Browsing by Author "Erben, Jakub"
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- Item3D-Printed Magnetic Stirring Cages for Semidispersive Extraction of Bisphenols from Water Using Polymer Micro- and Nanofibers(AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2020-03-03) Šrámková, Ivana; Horstkotte, Burkhard; Erben, Jakub; Chvojka, Jiří; Švec, František; Solich, Petr; Satinský, DaliborA magnetic stirring device allowing semidispersive solid phase extraction of eight bisphenols (A, AF, AP, C, BP, G, M, and Z) from river waters using polymer nano- and microfibers followed by HPLC with spectrophotometric detection has been developed and applied. About 50 mg of fibers was placed in a round, cage-like housing consisting of two identical 3D printed pieces that were locked together by a magnetic stirring bar. Magnetic stirring action of the cage devices enabled highly efficient interaction of the fibers housed inside with the aqueous samples and analyte transfer without risking fiber compaction and/or damaging. Polypropylene was found to be the best-suited filament material for the cage 3D printing, and polycaprolactone fibers appeared the most efficient sorbent out of eight tested polymers. Experimental design revealed that analytes extraction from 100 mL aqueous samples was completed within 50 min and stripping in methanol required less than 35 min. Cage housing enabled simple and robust handling of the fibrous sorbent that could be used repeatedly up to at least 5 times. Procedural repeatability was less than 5% RSD, and limits of detection and quantitation were 0.1-2.1 and 0.4-7.0 mu g L-1, respectively. Analyte recoveries at 50 mu g L-1 level ranged from 87.1% to 106.5% in the analysis of two spiked river and two lake waters.
- Itemac Bubble Electrospinning Technology for Preparation of Nanofibrous Mats(AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2020-04-14) Erben, Jakub; Kalous, Tomáš; Chvojka, JiříThis study deals with a new combination of alternating current (ac) electrospinning and bubble electrospinning. Research devoted to the combination of these two methods for the preparation of nanofibrous and microfibrous mats has been carried out. The design, construction, and description of bubble electrospinning are described in this article. The final morphologies of the fibrous layers produced by these methods have been compared with other well-known electrospinning methods. The bubble electrospinning and ac electrospinning aspire to become new technologies that could be utilized in various technical areas and tissue-engineering applications.
- ItemThe combination of meltblown technology and electrospinning - The influence of the ratio of micro and nanofibers on cell viability(Elsevier, 2016) Erben, Jakub; Jenčová, Věra; Chvojka, Jiří; Blažková, Lenka; Strnadová, Kateřina; Modrak, Miroslav, Košťáková Kuželová EvaThis study describes the production, testing and characterization of biodegradable scaffolds for bone tissue, which consist of the exact ratio of meltblown microfibers and nanofibers produced through the electrostatic field. All fibrous materials were produced from polycaprolactone. Three kinds of materials were prepared in the experiment with the same area density and with different well-defined ratio of microfibers as a mechanical component and nanofibers as a cells adherent component. All prepared materials showed optimum porosity of the inner structure for cell proliferation and in comparison to the materials with nanofibers they had good mechanical properties. Important structural properties and homogenity of each material were observed by electron microscopy and analyzed by image analysis. The effect of various ratios of microfibers and nanofibers on adhesion and proliferation of osteoblasts in-vitro was characterized. © 2016 Elsevier B.V. All rights reserved.
- ItemImpact 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, JiříElectrospun 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.
- ItemImpact of Various Sterilization and Disinfection Techniques on Electrospun Poly-ϵ-caprolactone(American Chemical Society, 2020) Horáková, Jana; Klíčová, Markéta; Erben, Jakub; Klápšťová, Andrea; Novotný, Vít; Běhálek, Luboš; Chvojka, JiříElectrospun 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.
- ItemNovel nanofibrous sorbents for the extraction and determination of resveratrol in wine(2019-07-26) Háková, Martina; Chocholoušová Havlíková, Lucie; Švec, František; Solich, Petr; Erben, Jakub; Chvojka, Jiří; Šatínský, DaliborOn-line SPE HPLC method using nanofibrous sorbents for the extraction and determination of resveratrol in wine was developed and validated. Different types of nanofibrous and microfibrous polymers were tested and compared with commercial monolithic C18 sorbent. Polyamide and polyacrylonitrile nanofibers and composite materials composed of respective polycaprolactone and poly(vinylidene difluoride) nanofibers at microfibrous scaffold were included among tested materials. Two different polycaprolactone-based materials were prepared and their effect on the extraction properties studied. Alternatively, dopamine-coated polycaprolactone fibers were also used. Poly(vinylidene difluoride) nanofibers/polycaprolactone microfibers composite was found as the most effective sorbent and utilized for the method validation. Resveratrol in red wine was determined using our validated on-line SPE HPLC method.
- ItemPoly-epsilon-caprolactone Nanofibrous Polymers: A Simple Alternative to Restricted Access Media for Extraction of Small Molecules from Biological Matrixes(AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2020-05-19) Raabová, Hedvika; Háková, Martina; Chocholoušová Havlíková, Lucie; Erben, Jakub; Chvojka, Jiří; Solich, Petr; Švec, František; Šatínský, DaliborPoly-epsilon-caprolactone nanofibrous polymer has been used as an alternative to restricted access media for extraction of protein-containing biological samples and direct transfer in the chromatographic system. Three commercial cartridges differing in length and internal diameter have been manually packed with the composite material prepared from poly-epsilon-caprolactone nanofibers coated on poly-epsilon-caprolactone microfibrous scaffold and connected to the column-switching chromatographic system. Bovine milk and human serum (25 mu L) spiked with a mixture of methyl-, ethyl-, propyl-, and butylparaben in a concentration range of 1-100 mu g mL(-1) were online extracted using the cartridge-containing fibers. Then, 5 and 20% (v/v) aqueous methanol was applied as the washing mobile phase. While the ballast protein macromolecules were quantitatively eluted from the nano/microfibrous composite sorbent, the parabens were retained. After the mobile phase was switched to a stronger one, these compounds were then eluted from the extraction sorbent, directed in the analytical column, and finally separated. An extraction efficiency of 86-101% for all parabens achieved using the optimum-sized cartridge and a repeatability of the extraction procedure of 0.06-1.95% RSD were obtained.
- ItemPolycaprolactone nanofibers functionalized with a dopamine coating for on-line solid phase extraction of bisphenols, betablockers, nonsteroidal drugs, and phenolic acids(Springer-Verlag Wien, 2019-11) Háková, Martina; Chocholoušová Havlíková, Lucie; Chvojka, Jiří; Erben, Jakub; Solich, Petr; Švec, František; Šatínský, DaliborPolycaprolactone composite nanofibers coated with a polydopamine layer are introduced as a new type of absorption material for on-line solid phase extraction (SPE) in chromatographic system. A hybrid technology combining the electrospinning and melt blowing was used for the preparation of 3D-structured microfiber/nanofibrous polycaprolactone composite. The dopamine coating was then applied to functionalize the micro/nanofibers. Polydopamine-coated polycaprolactone fibers were tested as an extraction phase in on-line SPE prior to HPLC separation and UV detection. Four groups of biologically active substances including bisphenols (Bisphenol S, Bisphenol AF, Bisphenol A, Bisphenol C, Bisphenol AP, Bisphenol Z, Bisphenol BP, and Bisphenol M), betablockers (Timolol, Metoprolol, Labetalol, and Propranolol), nonsteroidal antiphlogistic drugs (Salicylic acid, Ketoprofen, Naproxen, Indomethacin, Diclofenac, Ibuprophen, and Meclofenamic acid), and phenolic acids (Chlorogenic acid, Caffeic acid, Sinapic acid, m-Coumaric acid, Benzoic acid, and Cinnamic acid) were used as the model analytes. Neat and coated fibers were compared and applied as sorbents for the on-line extraction set-up. Both materials produced good extraction potential for the determination of bisphenols and nonsteroidal drugs in model biological and environmental samples including river water, human urine, and blood serum. However, the polydopamine layer significantly increased the extraction efficiency of polar drugs. Typical repeatability of on-line extraction procedure on polydopamine coated fibers was in the range 0.12–4.11% for bisphenols, 0.55–1.41% for antiphlogistic drugs, 0.59–2.52% for phenolic acids, and 1.01–1.65% for betablockers.
- ItemScreening of extraction properties of nanofibers in a sequential injection analysis system using a 3D printed device(ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2019-05-15) Šrámková, Ivana H.; Carbonell-Rozas, Laura; Horstkotte, Burkhard; Háková, Martina; Erben, Jakub; Chvojka, Jiří; Švec, František; Solich, Petr; Garcia-Campana, Ana M.; Šatínský, DaliborA novel application of the three-dimensional printing technology for the automation of solid phase extraction procedures in a low-pressure sequential injection analysis system is presented. A 3D printed device was used as a housing for nanofiber membranes in solid phase extraction. The applicability of the device is demonstrated with the extraction of substances of various physical-chemical properties. Pharmaceuticals including non-steroidal anti-inflammatory drugs, andhistaminics, and steroidal structures, as well as emerging pollutants such as bi-sphenols and pesticide metsulfuron methyl were used as model analytes to study the extraction performance of the nanofibers. Six different nanofiber types comprising polyamide, polyethylene, polyvinylidene fluoride, polycaprolactone combined with polyvinylidene fluoride, and polyacrylonitrile, produced by electrospinning were tested in solid phase extraction. The suitability of specific nanofibers for particular analytes is demonstrated.
- ItemTvorba polykaprolaktonových vlákenných struktur technologií meltblown a studium jejich následných aplikacíErben, Jakub; Chvojka Jiří, doc. Ing. Ph.D. :58591Disertační práce je koncipována jako komentovaný soubor vědeckých publikací členěný do tří vzájemně navazujících částí. Představuje světově první zveřejněný výzkum zabývající se zpracováním samotného biodegradabilního polykaprolaktonu technologií meltblown do podoby mikrovláken tvořících základní složku unikátního vlákenného kompozitu a následným studiem jeho využití ve vybraných aplikacích. První část práce popisuje především výzkum vedoucí ke stanovení optimálních procesních podmínek spolu s jejich vlivem na výsledný vlákenný produkt po stránce strukturální, mechanické i chemické. Výsledky ukazují vhodné viskoelastické vlastnosti polykaprolaktonu spolu s jeho chemickou stabilitou, což umožňuje jeho zpracování pomocí technologie meltblown do podoby kompaktní mikrovlákenné vrstvy o vysokém stupni homogenity. Následně je popsán způsob výroby vysoce funkčního kompozitního materiálu ze směsi mikrovláken a nanovláken, kombinující technologii meltblown a elektrické zvlákňování. Další část práce shrnuje možnosti využití polykaprolaktonových vlákenných struktur v regenerativní medicíně jako tkáňových nosičů především pro kostní aplikace. Experimenty se zaměřují na testování mikro-nanovlákenného kompozitu v porovnání s rozdílnými vlákennými strukturami. Biologické testy in vitro prokazují biokompatibilitu testovaných struktur a jejich schopnost podpořit viabilitu kostních i kmenových buněk. Na základě in vivo testů v podobě implantací do kostního defektu králíka je prokazatelné, že testovaný kompozit je netoxický a dle histologických dat inhibuje růst nové kostní tkáně. Poslední část se zabývá využitím polykaprolaktonových vlákenných struktur v analytické chemii jako sorbentů pro úpravu vzorků metodou extrakce na tuhé fázi v kapalinových chromatografiích. Mikro-nanovlákenné kompozity jsou porovnávány s konvenčně využívanými nanovlákennými materiály i komerčními sorbenty. Sledován je především vliv technologie zpracování a výsledné struktury vlákenného sorbentu na extrakční vlastnosti, stabilitu v mobilní fázi a opakovatelnost použití. Popsána je funkcionalizace vlákenných sorbentů polyfenoly a možnosti jejich kombinace s 3D tiskem. Výsledky ukazují velmi dobrou stabilitu, nižší spotřebu organických rozpouštědel, zvýšenou extrakční kapacitu a selektivitu v porovnání s běžně používanými nanovlákennými materiály i komerčními sorbenty.
- ItemVývoj a studium struktury objemných mikro - nanovlákenných vrstev pro medicínské aplikace(Technická Univerzita v Liberci, 2014) Erben, Jakub; Chvojka, JiříTato diplomová práce se zabývá vývojem nového druhu biodegradabilního tkáňového nosiče složeného z objemné směsi mikro - nanovláken a jeho další funkcionalizace nanášením částic. Práce klade důraz na ověření využitelnosti vytvořené vlákenné vrstvy v rekonstrukční medicíně kostní tkáně. V teoretické části byly popsány vybrané technologie výroby mikro nanovláken a technologie funkcionalizace nanášením částic. Dále byla popsána morfologie kostní tkáně a princip tkáňového inženýrství. Experimentální část obsahuje popis vývoje vlákenných vrstev, optimalizace výrobního postupu a výběr vhodného materiálu. V této části je také popsán vliv použitého materiálu a technologických podmínek na strukturní parametry vlákenné vrstvy a následné testování její biokompatibility a biodegradability.
- ItemVývoj a testování technologie pro pokrývání třídimenzionálních struktur nanovlákny(Technická Univerzita v Liberci, 2012) Erben, Jakub; Mikeš, PetrThis thesis described the development a new method of covering three dimensional structures by nanofibers based on the Nanospider technology, and then testing the properties of the fibre layers created. The work emphasizes the verification of usability of fiber layers in reconstructive medicine. In theoretical part has been described technology and development of the production of fibrous polymer layers by three selected methods. And next was also prepared an overview of biodegradable polymers and outlined the issues the field of tissue engineering. The experimental part describes the development and optimization of technology of blowing nanofibers and preparation of models for this process. This section also describes the influence of the used polymeric material and technological conditions on the structure of the fiber layer and its subsequent testing.