More than half of the hospital-associated infections worldwide are related to the adhesion of bacteria cells to biomedical devices and implants. To prevent these infections, it is crucial to modify biomaterial surfaces to develop the antibacterial property. In this study, chitosan (CS) and chondroitin sulfate (ChS) were chosen as antibacterial coating materials on polylactic acid (PLA) surfaces. Plasma-treated PLA surfaces were coated with CS either direct coating method or the carbodiimide coupling method. As a next step for the combined saccharide coating, CS grafted samples were immersed in ChS solution, which resulted in the polyelectrolyte complex (PEC) formation. Also in this experiment, to test the drug loading and releasing efficiency of the thin film coatings, CS grafted samples were immersed into lomefloxacin-containing ChS solution. The successful modifications were confirmed by elemental composition analysis (XPS), surface topography images (SEM), and hydrophilicity change (contact angle measurements). The carbodiimide coupling resulted in higher CS grafting on the PLA surface. The coatings with the PEC formation between CS-ChS showed improved activity against the bacteria strains than the separate coatings. Moreover, these interactions increased the lomefloxacin amount adhered to the film coatings and extended the drug release profile. Finally, the zone of inhibition test confirmed that the CS-ChS coating showed a contact killing mechanism while drug-loaded films have a dual killing mechanism, which includes contact, and release killing.
Surface coatings of materials by polysaccharide polymers are an acknowledged strategy to modulate interfacial biocompatibility. Polysaccharides from various algal species represent an attractive source of structurally diverse compounds that have found application in the biomedical field. Furcellaran obtained from the red algae Furcellaria lumbricalis is a potential candidate for biomedical applications due to its gelation properties and mechanical strength. In the present study, immobilization of furcellaran onto polyethylene terephthalate surfaces by a multistep approach was studied. In this approach, N-allylmethylamine was grafted onto a functionalized polyethylene terephthalate (PET) surface via air plasma treatment. Furcellaran, as a bioactive agent, was anchored on such substrates. Surface characteristics were measured by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Subsequently, samples were subjected to selected cell interaction assays, such as antibacterial activity, anticoagulant activity, fibroblasts and stem cell cytocompatibility, to investigate the Furcellaran potential in biomedical applications. Based on these results, furcellaran-coated PET films showed significantly improved embryonic stem cell (ESC) proliferation compared to the initial untreated material.
Bio-inspired conductive scaffolds composed of sodium hyaluronate containing a colloidal dispersion of water-miscible polyaniline or polypyrrole particles (concentrations of 0.108, 0.054 and 0.036% w/w) were manufactured. For this purpose, either crosslinking with N-(3-dimethylaminopropyl-N-ethylcarbodiimide hydrochloride and N-hydroxysuccinimid or a freeze-thawing process in the presence of poly(vinylalcohol) was used. The scaffolds comprised interconnected pores with prevailing porosity values of ~ 30% and pore sizes enabling the accommodation of cells. A swelling capacity of 92-97% without any sign of disintegration was typical for all samples. The elasticity modulus depended on the composition of the scaffolds, with the highest value of ~ 50 kPa obtained for the sample containing the highest content of polypyrrole particles. The scaffolds did not possess cytotoxicity and allowed cell adhesion and growth on the surface. Using the in vivo-mimicking conditions in a bioreactor, cells were also able to grow into the structure of the scaffolds. The technique of scaffold preparation used here thus overcomes the limitations of conductive polymers (e.g. poor solubility in an aqueous environment, and limited miscibility with other hydrophilic polymer matrices) and moreover leads to the preparation of cytocompatible scaffolds with potentially cell-instructive properties, which may be of advantage in the healing of damaged electro-sensitive tissues.
Hydrophobic fibrous slippery liquid-infused porous surfaces (SLIPS) were fabricated by electrospinning polydimethylsiloxane (PDMS) and polystyrene (PS) as a carrier polymer on plasma-treated polyethylene (PE) and polyurethane (PU) substrates. Subsequent infusion of blackseed oil (BSO) into the porous structures was applied for the preparation of the SLIPS. SLIPS with infused lubricants can act as a repellency layer and play an important role in the prevention of biofilm formation. The effect of polymer solutions used in the electrospinning process was investigated to obtain well-defined hydrophobic fibrous structures. The surface properties were analyzed through various optical, macroscopic and spectroscopic techniques. A comprehensive investigation of the surface chemistry, surface morphology/topography, and mechanical properties was carried out on selected samples at optimized conditions. The electrospun fibers prepared using a mixture of PDMS/PS in the ratio of 1:1:10 (g/g/mL) using tetrahydrofuran (THF) solvent showed the best results in terms of fiber uniformity. The subsequent infusion of BSO into the fabricated PDMS/PS fiber mats exhibited slippery behavior regarding water droplets. Moreover, prepared SLIPS exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli bacterium strains.
- MeSH
- dimethylpolysiloxany * MeSH
- Escherichia coli MeSH
- polymery chemie MeSH
- polystyreny * MeSH
- poréznost MeSH
- Publikační typ
- časopisecké články MeSH
AIMS: To assess the use of skin conductance as an objective measure of pain in infants of different gestational age. A secondAIM was to investigate the relationship between skin conductivity and selected physiological and behavioural variables (oxygen saturation, heart rate and behavioural state). METHODS: Infants were divided according to gestational age into the following 3 groups; group A: 25+0-31+6 weeks (13 infants), group B: 32+0-35+6 weeks (25 infants), group C: 36+0-41+6 weeks (19 infants). The pain stimulus was blood sampling. RESULTS: The most sensitive parameter for describing changes in skin conductance related to pain was peak per second. No other parameter correlated with the physiological variables chosen. The results showed that the inability to determine basal skin conductance is a crucial disadvantage to practical application. The lack of correlation between conductance parameters and gestational age is surprising. CONCLUSION: We conclude that the Peak per Second is the best parameter for evaluating skin conductance in infants and it is not influenced by gestational age. Peaks per Second correlate only with Prechtl's Scale of behavioural state and not with the physiological parameters chosen.
- MeSH
- chování kojenců fyziologie MeSH
- galvanická kožní odpověď fyziologie MeSH
- gestační stáří MeSH
- kojenec MeSH
- lidé MeSH
- měření bolesti metody MeSH
- spotřeba kyslíku fyziologie MeSH
- srdeční frekvence fyziologie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: TheAIM of this study is to compare markers of glomerular filtration rate (GFR), estimated GFR (eGFR), and metabolic parameters between admission and recovery in 13 patients of Tomas Bata hospital with methanol poisoning during methanol problems in the Czech Republic in 2012. The impact of methanol concentration and age on metabolic parameters were discovered at the time of admission to hospital. MATERIALS AND METHODS: The serum osmolality, methanol, ethanol, creatinine, cystatin C, Troponin I, ALT, plasma pH and lactate were measured in these 13 patients. The eGFR from serum creatinine (creatnine eGFR) and from cystatin C (cystatin C eGFR) were also determined. RESULTS: Increased serum osmolality and markers of metabolic acidosis are key indirect laboratory findings in patients with methanol poisoning. There were no significant changes in eGFR in our patients between admission and recovery. Increased serum troponin I concentration was confirmed as an indicator of myocardial necrosis in four patients. Two patients developed acute kidney injury (AKI) before admission. CONCLUSIONS: We found statistically significant differences in serum osmolality concentration, plasma pH and lactate between admission and recovery. We found no changes in eGFR between admission and recovery. One patient had vision problems due to damage to the occipital lobes. Methanol poisoning may cause increase in markers of cardiac damage.
- MeSH
- akutní poškození ledvin chemicky indukované MeSH
- biologické markery krev MeSH
- dospělí MeSH
- hodnoty glomerulární filtrace MeSH
- hospitalizace MeSH
- ledviny patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- methanol otrava MeSH
- osmolární koncentrace MeSH
- senioři MeSH
- vyšetření funkce ledvin MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- akutní poškození ledvin chemicky indukované MeSH
- biologické markery krev MeSH
- ledviny patofyziologie MeSH
- lidé MeSH
- methanol otrava MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- komentáře MeSH
- Publikační typ
- abstrakt z konference MeSH
