External fixators of serious fractures could be an attractive substrate on which microorganisms can accumulate. Therefore, this study aimed to develop a suitable method for enabling the simulation of a real situation when osteosynthetic fixation material is open for the potential threat of bacterial attack. Agar-based media represented human tissue, and the metallic pin characterized the screw in the fixation. Various types of agar, supplements, and contamination strategy by Staphylococcus aureus were tested. The influence of the initial bacterial concentration was also examined. Surfaces were observed by scanning electron microscopy (SEM), and all results were compared. Brain Heart Infusion Agar with the Egg Yolk Tellurite Emulsion was established in a transparent test tube as a suitable system for enabling the good interpretability of bacterial contamination in the pin's surroundings. Pin contamination has been found to be an appropriate approach for testing microbial growth, rather than agar surface contamination, which distorted obtained results. A lower initial colony forming units (CFU) provided better clarity of the test. SEM observation of the pin surface was comparable with the visual evaluations in the test tubes. Results were assembled for positive and negative control samples as well. Screening method for the most common bacteria S. aureus has been standardized and developed. This experimental setup could also be a useful tool for surface modification with antibacterial properties testing.
- MeSH
- antibakteriální látky farmakologie MeSH
- biofilmy účinky léků růst a vývoj MeSH
- externí fixátory mikrobiologie MeSH
- kontaminace zdravotnického vybavení * MeSH
- kultivační média MeSH
- lidé MeSH
- mikroskopie elektronová rastrovací MeSH
- počet mikrobiálních kolonií MeSH
- Staphylococcus aureus účinky léků růst a vývoj ultrastruktura MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Titanium biomaterials are widely used in the medical field due to their biocompatibility and excellent corrosion and mechanical resistance. However, these materials have no antibacterial properties. To obtain an antibacterial active surface, a nanostructure of Ti6Al4V alloy was created. This specific nanostructure contained nanotubes and micro-cavities and was used as a substrate for silver anchoring. The electrochemical approach to silver reduction was studied. It is a common approach for silver deposition and in this work, inhomogeneities in the nanostructure were used as a preferential area for silver localisation. The galvanostatic regimen of deposition allowed for a technically quantitative process and the required silver placement. The experimental conditions used enabled testing and silver dissolution rate evaluation within a reasonable time span. Based on the corrosion and analytical results (EDS, XPS and ICP-MS), a two-phase silver release mechanism was confirmed. The openings of the individual nanotubes were filled with silver nanoparticles, whose release was relatively fast. By contrast, the silver anchored inside the cavities allowed the silver to release gradually. Antibacterial efficiency against Staphylococcus aureus and Escherichia coli was successfully demonstrated. Cytotoxicity testing with murine fibroblasts showed cell metabolic activity far above the normative limit of 70%.
- MeSH
- antibakteriální látky aplikace a dávkování chemie farmakologie MeSH
- biokompatibilní materiály chemie MeSH
- buněčné linie MeSH
- Escherichia coli účinky léků MeSH
- infekce vyvolané Escherichia coli farmakoterapie MeSH
- lidé MeSH
- myši MeSH
- nanostruktury chemie MeSH
- protézy a implantáty MeSH
- stafylokokové infekce farmakoterapie MeSH
- Staphylococcus aureus účinky léků MeSH
- stříbro aplikace a dávkování chemie farmakologie MeSH
- systémy cílené aplikace léků metody MeSH
- titan chemie MeSH
- uvolňování léčiv MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
3D printing seems to be the technology of the future for the preparation of metallic implants. For such applications, corrosion behaviour is pivotal. However, little is published on this topic and with inconsistent results. Therefore, we carried out a complex study in which we compared two techniques of the 3D printing technology - selective laser melting and electron beam melting. The corrosion behaviour was studied in physiological solution by standard electrochemical techniques and susceptibility to localised corrosion was estimated too. All samples showed typical passive behaviour. Localised corrosion was shown to be possible on the original as-printed surfaces. Corrosion experiments were repeated tree times. To reveal possible negative effects of 3D printing on cytocompatibility, direct in vitro tests were performed with U-2 OS cells. The cells showed good viability and proliferation, but their growth was impeded by surface unevenness. Our results suggest that both techniques are suitable for implants production. Statistical evaluation was performed by ANOVA followed by Tukey's test.
- MeSH
- 3D tisk * MeSH
- koroze MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- proliferace buněk účinky léků MeSH
- testování materiálů * MeSH
- titan * chemie farmakologie MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Nanotubes with diameters ranging from 40 to 60nm were prepared by electrochemical oxidation of the Ti-6Al-4V alloy in electrolyte containing ammonium sulphate and ammonium fluoride. The nanotubes were further modified with calcium and phosphate ions or were heat treated. Polished Ti-6Al-4V alloy served as a reference sample. The spreading of human osteoblast-like cells was similar on all nanotube samples but lower than on polished samples. The number of initially adhered cells was higher on non-modified nanotubes, but the final cell number was the highest on Ca-enriched nanotubes and the lowest on heat-treated nanotubes. However, these differences were relatively small and less pronounced than the differences in the concentration of specific molecular markers of cell adhesion and differentiation, estimated by their intensity of immunofluorescence staining. The concentration of vinculin, i.e. a protein of focal adhesion plaques, was the lowest on nanotubes modified with calcium. Collagen I, an early marker of osteogenic cell differentiation, was also the lowest on samples modified with calcium and was highest on polished samples. Alkaline phosphatase, a middle marker of osteogenic differentiation, was observed in lowest concentration on nanotubes modified with phosphorus and the highest on heat-treated samples. Osteocalcin concentrations, a late marker of osteogenic cell differentiation, were similar on all tested samples, although they tended to be the highest on heat-treated samples. Thus, osteogenic differentiation can be modulated by various additional treatments of nanotube coatings on Ti-6Al-4V implants.
- MeSH
- buněčná adheze účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- fluorescenční mikroskopie MeSH
- kolagen typu I metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nanotrubičky chemie MeSH
- osteoblasty cytologie metabolismus MeSH
- osteokalcin metabolismus MeSH
- titan chemie farmakologie MeSH
- vápník chemie MeSH
- vinkulin chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- dospělí MeSH
- hlava zranění MeSH
- hojení ran MeSH
- kůže transplantace zranění MeSH
- lidé středního věku MeSH
- lidé MeSH
- rány a poranění etiologie patologie terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
