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The modification of biomaterial surfaces has become increasingly relevant in the context of ongoing advancements in tissue engineering applications and the development of tissue-mimicking polymer materials. In this study, we investigated the layer-by-layer (LbL) deposition of polyelectrolyte multilayer protein reservoirs consisting of poly-l-lysine (PLL) and hyaluronic acid (HA) on the hydrophobic surface of poly(glycerol sebacate) (PGS) elastomer. Using the methods of isothermal titration calorimetry and surface plasmon resonance, we systematically investigated the interactions between the polyelectrolytes and evaluated the deposition process in real time, providing insight into the phenomena associated with film assembly. PLL/HA LbL films deposited on PGS showed an exceptional ability to incorporate bone morphogenetic protein-2 (BMP-2) compared to other growth factors tested, thus highlighting the potential of PLL/HA LbL films for osteoregenerative applications. The concentration of HA solution used for film assembly did not affect the thickness and topography of the (PLL/HA)10 films, but had a notable impact on the hydrophilicity of the PGS surface and the BMP-2 release kinetics. The release kinetics were successfully described using the Weibull model and hyperbolic tangent function, underscoring the potential of these less frequently used models to compare the protein release from LbL protein reservoirs.
Orální implantologie v současnosti užívá ve velké šíři technicky čistý titan nebo jeho slitiny. Tento materiál má optimální biologické vlastnosti, je však obtížně zpracovatelný. Cílem našeho výzkumu z hlediska zlepšení zpracovatelnosti materiálu se zachováním odpovídajících biologických vlastností se stala chromkobaltová slitina povrchově upravená biomateriálem nitridem titanu, nitridem zirkonia. Práce podává zprávu z výzkumu hodnocení mechanicko-fyzikálních vlastností takto upraveného povrchu chromkobaltové slitiny. Výsledky se jeví pro implantaci příznivé. Studie je součástí grantového výzkumu IGA MZ ČR ND č. 7356-3.
Technically pure titanium or its alloys are broadly used in recent oral implantology. The material has optimal biological characteristics but its technological processing is difficult. The aim of our research was to improve the technological processing of a cromium cobalt alloy and to maintain the biological characteristics of the material. We focused on a cromium cobalt alloy coated with biomaterials titanium nitride and zirconium nitride. Our study brings a report from the evaluation of mechanical and physical characteristics of the coated surface of the cromium cobalt alloy. The obtained results are promising for oral implantology. The study is a part of the project No. 7356-3 of the Internal Grant Agency of the Ministry of Health of the Czech Republic.
Active pharmaceutical ingredients (APIs) are predominantly organic solid powders. Due to their bulk properties many APIs require processing to improve pharmaceutical formulation and manufacturing in the preparation for various drug dosage forms. Improved powder flow and protection of the APIs are often anticipated characteristics in pharmaceutical manufacturing. In this work, we have modified acetaminophen particles with atomic layer deposition (ALD) by conformal nanometer scale coatings in a one-step coating process. According to the results, ALD, utilizing common chemistries for Al2O3, TiO2and ZnO, is shown to be a promising coating method for solid pharmaceutical powders. Acetaminophen does not undergo degradation during the ALD coating process and maintains its stable polymorphic structure. Acetaminophen with nanometer scale ALD coatings shows slowed drug release. ALD TiO2coated acetaminophen particles show cytocompatibility whereas those coated with thicker ZnO coatings exhibit the most cytotoxicity among the ALD materials under study when assessed in vitro by their effect on intestinal Caco-2 cells.
- MeSH
- Caco-2 buňky MeSH
- lidé MeSH
- nanotechnologie * MeSH
- paracetamol chemie MeSH
- pomocné látky chemie MeSH
- povrchové vlastnosti MeSH
- prášky, zásypy, pudry MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Pulsed laser deposition was proved as a suitable method for hydroxyapatite (HA) coating of coaxial poly-ɛ-caprolactone/polyvinylalcohol (PCL/PVA) nanofibers. The fibrous morphology of PCL/PVA nanofibers was preserved, if the nanofiber scaffold was coated with thin layers of HA (200 nm and 400 nm). Increasing thickness of HA, however, resulted in a gradual loss of fibrous character. In addition, biomechanical properties were improved after HA deposition on PCL/PVA nanofibers as the value of Young's moduli of elasticity significantly increased. Clearly, thin-layer hydroxyapatite deposition on a nanofiber surface stimulated mesenchymal stem cell viability and their differentiation into osteoblasts. The optimal depth of HA was 800 nm.
- MeSH
- buněčná diferenciace účinky léků MeSH
- hydroxyapatit chemie farmakologie MeSH
- mezenchymální kmenové buňky cytologie MeSH
- nanovlákna chemie MeSH
- osteoblasty cytologie MeSH
- polyestery chemie MeSH
- polyvinylalkohol chemie MeSH
- prasata MeSH
- proliferace buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Using the layer-by-layer technique, ELISA polystyrene plates were coated with multilayer assemblies of albumin with various heparins or with multilayer assemblies of albumin. The coatings containing heparin were tested for their ability to potentiate thrombin inhibition by antithrombin and its dependence on the layer arrangement. The order of activities of surface bound heparins matched their order in solution; however their activity was reduced to less than 10% due to binding. The increasing number of layers increased the activity of the coatings suggesting that heparin inside the assemblies is available for the interaction. The albumin-heparin assemblies overcoated with albumin layers preserved about half of heparin activity. Platelets adhered in similar amounts to albumin-heparin and albumin coatings; however, in both cases platelets adhered more to single layer than to multilayer coatings. The adhesion of platelets to single layer coatings was also affected by the crosslinking of the coatings; more platelets adhered to less crosslinked single layer coatings while multilayer coatings remained essentially unaffected by crosslinking. If the coatings were dried and reswollen, a substantial number of platelets adhered to the reconditioned single layer coatings but the two layer coatings were affected much less and the adhesion of platelets to the coatings with three layers was close to normal. A minimum of three albumin-heparin or albumin layers is apparently required to shield the underlying surface and to achieve proper functioning of the coatings.
- MeSH
- adhezivita trombocytů účinky léků MeSH
- biokompatibilní potahované materiály chemická syntéza MeSH
- financování organizované MeSH
- heparin metabolismus MeSH
- lidé MeSH
- počet trombocytů MeSH
- prasata MeSH
- reagencia zkříženě vázaná farmakologie MeSH
- sérový albumin hovězí metabolismus MeSH
- skot MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- testování materiálů metody MeSH
- trombin antagonisté a inhibitory MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
The electrocardiogram (ECG) is one of the most common ways to record, in an non-invasive manner, a patient's cardiac activity. Once recorded the information can be pre-processed and subsequently analyzed to assess if the patient is suffering from any forms of cardiac abnormality which may require clinical intervention. In the current study we investigate ways in which more can be obtained from the ECG through analysis of the diagnostic properties of body surface potential maps (BSPM). A set of 192 lead BSPMs recorded from a mixture of 116 normal and abnormal subjects (59 normal vs 57 old myocardial infarction) were analyzed. For each patient, diagnostic features were obtained by calculating isointegral measurements from the QRS, STT, and entire QRST segments. These isointegrals provide a measure of the mean distribution of potential during ventricular depolarization, repolarisation, and a combination of both, respectively. For each isointegral type, 192 discrete measurements, and hence 192 features, were obtained; these correspond with the 192 leads recorded. Subsequent to this a signal-to-noise ratio-based feature ranking methodology was applied to select subsets of the best three, six and ten measurements (features) from the 192 available for each isointegral. These subsets of features were then applied to four different classifiers Naive Bayes (NB), support vector machine (SVM), multi-layer perceptron (MLP) and random forest (RF) and in each application ten-fold cross validation was employed. It was found that when using the subsets of features obtained from the STT or QRST isointegrals, classification results in excess of 80% were attainable. This was in contrast to the results obtained using the QRS isointegral features where poorer performance (between 62.9% and 74.1%) was observed. The results from this study have illustrated that, for the studied dataset, the mean distribution of potentials during ventricular depolarization, and during ventricular repolarization and depolarization combined possessed greater diagnostic information. Overall it was concluded that this approach to BSPM analysis does provide a useful means for illustrating the usefulness of various features in diagnostic classification.
Hydrophilic interaction liquid chromatography (HILIC) represents a modern MS-friendly approach to the analysis of polar compounds. To date especially silica-based HILIC stationary phases are utilized. Recently the papers concerning retention of polar analytes on unmodified titania and zirconia as well as a polybutadiene modified zirconia stationary phase under HILIC conditions have been published. In this work the investigation of a highly hydrophobic carbon-coated zirconia column under HILIC conditions was reported. The influence of buffer concentration, buffer type, pH and temperature on the elution and chromatographic efficiency were studied. The processes participating on the retention of polar compounds showed a multimodal character. The retention was governed rather by surface adsorption than phase partition in high ACN mobile phases. The ligand exchange remained an important retention force although the access of the analytes to the active surface was significantly hindered by the carbon coating. Besides ligand exchange and hydrophilic interactions also the hydrophobic carbon layer was involved in the retention of carboxylic acids and especially xanthines in the organic rich mobile phase.
- MeSH
- acetonitrily chemie MeSH
- adsorpce MeSH
- chromatografie kapalinová přístrojové vybavení metody MeSH
- hydrofobní a hydrofilní interakce MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny karboxylové chemie MeSH
- regresní analýza MeSH
- uhlík chemie MeSH
- xanthiny chemie MeSH
- zirkonium chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
