Publications by authors named "Martin Kostejn"

10 Publications

  • Page 1 of 1

Cultivation of with Feedback Regulation of Glucose Concentration Controlled by Optical Fiber Glucose Sensor.

Sensors (Basel) 2021 Jan 14;21(2). Epub 2021 Jan 14.

Faculty of Environment, Jan Evangelista Purkyně University in Ústí nad Labem, Pasteurova 3632/15, 40096 Ústí nad Labem, Czech Republic.

Glucose belongs among the most important substances in both physiology and industry. Current food and biotechnology praxis emphasizes its on-line continuous monitoring and regulation. These provoke increasing demand for systems, which enable fast detection and regulation of deviations from desired glucose concentration. We demonstrated control of glucose concentration by feedback regulation equipped with in situ optical fiber glucose sensor. The sensitive layer of the sensor comprises oxygen-dependent ruthenium complex and preimmobilized glucose oxidase both entrapped in organic-inorganic polymer ORMOCER. The sensor was placed in the laboratory bioreactor (volume 5 L) to demonstrate both regulations: the control of low levels of glucose concentrations (0.4 and 0.1 mM) and maintenance of the glucose concentration (between 2 and 3.5 mM) during stationary phase of cultivation of . Response times did not exceed 6 min (average 4 min) with average deviation of 4%. Due to these regulation characteristics together with durable and long-lasting (≥2 month) sensitive layer, this feedback regulation system might find applications in various biotechnological processes such as production of low glucose content beverages.
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http://dx.doi.org/10.3390/s21020565DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830682PMC
January 2021

Three-Year Study of Markers of Oxidative Stress in Exhaled Breath Condensate in Workers Producing Nanocomposites, Extended by Plasma and Urine Analysis in Last Two Years.

Nanomaterials (Basel) 2020 Dec 6;10(12). Epub 2020 Dec 6.

J. Heyrovský Institute of Physical Chemistry CAS, Dolejškova 3, 182 23 Prague 8, Czech Republic.

Human data concerning exposure to nanoparticles are very limited, and biomarkers for monitoring exposure are urgently needed. In a follow-up of a 2016 study in a nanocomposites plant, in which only exhaled breath condensate (EBC) was examined, eight markers of oxidative stress were analyzed in three bodily fluids, i.e., EBC, plasma and urine, in both pre-shift and post-shift samples in 2017 and 2018. Aerosol exposures were monitored. Mass concentration in 2017 was 0.351 mg/m during machining, and 0.179 and 0.217 mg/m during machining and welding, respectively, in 2018. In number concentrations, nanoparticles formed 96%, 90% and 59%, respectively. In both years, pre-shift elevations of 50.0% in EBC, 37.5% in plasma and 6.25% in urine biomarkers were observed. Post-shift elevation reached 62.5% in EBC, 68.8% in plasma and 18.8% in urine samples. The same trend was observed in all biological fluids. Individual factors were responsible for the elevation of control subjects' afternoon vs. morning markers in 2018; all were significantly lower compared to those of workers. Malondialdehyde levels were always acutely shifted, and 8-hydroxy-2-deoxyguanosine levels best showed chronic exposure effect. EBC and plasma analysis appear to be the ideal fluids for bio-monitoring of oxidative stress arising from engineered nanomaterials. Potential late effects need to be targeted and prevented, as there is a similarity of EBC findings in patients with silicosis and asbestosis.
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http://dx.doi.org/10.3390/nano10122440DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7762143PMC
December 2020

Novel perspectives of laser ablation in liquids: the formation of a high-pressure orthorhombic FeS phase and absorption of FeS-derived colloids on a porous surface for solar-light photocatalytic wastewater cleaning.

Dalton Trans 2020 Oct;49(38):13262-13275

New Technologies-Research Center, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.

A pulsed Nd : YAG laser ablation of FeS in water and ethanol produces FeS-derived colloidal nanoparticles that absorb onto immersed porous ceramic substrates and create solar-light photocatalytic surfaces. The stability, size distribution and zeta potential of the nanoparticles were assessed by dynamic light scattering. Raman, UV-Vis and XP spectroscopy and electron microscopy reveal that the sol nanoparticles have their outmost layer composed of ferrous and ferric sulphates and those produced in water are made of high-pressure orthorhombic FeS, cubic magnetite Fe3O4 and tetragonal maghemite γ-Fe2O3, while those formed in ethanol contain hexagonal FeS and cubic magnetite Fe3O4. Both colloids absorb solar light and their adsorption to porous ceramic surfaces creates functionalized ceramic surfaces that induce methylene blue degradation by daylight. The laser induced process thus offers an easy and efficient way for the functionalization of porous surfaces by photocatalytic nanoparticles that avoids aggregation in the liquid phase. The formation of an orthorhombic high-pressure FeS phase stable under ambient conditions is the first example of high-pressure structures produced by laser ablation in liquid without the assistance of an electric field.
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http://dx.doi.org/10.1039/d0dt01999bDOI Listing
October 2020

DNA Methylation Profiles in a Group of Workers Occupationally Exposed to Nanoparticles.

Int J Mol Sci 2020 Mar 31;21(7). Epub 2020 Mar 31.

Department of Machining and Assembly, Department of Engineering Technology, Department of Material Science, Faculty of Mechanical Engineering, Technical University in Liberec, Studentska 1402/2 Liberec, Czech Republic.

The risk of exposure to nanoparticles (NPs) has rapidly increased during the last decade due to the vast use of nanomaterials (NMs) in many areas of human life. Despite this fact, human biomonitoring studies focused on the effect of NP exposure on DNA alterations are still rare. Furthermore, there are virtually no epigenetic data available. In this study, we investigated global and gene-specific DNA methylation profiles in a group of 20 long-term (mean 14.5 years) exposed, nanocomposite, research workers and in 20 controls. Both groups were sampled twice/day (pre-shift and post-shift) in September 2018. We applied Infinium Methylation Assay, using the Infinium MethylationEPIC BeadChips with more than 850,000 CpG loci, for identification of the DNA methylation pattern in the studied groups. Aerosol exposure monitoring, including two nanosized fractions, was also performed as proof of acute NP exposure. The obtained array data showed significant differences in methylation between the exposed and control groups related to long-term exposure, specifically 341 CpG loci were hypomethylated and 364 hypermethylated. The most significant CpG differences were mainly detected in genes involved in lipid metabolism, the immune system, lung functions, signaling pathways, cancer development and xenobiotic detoxification. In contrast, short-term acute NP exposure was not accompanied by DNA methylation changes. In summary, long-term (years) exposure to NP is associated with DNA epigenetic alterations.
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http://dx.doi.org/10.3390/ijms21072420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177382PMC
March 2020

Structured cobalt oxide catalysts for VOC abatement: the effect of preparation method.

Environ Sci Pollut Res Int 2020 Mar 29;27(7):7608-7617. Epub 2019 Dec 29.

Department of Solid State Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague, Czech Republic.

Magnetron sputtering was employed for the deposition of cobalt oxide thin films on stainless steel meshes. Catalysts prepared by sputtering in inert and oxidation atmosphere were compared with those obtained by electrochemical deposition and hydrothermal synthesis. Systematic characterization using X-ray diffraction, scanning electron microscopy, N physisorption, infrared spectroscopy, Raman spectroscopy, and temperature-programmed reduction by hydrogen allowed detailed monitoring of their physicochemical properties. Ethanol gas-phase oxidation was employed as a model reaction to reveal the catalytic performance of the catalysts. It was shown that the catalyst prepared by magnetron sputtering in oxidation atmosphere exhibited the best mechanical stability among all studied catalysts. Moreover, its catalytic activity was 18 times higher than that of pelletized commercial cobalt oxide.
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http://dx.doi.org/10.1007/s11356-019-06974-2DOI Listing
March 2020

The repeated cytogenetic analysis of subjects occupationally exposed to nanoparticles: a pilot study.

Mutagenesis 2019 09;34(3):253-263

Department of Machining and Assembly, Technical University in Liberec, Liberec, Czech Republic.

The application of nanomaterials has been rapidly increasing during recent years. Inhalation exposure to nanoparticles (NP) may result in negative toxic effects but there is a critical lack of human studies, especially those related to possible DNA alterations. We analyzed pre-shift and post-shift a group of nanocomposite researchers with a long-term working background (17.8 ± 10.0 years) and matched controls. The study group consisted of 73.2% males and 26.8% females. Aerosol exposure monitoring during a working shift (involving welding, smelting, machining) to assess the differences in exposure to particulate matter (PM) including nanosized fractions <25-100 nm, and their chemical analysis, was carried out. A micronucleus assay using Human Pan Centromeric probes, was applied to distinguish between the frequency of centromere positive (CEN+) and centromere negative (CEN-) micronuclei (MN) in the binucleated cells. This approach allowed recognition of the types of chromosomal damage: losses and breaks. The monitoring data revealed differences in the exposure to NP related to individual working processes, and in the chemical composition of nanofraction. The cytogenetic results of this pilot study demonstrated a lack of effect of long-term (years) exposure to NP (total frequency of MN, P = 0.743), although this exposure may be responsible for DNA damage pattern changes (12% increase of chromosomal breaks-clastogenic effect). Moreover, short-term (daily shift) exposure could be a reason for the increase of chromosomal breaks in a subgroup of researchers involved in welding and smelting processes (clastogenic effect, P = 0.037). The gender and/or gender ratio of the study participants was also an important factor for the interpretation of the results. As this type of human study is unique, further research is needed to understand the effects of long-term and short-term exposure to NP.
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http://dx.doi.org/10.1093/mutage/gez016DOI Listing
September 2019

Leukocyte telomere length is not affected by long-term occupational exposure to nano metal oxides.

Ind Health 2019 Nov 28;57(6):741-744. Epub 2019 Mar 28.

Institute of Chemical Process Fundamentals CAS, Czech Republic.

The aim of this study was to ascertain whether long-term occupational exposure to nanoparticles would affect relative leukocyte telomere length (LrTL). We analysed occupational exposure to size-resolved aerosol particles, with special emphasis on nanoparticles at two workshops: i/ the production of nanocomposites containing metal oxides; ii/ laboratory to test experimental exposure of nano-CuO to rodents. Thirty five exposed researchers (age 39.5 ± 12.6 yr; exposure duration 6.0 ± 3.7 yr) and 43 controls (40.4 ± 10.5 yr) were examined. LrTL did not significantly (p=0.14) differ between the exposed researchers (0.92 ± 0.13) and controls (0.86 ± 0.15). In addition, no significant correlation (r=-0.22, p=0.22) was detected between the duration of occupational exposure and LrTL. The results remained non-significant after multiple adjustments for age, sex and smoking status. Our pilot results suggest that relative leukocyte telomere length is not affected by occupational exposure to nanoparticles.
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http://dx.doi.org/10.2486/indhealth.2018-0146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885603PMC
November 2019

Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers.

Nanomaterials (Basel) 2018 Sep 16;8(9). Epub 2018 Sep 16.

UMass, Lowell, Department of Biomedical and Nutritional Sciences, Zuckerberg College of Health Sciences, Lowell, MA 01854, USA.

Thousands of researchers and workers worldwide are employed in nanocomposites manufacturing, yet little is known about their respiratory health. Aerosol exposures were characterized using real time and integrated instruments. Aerosol mass concentration ranged from 0.120 mg/m³ to 1.840 mg/m³ during nanocomposite machining processes; median particle number concentration ranged from 4.8 × 10⁴ to 5.4 × 10⁵ particles/cm³. The proportion of nanoparticles varied by process from 40 to 95%. Twenty employees, working in nanocomposite materials research were examined pre-shift and post-shift using spirometry and fractional exhaled nitric oxide (FeNO) in parallel with 21 controls. Pro-inflammatory leukotrienes (LT) type B4, C4, D4, and E4; tumor necrosis factor (TNF); interleukins; and anti-inflammatory lipoxins (LXA4 and LXB4) were analyzed in their exhaled breath condensate (EBC). Chronic bronchitis was present in 20% of researchers, but not in controls. A significant decrease in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) was found in researchers post-shift ( ˂ 0.05). Post-shift EBC samples were higher for TNF ( ˂ 0.001), LTB4 ( ˂ 0.001), and LTE4 ( ˂ 0.01) compared with controls. Nanocomposites production was associated with LTB4 ( ˂ 0.001), LTE4 ( ˂ 0.05), and TNF ( ˂ 0.001), in addition to pre-shift LTD4 and LXB4 (both ˂ 0.05). Spirometry documented minor, but significant, post-shift lung impairment. TNF and LTB4 were the most robust markers of biological effects. Proper ventilation and respiratory protection are required during nanocomposites processing.
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http://dx.doi.org/10.3390/nano8090731DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164906PMC
September 2018

Markers of Oxidative Stress in the Exhaled Breath Condensate of Workers Handling Nanocomposites.

Nanomaterials (Basel) 2018 Aug 10;8(8). Epub 2018 Aug 10.

Department of Biomedical and Nutritional Sciences, Zuckerberg College of Health Sciences, Lowell, MA 01854, USA.

Researchers in nanocomposite processing may inhale a variety of chemical agents, including nanoparticles. This study investigated airway oxidative stress status in the exhaled breath condensate (EBC). Nineteen employees (42.4 ± 11.4 y/o), working in nanocomposites research for 18.0 ± 10.3 years were examined pre-shift and post-shift on a random workday, together with nineteen controls (45.5 ± 11.7 y/o). Panels of oxidative stress biomarkers derived from lipids, nucleic acids, and proteins were analyzed in the EBC. Aerosol exposures were monitored during three major nanoparticle generation operations: smelting and welding (workshop 1) and nanocomposite machining (workshop 2) using a suite of real-time and integrated instruments. Mass concentrations during these operations were 0.120, 1.840, and 0.804 mg/m³, respectively. Median particle number concentrations were 4.8 × 10⁴, 1.3 × 10⁵, and 5.4 × 10⁵ particles/cm³, respectively. Nanoparticles accounted for 95, 40, and 61%, respectively, with prevailing Fe and Mn. All markers of nucleic acid and protein oxidation, malondialdehyde, and aldehydes C₆⁻C were elevated, already in the pre-shift samples relative to controls in both workshops. Significant post-shift elevations were documented in lipid oxidation markers. Significant associations were found between working in nanocomposite synthesis and EBC biomarkers. More research is needed to understand the contribution of nanoparticles from nanocomposite processing in inducing oxidative stress, relative to other co-exposures generated during welding, smelting, and secondary oxidation processes, in these workshops.
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http://dx.doi.org/10.3390/nano8080611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6116291PMC
August 2018

Preconcentration and detection of mercury with bioluminescent bioreporter E. coli ARL1.

Appl Microbiol Biotechnol 2015 Oct 23;99(20):8793-802. Epub 2015 Jun 23.

Institute of Geology of the Czech Academy of Sciences, Rozvojova 135, 16502, Prague 6, Czech Republic.

Cell wall envelopes treated with sodium hydroxide and spray-dried were used as mercury sorbents. The sorbent having sorption capacity 17.7 ± 0.1 μmol/g determined was employed for preconcentration of mercury containing 1-10 ng/L. After preconcentration, bioavailable mercury was detected in samples of soil, stream, and tap water via induction of bioluminescence of E. coli ARL1. Iron and manganese at concentrations of tenth microgram per liter interfered bioluminescence detection of mercury. In tap water was detected semiquantitatively 0.127 ± 0.1 nmol/L by the induction of bioluminescence of E. coli ARL1 in medium with tryptone after preconcentration using a method of standard addition.
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http://dx.doi.org/10.1007/s00253-015-6747-2DOI Listing
October 2015