Browsing by Author "Klíčová, Markéta"

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    Experimental fortification of intestinal anastomoses with nanofibrous materials in a large animal model
    (Nature Research, 2020-01-01) Rosendorf, Jáchym; Horáková, Jana; Klíčová, Markéta; Pálek, Richard; Červenková, Lenka; Kural, Tomáš; Hošek, Petr; Kříž, Tomáš; Tégl, Václav; Moulisová, Vladimíra; Tonar, Zbyněk; Treska, Vladislav; Lukáš, David; Liska, Václav
    Anastomotic leakage is a severe complication in gastrointestinal surgery. It is often a reason for reoperation together with intestinal passage blockage due to formation of peritoneal adhesions. Different materials as local prevention of these complications have been studied, none of which are nowadays routinely used in clinical practice. Nanofabrics created proved to promote healing with their structure similar to extracellular matrix. We decided to study their impact on anastomotic healing and formation of peritoneal adhesions. We performed an experiment on 24 piglets. We constructed 3 hand sutured end-to-end anastomoses on the small intestine of each pig. We covered the anastomoses with a sheet of polycaprolactone nanomaterial in the first experimental group, with a sheet of copolymer of polylactic acid with polycaprolactone in the second one and no fortifying material was used in the Control group. The animals were sacrificed after 3 weeks of observation. Clinical, biochemical and macroscopic signs of anastomotic leakage or intestinal obstruction were monitored, the quality of the scar tissue was assessed histologically, and a newly developed scoring system was employed to evaluate the presence of adhesions. The material is easy to manipulate with. There was no mortality or major morbidity in our groups. No statistical difference was found inbetween the groups in the matter of level of peritoneal adhesions or the quality of the anastomoses. We created a new adhesion scoring system. The material appears to be safe however needs to be studied further to prove itsʹ positive effects.
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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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    Novel double-layered planar scaffold combining electrospun PCL fibers and PVA hydrogels with high shape integrity and water stability
    (Elsevier B.V., 2020-03-01) Klíčová, Markéta; Klápšťová, Andrea; Chvojka, Jiří; Kopřivová, Barbora; Jenčová, Věra; Horáková, Jana
    Novel double-layered materials with different properties of each side were prepared via needleless electrospinning and compared in terms of morphology, wettability, adhesion and proliferation of mouse fibroblasts. The materials consist of hydrophilic poly(vinyl alcohol) fibers with low (PVA_L) or high (PVA_H) degree of hydrolysis, and hydrophobic poly(ε-caprolactone) (PCL) fibrous layer. Although the PVA_L fibers were fully dissolved following a water exposure, the shape of the scaffold was maintained due to water stable PCL layer. Exposing PVA_H based fibrous layer to water created a hydrogel-like structure with shape defined by the PCL layer. According to the MTT assay, the mouse fibroblasts seeded on the scaffold exhibited the greatest proliferative activity on the PCL fibers. These double-layered scaffolds with different features on each side are very promising for many novel medical applications such as wound dressing or abdominal adhesion prevention.
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    Příprava nanovláken na bázi kyseliny hyaluronové metodou elektrostatického zvlákňování
    (2015-10-20) Klíčová, Markéta; Rysová Miroslava, Ing.; Skolitel : 64111 Ducháčková Eva, prof. Ing. CSc.; Konzultant : 59251 Tunáková Veronika, Ing. Ph.D.; Konzultant2 : 65175 Baše Tomáš, Mgr. Ph.D.
    Tato práce se zabývá nalezením optimálních podmínek pro zvláknění kyseliny hyaluronové (HA) metodou elektrostatického zvlákňování z volné hladiny. Kyselina hyaluronová je přírodní polysacharid s širokým využitím v oblasti tkáňového inženýrství. Vytvoření nanovlákenné vrstvy metodou elektrostatického zvlákňování je, jako u většiny biopolymerů, obtížné. Problémem je jejich přílišná viskozita ve vodných roztocích a polyelektrolytická povaha. Tato práce shrnuje výběr dosavadních pokusů o vytvoření nanovláken na bázi kyseliny hyaluronové. Na teoretickou část navazuje část praktická, která ukazuje postup a dosažené výsledky vlastního snažení o vytvoření nanovláken, především ve směsi s nosným polymerem, kterým byl zvolen polyethylenoxid (PEO). Podařilo se takto zvláknit vysokomolekulární i nízkomolekulární kyselinu hyaluronovou v různých poměrech HA:PEO.
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    Vývoj dvouvrstvých vlákenných tkáňových nosičů s odlišnou smáčivostí povrchu pro zpevnění střevních anastomóz
    (2017-10-13) Klíčová, Markéta; Horáková Jana, RNDr. Ph.D. : 63138
    Netěsnost střevních anastomóz vede k seriózním pooperačním komplikacím. Překrytí chirurgické anastomózy dvouvrstvým vlákenným materiál představuje zcela inovativní způsob, jak zabránit prosakování střevního obsahu skrz anastomózu a usnadnit hojení. Předpokládá se, že hydrofilní strana přilne k anastomóze, a naopak hydrofóbní strana materiálu vytvoří kontakt s okolním prostředím a zabrání srůstům hladkých tkání v dutině břišní. V této diplomové práci jsou představeny dva materiály, které by potencionálně mohly sloužit pro tento účel. Tyto vlákenné materiály byly vytvořeny pomocí elektrostatického zvlákňování. První dvouvrstvu tvoří hydrofilní ultrajemná nanovlákna kyseliny hyaluronové (HA) a hydrofóbní vlákna poly--kaprolaktonu (PCL). Druhým materiálem je vrstva hydrofilních vláken polyvinylalkoholu (PVA) a vrstva hydrofóbních vláken PCL. Hydrofilní strany obou materiálů byly rovněž ošetřeny methanovým plazmatem, což vedlo ke zvýšení hydrofobicity vláken HA při zachování cytokompatibility. Materiály byly otestovány biologickými in vitro testy.