Polymethylmethacrylate (PMMA) bone cement mixed with antibiotics is used in orthopedic surgery to cope with implant-related infections which are typically associated with the formation of bacterial biofilms. Taking into account the growing bacterial resistance to current antibiotics, we examined here the efficacy of a selected antimicrobial peptide (AMP) mixed into the bone cement to inhibit bacterial adhesion and the consequent biofilm formation on its surface. In particular, we followed the formation of bacterial biofilms of methicillin-resistant Staphylococcus aureus (MRSA) on implants made from PMMA bone cement loaded with AMP composed of 12 amino acid residues. This was evaluated by CFU counting of bacteria released by sonication from the biofilms formed on their surfaces after these implants were retrieved from the infected murine femoral canals. The AMP loaded in these model implants prevented adhesion of MRSA and the subsequent formation of MRSA biofilm on the surfaces of more than 80% of these implants, whereas biofilms did form on control implants made from the plain cement. The results of our experiments performed in the murine femoral canal indicate the potential for this murine osteomyelitis model to mimic actual operations in orthopedics.

• MeSH
• adenosinmonofosfát MeSH
• aminokyseliny MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• antimikrobiální peptidy MeSH
• biofilmy MeSH
• kostní cementy MeSH
• methicilin rezistentní Staphylococcus aureus * MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• ortopedické výkony * MeSH
• polymethylmethakrylát chemie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• lékařství MeSH

• Konspekt
• Lékařské vědy. Lékařství
• NLK Obory
• lékařství
• NLK Publikační typ
• elektronické časopisy

• MeSH
• komunikace MeSH
• management péče o pacienta metody   organizace a řízení   MeSH
• motivace MeSH
• personální management MeSH
• vůdcovství MeSH
• vztahy mezi ošetřovatelkou a pacientem MeSH
• zdravotní sestry MeSH
• Publikační typ
• příručky MeSH

• Konspekt
• Veřejné zdraví a hygiena
• NLK Obory
• ošetřovatelství
• management, organizace a řízení zdravotnictví

A reference material for the biological monitoring of occupational exposure to toluene, benzene and phenol was prepared. O-cresol and hippuric acid (metabolites of toluene) are used for the biological monitoring of occupational exposure to toluene. Phenol, a metabolite of benzene, is used for the biological monitoring of exposure to benzene, but phenol can of course also be used as an indicator of exposure to phenol as well. The reference material (RM) used for the determination of these metabolites was prepared by freeze-drying pooled urine samples obtained from healthy persons occupationally exposed to toluene and those taking part in an inhalation experiment. Tests for homogeneity and stability were performed by determining urine concentrations of o-cresol, hippuric acid, creatinine and phenol. To investigate the stability of the RM, the urinary concentrations of o-cresol and phenol were monitored for eighteen months using GC and HPLC, while those of hippuric acid and creatinine were followed for five and six years, respectively, using HPLC. Analysis of variance showed that the concentrations did not change. The certified concentration values (and their uncertainties) of the substances in this reference material (phenol concentration c=6.46+/-0.58 mg l(-1); o-cresol concentration c=1.17+/-0.15 mg l(-1); hippuric acid concentration c=1328+/-30 mg l(-1); creatinine concentration c=0.82+/-0.10 g l(-1)) were evaluated via the interactive statistical programme IPECA.

• MeSH
• analýza moči metody   normy   MeSH
• benzen analýza   MeSH
• chemické techniky analytické metody   normy   MeSH
• fenoly analýza   MeSH
• financování organizované MeSH
• hippuráty analýza   MeSH
• kalibrace MeSH
• kreatin moč   MeSH
• kresoly analýza   MeSH
• lidé MeSH
• moč chemie   MeSH
• reprodukovatelnost výsledků MeSH
• toluen moč   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• zmrazování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• multicentrická studie MeSH

Polymer layers capable of suppressing protein adsorption from biological media while presenting extracellular matrix-derived peptide motifs offer valuable new options for biomimetic surface engineering. Herein, we provide detailed insights into physicochemical changes induced in a nonfouling poly(ethylene oxide) (PEO) brush/polydopamine (PDA) system by incorporation of adhesion ligand (RGD) peptides. Brushes with high surface chain densities (σ ≥ 0.5 chains·nm-2) and pronounced hydrophilicity (water contact angles ≤ 10°) were prepared by end-tethering of heterobifunctional PEOs ( Mn ≈ 20 000 g·mol-1) to PDA-modified surfaces from a reactive melt. Using alkyne distal end group on the PEO chains, azidopentanoic-bearing peptides were coupled through a copper-catalyzed Huisgen azide-alkyne "click" cycloaddition reaction. The surface concentration of RGD was tuned from complete saturation of the PEO surface with peptides (1.7 × 105 fmol·cm-2) to values which may induce distinct differences in cell adhesion (<6.0 × 102 fmol·cm-2). Infrared reflection-absorption and X-ray photoelectron spectroscopies proved the PDA-PEO layers covalent structure and the immobilization of RGD peptides. The complete reconstruction of experimental electrohydrodynamics data utilizing mean-field theory predictions further verified the attained brush structure of the end-tethered PEO chains which provided hydrodynamic screening of the PDA anchor. Increasing the surface concentration of immobilized RGD peptides led to increased interfacial charging. Supported by simulations, this observation was attributed to the ionization of functional groups in the amino acid sequence and to the pH-dependent adsorption of water ions (OH- > H3O+) from the electrolyte. Despite the distinct differences observed in the electrokinetic analysis of the surfaces bearing different amounts of RGD, it was found that the peptide presence on PEO(20 000)-PDA layers does not have a significant effect on the nonfouling properties of the system. Notably, the presented PEO(20 000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 × 105 fmol·cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng·cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 x 105 fmol.cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng.cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.

• MeSH
• adsorpce MeSH
• buněčná adheze MeSH
• fotoelektronová spektroskopie MeSH
• molekulární struktura MeSH
• peptidy * chemie   MeSH
• polyethylenglykoly * chemie   MeSH
• povrchové vlastnosti MeSH

• MeSH
• dokumentace metody   využití   MeSH
• zdravotničtí pracovníci statistika a číselné údaje   MeSH
• Publikační typ
• směrnice MeSH