Výzkumná skupina syntézy a chemické analýzy

@article{nokey,

title = {Trace level voltammetric determination of Zn(II) in selected nutrition related samples by bismuth-oxychloride-multiwalled carbon nanotube composite based electrode},

author = {Sandra Petrović and Valéria Guzsvány and Nikola Ranković and Jelena Beljin and Srđan Rončević and Božo Dalmacija and Amir M. Ashrafi and Zoltán Kónya and Ivan Švancara and Karel Vytřas},

doi = {https://doi.org/10.1016/j.microc.2018.12.053},

issn = {0026-265X},

year  = {2022},

date = {2022-12-27},

urldate = {2022-12-27},

journal = {Microchemical Journal},

volume = {146},

pages = {178-186},

abstract = {Bismuth-oxychloride-multiwalled carbon nanotube composite material was applied as surface modifier of glassy carbon electrode (BiOCl-MWCNT/GCE) for rapid and reliable trace level determination of Zn(II) in selected foodstuffs. The method development encompasses the optimization of electrode preparation including the transmission electron microscopic study of the modifier suspension, selection of the supporting electrolyte pH, the adjustment of the operation parameters of the SW-ASV measurements and the investigation of matrix effects. By the BiOCl-MWCNT/GCE recorded calibration curve showed an excellent linearity towards Zn reoxidation peak intensity in the concentration range from 2.50 to 80.0 μg L−1 with the calculated LOD of 0.75 μg L−1 which was associated with 120 s accumulation time and accumulation potential −1.40 V vs SCE in acetate buffer pH 4.5. A satisfactory repeatability expressed as relative standard deviation of 4.8% was obtained in the case of 10.0 μg L−1 Zn(II) in model solution. The Zn(II) reoxidation signal from BiOCl-MWCNT/GCE received by the optimized SW-ASV method was compared with those recorded with bare, classical bismuth-film, multiwalled carbon nanotubes and by in situ made advanced bismuth-film-MWCNTs working electrodes. The applicability of the proposed BiOCl-MWCNT/GCE based method was corroborated via measuring the target analyte in two nutrition related real samples: in a dietary supplement and in a brewer's yeast sample. Comparative flame atomic absorption spectrometric measurements verified the obtained results in the case of yeast sample.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34303137,

title = {A critical comparison of natural enzymes and nanozymes in biosensing and bioassays},

author = {Amir M Ashrafi and Zuzana Bytesnikova and Jiri Barek and Lukas Richtera and Vojtech Adam},

doi = {10.1016/j.bios.2021.113494},

issn = {1873-4235},

year  = {2021},

date = {2021-11-01},

journal = {Biosens Bioelectron},

volume = {192},

pages = {113494},

abstract = {Nanozymes (NZs) are nanomaterials that mimic enzyme-like catalytic activity. They have attracted substantial attention due to their inherent physicochemical properties for use as promising alternatives to natural enzymes (NEs) in a variety of research fields. Particularly, in biosensing and bioassays, NZs have opened a new horizon to eliminate the intrinsic limitations of NEs, including their denaturation at extreme pH values and temperatures, poor reusability and recyclability, and high production costs. Moreover, the catalytic activity of NZs can be modulated in the preparation step by following an appropriate synthesis strategy. This review aims to gain insight into the potential substitution of NEs by NZs in biosensing and bioassays while considering both the pros and cons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {New insights into mechanisms of copper nanoparticle toxicity in freshwater algae Chlamydomonas reinhardtii: Effects on the pathways of secondary metabolites},

author = {Anna Janova and Martina Kolackova and Zuzana Bytesnikova and Petr Capal and Pavel Chaloupsky and Pavel Svec and Andrea Ridoskova and Natalia Cernei and Borivoj Klejdus and Lukas Richtera and Vojtech Adam and Dalibor Huska},

doi = {https://doi.org/10.1016/j.algal.2021.102476},

year  = {2021},

date = {2021-09-03},

urldate = {2021-09-03},

journal = {Algal Research},

volume = {60},

abstract = {The effects of copper nanoparticles (Cu-NPs), including their stability in the medium, were studied with the green unicellular algae Chlamydomonas reinhardtii (CC-125). Cu-NPs were synthesized and characterized. Cu-NP particles were uniform, regular, and largely spherical, and they had smooth surfaces; the average size was estimated to be 137.4 ± 2.1 nm. Chlamydomonas cells were cultivated for 96 h under controlled conditions in the presence of Cu-NPs, according to OECD guidelines, and then subjected to toxicological bioassays. Based on scanning electron microscopy (SEM) observations, the effects of Cu-NPs resulted in part from the dissolution of nanoparticles (NPs) and the action of copper itself, which shows the importance of studying NP stability in the testing environment. In this assay, deleterious effects were enhanced by increasing Cu-NP concentrations (5, 10, 25, 50, and 100 mg/L). Concentrations higher than 25 mg/L exhibited extreme toxicity. We confirmed the known toxic effects of metal NPs, namely, growth inhibition, reduction of chlorophyll levels in cells, cell penetration and increased ROS production. Attention was also paid to select underexplored metabolites, which were studied with a LC-MS/MS system. Treatments caused changes in metabolites profiles, and levels of p-hydroxybenzaldehyde and protocatechuic acid were especially enhanced, suggesting their positive roles in the antioxidant defence response. Furthermore, a repeatable increase in suberic acid levels was observed for various stress conditions tested, and we expect that this was the result of lipid peroxidation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34473486,

title = {In Situ Investigation of the Cytotoxic and Interfacial Characteristics of Titanium When Galvanically Coupled with Magnesium Using Scanning Electrochemical Microscopy},

author = {Abdelilah Asserghine and Amir M Ashrafi and Atripan Mukherjee and Frantisek Petrlak and Zbynek Heger and Pavel Svec and Lukas Richtera and Livia Nagy and Ricardo M Souto and Geza Nagy and Vojtech Adam},

doi = {10.1021/acsami.1c10584},

issn = {1944-8252},

year  = {2021},

date = {2021-09-01},

journal = {ACS Appl Mater Interfaces},

volume = {13},

number = {36},

pages = {43587--43596},

abstract = {Recently, the cytotoxic properties of galvanically coupled Ti-Mg particles have been shown in different cells. This cytotoxic effect has been attributed mainly to Mg due to its tendency to undergo activation when coupled with Ti, forming a galvanic cell consisting of an anode (Mg) and a cathode (Ti). However, the role of the Ti cathode has been ignored in explaining the cytotoxic effect of Ti-Mg particles due to its high resistance to corrosion. In this work, the role of titanium (Ti) in the cytotoxic mechanism of galvanically coupled Ti-Mg particles was examined. A model galvanic cell (MGC) was prepared to simulate the Mg-Ti particles. The electrochemical reactivity of the Ti sample and the pH change in it due to galvanic coupling with Mg were investigated using scanning electrochemical microscopy (SECM). It was observed that the Ti surface changed from passive to electrochemically active when coupled with Mg. Furthermore, after only 15 min of galvanic coupling with Mg, the pH in the electrolyte volume adjacent to the Ti surface increased to an alkaline pH value. The effects of the galvanic coupling of Ti and Mg, as well as those of the alkaline pH environment, on the viability of Hs27 fibroblast cells were investigated. It was shown that the viability of Hs27 cells significantly diminished when Mg and Ti were galvanically coupled compared to when the two metals were electrically disconnected. Thus, although Ti usually exhibited high corrosion resistance when exposed to physiological environments, an electrochemically active surface was observed when galvanically coupled with Mg, and this surface may participate in electron transfer reactions with chemical species in the neighboring environment; this participation resulted in the increased pH values above its surface and enhanced generation of reactive oxygen species. These features contributed to the development of cytotoxic effects by galvanically coupled Ti-Mg particles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34205105,

title = {What about Dinner? Chemical and Microresidue Analysis Reveals the Function of Late Neolithic Ceramic Pans},

author = {Jaromír Beneš and Valentina Todoroska and Kristýna Budilová and Jaromír Kovárník and Jaroslav Pavelka and Nevenka Atanasoska and Jiří Bumerl and Assunta Florenzano and Tereza Majerovičová and Václav Vondrovský and Michaela Ptáková and Petr Bednář and Lukáš Richtera and Lukáš Kučera},

doi = {10.3390/molecules26113391},

issn = {1420-3049},

year  = {2021},

date = {2021-06-01},

journal = {Molecules},

volume = {26},

number = {11},

abstract = {The Late Neolithic palafitte site, Ustie na Drim, in the northern part of Lake Ohrid (North Macedonia), excavated in 1962, offered ceramic fragments of large, flat, elongated pans. These artifacts could be dated by relative chronology to roughly around 5200-5000 BC. According to their shape and technological traits, the ceramic pans were probably used for baking. The attached materials on the surface of studied pan fragments were sampled for consequent chemical and microscopical analyses (i.e., analyses of starch, phytoliths, and microscopic animal remains). An immunological method revealed the presence of pork proteins in samples. The presence of organic residues of animal origin was, moreover, confirmed by the detection of cholesterol using gas chromatography coupled to mass spectrometry. Analysis of detected microscopic botanical objects revealed starch grains of several plants (i.e., oak, cattail, and grasses). An interesting find was the hair of a beetle larva, which could be interpreted contextually as the khapra beetle, a pest of grain and flour. Based on our data, we suppose that the ceramic pans from Ustie na Drim were used for the preparation of meals containing meat from common livestock in combination with cereals and wild plants.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33662844,

title = {Peptide-based electrochemical biosensors utilized for protein detection},

author = {Veronika Vanova and Katerina Mitrevska and Vedran Milosavljevic and David Hynek and Lukas Richtera and Vojtech Adam},

doi = {10.1016/j.bios.2021.113087},

issn = {1873-4235},

year  = {2021},

date = {2021-05-01},

journal = {Biosens Bioelectron},

volume = {180},

pages = {113087},

abstract = {Proteins are generally detected as biomarkers for tracing or determining various disorders in organisms. Biomarker proteins can be tracked in samples with various origins and in different concentrations, revealing whether an organism is in a healthy or unhealthy state. In regard to detection, electrochemical biosensors are a potential fusion of electronics, chemistry, and biology, allowing for fast and early point-of-care detection from a biological sample with the advantages of high sensitivity, simple construction, and easy operation. Peptides present a promising approach as a biorecognition element when connected with electrochemical biosensors. The benefits of short peptides lie mainly in their good stability and selective affinity to a target analyte. Therefore, peptide-based electrochemical biosensors (PBEBs) represent an alternative approach for the detection of different protein biomarkers. This review provides a summary of the past decade of recently proposed PBEBs designed for protein detection, dividing them according to different protein types: (i) enzyme detection, including proteases and kinases; (ii) antibody detection; and (iii) other protein detection. According to these protein types, different sensing mechanisms are discussed, such as the peptide cleavage by a proteases, phosphorylation by kinases, presence of antibodies, and exploiting of affinities; furthermore, measurements are obtained by different electrochemical methods. A discussion and comparison of various constructions, modifications, immobilization strategies and different sensing techniques in terms of high sensitivity, selectivity, repeatability, and potential for practical application are presented.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {2D transition metal dichalcogenide nanomaterial-based miRNA biosensors},

author = {Katerina Mitrevska and Vedran Milosavljevic and Milica Gagic and Lukas Richtera and Vojtech Adam},

doi = {https://doi.org/10.1016/j.apmt.2021.101043},

issn = {2352-9407},

year  = {2021},

date = {2021-04-24},

journal = {Applied Materials Today},

volume = {23},

abstract = {MicroRNAs (miRNAs) are short oligonucleotides responsible for the regulation of basic cellular mechanisms. The detection of miRNA in clinical practice involves conventional methods (northern blot, microarrays, RT-qPCR) that provide good sensitivity and specificity. However, their high cost and time-consuming nature prevent their implementation as routine analysis. Biosensors, as alternative detection platforms, can compensate for these flaws, providing good sensitivity and specificity as well as low prices per assay and fast generation of results; therefore, biosensors may ultimately replace conventional methods. The fast progress in nanotechnology has created new prospects in biosensor fabrication, presenting a selection of nanomaterials compatible for the detection of various biomolecules. Two-dimensional transition metal dichalcogenides (2D TMDCs) demonstrate promising qualities, such as biocompatibility, a large surface area for detection and diverse possibilities for altering electrochemical and optical properties; hence, an improved detection performance can be achieved. In this review, the recent progress in biosensor fabrication for detecting miRNAs based on 2D TMDCs is summarized and supported by the basic understanding of miRNA biosynthetic pathways and detection methods. Additionally, insight into the structure and properties of TMDCs will be disclosed as well as suitable methods for their synthesis and the mechanisms for tuning their properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Silver nanoparticles eliminate Xanthomonas campestris pv. campestris in cabbage seeds more efficiently than hot water treatment},

author = {Pečenka, Jakub and Bytešníková, Zuzana and Kiss, Tomas and Hakalova, Eliska and Baránek, Miroslav and Eichmeier, Ales and Tekielska, Dorota and Richtera, Lukáš and Pokluda, Robert and Adam, Vojtech},

doi = {https://doi.org/10.1016/j.mtcomm.2021.102284},

year  = {2021},

date = {2021-03-27},

urldate = {2021-03-27},

journal = {Materials Today Communications},

volume = {27},

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.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {“Gold corrosion”: An alternative source of red stains on gold coins},

author = {Lukáš Kučera and Jan Rozsypal and Petr Bednář and Matěj Březina and Lukáš Kalina and Petr Bezdička and Miroslav Mašláň and Lukáš Richtera

},

doi = {https://doi.org/10.1016/j.mtla.2021.101025},

issn = {2589-1529},

year  = {2021},

date = {2021-02-01},

journal = {Materialia},

volume = {15},

abstract = {Recently, the phenomena of red stains defects was found on historical and modern golden coins around the world. This “Gold corrosion” can be the reason for reduction of coin value, especially of modern high-premium coins. In such modern investment coins, the contamination of the surface by microscopic particles of metallic silver is reported to be a common cause of such stains. Corrosion of these particles (or even back reduction) is associated with a distinct change of colour. In the case of historical coins, this relatively simple explanation does not respond in some cases. The submitted study is dealing with analysis of red stains on of Austro-Hungarian gold ten crowns coins, which served as a common part of circulating currency. They were therefore minted in thousands/million pieces by standard procedures each year. It is therefore quite logical that these coins can have different mechanisms of red spots formation than modern high-premium coins. Red stains on Austro-Hungarian coins were analysed by the means of light (LM) and digital microscopy (DM), energy-dispersive X-ray spectroscopy (EDS), energy dispersive X-ray fluorescence spectroscopy (XRF), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Mössbauer spectroscopy, X-ray powder micro-diffraction (µ-XRPD) and Raman microscopy. The EDS, XRF and XPS analysis points to the presence of iron and oxygen in red stains, no silver or its corrosion products were detected. The exact determination of red stains was done by µ-XRPD and Raman microscopy where an iron(III) oxide-hydroxide (Goethite) was found as main product.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34234435,

title = {The Anti-Proliferative Activity of Coordination Compound-Based ZnO Nanoparticles as a Promising Agent Against Triple Negative Breast Cancer Cells},

author = {Hana Stepankova and Marcin Swiatkowski and Rafal Kruszynski and Pavel Svec and Hana Michalkova and Vendula Smolikova and Andrea Ridoskova and Zbynek Splichal and Petr Michalek and Lukas Richtera and Pavel Kopel and Vojtech Adam and Zbynek Heger and Simona Rex},

doi = {10.2147/IJN.S304902},

issn = {1178-2013},

year  = {2021},

date = {2021-01-01},

journal = {Int J Nanomedicine},

volume = {16},

pages = {4431--4449},

abstract = {PURPOSE: The present study deals with the in vitro evaluation of the potential use of coordination compound-based zinc oxide (ZnO) nanoparticles (NPs) for the treatment of triple negative breast cancer cells (TNBrCa). As BrCa is one of the most prevalent cancer types and TNBrCa treatment is difficult due to poor prognosis and a high metastasis rate, finding a more reliable treatment option should be of the utmost interest.



METHODS: Prepared by reacting zinc carboxylates (formate, acetate, propionate, butyrate, isobutyrate, valerate) and hexamethylenetetramine, 4 distinct coordination compounds were further subjected to two modes of conversion into ZnO NPs - ultrasonication with oleic acid or heating of pure precursors in an air atmosphere. After detailed characterization, the resulting ZnO NPs were subjected to in vitro testing of cytotoxicity toward TNBrCa and normal breast epithelial cells. Further, their biocompatibility was evaluated.



RESULTS: The resulting ZnO NPs provide distinct morphological features, size, biocompatibility, and selective cytotoxicity toward TNBrCa cells. They internalize into two types of TNBrCa cells and imbalance their redox homeostasis, influencing their metabolism, morphology, and ultimately leading to their death via apoptosis or necrosis.



CONCLUSION: The crucial properties of ZnO NPs seem to be their morphology, size, and zinc content. The ZnO NPs with the most preferential values of all three properties show great promise for a future potential use in the therapy of TNBrCa.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33573241,

title = {Imaging Viral Infection by Fluorescence Microscopy: Focus on HIV-1 Early Stage},

author = {Soumajit Mukherjee and Emmanuel Boutant and Eleonore Réal and Yves Mély and Halina Anton},

doi = {10.3390/v13020213},

issn = {1999-4915},

year  = {2021},

date = {2021-01-01},

journal = {Viruses},

volume = {13},

number = {2},

abstract = {During the last two decades, progresses in bioimaging and the development of various strategies to fluorescently label the viral components opened a wide range of possibilities to visualize the early phase of Human Immunodeficiency Virus 1 (HIV-1) life cycle directly in infected cells. After fusion of the viral envelope with the cell membrane, the viral core is released into the cytoplasm and the viral RNA (vRNA) is retro-transcribed into DNA by the reverse transcriptase. During this process, the RNA-based viral complex transforms into a pre-integration complex (PIC), composed of the viral genomic DNA (vDNA) coated with viral and host cellular proteins. The protective capsid shell disassembles during a process called uncoating. The viral genome is transported into the cell nucleus and integrates into the host cell chromatin. Unlike biochemical approaches that provide global data about the whole population of viral particles, imaging techniques enable following individual viruses on a single particle level. In this context, quantitative microscopy has brought original data shedding light on the dynamics of the viral entry into the host cell, the cytoplasmic transport, the nuclear import, and the selection of the integration site. In parallel, multi-color imaging studies have elucidated the mechanism of action of host cell factors implicated in HIV-1 viral cycle progression. In this review, we describe the labeling strategies used for HIV-1 fluorescence imaging and report on the main advancements that imaging studies have brought in the understanding of the infection mechanisms from the viral entry into the host cell until the provirus integration step.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Graphene Oxide as a Nanocarrier for Biochemical Molecules: Current Understanding and Trends},

author = {Mukherjee, S. and Bytešníková, Z. and Ashrafí, AM and Adam, V. and Richtera, L. },

doi = {https://doi.org/10.3390/pr8121636},

year  = {2020},

date = {2020-12-11},

journal = {MDPI Proceedings Journals},

volume = {8},

issue = {12},

abstract = {The development of an advanced and efficient drug delivery system with significant improvement in its efficacy and enhanced therapeutic value is one of the critical challenges in modern medicinal biology. The integration of nanomaterial science with molecular and cellular biology has helped in the advancement and development of novel drug delivery nanocarrier systems with precision and decreased side effects. The design and synthesis of nanocarriers using graphene oxide (GO) have been rapidly growing over the past few years. Due to its remarkable physicochemical properties, GO has been extensively used in efforts to construct nanocarriers with high specificity, selectivity, and biocompatibility, and low cytotoxicity. The focus of this review is to summarize and address recent uses of GO-based nanocarriers and the improvements as efficient drug delivery systems. We briefly describe the concepts and challenges associated with nanocarrier systems followed by providing critical examples of GO-based delivery of drug molecules and genes. Finally, the review delivers brief conclusions on the current understanding and prospects of nanocarrier delivery systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33383885,

title = {Bis(2,2'-bipyridil)Copper(II) Chloride Complex: Tyrosinase Biomimetic Catalyst or Redox Mediator?},

author = {Milan Sýs and Atripan Mukherjee and Granit Jashari and Vojtěch Adam and Amir M Ashrafi and Miroslav Novák and Lukáš Richtera},

doi = {10.3390/ma14010113},

issn = {1996-1944},

year  = {2020},

date = {2020-12-01},

journal = {Materials (Basel)},

volume = {14},

number = {1},

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)Cl]Cl∙5HO 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?},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33153095,

title = {Label-Free DNA Biosensor Using Modified Reduced Graphene Oxide Platform as a DNA Methylation Assay},

author = {Eliska Sedlackova and Zuzana Bytesnikova and Eliska Birgusova and Pavel Svec and Amir M Ashrafi and Pedro Estrela and Lukas Richtera},

doi = {10.3390/ma13214936},

issn = {1996-1944},

year  = {2020},

date = {2020-11-01},

journal = {Materials (Basel)},

volume = {13},

number = {21},

abstract = {This work reports the use of modified reduced graphene oxide (rGO) as a platform for a label-free DNA-based electrochemical biosensor as a possible diagnostic tool for a DNA methylation assay. The biosensor sensitivity was enhanced by variously modified rGO. The rGO decorated with three nanoparticles (NPs)-gold (AuNPs), silver (AgNPs), and copper (CuNPs)-was implemented to increase the electrode surface area. Subsequently, the thiolated DNA probe (single-stranded DNA, ssDNA-1) was hybridized with the target DNA sequence (ssDNA-2). After the hybridization, the double-stranded DNA (dsDNA) was methylated by M.SssI methyltransferase (MTase) and then digested via a HpaII endonuclease specific site sequence of CpG (5'-CCGG-3') islands. For monitoring the MTase activity, differential pulse voltammetry (DPV) was used, whereas the best results were obtained by rGO-AuNPs. This assay is rapid, cost-effective, sensitive, selective, highly specific, and displays a low limit of detection (LOD) of 0.06 U·mL. Lastly, this study was enriched with the real serum sample, where a 0.19 U·mL LOD was achieved. Moreover, the developed biosensor offers excellent potential in future applications in clinical diagnostics, as this approach can be used in the design of other biosensors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {The effect of synthesis procedure on hydrogen peroxidase-like catalytic activity of iron oxide magnetic particles},

author = {Mukherjee, A. and Ashrafi, A.M. and Svec, P. and Richtera, L. and Přibyl, J. and Brtnický, M. and Kynicky, J. and Adam, V.},

doi = {https://doi.org/10.3390/app10196756},

year  = {2020},

date = {2020-09-26},

journal = {MDPI Applied Sciences},

volume = {10},

issue = {19},

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.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Graphene oxide as a novel tool for mycotoxin removal},

author = {Zuzana Bytesnikova and Vojtech Adam and Lukas Richtera

},

doi = {https://doi.org/10.1016/j.foodcont.2020.107611},

year  = {2020},

date = {2020-09-08},

urldate = {2020-09-08},

journal = {Food Control},

volume = {121},

abstract = {Mycotoxins, as a food and feed toxins, pose serious health risks for humans and animals and cause huge economic losses. Preventive measures against mycotoxins are not successful, and mycotoxins are commonly present in food and feed, which are easily contaminated. Moreover, this represents entry into the food chain, endangering all, including humans. Graphene oxide (GO) and its composites, thanks to their number of different functional groups on their surface, seem to be a promising tool for capturing and removing mycotoxins from contaminated food and feed without creating health risks or decreasing the quality of products.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32229323,

title = {A chemometric-assisted voltammetric analysis of free and Zn(II)-loaded metallothionein-3 states},

author = {Manuel David Peris-Díaz and Lukas Richtera and Ondrej Zitka and Artur Krężel and Vojtech Adam},

doi = {10.1016/j.bioelechem.2020.107501},

issn = {1878-562X},

year  = {2020},

date = {2020-08-01},

journal = {Bioelectrochemistry},

volume = {134},

pages = {107501},

abstract = {We focused on the application of mass spectrometry and electrochemical methods combined with a chemometric analysis for the characterization of partially metallothionein-3 species. The results showed decreased Cat1 and Cat2 signals for the Zn(II)-loaded MT3 species with respect to the metal-free protein, which might be explained by the arrangement of tetrahedral metal-thiolate coordination environments and the formation of metal clusters. Moreover, there was a decrease in the Cat1 and Cat2 signals, and a plateau was reached with 4-5 Zn(II) ions that corresponded to the formation of the C-terminal α-domain. Regarding the ZnMT3 complexes, we observed three different electrochemical behaviours for the ZnMT3, ZnMT3 and ZnMT3 species. The difference for ZnMT3 might be explained by the formation of independent ZnS cores in this stage that differ with respect to the formation of ZnCys clusters with an increased Zn(II) loading. The binding of the third Zn(II) ion to MT3 resulted in high sample heterogeneity due the co-existence of ZnMT3. Finally, the ZnMT3 protein showed a third type of behaviour. The fact that there were no free Cys residues might explain this phenomenon. Thus, this research identifies the major proteins responsible for zinc buffering in the cell.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {One-pot synthesis of natural amine-modified biocompatible carbon quantum dots with antibacterial activity},

author = {Milica Gagic and Silvia Kociova and Kristyna Smerkova and Hana Michalkova and Milena Setka and Pavel Svec and Jan Pribyl and Jiri Masilko and Radka Balkova and Zbynek Heger and Lukas Richtera and Vojtech Adam and Vedran Milosavljevic

},

doi = {https://doi.org/10.1016/j.jcis.2020.06.125.},

issn = {0021-9797},

year  = {2020},

date = {2020-07-05},

journal = {Journal of Colloid and Interface Science},

volume = {580},

abstract = {In the present study, the thermal decomposition of citric acid in the presence of biogenic amine was used to synthesize four different functionalized carbon quantum dots (CQDs), namely, histamine-(HCQDs), putrescine-(PCQDs), cadaverine-(CCQDs) and spermine-(SCQDs). The thermal decomposition of the precursors resulted in a decrease in stability and the formation of surface amides via a cross-linking process between the carboxyl and amine groups. The deposition of biogenic amines was confirmed by a structural characterization of the synthesized CQDs. The resulting CQDs, with a net zero charge, exhibited excellent stability in environments with different pH values. Through a set of different cytotoxicity tests, the absence of gene mutations, apoptosis, necrosis or disruption in cell membranes revealed the high biocompatibility of the CQDs. The antimicrobial activity of the synthesized CQDs was investigated against different bacterial species (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia). We determined the growth kinetics, production of reactive oxygen species (ROS), cell viability and changes in membrane integrity by scanning electron microscopy (SEM). The minimal inhibitory concentrations (MICs) for S. aureus ranged from 3.4 to 6.9 µg/mL. Regarding E.coli and K. pneumonia, all CQD formulations reduced growth, and the MICs were determined for CCQDs and HCQDs (6.9–19.4 µg/mL). The antibacterial activity mechanism was attributed to the oxidative stress generated after CQD treatment, which resulted in the destabilization of the bacterial membrane. The bacterial permeability to propidium iodide indicated a change in membrane integrity, and the effect of CQDs on the morphology of the bacterial cells was evidenced by SEM.

Keywords: Carbon quantum dots; Amines; Thermal decomposition; Toxicity; Antibacterial activity; ROS},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32660596,

title = {Norepinephrine transporter-derived homing peptides enable rapid endocytosis of drug delivery nanovehicles into neuroblastoma cells},

author = {Yazan Haddad and Marketa Charousova and Hana Zivotska and Zbynek Splichal and Miguel Angel Merlos Rodrigo and Hana Michalkova and Sona Krizkova and Barbora Tesarova and Lukas Richtera and Petr Vitek and Kamila Stokowa-Soltys and David Hynek and Vedran Milosavljevic and Simona Rex and Zbynek Heger},

doi = {10.1186/s12951-020-00654-x},

issn = {1477-3155},

year  = {2020},

date = {2020-07-01},

journal = {J Nanobiotechnology},

volume = {18},

number = {1},

pages = {95},

abstract = {BACKGROUND: Currently, the diagnosis and treatment of neuroblastomas-the most frequent solid tumors in children-exploit the norepinephrine transporter (hNET) via radiolabeled norepinephrine analogs. We aim to develop a nanomedicine-based strategy towards precision therapy by targeting hNET cell-surface protein with hNET-derived homing peptides.



RESULTS: The peptides (seq. GASNGINAYL and SLWERLAYGI) were shown to bind high-resolution homology models of hNET in silico. In particular, one unique binding site has marked the sequence and structural similarities of both peptides, while most of the contribution to the interaction was attributed to the electrostatic energy of Asn and Arg (< - 228 kJ/mol). The peptides were comprehensively characterized by computational and spectroscopic methods showing ~ 21% β-sheets/aggregation for GASNGINAYL and ~ 27% α-helix for SLWERLAYGI. After decorating 12-nm ferritin-based nanovehicles with cysteinated peptides, both peptides exhibited high potential for use in actively targeted neuroblastoma nanotherapy with exceptional in vitro biocompatibility and stability, showing minor yet distinct influences of the peptides on the global expression profiles. Upon binding to hNET with fast binding kinetics, GASNGINAYLC peptides enabled rapid endocytosis of ferritins into neuroblastoma cells, leading to apoptosis due to increased selective cytotoxicity of transported payload ellipticine. Peptide-coated nanovehicles significantly showed higher levels of early apoptosis after 6 h than non-coated nanovehicles (11% and 7.3%, respectively). Furthermore, targeting with the GASNGINAYLC peptide led to significantly higher degree of late apoptosis compared to the SLWERLAYGIC peptide (9.3% and 4.4%, respectively). These findings were supported by increased formation of reactive oxygen species, down-regulation of survivin and Bcl-2 and up-regulated p53.



CONCLUSION: This novel homing nanovehicle employing GASNGINAYLC peptide was shown to induce rapid endocytosis of ellipticine-loaded ferritins into neuroblastoma cells in selective fashion and with successful payload. Future homing peptide development via lead optimization and functional analysis can pave the way towards efficient peptide-based active delivery of nanomedicines to neuroblastoma cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Engineered nanoselenium supplemented fish diet: toxicity comparison with ionic selenium and stability against particle dissolution, aggregation and release},

author = {Abdolahpur Monikh, F. and Chupani, L. and Smerková, K. and Bosker, T. and Cízar, P. and Krzyzanek, V. and Richtera, L. and Franěk, R. and Zusková, E. and Skoupy, R. and Darbha, GK and Vijver, M. and Valsami-Jones, E. and Peijnenburg, W.},

url = {https://pubs.rsc.org/en/content/articlelanding/2020/EN/D0EN00240B},

year  = {2020},

date = {2020-06-08},

journal = {Environmental Science: Nano},

issue = {8},

abstract = {Transformation of nutrients to their nano-form, such as selenium (Se) engineered nanonutrients (Se-ENNs), is expected to enhance the absorption of the nutrients into fish and increase the efficiency of the feed. However, dissolution, aggregation, and release of ENNs from the feed matrix may decrease the efficiency of the Se-ENNs. In this study, we provided fish feed supplemented with Se-ENNs which do not aggregate or dissolve and the particles are also not released from the feed matrix. As a proof of principle, we compared the toxicity of a diet containing Se-ENNs of two different sizes (60 nm and 120 nm) with diets containing ionic Se. The adverse effects were measured by monitoring the survival rate, acetylcholinesterase (AChE) levels and swimming behavior of zebrafish over 21 days of feeding with either the Se-ENNs or ionic Se supplemented fish diets. The number size distribution of the 60 nm Se-ENNs in the diet was similar to that in MilliQ water, while the size distribution of the 120 nm Se-ENNs in the diet was slightly wider. Ion and particle release from Se-ENNs containing diets in the exposure media was not observed, indicating the stability of the particles in the feed matrices. To determine toxicity, zebrafish (Danio rerio) were nourished using a control diet (without Se and Se-ENNs), Se (sodium selenite) containing diets (with 2.4 or 240 mg Se per kg feed) and Se-ENNs containing diets (with 2.4 or 240 mg Se-ENNs of 60 or 120 nm per kg feed) for 21 days. Both sizes of Se-ENNs were taken up in the fish, however only the 120 nm Se-ENNs were detected in the brains of fish. Zebrafish fed with Se-ENNs supplemented diets (60 and 120 nm) showed normal swimming behavior compared to the control. No significant alteration was determined in the AChE activity of the fish fed with the Se-ENNs supplemented diet. In contrast, feeding the zebrafish with a diet containing 240 mg kg−1 Se led to lethal effects. These observations clearly depict the potential benefits of using Se-ENNs as nutrients in fish feed.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32224413b,

title = {Food waste composting - Is it really so simple as stated in scientific literature? - A case study},

author = {Stanislava Voběrková and Alžbeta Maxianová and Nikola Schlosserová and Dana Adamcová and Martina Vršanská and Lukáš Richtera and Milica Gagić and Jan Zloch and Magdalena Daria Vaverková},

doi = {10.1016/j.scitotenv.2020.138202},

issn = {1879-1026},

year  = {2020},

date = {2020-06-01},

journal = {Sci Total Environ},

volume = {723},

pages = {138202},

abstract = {Food waste has recently gained much worldwide interest due to its influence on the environment, economy and society. Gathering and recycling of food waste is the essential issue in the waste management and the interest in processing food waste arises mainly out of influence of the processes of food putrefaction on the environment. Composting of food waste encounters a number of technical challenges, arising weak physical structure of food waste with weak porosity, high content of water, low carbon-to-nitrogen relation and fast hydrolysis and accumulation of organic acids during composting. Therefore, the aim of this study was to investigate the challenges facing installations intended for food waste composting, with the purpose to their optimization with use of appropriate additives. Physico-chemical, biochemical characteristics and phytotoxicity of the produced compost has been measured. Two additives (20% biochar and 20% sawdust) were chosen from experimental variants I-XII containing different additives (biochar, Devonian sand, sawdust) in diverse concentration. The use of selected additives seems to slightly increase potential of hydrogen value and carbon-to-nitrogen ratio, while decreasing electrical conductivity in comparison with control sample. The results obtained also show that the addition of biochar leads to an increase dehydrogenase, phosphatase and arylsulphatase activities and addition of sawdust has a positive effect on beta-D-glucosidase, protease, phosphatase and arylsulphatase activities. The phytotoxicity test shows that the compost made of food waste (control sample) and with addition of biochar is toxic to plants. By contrast, the addition of sawdust shows that the compost was not phytotoxic. In conclusion, the addition of additives does not provide unambiguous results in terms of the quality of the final product in all monitored parameters. Therefore, we can state that food waste was reduced and hygienized, and that the final product does not meet conditions for mature compost.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32307169,

title = {Molecularly imprinted polymers and capillary electrophoresis for sensing phytoestrogens in milk},

author = {Jaroslava Bezdekova and Marcela Vlcnovska and Kristyna Zemankova and Romana Bacova and Martina Kolackova and Tomas Lednicky and Jan Pribyl and Lukas Richtera and Lucie Vanickova and Vojtech Adam and Marketa Vaculovicova},

doi = {10.3168/jds.2019-17367},

issn = {1525-3198},

year  = {2020},

date = {2020-06-01},

journal = {J Dairy Sci},

volume = {103},

number = {6},

pages = {4941--4950},

abstract = {Dairy cow feed contains, among other ingredients, soybeans, legumes, and clover, plants that are rich in phytoestrogens. Several publications have reported a positive influence of phytoestrogens on human health; however, several unfavorable effects have also been reported. In this work, a simple, selective, and eco-friendly method of phytoestrogen isolation based on the technique of noncovalent molecular imprinting was developed. Genistein was used as a template, and dopamine was chosen as a functional monomer. A layer of molecularly imprinted polymers was created in a microtitration well plate. The binding capability and selective properties of obtained molecularly imprinted polymers were investigated. The imprinted polymers exhibited higher binding affinity toward chosen phytoestrogen than did the nonimprinted polymers. A selectivity factor of 6.94 was calculated, confirming satisfactory selectivity of the polymeric layer. The applicability of the proposed sensing method was tested by isolation of genistein from a real sample of bovine milk and combined with micellar electrokinetic capillary chromatography with UV-visible detection.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32224413,

title = {Food waste composting - Is it really so simple as stated in scientific literature? - A case study},

author = {Stanislava Voběrková and Alžbeta Maxianová and Nikola Schlosserová and Dana Adamcová and Martina Vršanská and Lukáš Richtera and Milica Gagić and Jan Zloch and Magdalena Daria Vaverková},

doi = {10.1016/j.scitotenv.2020.138202},

issn = {1879-1026},

year  = {2020},

date = {2020-06-01},

journal = {Sci Total Environ},

volume = {723},

pages = {138202},

abstract = {Food waste has recently gained much worldwide interest due to its influence on the environment, economy and society. Gathering and recycling of food waste is the essential issue in the waste management and the interest in processing food waste arises mainly out of influence of the processes of food putrefaction on the environment. Composting of food waste encounters a number of technical challenges, arising weak physical structure of food waste with weak porosity, high content of water, low carbon-to-nitrogen relation and fast hydrolysis and accumulation of organic acids during composting. Therefore, the aim of this study was to investigate the challenges facing installations intended for food waste composting, with the purpose to their optimization with use of appropriate additives. Physico-chemical, biochemical characteristics and phytotoxicity of the produced compost has been measured. Two additives (20% biochar and 20% sawdust) were chosen from experimental variants I-XII containing different additives (biochar, Devonian sand, sawdust) in diverse concentration. The use of selected additives seems to slightly increase potential of hydrogen value and carbon-to-nitrogen ratio, while decreasing electrical conductivity in comparison with control sample. The results obtained also show that the addition of biochar leads to an increase dehydrogenase, phosphatase and arylsulphatase activities and addition of sawdust has a positive effect on beta-D-glucosidase, protease, phosphatase and arylsulphatase activities. The phytotoxicity test shows that the compost made of food waste (control sample) and with addition of biochar is toxic to plants. By contrast, the addition of sawdust shows that the compost was not phytotoxic. In conclusion, the addition of additives does not provide unambiguous results in terms of the quality of the final product in all monitored parameters. Therefore, we can state that food waste was reduced and hygienized, and that the final product does not meet conditions for mature compost.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32113552,

title = {Fully automated process for histamine detection based on magnetic separation and fluorescence detection},

author = {Milica Gagic and Lukas Nejdl and Kledi Xhaxhiu and Natalia Cernei and Ondrej Zitka and Ewelina Jamroz and Pavel Svec and Lukas Richtera and Pavel Kopel and Vedran Milosavljevic and Vojtech Adam},

doi = {10.1016/j.talanta.2020.120789},

issn = {1873-3573},

year  = {2020},

date = {2020-05-01},

journal = {Talanta},

volume = {212},

pages = {120789},

abstract = {To ensure food safety and to prevent unnecessary foodborne complications this study reports fast, fully automated process for histamine determination. This method is based on magnetic separation of histamine with magnetic particles and quantification by the fluorescence intensity change of MSA modified CdSe Quantum dots. Formation of FeO particles was followed by adsorption of TiO on their surface. Magnetism of developed probe enabled rapid histamine isolation prior to its fluorescence detection. Quantum dots (QDs) of approx. 3 nm were prepared via facile UV irradiation. The fluorescence intensity of CdSe QDs was enhanced upon mixing with magnetically separated histamine, in concentration-dependent manner, with a detection limit of 1.6 μM. The linear calibration curve ranged between 0.07 and 4.5 mM histamine with a low LOD and LOQ of 1.6 μM and 6 μM. The detection efficiency of the method was confirmed by ion exchange chromatography. Moreover, the specificity of the sensor was evaluated and no cross-reactivity from nontarget analytes was observed. This method was successfully applied for the direct analysis of histamine in white wine providing detection limit much lower than the histamine maximum levels established by EU regulation in food samples. The recovery rate was excellent, ranging from 84 to 100% with an RSD of less than 4.0%. The main advantage of the proposed method is full automation of the analytical procedure that reduces the time and cost of the analysis, solvent consumption and sample manipulation, enabling routine analysis of large numbers of samples for histamine and highly accurate and precise results.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Highly sensitive simultaneous electrochemical determination of reduced and oxidized glutathione in urine samples using antimony trioxide modified carbon paste electrode},

author = {Zorica S. Stojanović and Ana D. Đurović and Amir M. Ashrafi and Zuzana Koudelková and Ondřej Zítka and Lukáš Richtera

},

doi = {https://doi.org/10.1016/j.snb.2020.128141},

issn = {0925-4005},

year  = {2020},

date = {2020-04-22},

journal = {Sensors and Actuators B: Chemical},

volume = {318},

abstract = {A simple and reproducible electroanalytical sensor using antimony trioxide modified-carbon paste electrode (Sb2O3–CPE) as sensing element was employed for the first time for simultaneous determination of glutathione (GSH) and glutathione disulphide (GSSG). The electrochemical response of Sb2O3–CPE was characterized by cyclic voltammetry and square-wave voltammetry. Scanning electron microscopy (SEM), scanning electrochemical microscopy (SECM) and Raman mapping were used to characterize the morphology and surface modification. A significant enhancement in the peak current response of GSH and GSSG accompanied with a good separation of the peaks were obtained at the modified electrode compared to the bare CPE. GSH and GSSG exhibited well-defined oxidation peaks at +1.08 V and +1.36 V (vs. Ag/AgCl, 3 mol/L) in Britton-Robinson buffer at pH 6.0. Parameters such as used supporting electrolyte and its pH value, amplitude and frequency were optimized for square-wave voltammetric determination. Under optimal conditions, voltammetric responses were linear in the concentration range of 2–200 μmol/L for GSH and GSSG. The limits of detection were 0.34 μmol/L and 0.10 μmol/L for GSH and GSSG, respectively. Moreover, the proposed sensor also showed good reproducibility, stability and selectivity. Finally, the proposed sensor was applied for the simultaneous determination of GSH and GSSG in urine samples with satisfactory results.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Determination of Trolox Equivalent Antioxidant Capacity in Berries Using Amperometric Tyrosinase Biosensor Based on Multi-Walled Carbon Nanotubes},

author = {Frangu, A. and Ashrafi, AM and Sýs, M. and Arbneshi, T. and Metelka, R. and Adam, V. and Vlček, M. and Richtera, L.},

doi = {https://doi.org/10.3390/app10072497},

year  = {2020},

date = {2020-04-05},

journal = {MDPI Applied Sciences},

volume = {10},

issue = {7},

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.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32316666,

title = {A Novel Biocompatible Titanium-Gadolinium Quantum Dot as a Bacterial Detecting Agent with High Antibacterial Activity},

author = {Vishma Pratap Sur and Aninda Mazumdar and Amirmansoor Ashrafi and Atripan Mukherjee and Vedran Milosavljevic and Hana Michalkova and Pavel Kopel and Lukáš Richtera and Amitava Moulick},

doi = {10.3390/nano10040778},

issn = {2079-4991},

year  = {2020},

date = {2020-04-01},

journal = {Nanomaterials (Basel)},

volume = {10},

number = {4},

abstract = { In this study, the titanium-gadolinium quantum dots (TGQDs) were novel, first of its type to be synthesized, and fully characterized to date. Multiple physical characterization includes scanning electron microscopy (SEM), scanning electrochemical microscope (SCEM), x-ray fluorescence, spectrophotometry, and dynamic light scattering were carried out. The obtained results confirmed appropriate size and shape distributions in addition to processing optical features with high quantum yield. The synthesized TGQD was used as a fluorescent dye for bacterial detection and imaging by fluorescent microscopy and spectrophotometry, where TGQD stained only bacterial cells, but not human cells. The significant antibacterial activities of the TGQDs were found against a highly pathogenic bacterium () and its antibiotic resistant strains (vancomycin and methicillin resistant ) using growth curve analysis and determination of minimum inhibitory concentration (MIC) analysis. Live/dead cell imaging assay using phase-contrast microscope was performed for further confirmation of the antibacterial activity. Cell wall disruption and release of cell content was observed to be the prime mode of action with the reduction of cellular oxygen demand (OD).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32290102,

title = {An Investigation on the Electrochemical Behavior and Antibacterial and Cytotoxic Activity of Nickel Trithiocyanurate Complexes},

author = {Amir M Ashrafi and Pavel Kopel and Lukas Richtera},

doi = {10.3390/ma13071782},

issn = {1996-1944},

year  = {2020},

date = {2020-04-01},

journal = {Materials (Basel)},

volume = {13},

number = {7},

abstract = {The electrochemical redox behavior of three trinuclear Ni(II) complexes [Ni(abb)(HO)(µ-ttc)](ClO) (), [Ni(tebb)(HO)(µ-ttc)](ClO)·HO (), and [Ni(pmdien)(µ-ttc)](ClO) (), where abb = 1-(1H-benzimidazol-2-yl)-N-(1H-benzimidazol-2-ylmethyl)methan-amine, ttcH = trithiocyanuric acid, tebb = 2-[2-[2-(1H-benzimidazol-2-yl)ethylsulfanyl]ethyl]-1H-benzimidazole, and pmdien = N,N,N',N″,N″-pentamethyldiethylenetriamine is reported. Cyclic voltammetry (CV) was applied for the study of the electrochemical behavior of these compounds. The results confirmed the presence of ttc and nickel in oxidation state +2 in the synthesized complexes. Moreover, the antibacterial properties and cytotoxic activity of complex  was investigated. All the complexes show antibacterial activity against  and  to different extents. The cytotoxic activity of complex  and ttcNa were studied on G-361, HOS, K-562, and MCF7 cancer cell lines. It was found out that complex  possesses the cytotoxic activity against the tested cell lines, whereas ttcNa did not show any cytotoxic activity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32294961,

title = {Integrated Electrochemical Biosensors for Detection of Waterborne Pathogens in Low-Resource Settings},

author = {Joshua Rainbow and Eliska Sedlackova and Shu Jiang and Grace Maxted and Despina Moschou and Lukas Richtera and Pedro Estrela},

doi = {10.3390/bios10040036},

issn = {2079-6374},

year  = {2020},

date = {2020-04-01},

journal = {Biosensors (Basel)},

volume = {10},

number = {4},

abstract = {More than 783 million people worldwide are currently without access to clean and safe water. Approximately 1 in 5 cases of mortality due to waterborne diseases involve children, and over 1.5 million cases of waterborne disease occur every year. In the developing world, this makes waterborne diseases the second highest cause of mortality. Such cases of waterborne disease are thought to be caused by poor sanitation, water infrastructure, public knowledge, and lack of suitable water monitoring systems. Conventional laboratory-based techniques are inadequate for effective on-site water quality monitoring purposes. This is due to their need for excessive equipment, operational complexity, lack of affordability, and long sample collection to data analysis times. In this review, we discuss the conventional techniques used in modern-day water quality testing. We discuss the future challenges of water quality testing in the developing world and how conventional techniques fall short of these challenges. Finally, we discuss the development of electrochemical biosensors and current research on the integration of these devices with microfluidic components to develop truly integrated, portable, simple to use and cost-effective devices for use by local environmental agencies, NGOs, and local communities in low-resource settings.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32316666b,

title = {A Novel Biocompatible Titanium-Gadolinium Quantum Dot as a Bacterial Detecting Agent with High Antibacterial Activity},

author = {Vishma Pratap Sur and Aninda Mazumdar and Amirmansoor Ashrafi and Atripan Mukherjee and Vedran Milosavljevic and Hana Michalkova and Pavel Kopel and Lukáš Richtera and Amitava Moulick},

doi = {10.3390/nano10040778},

issn = {2079-4991},

year  = {2020},

date = {2020-04-01},

journal = {Nanomaterials (Basel)},

volume = {10},

number = {4},

abstract = { In this study, the titanium-gadolinium quantum dots (TGQDs) were novel, first of its type to be synthesized, and fully characterized to date. Multiple physical characterization includes scanning electron microscopy (SEM), scanning electrochemical microscope (SCEM), x-ray fluorescence, spectrophotometry, and dynamic light scattering were carried out. The obtained results confirmed appropriate size and shape distributions in addition to processing optical features with high quantum yield. The synthesized TGQD was used as a fluorescent dye for bacterial detection and imaging by fluorescent microscopy and spectrophotometry, where TGQD stained only bacterial cells, but not human cells. The significant antibacterial activities of the TGQDs were found against a highly pathogenic bacterium () and its antibiotic resistant strains (vancomycin and methicillin resistant ) using growth curve analysis and determination of minimum inhibitory concentration (MIC) analysis. Live/dead cell imaging assay using phase-contrast microscope was performed for further confirmation of the antibacterial activity. Cell wall disruption and release of cell content was observed to be the prime mode of action with the reduction of cellular oxygen demand (OD).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32290291,

title = {A Novel Ruthenium Based Coordination Compound Against Pathogenic Bacteria},

author = {Vishma Pratap Sur and Aninda Mazumdar and Pavel Kopel and Soumajit Mukherjee and Petr Vítek and Hana Michalkova and Markéta Vaculovičová and Amitava Moulick},

doi = {10.3390/ijms21072656},

issn = {1422-0067},

year  = {2020},

date = {2020-04-01},

journal = {Int J Mol Sci},

volume = {21},

number = {7},

abstract = {The current epidemic of antibiotic-resistant infections urges to develop alternatives to less-effective antibiotics. To assess anti-bacterial potential, a novel coordinate compound (RU-S4) was synthesized using ruthenium-Schiff base-benzimidazole ligand, where ruthenium chloride was used as the central atom. RU-S4 was characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Antibacterial effect of RU-S4 was studied against  (NCTC 8511), vancomycin-resistant  (VRSA) (CCM 1767), methicillin-resistant  (MRSA) (ST239: SCCmecIIIA), and hospital isolate . The antibacterial activity of RU-S4 was checked by growth curve analysis and the outcome was supported by optical microscopy imaging and fluorescence LIVE/DEAD cell imaging. In vivo (balb/c mice) infection model prepared with VRSA (CCM 1767) and treated with RU-S4. In our experimental conditions, all infected mice were cured. The interaction of coordination compound with bacterial cells were further confirmed by cryo-scanning electron microscope (Cryo-SEM). RU-S4 was completely non-toxic against mammalian cells and in mice and subsequently treated with synthesized RU-S4.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32075033,

title = {Peptide-Carbon Quantum Dots conjugate, Derived from Human Retinoic Acid Receptor Responder Protein 2, against Antibiotic-Resistant Gram Positive and Gram Negative Pathogenic Bacteria},

author = {Aninda Mazumdar and Yazan Haddad and Vedran Milosavljevic and Hana Michalkova and Roman Guran and Sukanya Bhowmick and Amitava Moulick},

doi = {10.3390/nano10020325},

issn = {2079-4991},

year  = {2020},

date = {2020-02-01},

journal = {Nanomaterials (Basel)},

volume = {10},

number = {2},

abstract = {Antibiotic-resistant bacterial infections have become global issues for public health, which increases the utter need to develop alternatives to antibiotics. Here, the HSER ( retinoic acid receptor) peptide was designed from retinoic acid receptor responder protein 2 of  and was conjugated with synthesized CQDs (carbon quantum dots) for enhanced antibacterial activity in combination, as individually they are not highly effective. The HSER-CQDs were characterized using spectrophotometer, HPLC coupled with electrospray-ionization quadrupole time-of-flight mass spectrometer (ESI-qTOF) mass spectrometer, zeta potential, zeta size, and FTIR. Thereafter, the antibacterial activity against Vancomycin-Resistant  (VRSA) and  (carbapenem resistant) was studied using growth curve analysis, further supported by microscopic images showing the presence of cell debris and dead bacterial cells. The antibacterial mechanism of HSER-CQDs was observed to be via cell wall disruption and also interaction with gDNA (genomic DNA). Finally, toxicity test against normal human epithelial cells showed no toxicity, confirmed by microscopic analysis. Thus, the HSER-CQDs conjugate, having high stability and low toxicity with prominent antibacterial activity, can be used as a potential antibacterial agent.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31954312,

title = {Complex cytotoxicity mechanism of bundles formed from self-organised 1-D anodic TiO nanotubes layers},

author = {Hana Michalkova and Zuzana Skubalova and Hanna Sopha and Vladislav Strmiska and Barbora Tesarova and Simona Dostalova and Pavel Svec and Ludek Hromadko and Martin Motola and Jan M Macak and Vojtech Adam and Zbynek Heger},

doi = {10.1016/j.jhazmat.2020.122054},

issn = {1873-3336},

year  = {2020},

date = {2020-01-01},

journal = {J Hazard Mater},

volume = {388},

pages = {122054},

abstract = {The present study reports on a comprehensive investigation of mechanisms of in vitro cytotoxicity of high aspect ratio (HAR) bundles formed from anodic TiO nanotube (TNT) layers. Comparative cytotoxicity studies were performed using two types of HAR TNTs (diameter of ∼110 nm), differing in initial thickness of the nanotubular layer (∼35 μm for TNTs-1 vs. ∼10 μm for TNTs-2). Using two types of epithelial cell lines (MDA-MB-231, HEK-293), it was found that nanotoxicity is highly cell-type dependent and plausibly associates with higher membrane fluidity and decreased rigidity of cancer cells enabling penetration of TNTs to the cell membrane towards disruption of membrane integrity and reorganization of cytoskeletal network. Upon penetration, TNTs dysregulated redox homeostasis followed by DNA fragmentation and apoptotic/necrotic cell death. Both TNTs exhibited haemolytic activity and rapidly activated polarization of RAW 264.7 macrophages. Throughout the whole study, TNTs-2 possessing a lower aspect ratio manifested significantly higher cytotoxic effects. Taken together, this is the first report comprehensively investigating the mechanisms underlying the nanotoxicity of bundles formed from self-organised 1-D anodic TNT layers. Except for description of nanotoxicity of industrially-interesting nanomaterials, the delineation of the nanotoxicity paradigm in cancer cells could serve as solid basis for future efforts in rational engineering of TNTs towards selective anticancer nanomedicine.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31954312b,

title = {Complex cytotoxicity mechanism of bundles formed from self-organised 1-D anodic TiO nanotubes layers},

author = {Hana Michalkova and Zuzana Skubalova and Hanna Sopha and Vladislav Strmiska and Barbora Tesarova and Simona Dostalova and Pavel Svec and Ludek Hromadko and Martin Motola and Jan M Macak and Vojtech Adam and Zbynek Heger},

doi = {10.1016/j.jhazmat.2020.122054},

issn = {1873-3336},

year  = {2020},

date = {2020-01-01},

journal = {J Hazard Mater},

volume = {388},

pages = {122054},

abstract = {The present study reports on a comprehensive investigation of mechanisms of in vitro cytotoxicity of high aspect ratio (HAR) bundles formed from anodic TiO nanotube (TNT) layers. Comparative cytotoxicity studies were performed using two types of HAR TNTs (diameter of ∼110 nm), differing in initial thickness of the nanotubular layer (∼35 μm for TNTs-1 vs. ∼10 μm for TNTs-2). Using two types of epithelial cell lines (MDA-MB-231, HEK-293), it was found that nanotoxicity is highly cell-type dependent and plausibly associates with higher membrane fluidity and decreased rigidity of cancer cells enabling penetration of TNTs to the cell membrane towards disruption of membrane integrity and reorganization of cytoskeletal network. Upon penetration, TNTs dysregulated redox homeostasis followed by DNA fragmentation and apoptotic/necrotic cell death. Both TNTs exhibited haemolytic activity and rapidly activated polarization of RAW 264.7 macrophages. Throughout the whole study, TNTs-2 possessing a lower aspect ratio manifested significantly higher cytotoxic effects. Taken together, this is the first report comprehensively investigating the mechanisms underlying the nanotoxicity of bundles formed from self-organised 1-D anodic TNT layers. Except for description of nanotoxicity of industrially-interesting nanomaterials, the delineation of the nanotoxicity paradigm in cancer cells could serve as solid basis for future efforts in rational engineering of TNTs towards selective anticancer nanomedicine.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31738540b,

title = {Encapsulation of Doxorubicin in Furcellaran/Chitosan Nanocapsules by Layer-by-Layer Technique for Selectively Controlled Drug Delivery},

author = {Vedran Milosavljevic and Ewelina Jamroz and Milica Gagic and Yazan Haddad and Hana Michalkova and Radka Balkova and Barbora Tesarova and Amitava Moulick and Zbynek Heger and Lukas Richtera and Pavel Kopel and Vojtech Adam},

doi = {10.1021/acs.biomac.9b01175},

issn = {1526-4602},

year  = {2020},

date = {2020-01-01},

journal = {Biomacromolecules},

volume = {21},

number = {2},

pages = {418--434},

abstract = {Minimization of drug side effects is a hallmark of advanced targeted therapy. Herein we describe the synthesis of polysaccharide-based nanocapsules prepared from furcellaran and chitosan via layer-by-layer deposition using electrostatic interaction. Using doxorubicin as a model drug, prepared nanocapsules showed excellent drug loading properties and release influence by pH and stability. Targeted delivery of doxorubicin was achieved by nanocapsule surface modification using homing peptide (seq SMSIARLC). The synthesized nanocapsules possess excellent compatibility to eukaryotic organisms. In the case of nonmalignant cells (PNT1A and HEK-293), toxicity tests revealed the absences of DNA fragmentation, apoptosis, necrosis, and also disruption of erythrocyte membranes. In contrast, results from treatment of malignant cell lines (MDA-MB-231 and PC3) indicate good anticancer effects of synthesized bionanomaterial. Internalization studies revealed the nanocapsule's ability to enter the malignant cell lines by endocytosis and triggering the apoptosis. The occurrence of apoptosis is mostly connected to the presence of ROS and inability of DNA damage reparation. Additionally, the obtained results strongly indicate that peptide modification increases the speed of nanocapsule internalization into malignant cell lines while simultaneously nonmalignant cell lines are untouched by nanocapsules highlighting the strong selectivity of the peptide.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32983007,

title = {Characterization and  Analysis of Probiotic-Derived Peptides Against Multi Drug Resistance Bacterial Infections},

author = {Aninda Mazumdar and Yazan Haddad and Vishma Pratap Sur and Vedran Milosavljevic and Sukanya Bhowmick and Hana Michalkova and Roman Guran and Radek Vesely and Amitava Moulick},

doi = {10.3389/fmicb.2020.01963},

issn = {1664-302X},

year  = {2020},

date = {2020-01-01},

journal = {Front Microbiol},

volume = {11},

pages = {1963},

abstract = {An inexorable switch from antibiotics has become a major desideratum to overcome antibiotic resistance. Bacteriocin from , a cardinal probiotic was used to design novel antibacterial peptides named as Probiotic Bacteriocin Derived and Modified (PBDM) peptides (PBDM1: YKWFAHLIKGLC and PBDM2: YKWFRHLIKKLC). The loop-shaped 3D structure of peptides was characterized  via molecular dynamics simulation as well as biophysically via spectroscopic methods. Thereafter,  results against multidrug resistant bacterial strains and hospital samples demonstrated the strong antimicrobial activity of PBDM peptides. Further,  studies with PBDM peptides showed downright recovery of balb/c mice from Vancomycin Resistant  (VRSA) infection to its healthy condition. Thereafter,  study with human epithelial cells showed no significant cytotoxic effects with high biocompatibility and good hemocompatibility. In conclusion, PBDM peptides displayed significant antibacterial activity against certain drug resistant bacteria which cause infections in human beings. Future analysis are required to unveil its mechanism of action in order to execute it as an alternative to antibiotics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Electrochemical Determination of Vitamin D 3 in Pharmaceutical Products by Using Boron Doped Diamond Electrode},

author = {Djurovic, Ana and Stojanovic, Zorica and Kravić, Snežana and Kos, Jovana and Richtera, Lukáš},

doi = {https://doi.org/10.1002/elan.201900532},

issn = {1521-4109},

year  = {2019},

date = {2019-12-11},

urldate = {2019-12-11},

journal = {Electroanalysis},

abstract = {A sensitive square‐wave voltammetry method was developed to determine cholecalciferol (vitamin D3) in pharmaceutical products at boron‐doped diamond electrode as a working electrode. Vitamin D3 provided a well‐defined voltammetric peak at around +1.00 V (vs. Ag/AgCl, 3.5 mol dm−3) in 0.02 mol dm−3 Britton‐Robinson buffer pH 5.0 prepared in 50 % ethanol. The influence of various factors such as type and pH of the supporting electrolyte, scan rate and square‐wave parameters were studied and optimized. Under optimum conditions, the oxidation peak current increased linearly with the concentration of vitamin D3 over the range of 2 to 200 μmol dm−3. The calculated limit of detection and limit of quantitation were 0.17 μmol dm−3 and 0.51 μmol dm−3, respectively. The boron‐doped diamond electrode exhibited specific recognition capability for cholecalciferol amongst possible interferences, and the determination of vitamin D3 was possible in samples such as commercial pharmaceutical products without complicated sample pretreatments.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31835441,

title = {Nanocomposite Furcellaran Films-the Influence of Nanofillers on Functional Properties of Furcellaran Films and Effect on Linseed Oil Preservation},

author = {Ewelina Jamróz and Pavel Kopel and Joanna Tkaczewska and Dani Dordevic and Simona Jancikova and Piotr Kulawik and Vedran Milosavljevic and Kristyna Dolezelikova and Kristyna Smerkova and Pavel Svec and Vojtech Adam},

doi = {10.3390/polym11122046},

issn = {2073-4360},

year  = {2019},

date = {2019-12-01},

journal = {Polymers (Basel)},

volume = {11},

number = {12},

abstract = {Nanocomposite films that were based on furcellaran (FUR) and nanofillers (carbon quantum dots (CQDs), maghemite nanoparticles (MAN), and graphene oxide (GO)) were obtained by the casting method. The microstructure, as well as the structural, physical, mechanical, antimicrobial, and antioxidant properties of the films was investigated. The incorporation of MAN and GO remarkably increased the tensile strength of furcellaran films. However, the water content, solubility, and elongation at break were significantly reduced by the addition of the nanofillers. Moreover, furcellaran films containing the nanofillers exhibited potent free radical scavenging ability. FUR films with CQDs showed an inhibitory effect on the growth of  and . The nanocomposite films were used to cover transparent glass containers to study the potential UV-blocking properties in an oil oxidation test and compare with tinted glass. The samples were irradiated for 30 min. with UV-B and then analyzed for oxidation markers (peroxide value, free fatty acids, malondialdehyde content, and degradation of carotenoids). The test showed that covering the transparent glass with MAN films was as effective in inhibiting the oxidation as the use of tinted glass, while the GO and CQDs films did not inhibit oxidation. It can be concluded that the active nanocomposite films can be used as a desirable material for food packaging.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31835441b,

title = {Nanocomposite Furcellaran Films-the Influence of Nanofillers on Functional Properties of Furcellaran Films and Effect on Linseed Oil Preservation},

author = {Ewelina Jamróz and Pavel Kopel and Joanna Tkaczewska and Dani Dordevic and Simona Jancikova and Piotr Kulawik and Vedran Milosavljevic and Kristyna Dolezelikova and Kristyna Smerkova and Pavel Svec and Vojtech Adam},

doi = {10.3390/polym11122046},

issn = {2073-4360},

year  = {2019},

date = {2019-12-01},

journal = {Polymers (Basel)},

volume = {11},

number = {12},

abstract = {Nanocomposite films that were based on furcellaran (FUR) and nanofillers (carbon quantum dots (CQDs), maghemite nanoparticles (MAN), and graphene oxide (GO)) were obtained by the casting method. The microstructure, as well as the structural, physical, mechanical, antimicrobial, and antioxidant properties of the films was investigated. The incorporation of MAN and GO remarkably increased the tensile strength of furcellaran films. However, the water content, solubility, and elongation at break were significantly reduced by the addition of the nanofillers. Moreover, furcellaran films containing the nanofillers exhibited potent free radical scavenging ability. FUR films with CQDs showed an inhibitory effect on the growth of  and . The nanocomposite films were used to cover transparent glass containers to study the potential UV-blocking properties in an oil oxidation test and compare with tinted glass. The samples were irradiated for 30 min. with UV-B and then analyzed for oxidation markers (peroxide value, free fatty acids, malondialdehyde content, and degradation of carotenoids). The test showed that covering the transparent glass with MAN films was as effective in inhibiting the oxidation as the use of tinted glass, while the GO and CQDs films did not inhibit oxidation. It can be concluded that the active nanocomposite films can be used as a desirable material for food packaging.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31450441,

title = {One-step detection of human papilloma viral infection using quantum dot-nucleotide interaction specificity},

author = {Ana Maria Jimenez Jimenez and Amitava Moulick and Sukanya Bhowmick and Vladislav Strmiska and Milica Gagic and Zuzana Horakova and Rom Kostrica and Michal Masarik and Zbynek Heger and Vojtech Adam},

doi = {10.1016/j.talanta.2019.07.006},

issn = {1873-3573},

year  = {2019},

date = {2019-12-01},

journal = {Talanta},

volume = {205},

pages = {120111},

abstract = {Due to the close relationship between carcinogenesis and human papillomavirus (HPV), and since they are transmitted via huge number of asymptomatic carriers, the detection of HPV is really needed to reduce the risk of developing cancer. According to the best of our knowledge, our study provides the very first method for one-step detection of viral infection and if it has initiated the subsequent cancer proliferation. The proposed novel nanosystem consists of magnetic glass particles (MGPs), which were attached with DNA probe on their surface to hybridize with target DNAs. The MGP-probe-DNA hybrid was finally conjugated with CdTe/ZnSe core/shell quantum dots (QDs). The proposed detection system is based on a novel mechanism in which the MGPs separate out the target DNAs from different biological samples using external magnetic field for better and clear detection and the QDs give different fluorescent maxima for different target DNAs due to their ability to interact differently with different nucleotides. Firstly, the method was optimized using HPV genes cloned into synthetic plasmids. Then it was applied directly on the samples from normal and cancerous cells. After that, the real hospital samples of head and neck squamous cell carcinoma (HNSCC) with or without the infection of HPV were also analyzed. Our novel nano-system is proved successful in detecting and distinguishing between the patients suffering by HPV infection with or without subsequent cancer having detection limit estimated as 1.0 x 10 (GEq/mL). The proposed methodology is faster and cost-effective, which can be applied at the clinical level to help the doctors to decide the strategy of medication that may save the life of the patients with an early treatment.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Intelligent and active composite films based on furcellaran: Structural characterization, antioxidant and antimicrobial activities},

author = {Ewelina Jamróz and Piotr Kulawik and Pavel Kopel and Radka Balková and David Hynek and Zuzana Bytesnikova and Milica Gagic and Vedran Milosavljevic, Vojtech Adam

},

doi = {https://doi.org/10.1016/j.fpsl.2019.100405},

issn = {2214-2894},

year  = {2019},

date = {2019-10-05},

journal = {Food Packaging and Shelf Life},

volume = {22},

abstract = {Intelligent and active films were prepared using furcellaran (FUR). The FUR films were modified with various antibacterial material including natural extracts from green tea (GTE) and yerba mate (YM) and synthetized selenium (SeNPs) and zinc oxide (ZnONPs) nanoparticles. The bionanocomposite films were characterized by X-ray diffraction, SEM, TGA and UV–vis spectroscopy. The structural characteristics confirmed successfully formation of FUR films in the presence of tea extracts and NPs. SEM analysis showed smooth and compact surface morphology for FUR, YM and GTE films. Structure of composite films with NPs becomes less homogeneous, with some aggregations or agglomerates of NPs. The addition of both NPs into the films increases their thermal stability, while the incorporation of ZnONPs and YM increased UV-light barrier properties. Films presented different physical properties depending on the composition of the active compounds. The addition of ZnONPs caused the reduction in solubility of prepared films. On the other side, FUR films with the tea extracts show great antioxidant activity based on the ABTS test (inhibition of 37.3% for YM films and of 67.6% for GTE films). However, the FUR films with SeNPs had the highest antimicrobial activity against S. aureus, MRSA and E.coli, with inhibition zone diameters of 21.8 mm, 26.6 mm and 26.7 mm, respectively. The carp spoilage test was done to evaluate possible application of the films as intelligent packages, and color change indicated the film could be used as a sensor in the food industry. The results indicate that composite films based on FUR can be used as smart packaging showing good antioxidant and antimicrobial properties for food packaging applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31115815,

title = {Graphene oxide as a tool for antibiotic-resistant gene removal: a review},

author = {Zuzana Bytesnikova and Lukas Richtera and Kristyna Smerkova and Vojtech Adam},

doi = {10.1007/s11356-019-05283-y},

issn = {1614-7499},

year  = {2019},

date = {2019-07-01},

journal = {Environ Sci Pollut Res Int},

volume = {26},

number = {20},

pages = {20148--20163},

abstract = {Environmental pollutants, including antibiotics (ATBs), have become an increasingly common health hazard in the last several decades. Overdose and abuse of ATBs led to the emergence of antibiotic-resistant genes (ARGs), which represent a serious health threat. Moreover, water bodies and reservoirs are places where a wide range of bacterial species with ARGs originate, owing to the strong selective pressure from presence of ATB residues. In this regard, graphene oxide (GO) has been utilised in several fields including remediation of the environment. In this review, we present a brief overview of resistant genes of frequently used ATBs, their occurrence in the environment and their behaviour. Further, we discussed the factors influencing the binding of nucleic acids and the response of ARGs to GO, including the presence of salts in the water environment or water pH, because of intrinsic properties of GO of not only binding to nucleic acids but also catalysing their decomposition. This would be helpful in designing new types of water treatment facilities.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31277338,

title = {Application of the Enzymatic Electrochemical Biosensors for Monitoring Non-Competitive Inhibition of Enzyme Activity by Heavy Metals},

author = {Amir M Ashrafi and Milan Sýs and Eliška Sedláčková and Amir Shaaban Farag and Vojtěch Adam and Jan Přibyl and Lukáš Richtera},

doi = {10.3390/s19132939},

issn = {1424-8220},

year  = {2019},

date = {2019-07-01},

journal = {Sensors (Basel)},

volume = {19},

number = {13},

abstract = {The inhibition effect of the selected heavy metals (Ag, Cd, Cu, and Hg) on glucose oxidase (GOx) enzyme from   (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.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31200496,

title = {Preparation and Characterization of Carbon Paste Electrode Bulk-Modified with Multiwalled Carbon Nanotubes and Its Application in a Sensitive Assay of Antihyperlipidemic Simvastatin in Biological Samples},

author = {Amir M Ashrafi and Lukáš Richtera},

doi = {10.3390/molecules24122215},

issn = {1420-3049},

year  = {2019},

date = {2019-06-01},

journal = {Molecules},

volume = {24},

number = {12},

abstract = {Determination of an antihyperlipidemic drug simvastatin (SIM) was carried out using a carbon paste electrode bulk-modified with multiwalled carbon nanotubes (MWCNT-CPE). Scanning electrochemical microscopy (SECM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used for the characterization of the prepared electrodes. Different electrodes were prepared varying in mass percentage of MWCNTs to find out the optimum amount of MWCNTs in the paste. The MWCNT-CPE in which the mass percentage of MWCNTs was 25% () was found as the optimum. Then, the prepared electrode was used in a mechanistic study and sensitive assay of SIM in pharmaceutical dosage form and a spiked human plasma sample using differential pulse voltammetry (DPV). The prepared electrode shows better sensitivity compared to the bare carbon paste and glassy carbon electrode (GCE). The detection limit and the limit of quantification were calculated to be 2.4 × 10 and 8 × 10, respectively. The reproducibility of the electrode was confirmed by the low value of the relative standard deviation (RSD% = 4.8%) when eight measurements of the same sample were carried out. Determination of SIM in pharmaceutical dosage form was successfully performed with a bias of 0.3% and relative recovery rate of 99.7%. Furthermore, the human plasma as a more complicated matrix was spiked with a known concentration of SIM and the spiking recovery rate was determined with the developed method to be 99.5%.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Development of furcellaran-gelatin films with Se-AgNPs as an active packaging system for extension of mini kiwi shelf life},

author = {Ewelina Jamróz and Pavel Kopel and Lesław Juszczak and Agnieszka Kawecka and Zuzana Bytesnikova and Vedran Milosavljevic and Małgorzata Makarewicz

},

doi = {https://doi.org/10.1016/j.fpsl.2019.100339},

issn = {2214-2894},

year  = {2019},

date = {2019-05-30},

journal = {Food Packaging and Shelf Life},

volume = {21},

abstract = {Nanocomposite films were obtained by solvent casting method from aqueous solutions of furcellaran (FUR) and gelatin (GEL) with addition of various concentrations of nanoparticles (Se-AgNPs). The incorporation of Se-AgNPs gave rise to changes in the physical and mechanical properties of the nanocomposite films. The increase in the concentration of Se-AgNPs results in change of elasticity and elongation at break. The films with Se-AgNPs possess strong antibacterial activity against Staphylococcus aureus, Multi Resistant Staphylococcus aureus (MRSA) and Escherichia coli. This work aims to study the effect of nanocomposite films on quality of kiwi (Actinidia arguta) during storage period. Fresh kiwis in nanocomposite films had longer shelf lives than fruits in LDPE film. It follows from the study that the films are suitable for storage of kiwis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30605810,

title = {Assessment of phytotoxicity, environmental and health risks of historical urban park soils},

author = {Martin Brtnický and Václav Pecina and Jan Hladký and Maja Radziemska and Zuzana Koudelková and Martin Klimánek and Lukáš Richtera and Dana Adamcová and Jakub Elbl and Michaela Vašinová Galiová and Ludmila Baláková and Jindřich Kynický and Vendula Smolíková and Jakub Houška and Magdalena Daria Vaverková},

doi = {10.1016/j.chemosphere.2018.12.188},

issn = {1879-1298},

year  = {2019},

date = {2019-04-01},

journal = {Chemosphere},

volume = {220},

pages = {678--686},

abstract = {Urban soil areas can be contaminated with potentially dangerous heavy metals (HM), which might have got there by means of the human activity. The aim of the present study was to determine the contamination level of the city park soils and its impact on urban ecosystem. The indices assessing soil contamination such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Nemerow Pollution Index (IPI), and indices assessing health risks, namely Hazard Index (HI) and Carcinogenic Risk (CR), have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined. The soil contains in average 58.6 mg/kg Zn, 0.3 mg/kg Cd, 27.2 mg/kg Pb and 16.6 mg/kg Cu. Based on EF index, it has been confirmed that the increased amounts of Zn, Cd and Pb in the soil are of the anthropogenic origin. The soil may be classified as moderately to strongly polluted in the case of Zn and Pb according to Igeo. Nevertheless, soil contamination in the park is at a safe level as per IPI Based on HI and CR indices, it is possible to state that the soil in the park does not pose any health risks. Subject to the outcomes of the toxicity test, the concentrations of HMs found out in the soils are not inhibitory for plants.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30889907,

title = {Electrochemical Evaluation of Selenium (IV) Removal from Its Aqueous Solutions by Unmodified and Modified Graphene Oxide},

author = {Zuzana Koudelkova and Zuzana Bytesnikova and Kledi Xhaxhiu and Monika Kremplova and David Hynek and Vojtech Adam and Lukas Richtera},

doi = {10.3390/molecules24061063},

issn = {1420-3049},

year  = {2019},

date = {2019-03-01},

journal = {Molecules},

volume = {24},

number = {6},

abstract = {The removal of selenium from superficial and waste water is a worldwide problem. The maximum limit according to the World Health Organization (WHO) for the selenium in the water is set at a concentration of 10 μg/L. Carbon based adsorbents have attracted much attention and recently demonstrated promising performance in removal of selenium. In this work, several materials (iron oxide based microparticles and graphene oxides materials) and their composites were prepared to remove Se(IV) from water. The graphene oxides were prepared according to the simplified Hummer's method. In addition, the effect of pH, contact time and initial Se(IV) concentration was tested. An electrochemical method such as the differential pulse cathodic stripping voltammetry was used to determine the residual selenium concentration. From the experimental data, Langmuir adsorption model was used to calculate the maximum adsorption capacity. Graphene oxide particles modified by iron oxide based microparticles was the most promising material for the removal of Se(IV) from its aqueous solution at pH 2.0. Its adsorption efficiency reached more than 90% for a solution with given Se(IV) concentration, meanwhile its maximal recorded adsorption capacity was 18.69 mg/g.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31571866b,

title = {Tuning the surface coating of IONs toward efficient sonochemical tethering and sustained liberation of topoisomerase II poisons},

author = {Hana Michalkova and Vladislav Strmiska and Jiri Kudr and Zuzana Skubalova and Barbora Tesarova and Pavel Svec and Lukas Richtera and Ondrej Zitka and Vojtech Adam and Zbynek Heger},

doi = {10.2147/IJN.S208810},

issn = {1178-2013},

year  = {2019},

date = {2019-01-01},

journal = {Int J Nanomedicine},

volume = {14},

pages = {7609--7624},

abstract = {BACKGROUND: Iron oxide nanoparticles (IONs) have been increasingly utilized in a wide spectrum of biomedical applications. Surface coatings of IONs can bestow a number of exceptional properties, including enhanced stability of IONs, increased loading of drugs or their controlled release.



METHODS: Using two-step sonochemical protocol, IONs were surface-coated with polyoxyethylene stearate, polyvinylpyrrolidone or chitosan for a loading of two distinct topo II poisons (doxorubicin and ellipticine). The cytotoxic behavior was tested in vitro against breast cancer (MDA-MB-231) and healthy epithelial cells (HEK-293 and HBL-100). In addition, biocompatibility studies (hemotoxicity, protein corona formation, binding of third complement component) were performed.



RESULTS: Notably, despite surface-coated IONs exhibited only negligible cytotoxicity, upon tethering with topo II poisons, synergistic or additional enhancement of cytotoxicity was found in MDA-MB-231 cells. Pronounced anti-migratory activity, DNA fragmentation, decrease in expression of procaspase-3 and enhancement of p53 expression were further identified upon exposure to surface-coated IONs with tethered doxorubicin and ellipticine. Moreover, surface-coated IONs nanoformulations of topo II poisons exhibited exceptional stability in human plasma with no protein corona and complement 3 binding, and only a mild induction of hemolysis in human red blood cells.



CONCLUSION: The results imply a high potential of an efficient ultrasound-mediated surface functionalization of IONs as delivery vehicles to improve therapeutic efficiency of topo II poisons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31571866,

title = {Tuning the surface coating of IONs toward efficient sonochemical tethering and sustained liberation of topoisomerase II poisons},

author = {Hana Michalkova and Vladislav Strmiska and Jiri Kudr and Zuzana Skubalova and Barbora Tesarova and Pavel Svec and Lukas Richtera and Ondrej Zitka and Vojtech Adam and Zbynek Heger},

doi = {10.2147/IJN.S208810},

issn = {1178-2013},

year  = {2019},

date = {2019-01-01},

journal = {Int J Nanomedicine},

volume = {14},

pages = {7609--7624},

abstract = {BACKGROUND: Iron oxide nanoparticles (IONs) have been increasingly utilized in a wide spectrum of biomedical applications. Surface coatings of IONs can bestow a number of exceptional properties, including enhanced stability of IONs, increased loading of drugs or their controlled release.



METHODS: Using two-step sonochemical protocol, IONs were surface-coated with polyoxyethylene stearate, polyvinylpyrrolidone or chitosan for a loading of two distinct topo II poisons (doxorubicin and ellipticine). The cytotoxic behavior was tested in vitro against breast cancer (MDA-MB-231) and healthy epithelial cells (HEK-293 and HBL-100). In addition, biocompatibility studies (hemotoxicity, protein corona formation, binding of third complement component) were performed.



RESULTS: Notably, despite surface-coated IONs exhibited only negligible cytotoxicity, upon tethering with topo II poisons, synergistic or additional enhancement of cytotoxicity was found in MDA-MB-231 cells. Pronounced anti-migratory activity, DNA fragmentation, decrease in expression of procaspase-3 and enhancement of p53 expression were further identified upon exposure to surface-coated IONs with tethered doxorubicin and ellipticine. Moreover, surface-coated IONs nanoformulations of topo II poisons exhibited exceptional stability in human plasma with no protein corona and complement 3 binding, and only a mild induction of hemolysis in human red blood cells.



CONCLUSION: The results imply a high potential of an efficient ultrasound-mediated surface functionalization of IONs as delivery vehicles to improve therapeutic efficiency of topo II poisons.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30585064,

title = {Current Trends in Detection of Histamine in Food and Beverages},

author = {Milica Gagic and Ewelina Jamroz and Sona Krizkova and Vedran Milosavljevic and Pavel Kopel and Vojtech Adam},

doi = {10.1021/acs.jafc.8b05515},

issn = {1520-5118},

year  = {2019},

date = {2019-01-01},

journal = {J Agric Food Chem},

volume = {67},

number = {3},

pages = {773--783},

abstract = {Histamine is a heterocyclic amine formed by decarboxylation of the amino acid l-histidine. It is involved in the local regulation of physiological processes but also can occur exogenously in the food supply. Histamine is toxic at high intakes; therefore, determination of the histamine level in food is an important aspect of food safety. This article will review the current understanding of physiological functions of endogenous and ingested histamine with a particular focus placed on existing and emerging technologies for histamine quantification in food. Methods reported in this article are sequentially arranged and provide a brief overview of analytical methods reported, including those based on nanotechnologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}