic cells are being progressively developed. Here surfaces of disks of commercial grade 2 titanium for bone implant were grafted with gallium and silver ions by anodic spark deposition. Scanning electron microscopy of the surface morphology and energy dispersive X-ray spectroscopy were used for characterization. Gallium-grafted titanium was evaluated in comparison with silver-grafted titanium for both in vivo and in vitro antibiofilm properties and for in vitro compatibility with human primary gingival fibroblasts.
Formation of biofilm on various implant abutment materials
2018
The characteristics of prosthetic implant components, such as the type, material, and surface roughness of abutments, can affect biofilm formation. Since an ideal abutment surface for the reduction of bacterial adhesion has yet to be found, this in vitro study aimed to quantify biofilm formation on laser-treated titanium, zirconia, and titanium surfaces. Sterile titanium, zirconia, and laser-treated titanium discs were placed in sterile 48-well plates. Biofilm formation was induced by adding sterilized, unstimulated human saliva and suspensions of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), and Prevotella intermedia (Pi) to the wells. Viable bacteria in the biofilm were quantified with real-time polymerase chain reaction in conjunction with propidium monoazide. The disc material, the type of bacteria, and their interactions had significant effects on the bacterial counts. On all surfaces, the Pg count was significantly higher than both the Pi and Aa co...
Easy, Flexible and Standardizable Anti-Nascent Biofilm Activity Assay to Assess Implant Materials
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Medical implants have improved the quality of life of many patients. However, surgical intervention may eventually lead to implant microbial contamination. The aims of this research were to develop an easy, robust, quantitative assay to assess surface antimicrobial activities, especially the anti-nascent biofilm activity, and to identify control surfaces, allowing for international comparisons. Using new antimicrobial assays to assess the inhibition of nascent biofilm during persistent contact or after transient contact with bacteria, we show that the 5 cent Euro coin or other metal-based antibacterial coins can be used as positive controls, as more than 4 log reduction on bacterial survival was observed when using either S. aureus or P. aeruginosa as targets. The methods and controls described here could be useful to develop an easy, flexible and standardizable assay to assess relevant antimicrobial activities of new implant materials developed by industries and academics.
PLoS ONE, 2011
Bacterial infection of implants and prosthetic devices is one of the most common causes of implant failure. The nanostructured surface of biocompatible materials strongly influences the adhesion and proliferation of mammalian cells on solid substrates. The observation of this phenomenon has led to an increased effort to develop new strategies to prevent bacterial adhesion and biofilm formation, primarily through nanoengineering the topology of the materials used in implantable devices. While several studies have demonstrated the influence of nanoscale surface morphology on prokaryotic cell attachment, none have provided a quantitative understanding of this phenomenon. Using supersonic cluster beam deposition, we produced nanostructured titania thin films with controlled and reproducible nanoscale morphology respectively. We characterized the surface morphology; composition and wettability by means of atomic force microscopy, X-ray photoemission spectroscopy and contact angle measurements. We studied how protein adsorption is influenced by the physico-chemical surface parameters. Lastly, we characterized Escherichia coli and Staphylococcus aureus adhesion on nanostructured titania surfaces. Our results show that the increase in surface pore aspect ratio and volume, related to the increase of surface roughness, improves protein adsorption, which in turn downplays bacterial adhesion and biofilm formation. As roughness increases up to about 20 nm, bacterial adhesion and biofilm formation are enhanced; the further increase of roughness causes a significant decrease of bacterial adhesion and inhibits biofilm formation. We interpret the observed trend in bacterial adhesion as the combined effect of passivation and flattening effects induced by morphology-dependent protein adsorption. Our findings demonstrate that bacterial adhesion and biofilm formation on nanostructured titanium oxide surfaces are significantly influenced by nanoscale morphological features. The quantitative information, provided by this study about the relation between surface nanoscale morphology and bacterial adhesion points towards the rational design of implant surfaces that control or inhibit bacterial adhesion and biofilm formation.