Infekce ortopedických implantátů je stále obávanou komplikací. Implantáty nabízí bakteriím vhodný povrch ke kolonizaci a tlumí aktivitu a účinnost antibakteriální (AB) imunity. Po iniciální adhezi bakterií následuje tvorba biofilmu (BF). Když se na povrchu implantátu ustaví BF, je nutné implantát vyjmout. Součástí reoperace je radikální chirurgický débridement. U některých pacientů se nám nedaří udržet sterilní prostor navzdory několika operacím a opakovanému podávání antibiotik. V projektu navrhujeme vývoj povrchové úpravy s širokospektrým AB účinkem na bázi nanotrubic a nanostříbra. Kromě excelentního a dlouhotrvajícího AB efektu musí povlak splňovat všechny další nároky kladené na konkrétní typ implantátu. Navrhovaná strategie by měla být využita při výrobě implantátů s AB vlastnostmi. Jejich nasazením v klinické praxi by se měla snížit frekvence infekcí ortopedických implantátů. Konkrétně by mělo dojít k prodloužení životnosti kloubních náhrad, snížení morbidity/mortality pacientů podstupujících ortopedické operace a snížení nákladů spojených s řešením infekčních komplikací.; Biomaterial-associated infection (BAI) is a serious complication of modern orthopaedics. A critical pathogenic event in the process of biofilm formation (BF) is bacterial adhesion. Suppression of the local peri-implant immune response (IR) is important contributory factor. The most vulnerable patients are those undergoing repeated reoperations/tumour surgeries, and those with an immunodeficiency. Based on current knowledge the prevention of BAIs should be focused on two targets: inhibition of BF and minimizing local IR suppression. Here we propose the development of technology of implant surface treatment based on the strong antibacterial effect of nanotubes and nanosilver. Strict criteria related to the processes of innovation in this field will be respected. Provided the developed technology is implemented in the clinical practice BAI rate could be significantly decreased. As a result, it can be expected: i) longer survivorship of the orthopaedic implants; ii) decreased morbidity and mortality; iii) reduction of costs associated with BAI diagnostics/treatment.

• MeSH
• antibakteriální látky MeSH
• biofilmy MeSH
• infekce spojené s protézou prevence a kontrola   MeSH
• nanostruktury MeSH
• ortopedické fixační pomůcky trendy   MeSH
• protézy a implantáty trendy   MeSH
• sterilizace trendy   MeSH
• stříbro MeSH

• Konspekt
• Hygiena. Lidské zdraví
• NLK Obory
• hygiena
• technika lékařská, zdravotnický materiál a protetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

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

• MeSH
• antibakteriální látky terapeutické užití   MeSH
• chirurgická rána * ošetřování   MeSH
• infekce chirurgické rány * etiologie   prevence a kontrola   MeSH
• infekce spojené se zdravotní péčí prevence a kontrola   MeSH
• lidé MeSH
• perioperační péče MeSH
• pooperační komplikace etiologie   prevence a kontrola   MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy 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
• lékové transportní systémy metody   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
• titan chemie   MeSH
• uvolňování léčiv MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Silver nanoparticles have already been successfully applied in various biomedical and antimicrobial technologies and products used in everyday life. Although bacterial resistance to antibiotics has been extensively discussed in the literature, the possible development of resistance to silver nanoparticles has not been fully explored. We report that the Gram-negative bacteria Escherichia coli 013, Pseudomonas aeruginosa CCM 3955 and E. coli CCM 3954 can develop resistance to silver nanoparticles after repeated exposure. The resistance stems from the production of the adhesive flagellum protein flagellin, which triggers the aggregation of the nanoparticles. This resistance evolves without any genetic changes; only phenotypic change is needed to reduce the nanoparticles' colloidal stability and thus eliminate their antibacterial activity. The resistance mechanism cannot be overcome by additional stabilization of silver nanoparticles using surfactants or polymers. It is, however, strongly suppressed by inhibiting flagellin production with pomegranate rind extract.

• MeSH
• antibakteriální látky * chemie   farmakologie   MeSH
• bakteriální léková rezistence * MeSH
• Escherichia coli účinky léků   MeSH
• kovové nanočástice chemie   MeSH
• mikrobiální testy citlivosti MeSH
• Pseudomonas aeruginosa účinky léků   MeSH
• stabilita léku MeSH
• stříbro * chemie   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Surface bioactivity has been under intensive study with reference to its use in medical implants. Our study is focused on coatings prepared from an electroactive material which can support bone cell adhesion. Until now, hydroxyapatite films have usually been utilized as a chemically-active surface agent. However, electrically-active films could set a new direction in hard tissue replacement. As a base for these films, it is necessary to prepare an intermediate film, which can serve as a suitable barrier against the possible diffusion of some allergens and toxic elements from the substrate. The intermediate film also improves the adaptation of the mechanical properties of the basic material to an electroactive film. The aim of our work was to select an implantable and biocompatible material for this intermediate film that is suitable for coating several widely-used materials, to check the possibility of preparing an electroactive film for use on a material of this type, and to characterize the structure and several mechanical properties of this intermediate film. TiNb was selected as the material for the intermediate film, because of its excellent chemical and mechanical properties. TiNb coatings were deposited by magnetron sputtering on various substrates, namely Ti, Ti6Al4V, stainless steel, and bulk TiNb (as standard), and important properties of the layers, e.g. surface morphology and surface roughness, crystalline structure, etc., were characterized by several methods (SEM, EBSD, X-ray diffraction, nanoindentation and roughness measurement). It was found that the structure and the mechanical properties of the TiNb layer depended significantly on the type of substrate. TiNb was then used as a substrate for depositing a ferroelectrically active material, e.g., BaTiO3, and the adhesion, viability and proliferation of human osteoblast-like Saos-2 cells on this system were studied. We found that the electroactive BaTiO3 film was not only non-cytotoxic (i.e. it did not affect the cell viability). It also enhanced the growth of Saos-2 cells in comparison with pure TiNb and with standard tissue culture polystyrene wells, and also in comparison with BaTiO3 films deposited on Ti, i.e. a material clinically used for implantation into the bone.

• MeSH
• adheziva MeSH
• difrakce rentgenového záření MeSH
• hydroxyapatit MeSH
• lidé MeSH
• osteoblasty MeSH
• povrchové vlastnosti MeSH
• protézy a implantáty MeSH
• slitiny chemie   MeSH
• testování materiálů MeSH
• titan MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The timely and exact diagnosis of prosthetic joint infection (PJI) is crucial for surgical decision-making. Intraoperatively, delivery of the result within an hour is required. Alpha-defensin lateral immunoassay of joint fluid (JF) is precise for the intraoperative exclusion of PJI; however, for patients with a limited amount of JF and/or in cases where the JF is bloody, this test is unhelpful. Important information is hidden in periprosthetic tissues that may much better reflect the current status of implant pathology. We therefore investigated the utility of the gene expression patterns of 12 candidate genes (TLR1, -2, -4, -6, and 10, DEFA1, LTF, IL1B, BPI, CRP, IFNG, and DEFB4A) previously associated with infection for detection of PJI in periprosthetic tissues of patients with total joint arthroplasty (TJA) (n = 76) reoperated for PJI (n = 38) or aseptic failure (n = 38), using the ultrafast quantitative reverse transcription-PCR (RT-PCR) Xxpress system (BJS Biotechnologies Ltd.). Advanced data-mining algorithms were applied for data analysis. For PJI, we detected elevated mRNA expression levels of DEFA1 (P < 0.0001), IL1B (P < 0.0001), LTF (P < 0.0001), TLR1 (P = 0.02), and BPI (P = 0.01) in comparison to those in tissues from aseptic cases. A feature selection algorithm revealed that the DEFA1-IL1B-LTF pattern was the most appropriate for detection/exclusion of PJI, achieving 94.5% sensitivity and 95.7% specificity, with likelihood ratios (LRs) for positive and negative results of 16.3 and 0.06, respectively. Taken together, the results show that DEFA1-IL1B-LTF gene expression detection by use of ultrafast qRT-PCR linked to an electronic calculator allows detection of patients with a high probability of PJI within 45 min after sampling. Further testing on a larger cohort of patients is needed.

• MeSH
• alfa-defensiny analýza   genetika   MeSH
• biologické markery analýza   MeSH
• dospělí MeSH
• infekce spojené s protézou diagnóza   mikrobiologie   MeSH
• interleukin-1beta analýza   genetika   MeSH
• karboxylesterhydrolasy analýza   MeSH
• laktoferrin analýza   genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• náhrada kyčelního kloubu škodlivé účinky   MeSH
• polymerázová řetězová reakce MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• stanovení celkové genové exprese MeSH
• synoviální tekutina chemie   MeSH
• totální endoprotéza kolene škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Accurate and rapid diagnosis of prosthetic joint infection (PJI) is vital for rational and effective therapeutic management of this condition. Several diagnostic strategies have been developed for discriminating between infected and noninfected cases. However, none of them can reliably diagnose the whole spectrum of clinical presentations of PJI. Here, we report a new method for PJI detection based on magnetically assisted surface enhanced Raman spectroscopy (MA-SERS) using streptavidin-modified magnetic nanoparticles (MNP@Strep) whose surface is functionalized with suitable biotinylated antibodies and then coated with silver nanoparticles by self-assembly. The high efficiency of this approach is demonstrated by the diagnosis of infections caused by two bacterial species commonly associated with PJI, namely, Staphylococcus aureus and Streptococcus pyogenes. The method's performance was verified with model samples of bacterial lysates and with four real-matrix samples of knee joint fluid spiked with live pathogenic bacterial cells. This procedure is operationally simple, versatile, inexpensive, and quick to perform, making it a potentially attractive alternative to established diagnostic techniques based on Koch's culturing or colony counting methods.

• MeSH
• infekce spojené s protézou diagnóza   MeSH
• lidé MeSH
• magnetické jevy * MeSH
• magnetické nanočástice chemie   MeSH
• povrchové vlastnosti MeSH
• Ramanova spektroskopie * MeSH
• streptavidin chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND AND AIM: The aim of this study was to evaluate the characteristics of synovial fluid (SF) white cell count (SWCC) and neutrophil/lymphocyte percentage in the diagnosis of prosthetic joint infection (PJI) for particular threshold values. METHODS AND RESULTS: This was a prospective study of 391 patients in whom SF specimens were collected before total joint replacement revisions. SF was aspirated before joint capsule incision. The PJI diagnosis was based only on non-SF data. Receiver operating characteristic plots were constructed for the SWCC and differential counts of leukocytes in aspirated fluid. Logistic binomic regression was used to distinguish infected and non-infected cases in the combined data. PJI was diagnosed in 78 patients, and aseptic revision in 313 patients. The areas (AUC) under the curve for the SWCC, the neutrophil and lymphocyte percentages were 0.974, 0.962, and 0.951, respectively. The optimal cut-off for PJI was 3,450 cells/μL, 74.6% neutrophils, and 14.6% lymphocytes. Positive likelihood ratios for the SWCC, neutrophil and lymphocyte percentages were 19.0, 10.4, and 9.5, respectively. Negative likelihood ratios for the SWCC, neutrophil and lymphocyte percentages were 0.06, 0.076, and 0.092, respectively. CONCLUSIONS: Based on AUC, the present study identified cut-off values for the SWCC and differential leukocyte count for the diagnosis of PJI. The likelihood ratio for positive/negative SWCCs can significantly change the pre-test probability of PJI.

• MeSH
• biologické markery metabolismus   MeSH
• infekce spojené s protézou diagnóza   MeSH
• kyčelní protézy škodlivé účinky   mikrobiologie   MeSH
• leukocyty metabolismus   MeSH
• lidé MeSH
• náhrada kyčelního kloubu * škodlivé účinky   MeSH
• neutrofily metabolismus   MeSH
• plocha pod křivkou MeSH
• prediktivní hodnota testů MeSH
• prospektivní studie MeSH
• protézy kolene škodlivé účinky   mikrobiologie   MeSH
• senioři MeSH
• senzitivita a specificita MeSH
• synoviální tekutina cytologie   MeSH
• totální endoprotéza kolene * škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví 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