232 results on '"Vojtěch Adam"'
Search Results
2. Smart bactericide based on reduced graphene oxide decorated with copper and zinc nanoparticles
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Zuzana Bytešníková, Jakub Pečenka, Dorota Tekielska, Jana Pekárková, Andrea Ridošková, Petr Bezdička, Tomáš Kiss, Aleš Eichmeier, Vojtěch Adam, and Lukáš Richtera
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Graphene oxide ,Tomato ,Bacterial spot ,Xanthomonas ,Nanoparticles ,Agriculture - Abstract
Abstract Graphene oxide (GO) synthesised by modified Tour’s method was decorated with copper and zinc nanoparticles (NPs) and simultaneously reduced by sodium borohydride to obtain a nanocomposite of reduced GO with copper and zinc NPs (rGO–Cu–Zn). The nanocomposite rGO–Cu–Zn was characterised by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The rGO–Cu–Zn was tested against Xanthomonas euvesicatoria (X. euvesicatoria), which attacks tomatoes and causes bacterial spots (BSs), and compared with the commercial product Champion 50 WG. Total bacterial growth inhibition was observed for the 1% rGO–Cu–Zn, whereas Champion 50 WG at the same concentration inhibited but did not eradicate all the bacterial colonies. To evaluate the negative effect of the rGO–Cu–Zn on the molecular level, the expression of the genes associated with the action of abiotic and biotic stress factors was analysed. Gene expression in the plants treated with 10% rGO–Cu–Zn did not exhibit a noticeable increase. Graphical Abstract
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- 2023
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3. Reduced graphene oxide-based nanometal-composite containing copper and silver nanoparticles protect tomato and pepper against Xanthomonas euvesicatoria infection
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Zuzana Bytešníková, Jakub Pečenka, Dorota Tekielska, Tomáš Kiss, Pavel Švec, Andrea Ridošková, Petr Bezdička, Jana Pekárková, Aleš Eichmeier, Robert Pokluda, Vojtěch Adam, and Lukáš Richtera
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Graphene oxide ,Copper ,Silver ,Nanoparticles ,Bacterial spot disease ,Solanum lycopersicum ,Agriculture - Abstract
Abstract Xanthomonas euvesicatoria (Xe) is of the genera Xanthomonas, which causes a bacterial spot disease that affects tomato and pepper plants, resulting in significant economic losses. Commonly used bactericides lead to pathogen resistance, environmental contamination and a current risk to human health. Herein, a nanocomposite consisting of Cu and Ag loaded onto reduced graphene oxide (rGO) was synthesized, characterized and tested. After confirmation of the antibacterial properties in vitro, nanocomposites at concentrations of 50 and 500 µg mL−1 were applied to protect tomato and pepper plants under controlled greenhouse conditions. The tomato and pepper plants indicated significantly lower disease severity when treated with the nanocomposite (15.6 and 16.7%, respectively) than when treated with the commercial copper-based bactericide Kocide® 2000. The nanocomposite was demonstrated as a high-efficiency biocide and has the potential for crop disease management with no phytotoxic effect. Graphical Abstract
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- 2022
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4. Surface modification strategies and the functional mechanisms of gold nanozyme in biosensing and bioassay
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Sanam Garehbaghi, Amir M. Ashrafi, Vojtěch Adam, and Lukáš Richtera
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Gold nanozyme ,Catalytic activity ,Surface modification ,Biosensing and bioassay ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Gold nanozymes (GNZs) have been widely used in biosensing and bioassay due to their interesting catalytic activities that enable the substitution of natural enzyme. This review explains different catalytic activities of GNZs that can be achieved by applying different modifications to their surface. The role of Gold nanoparticles (GNPs) in mimicking oxidoreductase, helicase, phosphatase were introduced. Moreover, the effect of surface properties and modifications on each catalytic activity was thoroughly discussed. The application of GNZs in biosensing and bioassay was classified in five categories based on the combination of the enzyme like activities and enhancing/inhibition of the catalytic activities in presence of the target analyte/s that is realized by proper surface modification engineering. These categories include catalytic activity enhancer, reversible catalytic activity inhibitor, binding selectivity enhancer, agglomeration base, and multienzyme like activity, which are explained and exemplified in this review. It also gives examples of those modifications that enable the application of GNZs for in vivo biosensing and bioassays.
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- 2023
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5. Selected ginsenosides interfere efficiently with hepatitis B virus mRNA expression levels and suppress viral surface antigen secretion
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Ganesh Selvaraj Duraisamy, Eunji Jo, Ivana Huvarová, Kyu-Ho P. Park, Zbyněk Heger, Vojtěch Adam, Daniel Růžek, Marc P. Windisch, and Andrew D. Miller
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Ginsenoside ,Hepatitis B virus ,Lamivudine ,Nucleoside/nucleotide analogues ,Hepatitis B surface protein ,Hepatitis B surface antigen ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Ginsenosides are a class of natural steroid glycosides and triterpene saponins found in Panax ginseng. After screening of a commercial ginsenoside compound library for low cellular cytotoxicity and the ability to mediate efficient reductions in hepatitis B virus (HBV) mRNA expression levels in HepG2.2.15 cells, three ginsenosides (Rg6, Rh4, and Rb3) are selected. Thereafter, using the same cellular model, all three ginsenosides are shown to mediate efficient, selective inhibition of HBV mRNA expression levels, and also interfere with the secretion of both HBV particles and hepatitis B surface antigen (HBsAg). Drug combination studies are performed in both HepG2.2.15 and HBV-infected HepG2-NTCPsec+ cell models with the selected ginsenosides and lamivudine (LMV), a nucleoside analogue used to treat chronic hepatitis B (CHB) infections. These studies, involving RT-qPCR and ELISA, suggest that Rh4/LMV combinations in particular act synergistically to inhibit the secretion of HBV particles and HBsAg. Therefore, on the assumption that appropriate in vivo data are in future agreement, Rh4, in particular, might be used in combination with nucleoside/nucleotide analogues (NUCs) to devise an effective, cost-efficient combination therapy for the treatment of patients with CHB infections.
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- 2022
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6. Mutual influence of selenium nanoparticles and FGF2-STAB® on biocompatible properties of collagen/chitosan 3D scaffolds: in vitro and ex ovo evaluation
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Johana Muchová, Vanessa Hearnden, Lenka Michlovská, Lucie Vištejnová, Anna Zavaďáková, Kristýna Šmerková, Silvia Kočiová, Vojtěch Adam, Pavel Kopel, and Lucy Vojtová
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Selenium nanoparticles ,Collagen ,Chitosan ,Fibroblast growth factor 2 ,3D porous scaffold ,Biotechnology ,TP248.13-248.65 ,Medical technology ,R855-855.5 - Abstract
Abstract In a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.
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- 2021
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7. Correction: Sýs et al. Bis(2,2′-bipyridil)Copper(II) Chloride Complex: Tyrosinase Biomimetic Catalyst or Redox Mediator? Materials 2021, 14, 113
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Milan Sýs, Atripan Mukherjee, Granit Jashari, Vojtěch Adam, Amir M. Ashrafi, Miroslav Novák, and Lukáš Richtera
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n/a ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
In the original publication [...]
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- 2022
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8. Bis(2,2′-bipyridil)Copper(II) Chloride Complex: Tyrosinase Biomimetic Catalyst or Redox Mediator?
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Milan Sýs, Atripan Mukherjee, Granit Jashari, Vojtěch Adam, Amir M. Ashrafi, Miroslav Novák, and Lukáš Richtera
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electrochemical biomimetic devices ,bis(2,2′-bipyridil)copper(II) chloride complex ,flow injection analysis ,neurotransmitters ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
In this article, construction of amperometric sensor(s) based on screen-printed carbon electrodes covered by thin layers of two types of carbon nanomaterials serving as amplifiers, and containing [Cu(bipy)2Cl]Cl∙5H2O complex is reported. Their performance and biomimetic activity towards two selected neurotransmitters (dopamine and serotonin) was studied mainly using flow injection analysis (FIA). The important parameters of FIA such as working potential, flow rate, and pH were optimized. The mechanism of the catalytic activity is explained and experimentally confirmed. It reveals that presence of hydrogen peroxide plays a crucial role which leads to answer the title question: can presented complex really be considered as a tyrosinase biomimetic catalyst or only as a redox mediator?
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- 2020
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9. Synergistic Effect of Chitosan and Selenium Nanoparticles on Biodegradation and Antibacterial Properties of Collagenous Scaffolds Designed for Infected Burn Wounds
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Jana Dorazilová, Johana Muchová, Kristýna Šmerková, Silvia Kočiová, Pavel Diviš, Pavel Kopel, Radek Veselý, Veronika Pavliňáková, Vojtěch Adam, and Lucy Vojtová
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tissue engineering ,drug release ,freeze-drying ,collagen ,chitosan ,selenium nanoparticles ,Chemistry ,QD1-999 - Abstract
A highly porous scaffold is a desirable outcome in the field of tissue engineering. The porous structure mediates water-retaining properties that ensure good nutrient transportation as well as creates a suitable environment for cells. In this study, porous antibacterial collagenous scaffolds containing chitosan and selenium nanoparticles (SeNPs) as antibacterial agents were studied. The addition of antibacterial agents increased the application potential of the material for infected and chronic wounds. The morphology, swelling, biodegradation, and antibacterial activity of collagen-based scaffolds were characterized systematically to investigate the overall impact of the antibacterial additives. The additives visibly influenced the morphology, water-retaining properties as well as the stability of the materials in the presence of collagenase enzymes. Even at concentrations as low as 5 ppm of SeNPs, modified polymeric scaffolds showed considerable inhibition activity towards Gram-positive bacterial strains such as Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in a dose-dependent manner.
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- 2020
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10. The Effect of Synthesis Procedure on Hydrogen Peroxidase-Like Catalytic Activity of Iron Oxide Magnetic Particles
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Atripan Mukherjee, Amir M. Ashrafi, Pavel Svec, Lukáš Richtera, Jan Přibyl, Martin Brtnický, Jindrich Kynicky, and Vojtěch Adam
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magnetic nanoparticle ,nanozyme ,chronoamperometry ,biosensor ,peroxidase-like activity ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A comparative study was carried out using magnetic nanoparticles (MNPs) for the fabrication of non-enzymatic sensors for the continuous and rapid detection and monitoring of H2O2. Various MNPs, differing in terms of their synthesis procedure and modification, were synthesized and characterized by different techniques. The electrochemical catalytic activity of the synthesized MNPs toward the reduction in H2O2 was investigated by cyclic voltammetry. The naked MNPs showed the highest catalytic activity among all the synthesized MNPs. The biosensor based on the naked MNPs was then applied in the determination of H2O2 using chronoamperometry. The parameters such as the applied cathodic potential and the amount of MNPs on the developed biosensor were optimized. Moreover, the analytical figures of merit, including reproducibility (RSD = 6.14%), sensitivity (m = 0.0676 µA µM−1), limit of detection (LOD) = 27.02 µmol L−1, and limit of quantification (LOQ) = 89.26 µmol L−1 of the developed biosensor indicate satisfactory analysis. Finally, MNPs were successfully utilized for the determination of H2O2 in milk.
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- 2020
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11. Determination of Trolox Equivalent Antioxidant Capacity in Berries Using Amperometric Tyrosinase Biosensor Based on Multi-Walled Carbon Nanotubes
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Arbër Frangu, Amir M. Ashrafi, Milan Sýs, Tahir Arbneshi, Radovan Metelka, Vojtěch Adam, Milan Vlček, and Lukáš Richtera
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amperometry ,ascorbic acid ,berries ,biosensor ,multi-wall carbon nanotubes ,carbon paste electrode ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In this contribution, Trolox equivalent antioxidant capacity (TEAC) was determined in various berries using carbon paste tyrosinase biosensor with multi-walled carbon nanotubes (MWCNTs), coated with Nafion® layer. Electrochemical behaviour of the biosensor and influence of MWCNTs on carbon paste surface were studied with respect to the sensitive amperometric detection of total content of phenolic compounds in berries, expressed as concentration equivalent of Trolox. After optimization of key instrumental and electroanalytical parameters, the biosensor was used for determination of TEAC in blackberries, blueberries, cranberries, raspberries and strawberries by method of multiple standard additions. Electrochemical TEAC assays corresponded well with results obtained by spectrophotometric 1,1-diphenyl-2-picrylhydrazyl radical method, known as DPPH assay. Obtained values were compared with those listed in the National Nutrient Database for additional antioxidant capacity assays as well.
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- 2020
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12. Melatonin Regulates Oxidative Stress Initiated by Freund’s Complete Adjuvant
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Miroslav Pohanka, Branislav Ruttkay-Nedecký, Josef Fusek, Vojtěch Adam, and René Kizek
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Antioxidant ,Oxidative stress ,Melatonin ,Reactive oxygen species ,Epiphysis ,Hormone ,Medicine - Abstract
Melatonin is a hormone with strong antioxidant properties. In this experiment, Freund’s complete adjuvant was used as a stressogenic substance given to laboratory outbred mice, whereas melatonin was investigated as a protectant against the stressogenic effect. Levels of low molecular weight antioxidants, thiobarbituric acid reactive substances, and tumor necrosis factor α and activity of glutathione reductase were determined in blood from the animals. Surprisingly, melatonin was not involved in direct regulation of antioxidants, thiobarbituric acid reactive substances and tumor necrosis factor α. On the other hand, melatonin regulated glutathione reductase activity. We can conclude on regulation of metabolism caused by melatonin in the model. The effect was more important than the expected regulation of immunity and basal oxidative homeostasis.
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- 2015
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13. Trk Receptors and Neurotrophin Cross-Interactions: New Perspectives Toward Manipulating Therapeutic Side-Effects
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Yazan Haddad, Vojtěch Adam, and Zbyněk Heger
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tropomyosin receptor kinase ,neurotrophic tyrosine kinase receptor ,neurotrophin ,drug side-effect ,molecular dynamics ,molecular mechanics ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Some therapeutic side-effects result from simultaneous activation of homolog receptors by the same ligand. Tropomyosin receptor kinases (TrkA, TrkB and TrkC) play a major role in the development and biology of neurons through neurotrophin signaling. The wide range of cross-interactions between Trk receptors and neurotrophins vary in selectivity, affinity and function. In this study, we discuss new perspectives to the manipulation of side-effects via a better understanding of the cross-interactions at the molecular level, derived by computational methods. Available crystal structures of Trk receptors and neurotrophins are a valuable resource for exploitation via molecular mechanics (MM) and dynamics (MD). The study of the energetics and dynamics of neurotrophins or neurotrophic peptides interacting with Trk receptors will provide insight to structural regions that may be candidates for drug targeting and signaling pathway selection.
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- 2017
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14. Algal Biomass Analysis by Laser-Based Analytical Techniques—A Review
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Pavel Pořízka, Petra Prochazková, David Prochazka, Lucia Sládková, Jan Novotný, Michal Petrilak, Michal Brada, Ota Samek, Zdeněk Pilát, Pavel Zemánek, Vojtěch Adam, René Kizek, Karel Novotný, and Jozef Kaiser
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Laser-Induced Breakdown Spectroscopy ,LIBS ,Laser-Ablation Inductively Coupled Plasma coupled with Mass Spectroscopy and Optical Emission Spectroscopy ,LA-ICP-MS ,LA-ICP-OES ,ICP-OES ,Raman spectroscopy ,algae ,algal biomass ,biofuel ,bioremediation ,Chemical technology ,TP1-1185 - Abstract
Algal biomass that is represented mainly by commercially grown algal strains has recently found many potential applications in various fields of interest. Its utilization has been found advantageous in the fields of bioremediation, biofuel production and the food industry. This paper reviews recent developments in the analysis of algal biomass with the main focus on the Laser-Induced Breakdown Spectroscopy, Raman spectroscopy, and partly Laser-Ablation Inductively Coupled Plasma techniques. The advantages of the selected laser-based analytical techniques are revealed and their fields of use are discussed in detail.
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- 2014
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15. Identification of Human Enzymes Oxidizing the Anti-Thyroid-Cancer Drug Vandetanib and Explanation of the High Efficiency of Cytochrome P450 3A4 in its Oxidation
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Radek Indra, Petr Pompach, Václav Martínek, Paulína Takácsová, Katarína Vavrová, Zbyněk Heger, Vojtěch Adam, Tomáš Eckschlager, Kateřina Kopečková, Volker Manfred Arlt, and Marie Stiborová
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vandetanib ,tyrosine kinase inhibitor ,metabolism ,cytochromes P450 ,flavin-containing monoxygenases ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The metabolism of vandetanib, a tyrosine kinase inhibitor used for treatment of symptomatic/progressive medullary thyroid cancer, was studied using human hepatic microsomes, recombinant cytochromes P450 (CYPs) and flavin-containing monooxygenases (FMOs). The role of CYPs and FMOs in the microsomal metabolism of vandetanib to N-desmethylvandetanib and vandetanib-N-oxide was investigated by examining the effects of CYP/FMO inhibitors and by correlating CYP-/FMO-catalytic activities in each microsomal sample with the amounts of N-desmethylvandetanib/vandetanib-N-oxide formed by these samples. CYP3A4/FMO-activities significantly correlated with the formation of N-desmethylvandetanib/ vandetanib-N-oxide. Based on these studies, most of the vandetanib metabolism was attributed to N-desmethylvandetanib/vandetanib-N-oxide to CYP3A4/FMO3. Recombinant CYP3A4 was most efficient to form N-desmethylvandetanib, while FMO1/FMO3 generated N-oxide. Cytochrome b5 stimulated the CYP3A4-catalyzed formation of N-desmethylvandetanib, which is of great importance because CYP3A4 is not only most efficient in generating N-desmethylvandetanib, but also most significant due to its high expression in human liver. Molecular modeling indicated that binding of more than one molecule of vandetanib into the CYP3A4-active center can be responsible for the high efficiency of CYP3A4 N-demethylating vandetanib. Indeed, the CYP3A4-mediated reaction exhibits kinetics of positive cooperativity and this corresponded to the in silico model, where two vandetanib molecules were found in CYP3A4-active center.
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- 2019
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16. Application of the Enzymatic Electrochemical Biosensors for Monitoring Non-Competitive Inhibition of Enzyme Activity by Heavy Metals
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Amir M. Ashrafi, Milan Sýs, Eliška Sedláčková, Amir Shaaban Farag, Vojtěch Adam, Jan Přibyl, and Lukáš Richtera
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glucose oxidase ,heavy metals ,amperometric biosensor ,non-competitive inhibition ,Chemical technology ,TP1-1185 - Abstract
The inhibition effect of the selected heavy metals (Ag+, Cd2+, Cu2+, and Hg2+) on glucose oxidase (GOx) enzyme from Aspergillus niger (EC 1.1.3.4.) was studied using a new amperometric biosensor with an electrochemical transducer based on a glassy carbon electrode (GCE) covered with a thin layer of multi-wall carbon nanotubes (MWCNTs) incorporated with ruthenium(IV) oxide as a redox mediator. Direct adsorption of multi-wall carbon nanotubes (MWCNTs) and subsequent covering with Nafion® layer was used for immobilization of Gox. The analytical figures of merit of the developed glucose (Glc) biosensor are sufficient for determination of Glc in body fluids in clinical analysis. From all tested heavy metals, mercury(II) has the highest inhibition effect. However, it is necessary to remember that cadmium and silver ions also significantly inhibit the catalytic activity of Gox. Therefore, the development of Gox biosensors for selective indirect determination of each heavy metal still represents a challenge in the field of bioelectroanalysis. It can be concluded that amperometric biosensors, differing in the utilized enzyme, could find their application in the toxicity studies of various poisons.
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- 2019
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17. Influence of potassium on growth, content of mineral nutrients and yield formation of the spring barley (Hordeum vulgare L.)
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Josef Zehnálek, Vojtěch Adam, and René Kizek
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Barley (Hordeum vulgare L.) ,plant nutrition ,potassium ,transport ,yield formation ,growth ,Agriculture ,Biology (General) ,QH301-705.5 - Abstract
In model experiment, an influence of increasing KCl doses on spring barley growth, accumulation of main mineral nutrients (N, P, K, Ca, Mg and Na) in main stalks, offshoots and roots and on yield formation and its structure was observed. Increase of weight of above-ground parts of plants was inhibited only at the beginning of experiment by increasing KCl doses, particularly, significantly lower growth of offshoots, but on the other hand production of dry weight of roots was negatively influenced during whole cultivation. Accumulation of main mineral nutrients in the plants was mostly influenced at potassium. Uptake of potassium by plant increased up to 37%. Yield of kernels was higher at variants with application of KCl but the correlation between higher K doses and the yield increase has not been statistically proved. Increase in the yield was reached by higher number of offshoots, higher number of kernels and higher weight of kernels in comparison with control. Content of main mineral nutrients in kernel was not influenced by application of KCl, but potassium content in straw was significantly increased.
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- 2006
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18. Single-cell transcriptomics of neuroblastoma identifies chemoresistance-associated genes and pathways
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Avitabile, Marianna, Bonfiglio, Ferdinando, Aievola, Vincenzo, Cantalupo, Sueva, Maiorino, Teresa, Lasorsa, Vito Alessandro, Domenicotti, Cinzia, Marengo, Barbara, Zbyněk, Heger, Vojtěch, Adam, Iolascon, Achille, and Capasso, Mario
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- 2022
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19. DIGITALIZACE ZDRAVOTNICTVÍ VE FINSKU
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Vojtěch, Adam, primary
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- 2023
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20. The in vitro effects of selected substances and nanomaterials against Diaporthe eres , Diplodia seriata and Eutypa lata
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Kateřina Štůsková, Jakub Pečenka, Dorota Anna Tekielska, Milan Špetík, Zuzana Bytešníková, Pavel Švec, František Ondreáš, Andrea Ridošková, Lukáš Richtera, Vojtěch Adam, and Aleš Eichmeier
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Agronomy and Crop Science - Published
- 2022
21. Metabolic adaptations of Escherichia coli to extended zinc exposure: insights into tricarboxylic acid cycle and trehalose synthesis
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Martin Rihacek, Ludmila Kosaristanova, Tatiana Fialova, Tomas Rypar, Dagmar Skopalova Sterbova, Vojtech Adam, Ludek Zurek, and Kristyna Cihalova
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Zinc ,Zinc oxide ,Nanoparticles ,Trehalose synthesis ,Carbohydrate metabolism ,Virulence ,Microbiology ,QR1-502 - Abstract
Abstract Balanced bacterial metabolism is essential for cell homeostasis and growth and can be impacted by various stress factors. In particular, bacteria exposed to metals, including the nanoparticle form, can significantly alter their metabolic processes. It is known that the extensive and intensive use of food and feed supplements, including zinc, in human and animal nutrition alters the intestinal microbiota and this may negatively impact the health of the host. This study examines the effects of zinc (zinc oxide and zinc oxide nanoparticles) on key metabolic pathways of Escherichia coli. Transcriptomic and proteomic analyses along with quantification of intermediates of tricarboxylic acid (TCA) were employed to monitor and study the bacterial responses. Multi-omics analysis revealed that extended zinc exposure induced mainly oxidative stress and elevated expression/production of enzymes of carbohydrate metabolism, especially enzymes for synthesis of trehalose. After the zinc withdrawal, E. coli metabolism returned to a baseline state. These findings shed light on the alteration of TCA and on importance of trehalose synthesis in metal-induced stress and its broader implications for bacterial metabolism and defense and consequently for the balance and health of the human and animal microbiome.
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- 2024
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22. New insight into the biocompatibility/toxicity of graphene oxides and their reduced forms on Chlamydomonas reinhardtii
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Zuzana Bytešníková, Martina Koláčková, Markéta Dobešová, Pavel Švec, Andrea Ridošková, Jana Pekárková, Jan Přibyl, Petr Cápal, Dalibor Húska, Vojtěch Adam, and Lukáš Richtera
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Materials Science (miscellaneous) ,Public Health, Environmental and Occupational Health ,Safety, Risk, Reliability and Quality ,Safety Research - Published
- 2023
23. Neutrophils in Cancer immunotherapy: friends or foes?
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Xueqin Huang, Eugenie Nepovimova, Vojtech Adam, Ladislav Sivak, Zbynek Heger, Marian Valko, Qinghua Wu, and Kamil Kuca
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Neutrophils ,Cancer ,Immunotherapy ,Antitumor activity ,Protumor activity ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Neutrophils play a Janus-faced role in the complex landscape of cancer pathogenesis and immunotherapy. As immune defense cells, neutrophils release toxic substances, including reactive oxygen species and matrix metalloproteinase 9, within the tumor microenvironment. They also modulate the expression of tumor necrosis factor-related apoptosis-inducing ligand and Fas ligand, augmenting their capacity to induce tumor cell apoptosis. Their involvement in antitumor immune regulation synergistically activates a network of immune cells, bolstering anticancer effects. Paradoxically, neutrophils can succumb to the influence of tumors, triggering signaling cascades such as JAK/STAT, which deactivate the immune system network, thereby promoting immune evasion by malignant cells. Additionally, neutrophil granular constituents, such as neutrophil elastase and vascular endothelial growth factor, intricately fuel tumor cell proliferation, metastasis, and angiogenesis. Understanding the mechanisms that guide neutrophils to collaborate with other immune cells for comprehensive tumor eradication is crucial to enhancing the efficacy of cancer therapeutics. In this review, we illuminate the underlying mechanisms governing neutrophil-mediated support or inhibition of tumor progression, with a particular focus on elucidating the internal and external factors that influence neutrophil polarization. We provide an overview of recent advances in clinical research regarding the involvement of neutrophils in cancer therapy. Moreover, the future prospects and limitations of neutrophil research are discussed, aiming to provide fresh insights for the development of innovative cancer treatment strategies targeting neutrophils.
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- 2024
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24. Ariel – a window to the origin of life on early earth?
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Jiří Šponer, Sohan Jheeta, Alan Heays, Adam Pastorek, Franz Saija, Helmut Lammer, Václav Čuba, Paul B. Rimmer, Zoe R. Todd, Elias Chatzitheodoridis, Judit E. Šponer, Vojtěch Adam, Antonín Knížek, Bertrand Lefloch, Barbora Drtinová, Svatopluk Civiš, Vladislav E. Chernov, Marketa Vaculovicova, Martin Ferus, Kristýna Zemánková, Lukáš Petera, Lukas Nejdl, Libor Lenža, Giuseppe Cassone, Petr Kubelík, Ákos Kereszturi, Raffaele Saladino, M. Krůs, Laurenz Sproß, Ferus, M [0000-0003-4008-2920], and Apollo - University of Cambridge Repository
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010308 nuclear & particles physics ,Computer science ,Hadean ,sub-05 ,Astronomy and Astrophysics ,Planetary system ,Geologic record ,Early Earth ,01 natural sciences ,Exoplanet ,Astrobiology ,5101 Astronomical Sciences ,Space and Planetary Science ,Abiogenesis ,Planet ,0103 physical sciences ,Earth (chemistry) ,51 Physical Sciences ,010303 astronomy & astrophysics - Abstract
Is there life beyond Earth? An ideal research program would first ascertain how life on Earth began and then use this as a blueprint for its existence elsewhere. But the origin of life on Earth is still not understood, what then could be the way forward? Upcoming observations of terrestrial exoplanets provide a unique opportunity for answering this fundamental question through the study of other planetary systems. If we are able to see how physical and chemical environments similar to the early Earth evolve we open a window into our own Hadean eon, despite all information from this time being long lost from our planet’s geological record. A careful investigation of the chemistry expected on young exoplanets is therefore necessary, and the preparation of reference materials for spectroscopic observations is of paramount importance. In particular, the deduction of chemical markers identifying specific processes and features in exoplanetary environments, ideally “uniquely”. For instance, prebiotic feedstock molecules, in the form of aerosols and vapours, could be observed in transmission spectra in the near future whilst their surface deposits could be observed from reflectance spectra. The same detection methods also promise to identify particular intermediates of chemical and physical processes known to be prebiotically plausible. Is Ariel truly able to open a window to the past and answer questions concerning the origin of life on our planet and the universe? In this paper, we discuss aspects of prebiotic chemistry that will help in formulating future observational and data interpretation strategies for the Ariel mission. This paper is intended to open a discussion and motivate future detailed laboratory studies of prebiotic processes on young exoplanets and their chemical signatures.
- Published
- 2020
25. Quantum Dots in Peroxidase-like Chemistry and Formamide-Based Hot Spring Synthesis of Nucleobases
- Author
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Lukáš Nejdl, Lukáš Petera, Judit Šponer, Kristýna Zemánková, Kristýna Pavelicová, Antonín Knížek, Vojtěch Adam, Markéta Vaculovičová, Ondřej Ivanek, and Martin Ferus
- Subjects
Formamides ,Agricultural and Biological Sciences (miscellaneous) ,Formamide ,Catalysis ,Hot Springs ,UV-induced nanoparticles ,Thiols ,Space and Planetary Science ,Origin of life ,Quantum Dots ,Nanoparticle world ,Nanozymes ,Metal ions ,Peroxidase - Abstract
Quantum dots (QDs) are usually seen as artificial semiconductor particles exhibiting optical and electronic properties interesting for nanotechnological applications. However, they may also play a role in prebiotic chemistry. Starting from zinc acetate, cadmium acetate, and mercaptosuccinic acid, we demonstrate the formation of ZnCd QDs upon UV irradiation in prebiotic liquid formamide. We show that ZnCd QDs are able to increase the yield of RNA nucleobase synthesis from formamide up to 300 times, suggesting they might have served as universal catalysts in a primordial milieu. Based on the experimentally observed peroxidase-like activity of ZnCd QDs upon irradiation with visible light, we propose that QDs could be relevant to a broad variety of processes relating to the emergence of terrestrial life.
- Published
- 2022
26. Age-associated changes in innate and adaptive immunity: role of the gut microbiota
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Haoyu Gao, Eugenie Nepovimova, Vojtech Adam, Zbynek Heger, Marian Valko, Qinghua Wu, and Kamil Kuca
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aging ,innate immunity ,adaptive immunity ,cGAS-STING ,gut microbiota aging ,gut microbiota ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Aging is generally regarded as an irreversible process, and its intricate relationship with the immune system has garnered significant attention due to its profound implications for the health and well-being of the aging population. As people age, a multitude of alterations occur within the immune system, affecting both innate and adaptive immunity. In the realm of innate immunity, aging brings about changes in the number and function of various immune cells, including neutrophils, monocytes, and macrophages. Additionally, certain immune pathways, like the cGAS-STING, become activated. These alterations can potentially result in telomere damage, the disruption of cytokine signaling, and impaired recognition of pathogens. The adaptive immune system, too, undergoes a myriad of changes as age advances. These include shifts in the number, frequency, subtype, and function of T cells and B cells. Furthermore, the human gut microbiota undergoes dynamic changes as a part of the aging process. Notably, the interplay between immune changes and gut microbiota highlights the gut’s role in modulating immune responses and maintaining immune homeostasis. The gut microbiota of centenarians exhibits characteristics akin to those found in young individuals, setting it apart from the microbiota observed in typical elderly individuals. This review delves into the current understanding of how aging impacts the immune system and suggests potential strategies for reversing aging through interventions in immune factors.
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- 2024
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27. c-Jun N-terminal kinase signaling in aging
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Yihao Li, Li You, Eugenie Nepovimova, Vojtech Adam, Zbynek Heger, Klaudia Jomova, Marian Valko, Qinghua Wu, and Kamil Kuca
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JNK ,aging ,molecular insights ,therapeutic targets ,longevity ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Aging encompasses a wide array of detrimental effects that compromise physiological functions, elevate the risk of chronic diseases, and impair cognitive abilities. However, the precise underlying mechanisms, particularly the involvement of specific molecular regulatory proteins in the aging process, remain insufficiently understood. Emerging evidence indicates that c-Jun N-terminal kinase (JNK) serves as a potential regulator within the intricate molecular clock governing aging-related processes. JNK demonstrates the ability to diminish telomerase reverse transcriptase activity, elevate β-galactosidase activity, and induce telomere shortening, thereby contributing to immune system aging. Moreover, the circadian rhythm protein is implicated in JNK-mediated aging. Through this comprehensive review, we meticulously elucidate the intricate regulatory mechanisms orchestrated by JNK signaling in aging processes, offering unprecedented molecular insights with significant implications and highlighting potential therapeutic targets. We also explore the translational impact of targeting JNK signaling for interventions aimed at extending healthspan and promoting longevity.
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- 2024
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28. Mapping of MeLiM melanoma combining ICP-MS and MALDI-MSI methods
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Lucie Vaníčková, Tomáš Do, Markéta Vejvodová, Vratislav Horák, Martin Hubálek, Gabriella Emri, Kristýna Zemánková, Kristýna Pavelicová, Soňa Křížková, Veronika Faltusová, Antonio Pompeiano, Markéta Vaculovičová, Ondřej Zítka, Tomáš Vaculovič, and Vojtěch Adam
- Subjects
Structural Biology ,Swine ,Tandem Mass Spectrometry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Animals ,Proteins ,Swine, Miniature ,General Medicine ,Molecular Biology ,Biochemistry ,Melanoma - Abstract
Here we developed a powerful tool for comprehensive data collection and mapping of molecular and elemental signatures in the Melanoma-bearing Libechov Minipig (MeLiM) model. The combination of different mass spectrometric methods allowed for detail investigation of specific melanoma markers and elements and their spatial distribution in tissue sections. MALDI-MSI combined with HPLC-MS/MS analyses resulted in identification of seven specific proteins, S100A12, CD163, MMP-2, galectin-1, tenascin, resistin and PCNA that were presented in the melanoma signatures. Furthermore, the ICP-MS method allowed for spatial detection of zinc, calcium, copper, and iron elements linked with the allocation of the specific binding proteins.
- Published
- 2021
29. Metallothionein-3 is a multifunctional driver that modulates the development of sorafenib-resistant phenotype in hepatocellular carcinoma cells
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Miguel Angel Merlos Rodrigo, Hana Michalkova, Ana Maria Jimenez Jimenez, Frantisek Petrlak, Tomas Do, Ladislav Sivak, Yazan Haddad, Petra Kubickova, Vivian de los Rios, J. Ignacio Casal, Marina Serrano-Macia, Teresa C. Delgado, Loreto Boix, Jordi Bruix, Maria L. Martinez Chantar, Vojtech Adam, and Zbynek Heger
- Subjects
Metallothionein-3 ,Resistance ,Hepatocellular carcinoma ,Sorafenib ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Abstract Background & aims Metallothionein-3 (hMT3) is a structurally unique member of the metallothioneins family of low-mass cysteine-rich proteins. hMT3 has poorly characterized functions, and its importance for hepatocellular carcinoma (HCC) cells has not yet been elucidated. Therefore, we investigated the molecular mechanisms driven by hMT3 with a special emphasis on susceptibility to sorafenib. Methods Intrinsically sorafenib-resistant (BCLC-3) and sensitive (Huh7) cells with or without up-regulated hMT3 were examined using cDNA microarray and methods aimed at mitochondrial flux, oxidative status, cell death, and cell cycle. In addition, in ovo/ex ovo chick chorioallantoic membrane (CAM) assays were conducted to determine a role of hMT3 in resistance to sorafenib and associated cancer hallmarks, such as angiogenesis and metastastic spread. Molecular aspects of hMT3-mediated induction of sorafenib-resistant phenotype were delineated using mass-spectrometry-based proteomics. Results The phenotype of sensitive HCC cells can be remodeled into sorafenib-resistant one via up-regulation of hMT3. hMT3 has a profound effect on mitochondrial respiration, glycolysis, and redox homeostasis. Proteomic analyses revealed a number of hMT3-affected biological pathways, including exocytosis, glycolysis, apoptosis, angiogenesis, and cellular stress, which drive resistance to sorafenib. Conclusions hMT3 acts as a multifunctional driver capable of inducing sorafenib-resistant phenotype of HCC cells. Our data suggest that hMT3 and related pathways could serve as possible druggable targets to improve therapeutic outcomes in patients with sorafenib-resistant HCC.
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- 2024
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30. DNA as a Functional Material and Functional Materials and DNA
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Martin Pumera, Katsuhiko Ariga, and Vojtěch Adam
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Biomaterials ,Electrochemistry ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2022
31. ZnO nanoparticles: synthesis and evolution
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Zuzana Bytesnikova, Vojtěch Adam, Pavel Svec, Lukas Richtera, and Vojtěch Přikryl
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Materials science ,Chemical engineering ,Zno nanoparticles ,chemistry ,nanowires ,Zinc oxide ,Nanowire ,Nanoparticle ,chemistry.chemical_element ,nanoparticles ,Zinc ,Chemical synthesis ,chemical synthesis - Abstract
ZnO is a material that is biocompatible, biodegradable, and has low toxicity. Recently it has emerged as an interesting material for use in biomedicine, cosmetics and agriculture. Chemical synthesis of ZnO nanoparticles was investigated due to its potential ease of preparation and upscalability. Ethanol was used as a solvent that promotes the continued growth of the as-prepared nanoparticles. This work presents facile methods of ZnO nanoparticle preparation and a potential method for ZnO nanowire growth at room temperature.
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- 2021
32. Stability of Copper Nanoparticles in Media Imitating the Real Environment
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Zuzana Bytesnikova, Martina Kolackova, Anna Janova, Pavel Svec, Vojtěch Adam, Dalibor Huska, and Lukas Richtera
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Materials science ,chemistry ,Chemical engineering ,chemistry.chemical_element ,Nanoparticle ,Copper - Published
- 2021
33. CONCEPT AND PRACTICE OF ELECTRONIC PRESCRIPTION
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Bruthans, Jan, primary, Kofránek, Jiří, additional, and Vojtěch, Adam, additional
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- 2021
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34. Bioavailability of mercury in contaminated soils assessed by the diffusive gradient in thin film technique in relation to uptake by Miscanthus × giganteus
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Andrea Ridošková, Vojtěch Adam, Aurélie Pelfrêne, Francis Douay, Vendula Smolikova, Pavlína Pelcová, and Analytical, Environmental & Geo-Chemistry
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010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Biological Availability ,chemistry.chemical_element ,010501 environmental sciences ,Poaceae ,Models, Biological ,01 natural sciences ,Soil ,Soil Pollutants ,Environmental Chemistry ,Miscanthus giganteus ,Thin film ,Chromatography, High Pressure Liquid ,0105 earth and related environmental sciences ,Contaminated soils ,biology ,Biological Transport ,Mercury ,Miscanthus ,biology.organism_classification ,Mercury (element) ,Rhizome ,Bioavailability ,chemistry ,Environmental chemistry ,Soil water ,Ion Exchange Resins ,Environmental Monitoring - Abstract
We assessed the relationship between the diffusive gradient in thin film (DGT) technique using the new ion-exchange resin Ambersep GT74 and the uptake of mercury (Hg) by a model plant cultivated on metal-contaminated agricultural soils under greenhouse conditions. Based on the total Hg content, 0.37 to 1.17% of the Hg passed to the soil porewater from the solid phase, and 2.18 to 9.18% of the Hg is DGT-available. These results were confirmed by calculating the R value (the ratio of the concentrations of bioavailable Hg measured by DGT and soil solution), which illustrated the strong bonding of Hg to the solid phase of soil and its extremely low mobility. Only inorganic Hg2+ species were found in the metal-contaminated agricultural soils, as determined by a high-performance liquid chromatography-cold vapor atomic fluorescence spectrometry speciation analysis. The Hg was distributed in Miscanthus × giganteus organs in the following order for all sampling sites: roots (55-82%) >> leaves (8-27%) > stems (7-16%) > rhizomes (4-7%). Environ Toxicol Chem 2019;38:321-328. © 2018 SETAC.
- Published
- 2019
35. Mutual influence of selenium nanoparticles and FGF2-STAB® on biocompatible properties of collagen/chitosan 3D scaffolds: in vitro and ex ovo evaluation
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Kristýna Šmerková, Pavel Kopel, Silvia Kociova, Lenka Michlovská, Lucy Vojtová, Vojtěch Adam, Anna Zavaďáková, Johana Muchová, Lucie Vistejnova, and Vanessa Hearnden
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Biocompatibility ,Biomedical Engineering ,Pharmaceutical Science ,Medicine (miscellaneous) ,Biocompatible Materials ,Bioengineering ,02 engineering and technology ,Applied Microbiology and Biotechnology ,Cell Line ,Chitosan ,Selenium ,03 medical and health sciences ,chemistry.chemical_compound ,Dermis ,Tissue engineering ,3D porous scaffold ,Materials Testing ,Medical technology ,medicine ,Animals ,Humans ,R855-855.5 ,Cytotoxicity ,030304 developmental biology ,Wound Healing ,0303 health sciences ,Tissue Engineering ,Tissue Scaffolds ,Research ,Regeneration (biology) ,Fibroblast growth factor 2 ,Fibroblasts ,021001 nanoscience & nanotechnology ,In vitro ,Anti-Bacterial Agents ,medicine.anatomical_structure ,chemistry ,Biophysics ,Nanoparticles ,Molecular Medicine ,Collagen ,0210 nano-technology ,Antibacterial activity ,Porosity ,TP248.13-248.65 ,Selenium nanoparticles ,Biotechnology - Abstract
In a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.
- Published
- 2021
36. Komplex chloridu bis (2,2'-bipyridil) měďnatého: Tyrosinázový biomimetický katalyzátor nebo redox mediátor?
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Miroslav Novák, Lukas Richtera, Vojtěch Adam, Granit Jashari, Milan Sýs, Amir M. Ashrafi, and Atripan Mukherjee
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Tyrosinase ,chemistry.chemical_element ,02 engineering and technology ,neurotransmitery ,lcsh:Technology ,01 natural sciences ,Article ,neurotransmitters ,2 '-bipyridil)copper(II) chloride complex ,Catalysis ,komplex chloridu bis (2,2'-bipyridil) měďnatého ,chemistry.chemical_compound ,General Materials Science ,lcsh:Microscopy ,Hydrogen peroxide ,lcsh:QC120-168.85 ,Flow injection analysis ,Thin layers ,lcsh:QH201-278.5 ,flow injection analysis ,lcsh:T ,010405 organic chemistry ,bis(2,2′-bipyridil)copper(II) chloride complex ,electrochemical biomimetic devices ,bis(2 ,021001 nanoscience & nanotechnology ,Combinatorial chemistry ,Amperometry ,0104 chemical sciences ,elektrochemické biomimetická zařízení ,chemistry ,lcsh:TA1-2040 ,Copper(II) chloride ,lcsh:Descriptive and experimental mechanics ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,lcsh:Engineering (General). Civil engineering (General) ,0210 nano-technology ,lcsh:TK1-9971 ,Carbon ,průtoková injekční analýza - Abstract
In this article, construction of amperometric sensor(s) based on screen-printed carbon electrodes covered by thin layers of two types of carbon nanomaterials serving as amplifiers, and containing [Cu(bipy)2Cl]Cl∙5H2O complex is reported. Their performance and biomimetic activity towards two selected neurotransmitters (dopamine and serotonin) was studied mainly using flow injection analysis (FIA). The important parameters of FIA such as working potential, flow rate, and pH were optimized. The mechanism of the catalytic activity is explained and experimentally confirmed. It reveals that presence of hydrogen peroxide plays a crucial role which leads to answer the title question: can presented complex really be considered as a tyrosinase biomimetic catalyst or only as a redox mediator? V tomto článku je popsána konstrukce amperometrických senzorů založených na sítotiskových uhlíkových elektrodách pokrytých tenkými vrstvami dvou typů uhlíkových nanomateriálů sloužících jako zesilovače a obsahujících komplex [Cu (bipy) 2Cl] Cl ∙ 5H2O. Jejich výkon a biomimetická aktivita vůči dvěma vybraným neurotransmiterům (dopaminu a serotoninu) byla studována hlavně pomocí průtokové injekční analýzy (FIA). Byly optimalizovány důležité parametry FIA, jako je pracovní potenciál, průtok a pH. Mechanismus katalytické aktivity je vysvětlen a experimentálně potvrzen. Ukazálo se, že přítomnost peroxidu vodíku hraje zásadní roli, která vede k zodpovězení otázky v titulku: lze skutečně prezentovaný komplex považovat za biomimetický katalyzátor tyrosinázy nebo pouze za redoxní mediátor?
- Published
- 2020
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37. Remodeling of the liver fibrosis microenvironment based on nilotinib-loaded multicatalytic nanozymes with boosted antifibrogenic activity
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Huaqing Jing, Yingzi Ren, Yue Zhou, Min Xu, Sona Krizkova, Zbynek Heger, Qiang Lu, Siyu Wang, Xiaoyang Liang, Vojtech Adam, and Nan Li
- Subjects
Liver fibrosis ,Microenvironment remodeling ,HSCs ,ECM ,Collagen ,Hypoxia ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Liver fibrosis is a reversible pathological process caused by chronic liver damage and a major risk factor for hepatocellular carcinoma (HCC). Hepatic stellate cell (HSC) activation is considered the main target for liver fibrosis therapy. However, the efficiency of this strategy is limited due to the complex microenvironment of liver fibrosis, including excessive extracellular matrix (ECM) deposition and hypoxia-induced imbalanced ECM metabolism. Herein, nilotinib (NIL)-loaded hyaluronic acid (HA)-coated Ag@Pt nanotriangular nanozymes (APNH NTs) were developed to inhibit HSCs activation and remodel the microenvironment of liver fibrosis. APNH NTs efficiently eliminated intrahepatic reactive oxygen species (ROS) due to their inherent superoxide dismutase (SOD) and catalase (CAT) activities, thereby downregulating the expression of NADPH oxidase-4 (NOX-4) and inhibiting HSCs activation. Simultaneously, the oxygen produced by the APNH NTs further alleviated the hypoxic microenvironment. Importantly, the released NIL promoted collagen depletion by suppressing the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), thus synergistically remodeling the microenvironment of liver fibrosis. Notably, an in vivo study in CCl4-induced mice revealed that APNH NTs exhibited significant antifibrogenic effects without obvious long-term toxicity. Taken together, the data from this work suggest that treatment with the synthesized APNH NTs provides an enlightening strategy for remodeling the microenvironment of liver fibrosis with boosted antifibrogenic activity.
- Published
- 2023
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38. The effect of synthesis procedure on hydrogen peroxidase-like catalytic activity of iron oxide magnetic particles
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Martin Brtnický, Lukas Richtera, Amir M. Ashrafi, Jan Přibyl, Pavel Svec, Jindrich Kynicky, Atripan Mukherjee, and Vojtěch Adam
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Iron oxide ,magnetic nanoparticle ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,biosensor ,01 natural sciences ,lcsh:Technology ,Catalysis ,lcsh:Chemistry ,chemistry.chemical_compound ,General Materials Science ,Instrumentation ,lcsh:QH301-705.5 ,Fluid Flow and Transfer Processes ,Detection limit ,lcsh:T ,Process Chemistry and Technology ,General Engineering ,Chronoamperometry ,021001 nanoscience & nanotechnology ,nanozyme ,lcsh:QC1-999 ,0104 chemical sciences ,Computer Science Applications ,chronoamperometry ,chemistry ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,Magnetic nanoparticles ,Cyclic voltammetry ,peroxidase-like activity ,0210 nano-technology ,lcsh:Engineering (General). Civil engineering (General) ,Biosensor ,lcsh:Physics ,Nuclear chemistry - Abstract
A comparative study was carried out using magnetic nanoparticles (MNPs) for the fabrication of non-enzymatic sensors for the continuous and rapid detection and monitoring of H2O2. Various MNPs, differing in terms of their synthesis procedure and modification, were synthesized and characterized by different techniques. The electrochemical catalytic activity of the synthesized MNPs toward the reduction in H2O2 was investigated by cyclic voltammetry. The naked MNPs showed the highest catalytic activity among all the synthesized MNPs. The biosensor based on the naked MNPs was then applied in the determination of H2O2 using chronoamperometry. The parameters such as the applied cathodic potential and the amount of MNPs on the developed biosensor were optimized. Moreover, the analytical figures of merit, including reproducibility (RSD = 6.14%), sensitivity (m = 0.0676 µ, A µ, M&minus, 1), limit of detection (LOD) = 27.02 µ, mol L&minus, 1, and limit of quantification (LOQ) = 89.26 µ, 1 of the developed biosensor indicate satisfactory analysis. Finally, MNPs were successfully utilized for the determination of H2O2 in milk.
- Published
- 2020
39. The importance of selenium in fruit nutrition
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Vojtěch Adam, Pavel Ryant, Eva Sapáková, Ladislav Ducsay, Jiří Antošovský, and Petr Škarpa
- Subjects
inorganic chemicals ,Antioxidant ,medicine.medical_treatment ,fungi ,Biofortification ,food and beverages ,chemistry.chemical_element ,Titratable acid ,Biology ,Shelf life ,Human nutrition ,chemistry ,medicine ,Palatability ,Food science ,Selenium - Abstract
Selenium is considered as an essential microelement. Selenium may prove a positive effect not only on human nutrition and health but also on livestock. However, the absolute necessity of selenium has not been determined in most of the higher plants so the biofortification of selected crops, especially fruits, can be appropriate to incorporate. Selenium is transported in several ways, but foliar nutrition is one of the most used applications. Positive effects of selenium on plants have been often confirmed. After the application of selenium, higher selenium content has been found in fruits, leading to higher fruit quality, particularly in terms of increased content of soluble substances and vitamins, improvement in palatability, or reduction in content of titratable acids. The application of selenium can show a significant effect on antioxidant ability supporting the plants during the stress period and increasing the shelf life.
- Published
- 2020
40. HIGHLY SELECTIVE AND SENSITIVE ELECTROCHEMICAL BIOSENSOR BASED ON ELECTROCHEMICALLY REDUCED GRAPHENE OXIDE FOR DETECTION OF MIRNA AS A CANCER BIOMARKER
- Author
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Lukas Richtera, Eliska Sedlackova, Vojtěch Adam, David Hynek, Veronika Vaňová, and Zuzana Bytesnikova
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Chemistry ,Graphene ,Oxide ,Cancer ,Nanotechnology ,biosensor ,Highly selective ,medicine.disease ,law.invention ,Biomarker ,chemistry.chemical_compound ,law ,electrochemical detection ,microRNA ,medicine ,Electrochemical biosensor ,Reduced graphene oxide ,Biosensor ,miRNA - Abstract
Nowadays, cancer is one of the most outrageous diseases affecting millions of people throughout the world. In this study, the sensitive biosensor for miRNA-21 detection was developed. Through a facile sulfonamide coupling reaction a miRNA-21 specific DNA hybridization probe was immobilized onto a glassy carbon electrode (GCE) modified with electrochemical reduced graphene oxide (erGO). miRNA is a small non-coding RNA molecule which plays an important role in gene expression. The level of miRNA in extracellular fluids varying in the presence of cancer and it can serve as potential biomarker for early detection of cancer. An elevated level of miRNA-21 represents a common feature of pathological cell growth or cell stress and is connected with almost all types of cancer and with cardiovascular diseases, as well. The aim of this study was improve the electrochemical properties by using erGO as a modification for better sensitivity of the developed biosensor. After the modification with erGO, 1-amino-2-naphthol-4-sulfonic acid (AN-SO3-) was electrodeposited on the GCE surface. --Finally, the amino terminated capture probe was immobilized on the GCE via the sulfonamide coupling reaction. The developed biosensor for the detection of specific miRNA sequence was optimized and modified for using in further experiments.
- Published
- 2020
41. Contributors
- Author
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Vojtěch Adam, Riaz Ahmad, Selena Ahmed, Kashif Akram, M.S. Alam, Paula Alayón Luaces, Wasayf J. Almalki, Muhammad Akbar Anjum, Chrysovalantou Antonopoulou, Jiří Antošovský, Margarida Arrobas, Ignácio Aspiazú, Cuihua Bai, Elena Baldi, Allen V. Barker, Betina Pereira de Bem, Adalberto Benavides-Mendoza, Maja Benkovi, Renato Vasconcelos Botelho, Alberto Fontanella Brighenti, Gustavo Brunetto, David R. Bryla, Hakan Burhan, Thomas O. Butler, Miaomiao Cai, Rodolfo Canet, Luciano Cavani, James Chapman, John M. Chater, Christos Chatzissavvidis, Jianjun Chen, Li-Song Chen, Marlise Nara Ciotta, Jucinei José Comin, Lessandro De Conti, Márcio Cleber de Medeiros Corrêa, Juan Manuel Covarrubias-Ramírez, Daniel Cozzolino, Sjoerd E.A.T.M. van der Zee, José Aridiano Lima de Deus, Sara Di Lonardo, Bartolomeo Dichio, Zhihao Dong, Ladislav Ducsay, Madeleine F. Dupont, Aaron Elbourne, Fatima Elmusa, Jeanette M. Van Emon, Hassan Etesami, Róger Fallas-Corrales, Umar Farooq, Laura Olivia Fuentes-Lara, José E. Gaiad, Bin Gao, Maciej Gąstoł, Melanie D. Gomez Herrera, Fulya Gulbagca, Peng Guo, Zafar Hayat, Jia-Dong He, Chengxiao Hu, Antonio Ibacache, Diego S. Intrigliolo, Maria Del Rosario Jacobo-Salcedo, Byoung Ryong Jeong, Wei Jia, Huan-Xin Jiang, Antonio Juárez-Maldonado, Tamara Jurina, Davie Kadyampakeni, Evangelos Karagiannis, Jasenka Gajdoš Kljusurić, Jinxue Li, Wenhuan Liu, Arcângelo Loss, Cledimar Rogério Lourenzi, Donglin Luo, YanYan Ma, Rui Machado, Victor Martins Maia, Belén Martínez-Alcántara, Renato de Mello Prado, George Wellington Bastos de Melo, Donald J. Merhaut, Michail Michailidis, Nebojša Milošević, Tomo Milošević, Alba N. Mininni, Athanassios Molassiotis, Isidro Morales, Babak Motesharezadeh, Seyed Majid Mousavi, Marcelo Marques Lopes Müller, William Natale, Erika Nava-Reyna, Rolf Nestby, Danúbia Aparecida Costa Nobre, Kenneth Nyombi, Dámaris Leopoldina Ojeda-Barrios, Fernanda Soares Oliveira, İbrahim Ortaş, Gloria Padmaperuma, Léon Etienne Parent, Víctor Manuel Parga-Torres, Margarita Parra, Betânia Vahl de Paula, Rodinei Facco Pegoraro, Ana Pérez-Piqueres, Raffaella Petruccelli, Aoife Power, John E. Preece, Fangying Qiu, Ana Quiñones, M.A. Rahim, R.A. Ram, Hermann Restrepo-Diaz, Jorge B. Retamales, Felipe Klein Ricachenevsky, Patrizia Ricciuti, M. Ângelo Rodrigues, Isabel Rodríguez-Carretero, Danilo Eduardo Rozane, José S. Rubio-Asensio, Pavel Ryant, Alefsi David Sánchez-Reinoso, Alberto Sandoval-Rangel, Eva Sapáková, Djalma Eugênio Schmitt, Fatih Sen, Ricardo Serralheiro, Afshan Shafi, Bo Shu, Faqih A.B. Ahmad Shuhaili, Petr Škarpa, Adriano Sofo, Giovambattista Sorrenti, André Luiz Kulkamp de Souza, Matheus Severo de Souza Kulmann, A.K. Srivastava, Lincon Oliveira Stefanello, Alyssa L. Stewart, Margie L. Stratton, Qiling Tan, Ning Tang, Georgia Tanou, Adriele Tassinari, Tadeu Luis Tiecher, Moreno Toselli, Vi Khanh Truong, Matjaž Turinek, Ana Jurinjak Tušek, Seetharaman Vaidyanathan, Davor Valinger, Tripti Vashisth, Nicolás Verdugo-Vásquez, Zonghua Wang, Xiangying Wei, Qiang-Sheng Wu, Cristos Xiloyannis, Lin-Tong Yang, Lixian Yao, Jovani Zalamena, Ting Zhan, Yuanyuan Zhao, Yongqiang Zheng, Vasileios Ziogas, and Andrés Zurita-Silva
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- 2020
42. The effect of different fatty acid sources on wound healing in rats assessed by matrix-assisted-laser-desorption-ionization mass-spectroscopy-imaging
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Břetislav Gál, Tomas Do, Zuzana Lackova, Vojtěch Adam, Jana Neuwirthová, Veronika Svehlova, Jan Wijacki, Zbysek Sladek, Tomas Komprda, Marcela Buchtová, Roman Guráň, and Ondřej Zítka
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eicosapentaenoic acid ,Context (language use) ,Schizochytrium ,Schizochytrium oil ,collagen alpha-1(III) ,Andrology ,03 medical and health sciences ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,General Veterinary ,biology ,Chemistry ,0402 animal and dairy science ,Fatty acid ,reepithelialization ,04 agricultural and veterinary sciences ,biology.organism_classification ,Fish oil ,040201 dairy & animal science ,Eicosapentaenoic acid ,Docosahexaenoic acid ,MALDI MSI ,Wound healing ,Polyunsaturated fatty acid - Abstract
The objective of the present study was to compare the effects of dietary oils containing polyunsaturated fatty acids (PUFA) n-3 and n-6, respectively, on cutaneous wound healing in rats, and to demonstrate the usefulness of the matrix-assisted-laser-desorption-ionization mass spectroscopy-imaging (MALDI MSI) method in this type of experiment. Superiority of PUFA n-3 in this context was the tested hypothesis. Four groups of male Wistar rats by twelve animals each were fed a diet with added 5% of palm oil (P; control), fish oil (F), Schizochytrium microalga oil (Sch) and safflower oil (S), respectively, for eight weeks. Consequently, dorsal full-thickness cutaneous excisions were performed, and selected markers of wound healing were evaluated 18 days post excision. The median of signal intensity corresponding to an amount of collagen α-1 (III) fragment, quantified using MALDI MSI, decreased in a sequence P > F > Sch > S (P < 0.001). Using haematoxylin-eosin staining of the histological preparations, semi-quantitatively assessed epithelium height tended to decrease in the order of P > S > Sch > F; the wound extent in the sequence of P > Sch > S > F; and the sequence of the progress of neo-angiogenesis was assessed as S > P > F ≈ Sch. It was concluded that the tested hypothesis was confirmed only partially: PUFA n-3 showed better results regarding the wound extent, but were inferior in terms of epithelium height and progress of neo-angiogenesis. This was the first time MALDI MSI was successfully employed for evaluating skin wound healing in a rat model.
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- 2019
43. Immobilization of ligninolytic enzymes from white-rot fungi in cross-linked aggregates
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Vojtěch Adam, Martina Vršanská, Veronika Solcany, and Stanislava Voběrková
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0106 biological sciences ,Environmental Engineering ,Ligninolytic enzymes ,Immobilized enzyme ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,Lignin ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Bioremediation ,010608 biotechnology ,Enzyme Stability ,Environmental Chemistry ,0105 earth and related environmental sciences ,Reusability ,chemistry.chemical_classification ,Chemistry ,Fungi ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Enzymes, Immobilized ,Pollution ,Combinatorial chemistry ,Cross-Linking Reagents ,Enzyme ,Peroxidases ,Glutaral ,Biocatalysis ,Glutaraldehyde - Abstract
Ligninolytic enzymes from white-rot fungi are widely used in biotechnological processes. However, the application of these enzymes as free enzymes is limited due to their instability and lack of reusability. Enzyme stabilization is therefore a major challenge in biocatalytic process research, and immobilization methods are desirable. Using cross-linked enzyme aggregates (CLEAs) such as magnetic CLEAs, porous-CLEAs and combi-CLEAs is a promising technique for overcoming these issues. Cross-linking methods can stabilize and immobilize enzymes by interconnecting enzyme molecules via multiple bonds using cross-linking agents such as glutaraldehyde. The high catalyst density and microporous assembly of CLEAs guarantee high catalyst activity, which, together with their long shelf life, operational stability, and reusability, provide a cost-efficient alternative to matrix-assisted immobilization approaches. Here, we review current progress in ligninolytic enzyme immobilization and provide a comprehensive review of CLEAs. Moreover, we summarize the use of these CLEAs for biocatalysis processes, bioremediation such as dye decolourization, wastewater treatment or pharmaceutically active compound elimination.
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- 2018
44. Synergistic antibacterial action of the iron complex and ampicillin against Staphylococcus aureus
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Ludmila Kosaristanova, Martin Rihacek, Frantiska Sucha, Vedran Milosavljevic, Pavel Svec, Jana Dorazilova, Lucy Vojtova, Peter Antal, Pavel Kopel, Zdenek Patocka, Vojtech Adam, Ludek Zurek, and Kristyna Dolezelikova
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Staphylococcus aureus ,Iron complex ,Ampicillin ,Synergy ,Antimicrobial activity ,Microbiology ,QR1-502 - Abstract
Abstract Objectives Resistance to antibiotics among bacteria of clinical importance, including Staphylococcus aureus, is a serious problem worldwide and the search for alternatives is needed. Some metal complexes have antibacterial properties and when combined with antibiotics, they may increase bacterial sensitivity to antimicrobials. In this study, we synthesized the iron complex and tested it in combination with ampicillin (Fe16 + AMP) against S. aureus. Methods An iron complex (Fe16) was synthesized and characterized using spectroscopy methods. Confirmation of the synergistic effect between the iron complex (Fe16) and ampicillin (AMP) was performed using ζ–potential, infrared spectra and FICI index calculated from the minimum inhibitory concentration (MIC) from the checkerboard assay. Cytotoxic properties of combination Fe16 + AMP was evaluated on eukaryotic cell line. Impact of combination Fe16 + AMP on chosen genes of S. aureus were performed by Quantitative Real-Time PCR. Results The MIC of Fe16 + AMP was significantly lower than that of AMP and Fe16 alone. Furthermore, the infrared spectroscopy revealed the change in the ζ–potential of Fe16 + AMP. We demonstrated the ability of Fe16 + AMP to disrupt the bacterial membrane of S. aureus and that likely allowed for better absorption of AMP. In addition, the change in gene expression of bacterial efflux pumps at the sub-inhibitory concentration of AMP suggests an insufficient import of iron into the bacterial cell. At the same time, Fe16 + AMP did not have any cytotoxic effects on keratinocytes. Conclusions Combined Fe16 + AMP therapy demonstrated significant synergistic and antimicrobial effects against S. aureus. This study supports the potential of combination therapy and further research.
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- 2023
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45. Synthesis and characterization of TiO2 nanoparticles combined with geraniol and their synergistic antibacterial activity
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Almotasem Bellah Younis, Vedran Milosavljevic, Tatiana Fialova, Kristyna Smerkova, Hana Michalkova, Pavel Svec, Peter Antal, Pavel Kopel, Vojtech Adam, Ludek Zurek, and Kristyna Dolezelikova
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Titanium dioxide ,Nanoparticles ,Geraniol ,Minimum inhibitory concentration ,Biofilm ,Methicillin-resistant Staphylococcus aureus ,Microbiology ,QR1-502 - Abstract
Abstract Background The emergence of antibiotic resistance in pathogenic bacteria has become a global threat, encouraging the adoption of efficient and effective alternatives to conventional antibiotics and promoting their use as replacements. Titanium dioxide nanoparticles (TiO2 NPs) have been reported to exhibit antibacterial properties. In this study, we synthesized and characterized TiO2 NPs in anatase and rutile forms with surface modification by geraniol (GER). Results The crystallinity and morphology of modified TiO2 NPs were analyzed by UV/Vis spectrophotometry, X-ray powder diffraction (XRD), and scanning electron microscopy (SEM) with elemental mapping (EDS). The antimicrobial activity of TiO2 NPs with geraniol was assessed against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli. The minimum inhibitory concentration (MIC) values of modified NPs ranged from 0.25 to 1.0 mg/ml against all bacterial strains, and the live dead assay and fractional inhibitory concentration (FIC) supported the antibacterial properties of TiO2 NPs with GER. Moreover, TiO2 NPs with GER also showed a significant decrease in the biofilm thickness of MRSA. Conclusions Our results suggest that TiO2 NPs with GER offer a promising alternative to antibiotics, particularly for controlling antibiotic-resistant strains. The surface modification of TiO2 NPs by geraniol resulted in enhanced antibacterial properties against multiple bacterial strains, including antibiotic-resistant MRSA. The potential applications of modified TiO2 NPs in the biomedical and environmental fields warrant further investigation.
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- 2023
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46. Silver nanoparticles eliminate Xanthomonas campestris pv. campestris in cabbage seeds more efficiently than hot water treatment
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Dorota Tekielska, Tomáš Kiss, Vojtěch Adam, Zuzana Bytesnikova, Lukas Richtera, Miroslav Baránek, Aleš Eichmeier, Robert Pokluda, Eliška Peňázová, and Jakub Pečenka
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Materials science ,biology ,Inoculation ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,medicine.disease_cause ,biology.organism_classification ,01 natural sciences ,Xanthomonas campestris ,Silver nanoparticle ,0104 chemical sciences ,Xanthomonas campestris pv. campestris ,Horticulture ,Mechanics of Materials ,Seedling ,Germination ,Infestation ,Materials Chemistry ,medicine ,General Materials Science ,0210 nano-technology ,Bacteria - Abstract
Silver nanoparticles (AgNPs) and the standard hot water treatment (HWT) method were examined as measures against the bacterium Xanthomonas campestris pv. campestris (Xcc). Three sizes (∼2 nm, ∼22 nm and ∼29 nm) of AgNPs were synthesized and characterized using transmission electron microscopy and dynamic light scattering. To evaluate the direct effect of the synthesized AgNPs on Xcc, an in vitro colony counting assay was carried out. Cabbage seeds (cv.’ Avak F1’) were inoculated with an Xcc (strain 1279a) suspension and treated with hot water or a AgNP solution. The Xcc infestation in the young seedlings was quantified using real-time PCR and dilution plating assays. The results of the colony counting assay indicated that the antibacterial effect of the AgNPs depended on the size and concentration of the NPs. The seedling analysis showed that all three sizes of AgNPs suppressed Xcc infestation at concentrations of 6.25 μg mL−1 and higher. HWT also had an antibacterial effect; nevertheless, in contrast to AgNP treatment, HWT strongly decreased the germination rate of treated seeds.
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- 2021
47. Antimicrobial Agent Based on Selenium Nanoparticles and Carboxymethyl Cellulose for the Treatment of Bacterial Infections
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Kristyna Cihalova, David Hynek, Vedran Milosavljevic, Pavel Kopel, Dagmar Hegerova, Vojtěch Adam, Roman Guráň, Zbynek Heger, Radek Veselý, Pavel Sedlacek, and Marketa Vaculovicova
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0301 basic medicine ,biology ,medicine.drug_class ,Antibiotics ,Biomedical Engineering ,Pharmaceutical Science ,Medicine (miscellaneous) ,chemistry.chemical_element ,Bioengineering ,biology.organism_classification ,Antimicrobial ,Carboxymethyl cellulose ,Microbiology ,Cell wall ,03 medical and health sciences ,030104 developmental biology ,chemistry ,Toxicity ,medicine ,General Materials Science ,Selenium ,Bacteria ,medicine.drug ,Gram ,Nuclear chemistry - Abstract
Our main objective was to analyse and study the effects of the synthesized composite based on selenium nanoparticles and carboxymethyl cellulose (Cekol), hereinafter denoted as SeNPs-Cekol. Firstly, physico-chemical properties of SeNPs-Cekol were characterized in greater detail (size of nanoparticles-from 50 to 150 nm; content of selenium-278 ppm; pH of composite-5.4-5.6; density-990-1010 kg/m(3)), together with assessment of its stability. In addition, the toxicity and mutagenicity on prokaryotic and eukaryotic cells was successfully evaluated. All of the tested bacterial strains were isolated from wound swabs of infectious patients (n = 300) and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). These strains were consequently exposed to SeNPs-Cekol composite. Almost all of the bacterial strains (n = 63) exhibited inhibition zones larger than 5 mm (limit for sensitivity to antibiotics) after the application of the SeNPs-Cekol (300 mu M). Furthermore, in some tested strains (n = 8 for gram positive (G(+)); n = 4 for gram negative (G(-))) even the inhibition zones larger than 12 mm (limit value for very sensitive bacteria to antibiotics) were observed. Overall, the effects of the composite were higher for the G(+) bacteria in comparison with G(-)bacteria, which are generally more resistant to antimicrobial agents, due to their cell wall structure. Further, we found that mutagenicity of the SeNPs-Cekol was found to be negligible. Even, non-target toxicity tests towards eukaryotic cells did not show any significant inhibition of the cells growth compared to the control. Therefore, it can be concluded that SeNPs-Cekol could be considered to have a potential in treatment of bacterial infections.
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- 2017
48. Application of the Enzymatic Electrochemical Biosensors for Monitoring Non-Competitive Inhibition of Enzyme Activity by Heavy Metals
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Jan Přibyl, Milan Sýs, Amir Shaaban Farag, Amir M. Ashrafi, Lukas Richtera, Vojtěch Adam, and Eliska Sedlackova
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Biosensing Techniques ,02 engineering and technology ,lcsh:Chemical technology ,Electrochemistry ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,law.invention ,amperometric biosensor ,Non-competitive inhibition ,Limit of Detection ,law ,non-competitive inhibition ,lcsh:TP1-1185 ,Glucose oxidase ,Enzyme Inhibitors ,heavy metals ,Instrumentation ,amperometrický biosenzor ,biology ,Chemistry ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,nekompetitivní inhibice ,visual_art ,Calibration ,visual_art.visual_art_medium ,Ruthenium Compounds ,Aspergillus niger ,0210 nano-technology ,Carbon nanotube ,Article ,Metal ,Adsorption ,Metals, Heavy ,Electrical and Electronic Engineering ,Electrodes ,Glukóza oxidáza ,Nanotubes, Carbon ,010401 analytical chemistry ,těžké kovy ,Electrochemical Techniques ,Hydrogen Peroxide ,Enzyme assay ,glucose oxidase ,0104 chemical sciences ,Glucose ,biology.protein ,Biosensor ,Nuclear chemistry - Abstract
The inhibition effect of the selected heavy metals (Ag+, Cd2+, Cu2+, and Hg2+) on glucose oxidase (GOx) enzyme from Aspergillus niger (EC 1.1.3.4.) was studied using a new amperometric biosensor with an electrochemical transducer based on a glassy carbon electrode (GCE) covered with a thin layer of multi-wall carbon nanotubes (MWCNTs) incorporated with ruthenium(IV) oxide as a redox mediator. Direct adsorption of multi-wall carbon nanotubes (MWCNTs) and subsequent covering with Nafion®, layer was used for immobilization of GOx. The analytical figures of merit of the developed glucose (Glc) biosensor are sufficient for determination of Glc in body fluids in clinical analysis. From all tested heavy metals, mercury(II) has the highest inhibition effect. However, it is necessary to remember that cadmium and silver ions also significantly inhibit the catalytic activity of GOx. Therefore, the development of GOx biosensors for selective indirect determination of each heavy metal still represents a challenge in the field of bioelectroanalysis. It can be concluded that amperometric biosensors, differing in the utilized enzyme, could find their application in the toxicity studies of various poisons.
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- 2019
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49. Ellipticine-loaded apoferritin nanocarrier retains DNA adduct-based cytochrome P450-facilitated toxicity in neuroblastoma cells
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Marketa Martinkova, Marek Wilhelm, Alžběta Lengálová, Volker M. Arlt, Zbyněk Heger, Simona Dostalova, Heinz H. Schmeiser, Tomas Eckschlager, Tereza Cerna, Radek Indra, Marie Stiborová, Vojtěch Adam, and Jan Hraběta
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0301 basic medicine ,Cell Survival ,Drug Compounding ,Cytotoxicity ,Antineoplastic Agents ,Toxicology ,Histones ,03 medical and health sciences ,chemistry.chemical_compound ,DNA Adducts ,Neuroblastoma ,0302 clinical medicine ,Cell Line, Tumor ,DNA adduct ,Water environment ,Cytochrome P-450 CYP3A ,Humans ,Ellipticines ,Phosphorylation ,chemistry.chemical_classification ,Drug Carriers ,Cytochrome P450-mediated metabolism ,biology ,Chemistry ,Ellipticine ,Cytochrome P450 ,DNA adducts ,Apoferritin nanoparticles ,Drug Liberation ,030104 developmental biology ,Enzyme ,Apoferritins ,Microsome ,Biophysics ,biology.protein ,Nanoparticles ,Nanocarriers ,030217 neurology & neurosurgery ,DNA - Abstract
Although ellipticine (Elli) is an efficient anticancer agent, it exerts several adverse effects. One approach to decrease the adverse effects of drugs is their encapsulation inside a suitable nanocarrier, allowing targeted delivery to tumour tissue whereas avoiding healthy cells. We constructed a nanocarrier from apoferritin (Apo) bearing ellipticine, ApoElli, and subsequently characterized. The nanocarrier exhibits a narrow size distribution suggesting its suitability for entrapping the hydrophobic ellipticine molecule. Ellipticine was released from ApoElli into the water environment under pH 6.5, but only less than 20% was released at pH 7.4. The interaction of ApoElli with microsomal membrane particles containing cytochrome P450 (CYP) biotransformation enzymes accelerated the release of ellipticine from this nanocarrier making it possible to be transferred into this membrane system even at pH 7.4 and facilitating CYP-mediated metabolism. Reactive metabolites were formed not only from free ellipticine, but also from ApoElli, and both generated covalent DNA adducts. ApoElli was toxic in UKF-NB-4 neuroblastoma cells, but showed significantly lower cytotoxicity in non-malignant fibroblast HDFn cells. Ellipticine either free or released from ApoElli was concentrated in the nuclei of neuroblastoma cells, concentrations of which being significantly higher in nuclei of UKF-NB-4 than in HDFn cells. In HDFn the higher amounts of ellipticine were sequestrated in lysosomes. The extent of ApoElli entering the nuclei in UKF-NB-4 cells was lower than that of free ellipticine and correlated with the formation of ellipticine-derived DNA adducts. Our study indicates that the ApoElli form of ellipticine seems to be a promising tool for neuroblastoma treatment.
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- 2019
50. Stability of Zn and Cu nanoparticles studied in aqueous medium by Scanning Electron Microscopy
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Lukas Richtera, Pavel Svec, Vojtěch Adam, and Zuzana Bytesnikova
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Cu nanoparticles ,Materials science ,Aqueous medium ,Scanning electron microscope ,ZnO nanoparticles ,Time stability ,SEM ,Nuclear chemistry - Abstract
The stability of nanoparticles in aquatic environment plays an important role for their environmental and biological application. The storage time has strong impact on the stability of zinc and copper nanoparticles (ZnONPs and CuNPs). The effect of the storage time was studied over time and the results showed a change in morphology of synthesized NPs. The time stability study was divided into three parts: short-term (0 - 72 h), medium-term (16 days) and long-term (5 months). In the case of CuNPs the SEM picture revealed the presence of crystal structure. This can be explained as the CuNPs surface layer was oxidized and the crystals on surface are copper oxides. Similar study was conducted on ZnONPs, but in shorter time scale (1 - 3 days). As in the case of CuNPs, ZnONPs showed the same tendency to crystalize. We can conclude that storage time and conditions have a strong impact on the NPs stability.
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- 2019
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