A Novel In Vitro Method to Assess the Microbial Barrier Function of Tissue Adhesives Using Bioluminescence Imaging Technique (original) (raw)
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BioMed Research International
Tissue adhesives as a physical barrier to microorganism penetration provide an alternative method with many advantages for wound closure in surgical settings compared to the clinical standard. This raises the need of developing and conducting in vitro methods that are sensitive and reproducible to assess their microbial barrier properties. In this study, three different polyurethane-based tissue adhesives with different physicochemical properties were evaluated in comparison to Dermabond® as a clinical gold standard for topical wound closure. Here, physicochemical properties varied in lactide concentration, viscosity, processing, and the full polymerization time. To evaluate the microbial barrier function, a 5 μl aliquot of E. coli Lux inoculum containing at least 1 × 10 9 CFU / ml was applied to the surface of each test adhesive and sterile filter paper as the control that was placed on an agar plate and incubated at 37°C. Plates were observed for bacterial growth (morphology), t...
Real time noninvasive monitoring of contaminating bacteria in a soft tissue implant infection model
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2009
Infection is the main cause of biomaterials-related failure. A simple technique to test in-vivo new antimicrobial and/or nonadhesive implant coatings is unavailable. Current in vitro methods for studying bacterial adhesion and growth on biomaterial surfaces lack the influence of the host immune system. Most in vivo methods to study biomaterials-related infections routinely involve implant-removal, preventing comprehensive longitudinal monitoring. In vivo imaging circumvents these drawbacks and is based on the use of noninvasive optical imaging of bioluminescent bacteria. Staphylococcus aureus Xen29 is genetically modified to be stably bioluminescent, by the introduction of a modified full lux operon onto its chromosome. Surgical meshes with adhering S. aureus Xen29 were implanted in mice and bacterial growth and spread into the surrounding tissue was monitored longitudinally from bioluminescence with a highly sensitive CCD camera. Distinct spatiotemporal bioluminescence patterns, extending beyond the mesh area into surrounding tissues were observed. After 10 days, the number of living organisms isolated from explanted meshes was found to correlate with bioluminescence prior to sacrifice of the animals. Therefore, it is concluded that in vivo imaging using bioluminescent bacteria is ideally suited to study antimicrobial coatings taking into account the host immune system. In addition, longitudinal monitoring of infection in one animal will significantly reduce the number of experiments and animals. '
Bacterial Adherence Around Sutures of Different Material at Grafted Site: A Microbiological Analysis
Materials
Closure of the surgical incision has been the primary function of sutures since their introduction. However, whatever the type, they are known to carry bacteria, which can be a source of infection. Five types of surgical sutures, Gut, Silk, Vicryl, PTFE, and Polyamide, were selected and tested on their ability to carry aerobic and anaerobic bacteria and were rated on the basis of forming colony-forming units (CFUs). Aerobic bacteria grown around gut sutures showed minimum CFUs (≈30 × 104/suture). Though very less anaerobic bacteria growth was seen among all tested suture materials, it was maximum around Vicryl and polyamide sutures. Every suture material is capable, albeit not equally, of holding bacterial biofilm formation, which can be a source of surgical site infection.
Potentiation of Infections by Biomaterials: A Comparison of Three Materials
Otolaryngology-Head and Neck Surgery, 1981
Biomaterial implants frequently potentiate infections in patients, yet rarely have we considered the interactions between bacteria and biomaterials responsible for this. There is extensive literature concerning suture materials of various types and a few studies comparing porous and solid implants. We have developed a simple, relatively atraumatic model for comparing rates of infection surrounding a biomaterial implant in paired single animal observations. Statistically significant differences between silicone and fluorocarbon implants and between silicone and bioglass implants are demonstrated. The relatively greater rate of infection with silicones is consistent with a previous clinical study. The further use of this model for evaluation of material-surface interfacial effects is proposed.
2016
RADU IONUT GRIGORAS1, CONSTANTIN COPOTOIU2, ADINA SIMONA COSARCA1, EMOKE FULOP2, ANCA MARE2, HORIA MIHAIL BARBU3, VIOLETA HANCU3, RALUCA MONICA COMANEANU3*, VICTOR IOAN SUCIU1, ALINA ORMENISAN1 1 UMF Targu Mures, Faculty of Dental Medicine, 38 Gh. Marinescu Str., 540139, Targu Mures, Romania 2 UMF Targu Mures, Faculty of Medicine, 38 Gh. Marinescu Str., 540139, Targu Mures, Romania 3 Titu Maiorescu University of Bucharest, Faculty of Dental Medicine, 67A Gh. Petrascu Str., 031593, Bucharest, Romania
Microbiology, 2010
Biomaterial-associated infections are the major cause of implant failure and can develop many years after implantation. Success or failure of an implant depends on the balance between host tissue integration and bacterial colonization. Here, we describe a new in vitro model for the postoperative bacterial contamination of implant surfaces and investigate the effects of contamination on the balance between mammalian cell growth and bacterial biofilm formation. U2OS osteosarcoma cells were seeded on poly(methyl methacrylate) in different densities and allowed to grow for 24 h in a parallel-plate flow chamber at a low shear rate (0.14 s "1 ), followed by contamination with Staphylococcus epidermidis ATCC 35983 at a shear rate of 11 s "1 . The U2OS cells and staphylococci were allowed to grow simultaneously for another 24 h under lowshear conditions (0.14 s "1 ). Mammalian cell growth was severely impaired when the bacteria were introduced to surfaces with a low initial cell density (2.5¾10 4 cells cm "2 ), but in the presence of higher initial cell densities (8.2¾10 4 cells cm "2 and 17¾10 4 cells cm "2 ), contaminating staphylococci did not affect cell growth. This study is believed to be the first to show that a critical coverage by mammalian cells is needed to effectively protect a biomaterial implant against contaminating bacteria.
Bacterial adhesion to orthopedic implant polymers
Journal of Biomedical Materials Research, 1996
The degradable polymers poly(orthoester) (POE), poly(Llactic acid) (PLA), and the nondegradable polymers polysulfone (PSF), polyethylene (PE), and poly(ether ether ketone) (PEEK) were exposed to cultures of Staphylococcus epidermidis, Pseudomonas aeruginosa, or Esckerichia coli. Bacteria washed and resuspended in phosphate buffered saline (PBS) adhered to polymers in amounts nearly twice those of bacteria that were left in their growth medium, tryptic soy broth (TSB). In TSB, there was variation in adhesion from species to species, but no significant variation from polymer to polymer within one species. In PBS there were significant differences in the amounts of bacteria adhering to the various polymers with the exception of s. epidermidis, which had similar adhesion to all polymers. As a whole, P. aeruginosa was the most adherent while S. epidermidis was the least adherent. The estimated values of the free energy of adhesion (AF,,,) correlated with the amount of adherent P. aeruginosa. When POE, PLA, and PSF were exposed to hyaluronic acid (HA) before exposure to the bacteria, there was 50% more adhesion of E. coli and P. aeruginosa on POE and PLA. With respect to bacterial adhesion, the biodegradable polymers (POE and PLA) in general were not significantly different from the nondegradable polymers.
Escherichia coli adhesion, biofilm development and antibiotic susceptibility on biomedical materials
Journal of biomedical materials research. Part A, 2015
The aim of this work was to test materials typically used in the construction of medical devices regarding their influence in the initial adhesion, biofilm development and antibiotic susceptibility of Escherichia coli biofilms. Adhesion and biofilm development was monitored in 12-well microtiter plates containing coupons of different biomedical materials-silicone (SIL), stainless steel (SS) and polyvinyl chloride (PVC)-and glass (GLA) as control. The susceptibility of biofilms to ciprofloxacin and ampicillin was assessed, and the antibiotic effect in cell morphology was observed by scanning electron microscopy. The surface hydrophobicity of the bacterial strain and materials was also evaluated from contact angle measurements. Surface hydrophobicity was related with initial E. coli adhesion and subsequent biofilm development. Hydrophobic materials, such as SIL, SS, and PVC, showed higher bacterial colonization than the hydrophilic GLA. Silicone was the surface with the greatest numbe...
Journal of materials chemistry. B, Materials for biology and medicine, 2014
Nosocomial infections due to bacteria have serious implications on the health and recovery of patients in a variety of medical scenarios. Since bacterial contamination on medical devices contributes to the majority of nosocomical infections, there is a need for redesigning the surfaces of medical devices, such as catheters and tracheal tubes, to resist the binding of bacteria. In this work, polyurethanes and polyacrylates/acrylamides, which resist binding by the major bacterial pathogens underpinning implant-associated infections, were identified using high-throughput polymer microarrays. Subsequently, two 'hit' polymers, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)) and PA515 (poly(methoxyethylmethacrylate-co-diethylaminoethylacrylate-co-methylmethacrylate)), were used to coat catheters and substantially shown to decrease binding of a variety of bacteria (including isolates from infected endotracheal tubes and heart valves from intensive care unit patients). Cathete...