Browsing by Author "Novotný, Vít"

Now showing 1 - 7 of 7
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    Glyphosate does not show higher phytotoxicity than cadmium: Cross talk and metabolic changes in common herb
    (Elsevier B.V., 2020-02-05) Kováčik Josef; Novotný, Vít; Bujdoš, Marek; Dresler, Sławomir; Hladký, Juraj; Babula, Petr
    Toxicity of glyphosate (G) alone or in combination with cadmium (Cd) was studied in Matricaria chamomilla. Cadmium accumulated in shoots and roots in relation to prolonged exposure while glyphosate and aminomethylphosphonic acid (AMPA) were detected only in roots. After 7 days of exposure, root Cd and G accumulation was similar (56 μg G or 47 μg Cd/g DW in 1 μM treatments and 330 μg G or 321 μg Cd/g DW in 10 μM treatments). Despite this fact, Cd stimulated higher ROS formation and G rather suppressed nitric oxide while H2O2 content was elevated by Cd. Subsequent assay of antioxidative enzymes (SOD, CAT, and APX) showed only the impact of Cd. Non-enzymatic antioxidants revealed more pronounced impact of Cd on ascorbic acid and soluble phenols while non-protein thiols showed synergistic effect of G and Cd in roots. Surprisingly, G alone or in combination with Cd depleted shoot citrate and tartrate accumulation despite no detectable G in shoots. In the roots, Cd evoked expected increase in malate and citrate content while G rather suppressed Cd-induced elevation. These data indicate that glyphosate is less toxic than cadmium but even low G doses are able to induce metabolic changes.
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    Impact of Various Sterilization and Disinfection Techniques on Electrospun Poly-epsilon-caprolactone
    (AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2020-04-21) Horáková, Jana; Klíčová, Markéta; Erben, Jakub; Klápšťová, Andrea; Novotný, Vít; Běhálek, Luboš; Chvojka, Jiří
    Electrospun materials made from biodegradable polycaprolactone are used widely in various tissue engineering and regenerative medicine applications because of their morphological similarity to the extracellular matrix. However, the main prerequisite for the use of such materials in clinical practice consists of the selection of the appropriate sterilization technique. This study is devoted to the study of the impact of traditional sterilization and disinfection methods on a nanofibrous polycaprolactone layer constructed by means of the needleless electrospinning technique. It was determined that hydrogen peroxide plasma treatment led to the loss of fibrous morphology and the creation of a foil. However, certain sterilization (ethylene oxide, gamma irradiation, and peracetic acid) and disinfection techniques (ethanol and UV irradiation) were found not to lead to a change in morphology; thus, the study investigates their impact on thermal properties, molecular weight, and interactions with a fibroblast cell line. It was determined that the surface properties that guide cell adhesion and proliferation were affected more than the bulk properties. The highest proliferation rate of fibroblasts seeded on nanofibrous scaffolds was observed with respect to gamma-irradiated polycaprolactone, while the lowest proliferation rate was observed following ethylene oxide sterilization.
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    Impact of Various Sterilization and Disinfection Techniques on Electrospun Poly-ϵ-caprolactone
    (American Chemical Society, 2020-01-01) Horáková, Jana; Klíčová, Markéta; Erben, Jakub; Klápšťová, Andrea; Novotný, Vít; Běhálek, Luboš; Chvojka, Jiří
    Electrospun materials made from biodegradable polycaprolactone are used widely in various tissue engineering and regenerative medicine applications because of their morphological similarity to the extracellular matrix. However, the main prerequisite for the use of such materials in clinical practice consists of the selection of the appropriate sterilization technique. This study is devoted to the study of the impact of traditional sterilization and disinfection methods on a nanofibrous polycaprolactone layer constructed by means of the needleless electrospinning technique. It was determined that hydrogen peroxide plasma treatment led to the loss of fibrous morphology and the creation of a foil. However, certain sterilization (ethylene oxide, gamma irradiation, and peracetic acid) and disinfection techniques (ethanol and UV irradiation) were found not to lead to a change in morphology; thus, the study investigates their impact on thermal properties, molecular weight, and interactions with a fibroblast cell line. It was determined that the surface properties that guide cell adhesion and proliferation were affected more than the bulk properties. The highest proliferation rate of fibroblasts seeded on nanofibrous scaffolds was observed with respect to gamma-irradiated polycaprolactone, while the lowest proliferation rate was observed following ethylene oxide sterilization.
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    Polyamide-Laccase Nanofiber Membrane for Degradation of Endocrine-Disrupting Bisphenol A, 17 alpha-ethinylestradiol, and Triclosan
    (MDPI, 2019-01-01) Maryšková, Milena; Rysová, Miroslava; Novotný, Vít; Ševců, Alena
    Contamination of potable water by endocrine disrupting chemicals (EDCs) is a growing problem worldwide. One of the possible treatments is the utilization of laccase enzyme catalyzing oxidation of phenolic structures of EDC when anchored in a polymeric nanofiber membrane. Previous studies failed to develop a membrane with a sufficiently active enzyme, or the immobilization process was too complicated and time-consuming. Here, we established an elegant method for immobilizing Trametes versicolor laccase onto polyamide 6 nanofibers (PA6-laccase) via adsorption and glutaraldehyde crosslinking, promoting high enzyme activity and easier applicability in water treatment technology. This simple and inexpensive immobilization ensures both repeated use, with over 88% of initial activity retained after five ABTS catalytic cycles, and enhanced storage stability. PA6-laccase was highly effective in degrading a 50-mu M EDC mixture, with only 7% of bisphenol A, 2% of 17 alpha-ethinylestradiol, and 30% of triclosan remaining after a 24-h catalytic process. The PA6-laccase membrane can lead to the improvement of novel technologies for controlling of EDC contamination in potable water.
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    Polyamide-laccase nanofiber membrane for degradation of endocrine-disrupting bisphenol A, 17α-ethinylestradiol, and triclosan
    (MDPI, 2019-10-01) Maryšková, Milena; Rysová, Miroslava; Novotný, Vít; Ševců, Alena
    Contamination of potable water by endocrine disrupting chemicals (EDCs) is a growing problem worldwide. One of the possible treatments is the utilization of laccase enzyme catalyzingoxidation of phenolic structures of EDC when anchored in a polymeric nanofiber membrane. Previous studies failed to develop a membrane with a suficiently active enzyme, or the immobilization process was too complicated and time-consuming. Here, we established an elegant method for immobilizing Trametes versicolor laccase onto polyamide 6 nanofibers (PA6-laccase) via adsorption and glutaraldehyde crosslinking, promoting high enzyme activity and easier applicability in water treatment technology. This simple and inexpensive immobilization ensures both repeated use, with over 88% of initial activity retained after five ABTS catalytic cycles, and enhanced storage stability. PA6-laccase was highly effective in degrading a 50-M EDC mixture, with only 7% of bisphenol A, 2% of 17α-ethinylestradiol, and 30% of triclosan remaining after a 24-h catalytic process. The PA6-laccase membrane can lead to the improvement of novel technologies for controlling of EDC contamination in potable water.
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    Wastewater Treatment by Novel Polyamide/Polyethylenimine Nanofibers with Immobilized Laccase
    (MDPI, 2020-02-24) Maryšková, Milena; Schaabová, Markéta; Tománková, Hana; Novotný, Vít; Rysová, Miroslava
    Endocrine-disrupting chemicals are highly resistant organic compounds, commonly occurring in the aquatic environment, that can interfere with the endocrine system of animals and humans, causing serious chronic diseases. In recent decades, enzymes from oxidoreductases have been studied for their potential to degrade these compounds effectively. In order to use such enzymes repeatedly, it is necessary to ensure their insolubility in water, a method termed enzyme immobilization. We developed novel polyamide/polyethylenimine (PA/PEI) nanofibers as a promising support material for the immobilization of various biomolecules. Our nanofibers are highly suitable due to a unique combination of mechanical endurance provided by polyamide 6 and their affinity toward biomolecules, ensured by numerous PEI amino groups. Enzyme laccase was successfully immobilized onto PA/PEI nanofibers using a simple and fast method, providing exceptional activity and stability of the attached enzyme. We then tested the degradation ability of the PA/PEI-laccase samples on a highly concentrated mixture of endocrine-disrupting chemicals in real wastewater with adjusted pH. The results indicate that the samples were a suitable material for wastewater treatment by degrading a highly concentrated mixture of bisphenol A, 17α-ethinylestradiol, triclosan, and diclofenac, in real wastewater effluent.