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Nanočástice jako transportér biomolekul do buněk Chlamydomonas reinhardtii
Bařinková, Magda
Biocompatibility of gold nanoparticles with unicellular green alga Chlamydomonas reinhardtii was investigated in order to design and optimize a method using nanoparticles as carriers of biomolecules and CRISPR/Cas systems for targeted genome editing. To optimize the delivery of molecular cargo to cells, the effect of physicochemical properties of gold nanoparticles including core size and surface modification with PEI polymer was tested on microalgae. PEI, which provides a positive charge to the nanoparticles and thus facilitates their adhesion to the surface of negatively charged membranes, has been shown to be toxic in unconjugated form. On the contrary AuNP-PEI conjugates promoted viability and thus the cell cycle of the mutant strain CW 15+ without cell wall, unlike the standard type of C. reinhardtii.
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Buněčné efekty vyvolané různými nanočásticemi a mechanismus jejich radio-sensitizačního účinku
Dobešová, Lucie
The application of nanoparticles in the treatment and diagnosis of cancer is one of the most studied scientific topics. Their properties predetermine them for wide use not only in radiotherapy. Treatment of cancer with ionizing radiation is one of the most widely used methods. Therefore, there is a great effort in scientific circles to improve this method towards the least possible damage to healthy tissue. For these reasons, this work was focused on the study of the effects of gold nanoparticles Au-c, Au-10, Aurion 10nm and Aurion 25nm on cancer (Sk-Br-3) and healthy / normal (NHDF) cells in the process of radiosensitization. Various methods have been used to study the cellular response to incubation with nanoparticles (MTT tetrazolium assays, cell viability assays and activation of apoptosis by flow cytometry, etc.). We found that Au-c nanoparticles show a cytotoxic effect in the Sk-Br-3 cell line, but not in the NHDF line. The selective cytotoxicity of these nanoparticles could be useful in other industries of cancer treatment. No effect was demonstrated for the other types of nanoparticles examined, but could occur with the use of another source of ionizing radiation.
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Molecular mechanism of cell death during gold nanoparticle based photothermal cancer therapy
Jakubcová, Tereza ; Žárská, Monika (advisor) ; Bábelová, Andrea (referee)
Plasmonic photothermal therapy (PPTT) is an innovative method of cancer treatment using nanomaterials, especially gold nanoparticles. Unlike clinically used cancer therapies, it promises minimisation the invasiveness and side effects as well as high specificity. Exposure of cancer cells to the near-infrared light leads to local hyperthermia, which is generated by gold nanoparticles. Nevertheless, the mechanism of induced cell death does not proceed each time in the same manner. This work aims to compare to date known mechanisms governing the different cellular responses to PPTT-induced hyperthermia and highlights its potential for clinical cancer therapy. It compares the mechanisms of cell death observed and identified during PPTT, including apoptosis, necrosis, necroptosis, lysosome-dependent cell death, autophagy- dependent cell death and NETosis, which differ at the molecular level. Understanding the molecular basis of the cell death pathways is crucial for optimizing the efficacy of PPTT and its future testing both in vivo and in clinical trials. Keywords: plasmonic photothermal therapy, gold nanoparticles, cell death
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Golden nanosystems for molecular detection of biological samples using Surface-Enhanced Raman Spectroscopy
Kebabová, Mona ; Bernátová,, Silva (referee) ; Samek, Ota (advisor)
Citlivá a přesná detekce analytů nebo bakterií je klíčovým krokem při identifikaci nebezpečných sloučenin či patogenů, ať už v oblasti medicíny nebo bezpečnosti potravin. Využití pokročilých metod, jako je povrchově zesílená Ramanova spektroskopie (SERS), by pomohlo identifikovat bakterie nebo analyty s vysokou citlivostí a přesností. Tato diplomová práce zaměřuje na syntézu a charakterizaci kovových nanočástic (NČ) pro citlivou detekci bakterií pomocí SERS, přičemž NČ zvyšují Ramanův signál lokalizovanou plazmonovou rezonancí. Nejdříve jsou diskutovány nejnovější přístupy k syntéze plazmonických nanostruktur. Hlavní část experimentální práce tvoří syntéza zlatých (Au) a stříbrných (Ag) NČ, jejich charakterizace a využití pro analýzu chemických a biologických vzorků pomocí SERS. Nanočástice byly použity pro detekci molekul barviv (rhodamin 6G a methylenová modř), a patogenních bakterií Staphylococcus aureus a Escherichia coli, adsorbovaných na povrch syntetizovaných NČ. Dále byl replikován vysoce specifický sendvičový imunotest detekovatelný pomocí SERS. Tato metoda umožňuje rychlou a přesnou detekci patogenů. Na povrch nanočástic se pomocí interakce avidin-biotin vážou protilátky, které slouží k zachycení bakterií (E. coli a S. aureus). Ačkoli dílčí kroky protokolu byly úspešné, ověření funkce sendvičového imunotestu se doposud nezdařilo, pravděpodobně kvůli změnám v použitých chemikáliích a protilátkách. Kroky nezbytné k replikaci protokolu budou provedeny v budoucnu.
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Gold nano systems for the detection of molecules using surface-enhanced Raman scattering (SERS)
Benešová, Markéta ; Bernatová,, Silvie (referee) ; Skoumalová, Petra (advisor)
This diploma thesis was focused on the production and use of gold nanosystems to enhance Raman scattering. Metal nanoparticles, when interacting with electromagnetic radiation, form so-called localized plasmons, which can enhance Raman scattering. SERS (surface-enhanced Raman scattering) is a non-destructive analytical technique used in this work to measure the concentration and chemical changes in the rhodamine B molecule. Rhodamine B was subjected to photocatalytic degradation using two types of photocatalysts before measurement: TiO2-(H) and TiO2-(H)-Ag. The quantitative dependence of rhodamine B photodegradation on the presence of photocatalysts in a given period time was sought using photodegradation processes. The results of measurements using the SERS method were compared with the results obtained by UV-VIS spectroscopy. From the measured data, it was found that the photocatalysts significantly accelerate the photodegradation processes, because the Raman signal of rhodamine B decreased, while the signal decrease was most pronounced for the catalyst with added TiO2-(H)-Ag, less prominent but still statistically significant signal decrease was observed for the TiO2-(H) catalyst. In the control sample without the addition of photocatalyst, no decrease in signal was observed. In the next phase of the thesis, a sandwich immunoassay was designed that uses SERS to detect E. coli bacteria or other specific microorganisms in the sample. The first component of the sandwich immunoassay is gold nanoparticles, which carry a so-called Raman reporter, which has a clear Raman response in the spectrum, and gold nanoparticles amplify this signal, and antibodies, thanks to which the particles specifically bind to the microorganism. Another component is either gold layered slides or magnetic nanoparticles, which are modified with antibodies and serve to immobilize microorganisms. This system can be a fast and very accurate way to identify a given microorganism in a sample.
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Enhancement of detection limits in Laser-Induced Breakdown Spectroscopy (LIBS) using nanoparticles
Képeš, Erik ; Prochazka, David (referee) ; Sládková, Lucia (advisor)
This bachelor's thesis describes the options of ehnancing the detection limits of laser-induced breakdown spectroscopy (LIBS). It summarizes different modifications of the classical LIBS apparatus, which are used by methods double-pulsed LIBS (DPLIBS), Townsend effect plasma sectroscopy (TEPS), resonance enhanced LIBS (RELIBS), spark discharge LIBS (SDLIBS), flame-enhanced LIBS (FELIBS), and new ways of sample preparation, such as are used in the method nanoparticle enhanced LIBS (NELIBS). It briefly describes the mechanisms, which are used by each method to reduce the detection limit and it contains an overview of obtained enhancements against the classical method LIBS. It deals with the method nanoparticle enhanced LIBS in more detail and experimentally verifies and studies the effects of nanoparticles of different types and sizes on the emission spectrum of the method LIBS.
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Plasmonically active electrochemical electrodes based on tungsten disulfide nanotubes decorated with gold nanoparticles
Salajková, Zita ; Daňhel,, Aleš (referee) ; Ligmajer, Filip (advisor)
When an electromagnetic wave illuminates metal nanostructure under right circumstances, it can couple to the motion of electrons and thus give rise to so-called LSPR. When these collective oscillations non-radiatively decay, they excite charge carriers that can have, for a short moment of time, highly non-thermal energy distribution. These so-called "hot" electrons and holes can then take part in photochemical applications, e.g. in reactions on photoactive electrodes where hot electrons act as catalysts. Gold nanoparticles seem to be a good candidate for fabrication of such electrodes because they exhibit resonantly enhanced absorption due to plasmon excitation in the visible and near infrared spectral range, which could make the solar energy harvesting more efficient. In this work we present electrohemical experiments that should help to clarify the underlying principles of photochemical reactions involving hot electrons. Our model system consists of indium tin oxide electrodes covered with tungsten disulphide nanotubes that were previously decorated by gold nanoparticles. By comparing the results of chronoamperometric measurements on individual components of this system it was shown that excitation of plasmonic nanoparticles indeed leads to photocurrents and that electrochemical methods can serve as a valuable tool for analysis of photochemical reactions catalyzed by hot electrons.
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Photoelectrochemical properties of titanium dioxide doped by metals
Vičarová, Monika ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
This thesis deals with the optimization of materials and processes for making layers of titanium dioxide enriched with metal nanostructured aggregates. These layers have a plasmonic effect in visible light radiation. Gold-doped titanium dioxide thin films were applied to the FTO glass substrate by spin-coating method and calcined at 450 ° C for 30 minutes. Two forms of titanium dioxide and two different gold precursors were used to make the layers. The structure of the layers was observed by optical and SEM microscopy. The photoelectrochemical properties of the prepared layers were studied by electroanalytical methods linear sweep voltammetry and chronoamperometry.
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Functionalized nanostructures
Váňa, Rostislav ; Kvapil, Michal (referee) ; Kolíbal, Miroslav (advisor)
This thesis deals with functionalized nanoparticles. In the first part there are mentioned materials suitable for a functionalization, the usage of functionalized nanoparticles in medicine and biochemistry and detection methods of changes of optical properties. In the second part changes of optical properties after functionalization are investigated by spectroscopic ellipsometry and FTIR spectroscopy.
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Synthesis of spherical gold nanoparticles for biomedical applications
Gablech, Evelína ; Adam, Vojtěch (referee) ; Drbohlavová, Jana (advisor)
Tato práce se zabývá syntézou sférických zlatých nanočástic pro biomedicínské aplikace. Zlaté nanočástice byly syntetizovány ekologicky nezávadnými metodami, kterým je věnována i značná část rešerše. Cílem bylo nasyntetizovat stabilní koloidní zlaté nanočástice vhodné pro různé biomedicínké aplikace zejména, pro in vivo a in vitro zobrazovací metody, kterých přehled je take obsažen v teoretické části práce. Také byl proveden test cytotoxicity, jelikož částice mají být použitelné pro in vivo aplikace. Částice byly dale charakterizovány metodami SEM, DLS a UV-VIS.
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