PURPOSE OF THE STUDY Nano-structuring and nano-silver have been extensively studied for improving the antibacterial ability of implants due to their powerful antibacterial activity; however, there is no clinical application as yet. The aim of the study was to determine the antibacterial, antiadhesive and cytotoxic features of Ti6Al4V modified with nano-texturing and silver nano-particles. MATERIAL AND METHODS The nanoparticles were applied on polished and nano-textured Ti6Al4V using sonoreduction. The surface topography, roughness, friction coefficients, hardness and elastic modulus values for prepared top layers were established. The materials were tested for antibacterial and antiadhesion activity using reference bacterial strains (Staphylococcus epidermidis CCM 7221, Staphylococcus aureus MRSA 4591, Enterococcus faecalis CCM 4224, Escherichia coli CCM 3954) and their cytocompatibility. RESULTS A strong antibacterial activity of samples treated with nano-texture and/or silver nanoparticles compared to all the tested bacterial strains at 24 hours was proven. This antibacterial activity was diminishing in relation to Staphylococcus aureusand Enterococcus faecalisat 48 and 72 hours but remained very effective against Staphylococcus epidermidisand Escherichia coli. We also demonstrated antibiofilm activity for samples treated with silver nanoparticles and nano-tubes in experiments lasting 24 and 72 hours. DISCUSSION Our main findings are in agreement with those reported in recent literature. The implant surfaces treated with nano-texture in combination with silver nanoparticles exhibit strong antibacterial and antibiofilm characteristics. Despite there is conclusive evidence of strong antibacterial functioning, why these implant modifications have not been widely applied in clinical practice remains a question. While many obstacles including legislative procedures required for clinical implementation are more or less known, it should be clearly demonstrated that this surface modification does neither harm the patient nor interfere with the long-term survivorship of the implants before their wide-range clinical application. CONCLUSIONS Surface modification of Ti6Al4V with nano-texturing and silver nanoparticles resulted in strong antibacterial and modest antibiofilm effects. Thus, our results confirmed the technological potential of nano-texturing and silver nanoparticles for the improvement of antibacterial properties of implants. Key words:prosthetic joint infection, anti-infective biomaterials, titanium alloy, silver nanoparticles, nanotubes, prevention of infection.
- MeSH
- antibakteriální látky * MeSH
- biokompatibilní potahované materiály MeSH
- kovové nanočástice * MeSH
- lidé MeSH
- nanotrubičky * MeSH
- stříbro MeSH
- titan MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Concerns regarding the potential toxic effects of zinc oxide nanoparticles (ZnO NPs) on aquatic organisms are growing due to the fact that NPs may be released into aquatic ecosystems. This study aimed to investigate the effects of dietary exposure to ZnO NPs on juvenile common carp (Cyprinus carpio). Fish were fed a spiked diets at doses 50 and 500mg of ZnO NPs per kg of feed for 6 weeks followed by a 2-week recovery period. Fish were sampled every 2 weeks for haematology trends, blood biochemistry measures, histology analyses, and determination of the accumulation of zinc in tissues. At the end of the exposure and post-exposure periods, fish were sampled for an assessment of lipid peroxidation levels. Dietborne ZnO NPs had no effects on haematology, blood biochemistry, and lipid peroxidation levels during the exposure period. After the recovery period, aspartate aminotransferase activity significantly (p < 0.05) increased and alanine transferase activity significantly (p < 0.05) decreased in the higher exposure group. The level of lipid peroxidation significantly (p < 0.05) decreased in liver of treated fish after 2 weeks post-exposure period. A histological examination revealed mild histopathological changes in kidneys during exposure. Our results did not show a significant increase of zinc content at the end of experiment in any of tested organs. However, chronic dietary exposure to ZnO NPs might affect kidney and liver function.
- MeSH
- časové faktory MeSH
- chemické látky znečišťující vodu metabolismus toxicita MeSH
- dieta MeSH
- játra účinky léků metabolismus MeSH
- kapři metabolismus fyziologie MeSH
- kovové nanočástice toxicita MeSH
- ledviny účinky léků metabolismus MeSH
- monitorování životního prostředí metody MeSH
- oxid zinečnatý metabolismus toxicita MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- tkáňová distribuce MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Prosthetic joint infection (PJI) is a feared complication of total joint arthroplasty associated with increased morbidity and mortality. There is a growing body of evidence that bacterial colonization and biofilm formation are critical pathogenic events in PJI. Thus, the choice of biomaterials for implanted prostheses and their surface modifications may significantly influence the development of PJI. Currently, silver nanoparticle (AgNP) technology is receiving much interest in the field of orthopaedics for its antimicrobial properties and a strong anti-biofilm potential. The great advantage of AgNP surface modification is a minimal release of active substances into the surrounding tissue and a long period of effectiveness. As a result, a controlled release of AgNPs could ensure antibacterial protection throughout the life of the implant. Moreover, the antibacterial effect of AgNPs may be strengthened in combination with conventional antibiotics and other antimicrobial agents. Here, our main attention is devoted to general guidelines for the design of antibacterial biomaterials protected by AgNPs, its benefits, side effects and future perspectives in PJI prevention.
- MeSH
- antibakteriální látky terapeutické užití MeSH
- biofilmy MeSH
- biokompatibilní materiály škodlivé účinky MeSH
- infekce spojené s protézou * prevence a kontrola MeSH
- lidé MeSH
- nanočástice terapeutické užití MeSH
- protézy kloubů škodlivé účinky MeSH
- sloučeniny stříbra * terapeutické užití MeSH
- techniky in vitro metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Bacterial resistance to conventional antibiotics is currently one of the most important healthcare issues, and has serious negative impacts on medical practice. This study presents a potential solution to this problem, using the strong synergistic effects of antibiotics combined with silver nanoparticles (NPs). Silver NPs inhibit bacterial growth via a multilevel mode of antibacterial action at concentrations ranging from a few ppm to tens of ppm. Silver NPs strongly enhanced antibacterial activity against multiresistant, β-lactamase and carbapenemase-producing Enterobacteriaceae when combined with the following antibiotics: cefotaxime, ceftazidime, meropenem, ciprofloxacin and gentamicin. All the antibiotics, when combined with silver NPs, showed enhanced antibacterial activity at concentrations far below the minimum inhibitory concentrations (tenths to hundredths of one ppm) of individual antibiotics and silver NPs. The enhanced activity of antibiotics combined with silver NPs, especially meropenem, was weaker against non-resistant bacteria than against resistant bacteria. The double disk synergy test showed that bacteria produced no β-lactamase when treated with antibiotics combined with silver NPs. Low silver concentrations were required for effective enhancement of antibacterial activity against multiresistant bacteria. These low silver concentrations showed no cytotoxic effect towards mammalian cells, an important feature for potential medical applications.
- MeSH
- antibakteriální látky farmakologie MeSH
- beta-laktamasy genetika metabolismus MeSH
- cefotaxim farmakologie MeSH
- ceftazidim farmakologie MeSH
- ciprofloxacin farmakologie MeSH
- Escherichia coli účinky léků enzymologie genetika růst a vývoj MeSH
- exprese genu MeSH
- gentamiciny farmakologie MeSH
- Klebsiella pneumoniae účinky léků enzymologie genetika růst a vývoj MeSH
- kovové nanočástice chemie toxicita MeSH
- mikrobiální testy citlivosti MeSH
- mnohočetná bakteriální léková rezistence účinky léků genetika MeSH
- stříbro farmakologie MeSH
- synergismus léků MeSH
- thienamyciny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Commercially manufactured nanomaterials are used massively for modification of products of everyday use, including products intended for children. Therefore their potential risks have to be ultimately studied. Aside from toxicity of nanomaterials with known specific parameters, the end-consumer is potentially endangered by materials with unknown specification. Commercially available products are not usually accompanied by parameter/specification sheet providing the consumer with sufficient chemico-physical parameters allowing the evaluation of possible toxic effects. The aim of this work was to evaluate the declared parameters of commercially available TiO2 and Ag NPs employing chemico-physical methods and consequently in vitro cytotoxicity and genotoxicity tests performed on non-cancer cell lines. Based on the results of our complex study we can conclude that the data provided by the producers are not in good agreement with the performed measurements. Furthermore, all tested NPs penetrated into the SVK14 cells and all NPs had significant effect on the kinetics of ROS production in all cell lines (note: the ROS production has not been established as the major mechanism of cell damage elicited by Ag NPs). The study revealed greater cytotoxic potential of Ag NPs in comparison with TiO2 NPs and all of the studied NPs caused significant DNA damage.
- MeSH
- apoptóza účinky léků MeSH
- buněčné linie účinky léků metabolismus MeSH
- buňky NIH 3T3 účinky léků MeSH
- kometový test MeSH
- kovové nanočástice chemie toxicita MeSH
- lidé MeSH
- membránový potenciál mitochondrií účinky léků MeSH
- mikroskopie atomárních sil MeSH
- myši MeSH
- Ramanova spektroskopie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- spektrofotometrie atomová MeSH
- stříbro chemie farmakokinetika toxicita MeSH
- titan farmakokinetika toxicita MeSH
- velikost částic MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Peroral administration of allergen during hyposensitization therapy with allergic patients is in comparison with an administration by injection of a wilder inductor of specific IgG antibodies. The peroral administration of bacterial immunomodulators increases IgG formation significantly. The described experiment examines the influence of bacterial immunomodulator Olimunostim on the level of specific antibodies during peroral hyposensitization therapy with allergic patients.
- MeSH
- adjuvancia imunologická aplikace a dávkování MeSH
- alergeny imunologie MeSH
- alergie terapie MeSH
- aplikace orální MeSH
- Bacteria MeSH
- desenzibilizace imunologická * MeSH
- dospělí MeSH
- ELISA MeSH
- imunoglobulin G biosyntéza MeSH
- lidé MeSH
- pyl imunologie MeSH
- specificita protilátek * MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The article summarises current knowledge about the preparation and standardisation of treatment and diagnosis of allergies. It summarises the basic conceptions, units, methods and conditions for preparation, conservation and the storage of allergens. The article is especially orientated towards grass pollen.
- MeSH
- alergeny * MeSH
- alergie diagnóza terapie MeSH
- imunologické techniky normy MeSH
- imunoterapie normy MeSH
- lidé MeSH
- referenční standardy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
