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Functionalized hybrid polymer structures for biomedical applications
Rabyk, Mariia ; Štěpánek, Petr (advisor) ; Sedláková, Zdeňka (referee) ; Kotek, Jan (referee)
This doctoral thesis is dedicated to the synthesis and characterization of novel functionalized hybrid structures for biomedical purposes. Systems reported in this work can be subdivided into the two main groups: natural-based materials and synthetic amphiphilic block copolymers. Both groups were studied as perspective theranostic agents for medical applications. In the first group, natural polysaccharides glycogen and mannan were selected as starting materials for preparation of novel nanoconjugates that possess ability for multimodal detection in vivo. Because grafting of natural macromolecules with synthetic polymers generally slows down the biodegradation rate, both polysaccharides were modified in two different ways to form nanoprobes with or without poly(2-methyl-2-oxazoline)s chains. The prepared nanoconjugates were functionalized with N-hydroxysuccinimide-activated fluorescence and magnetic resonance imaging labels. The resulting materials were tested both in vitro and in vivo and were shown to be completely biocompatible, biodegradable and exhibit some extra benefits in terms of their practical usage in biomedicine. Glycogen was functionalized with allyl and propargyl groups with following freeze-drying from aqueous solutions to form nano- and microfibrous materials. The presence of both...
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Multicomponental polyurethane systems with targeted properties. Preparation and characterization.
Serkis-Rodzeń, Magdalena ; Špírková, Milena (advisor) ; Uchman, Mariusz Marcin (referee) ; Sedláková, Zdeňka (referee)
Thermoplastic polyurethanes (PU) have been widely used for many applications due to their excellent functional properties, recycling included. PUs prepared in this Thesis are based on polycarbonate macrodiols and other bifunctional components, leading to linear solely aliphatic polymer materials. The main part of this study is focused on synthesis and analysis of polyurethane water dispersions (PUDs) and PUD-based films. The novelty of presented herein research involves ecofriendly method for preparation of thermoplastic PUs based on polycarbonates. The PU nanoparticles dispersed in water were measured by scattering methods, whereas the final films were characterized for their morphology and mechanical, thermal and water resistance. A balance between hydrophilic and hydrophobic parts of PUs for the particles stability and the films properties was investigated as well. The PUDs were blended with two types of colloidal silica for improve of the PUD- based films resistances with simultaneous preserving of their thermoplastic character. More significant enhancement was observed for the organic-inorganic nanocomposites containing silica with smaller particles, due to creation of higher physical crosslinking density between the nanofiller and PU matrix. We modified the acetone process of PUDs preparation...
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Responsive and non-responsive soft matter nanomedicines for biomedical applications
Jäger, Eliézer ; Štěpánek, Petr (advisor) ; Sedláková, Zdeňka (referee) ; Poučková, Pavla (referee)
The thesis outlines possible medical applications of soft matter assemblies as nanotechnology based systems as well as their potential in the emerging field of nanomedicine. Nanomedicine can be defined as the investigation area encompassing the design of diagnostics and therapeutics at the nanoscale, including nanobots, nanobiosensors, nanoparticles and other nanodevices, for the remediation, prevention and diagnosis of a variety of illnesses. The ultimate goal of nanomedicine is to improve patient quality-of-life. Because nanomedicine includes the rational design of an enormous number of nanotechnology-based products focused on miscellaneous diseases, a variety of nanomaterials can be employed. Therefore, the thesis is driven by a focus on recent advances in the manufacture of soft matter-based nanomedicines specifically designed to improve cancer diagnostics and chemotherapy efficacy. It will in particular highlight liposomes, polymer-drug conjugates, drug- loaded block copolymer micelles and biodegradable polymeric nanoparticles, emphasizing the current investigations and potential novel approaches towards overcoming the remaining challenges in the field as well as a brief overview of formulations that are in clinical trials and marketed products. Based on vehicle-related and...
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New Biodegradable Hydrogels
Vetrík, Miroslav ; Přádný, Martin (advisor) ; Sedláková, Zdeňka (referee) ; Dragan, Ecaterina Stela (referee)
The key tool for tissue engineering is the scaffold that supports cells for new tissue growth. Materials used for creating scaffolds are based on polymeric materials, carbon nanofibers, ceramics, and metals and their alloys. In my thesis, I describe the synthesis and characterization of new biodegradable hydrogels containing biodegradable crosslinks and biodegradable nanofibrous materials intended for scaffolds for tissue engineering. I also describe the preparation of macroporous hydrogels intended for neural tissue healing. In the first portion of this thesis, I examine a hydrogel based on a pH- responsive crosslinker. This hydrogel is stable at basic and neutral pHs but is degradable at pH < 7.4. The degradation rate of this hydrogel can be tailored. This hydrogel can be utilized as an esophageal stent or as a targeted drug release system in the stomach. The second portion of this thesis focuses on a biodegradable hydrogel designed for neural tissue repair. This hydrogel is composed of copolymers of N-(2- hydroxypropyl)methacrylamide and a newly synthesized biodegradable crosslinker based on 6,6'-dithiodinicotinic acid. This hydrogel can be stored in a neutral environment without degradation. Its long-term storage capability is another great advantage for clinical applications. During storage,...
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Polymer carriers for nuclear medicine
Sedláček, Ondřej ; Hrubý, Martin (advisor) ; Smrček, Stanislav (referee) ; Sedláková, Zdeňka (referee)
In the thesis, we developed and studied a novel polymer delivery system for the DNA-intercalator bearing radioisotope iodine-125. Auger electrons emitting radioisotopes (such as iodine-125 or indium-111) are a potentially effective cancer treatment. Their use as an effective cancer therapy requires that they will be transported within close proximity of DNA, where they induce double-strand breaks leading to the cell death. This type of therapy may be even more beneficial when associated with drug delivery systems. The DNA intercalators proved to be effective carriers for the delivery of Auger electron emitters into DNA. Therefore, the new radioiodinated DNA-intercalating ellipticinium derivatives were synthesized and characterized. These compounds were linked to N-(2-hydroxypropyl) methacrylamide copolymer with narrow molecular weight distribution via acid-sensitive hydrazone linker. The structure of the linker plays a crucial role in the biological effectivity of the delivery system, so it was optimized to be stable at pH 7.4 (representing the pH of blood plasma), whereas in slightly acidic pH in endosomes after the cell internalization, the radioiodine-containing biologically active intercalator is rapidly released from its polymer carrier. The intercalating ability of the active compound was...
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The increased diagnostic efficiency of QF-PCR for aneuploidy of amniotic fluid
Sedláková, Zdeňka ; Macek, Milan (advisor) ; Daňková, Pavlína (referee)
Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular genetic method based on the amplification of microsatellites (Short tandem repeats, STR) and measurement of the peak heights of amplicons in the electropherogram. Currently, the QF-PCR deemed reliable, fast, and inexpensive method that is gradually replacing conventional cytogenetic analysis of aneuploidy (examination of long-term cultures of amniotic fluid). However, in certain cases it is impossible to determine the parental origin and meiotic aneuploidy by QF-PCR. The aim of this work was to verify the new dinucleotide STR markers on chromozomes 13, 16, 18, 21, and 22 and further increase the diagnostic efficiency of QF-PCR retaining other STR markers on chromozome 15, 16, 22 and to determine the population and the analytical characteristics of these markers. For all dinucleotide STR markers stutter occurred in high frequency and therefore there were found not to be suitable for routine diagnostics. STR markers for chromozomes 15, 16 and 22 were tested on 100 patients. We selected four informative markers for both chromozome 16 and 22, and three markers for chromozome 15. Thus, I expanded set of diagnostic STR markers in this thesis.
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The increased diagnostic efficiency of QF-PCR for aneuploidy of amniotic fluid
Sedláková, Zdeňka ; Macek, Milan (advisor) ; Šolc, Roman (referee)
Quantitative fluorescence polymerase chain reaction (QF-PCR) is a molecular genetic method based on the amplification of microsatellites (Short tandem repeats, STR) and measurement of the peak heights of amplicons in the electropherogram. Currently, the QF- PCR deemed reliable, fast, and inexpensive method that is gradually replacing conventional cytogenetic analysis of aneuploidy (examination of long-term cultures of amniotic fluid). However, in certain cases it is impossible to determine the parental origin and meiotic aneuploidy by QF-PCR. The aim of this work was to verify the new dinucleotide STR markers on chromosomes 13, 16, 18, 21, and 22 and further increase the diagnostic efficiency of QF-PCR retaining other STR markers on chromosome 15, 16, 22 and to determine the population and the analytical characteristics of these markers. For all dinucleotide STR markers stutter occurred in high frequency and therefore there were found not to be suitable for routine diagnostics. STR markers for chromosomes 15, 16 and 22 were tested on 100 patients. We selected four informative markers for both chromosome 16 and 22, and three markers for chromosome 15. Thus, I expanded set of diagnostic STR markers in this thesis. Key words: QF-PCR, STR markers, prenatal diagnosis, trisomy.
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The synthesis of poly(butadiene)diol-based polyurethanes with LC properties
Poláková, Lenka ; Sedláková, Zdeňka (advisor) ; Šňupárek, Jaromír (referee) ; Hamplová, Věra (referee)
8 Summary The PhD thesis is focused on the synthesis and characterization of low-molecular mesogenic thiols and poly(butadiene)diols and polyurethanes with LC side chains. Within the frame of this work, following tasks have been solved: Two groups of low-molecular compounds containing a biphenyl or an azobenzene as a rigid mesogenic part have been synthesized: N YNOSHXO SH Y = -H -OCH3 -O(CH2)3CH3 -O(CH2)7CH3 X = -H -CN Composition and structure of the prepared units were confirmed by elemental analysis and 1 H NMR spectroscopy. Thermal behavior, with the respect to the temperature-dependent mesophase formation, was studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray scattering techniques (SAXS, WAXS). It was found that the presence and the type of the substituent on the mesogenic core play a crucial role in the ordering of the thiol molecules into a LC phase. The thiols synthesized were grafted onto double bonds of the commercially available telechelic poly(butadiene)diol Krasol LBH 3 000 (declared Mn ~ 2 600 Da, Mw/Mn = 1.10). The addition reactions proceeded in the presence of radical initiator (AIBN). Molar ratio of thiol/double bonds varied within the range of 0.15 (resp. 0.2) to 1.0 for each type of the thiol. The structure of the resulted comb-like...
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