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Self-cleaning ability of organic photo-active layers
Těthal, Vít ; Vala, Martin (referee) ; Veselý, Michal (advisor)
In this paper, methodes of determination of singlet oxygen (decolorization methodes, luminiscence detection, reaction with anorganic compounds, electon paramagnetic resonation, detecting of singlet oxygen luminiscence, detecting of absorption in IR region) and determination of efectivity of photoactive layers (photobleaching of dye aqueous solution, photodegradation of a solid fatty deposit, photoreduction of an organic dye, photooxidation of sodium salt of terephtalic acid, degradation of 1,3-diphenylisobenzofuran (DPIBF), degradation of diketopyrrolopyrrole (DPP), degradation of acridine orange) are summarized, including principle and procedure. In experimental part, 2 of these methodes (DPIBF and DPP degradation) were chosen and tested. Reaction rate constant and conversion were measured. It was found out that DPIBF methode is quick, reliable and reproducable.
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PEGylated micelles for diagnostic and therapy against solid tumors
Hoang, Stéphane ; Hrubý, Martin (advisor) ; Frochot, Céline (referee) ; Bianco, Alberto (referee)
Title : PEGylated micelles for diagnostic and therapy against solid tumors. Keywords : micelles, ferrocene, photolysis, vectorization, nanoparticle, singlet oxygen Abstract : Nanomedicine is an emerging field that addresses the challenges faced by conventional medicine. The use of nanometric objects makes it possible to reduce side effects through targeted, specific treatment at reduced doses. Among these nanoparticles, micelles are widely exploited thanks to their small size and high modularity. As a result, their application extends to many fields, including oncology. Indeed, their size enables them to take full advantage of the characteristics of the tumor microenvironment, resulting in increased accumulation and retention of micelles in tumor tissue. Thus, the use of micelles as nanovectors offers a theranostic approach to cancer therapy. In this context, the work presented here is divided into two distinct parts. The first presents the synthesis and formulation of photodegradable PEGylated micelles capable of both generating cytotoxicity and delivering a hydrophobic molecule intracellularly. The second part focuses on the enhancement of the EPR effect by sonoporation, a method considered to be non-invasive. Results on murine models demonstrated the positive effect of this method by greatly improving...
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Nanofiber membranes generating singlet oxygen with magnetic separation
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polyurethane nanofiber membrane with encapsulated 5,10,15,20-meso-tetraphenylporphyrin (TPP) photosensitizer and maghemite nanoparticles. The membrane was prepared by electrospinning and shows effective photogeneration of O2 (1 Δg) and photoantibacterial effect on the surface. The membrane can be easily separated by a magnetic field. The magnetic behaviour of the maghemite nanoparticles was studied using Mössbauer spectroscopy. Their size was estimated by DLS. The final nanofiber membrane was characterized by UV-VIS, emission spectroscopy, and by electronic microscopy (SEM). The kinetics of O2 (1 Δg) generation was studied by time-resolved spectroscopy and the relative efficiency of photooxidation was studied using external acceptor of O2 (1 Δg). Significant photoantibacterial properties against bacteria strain Escherichia coli were detected on the surface of the membrane functionalized with TPP photosensitizer.
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Photoctive Nanofiber Membranes for Oxygen Sensing
Ludačka, Pavel ; Mosinger, Jiří (advisor) ; Lang, Kamil (referee)
In this work, luminescent oxygen sensors based on the quenching of porphyrin sensor molecules encapsulated in a nanofibrous polymer matrix prepared by electrospinning were prepared and studied. The prepared sensors were characterized using electron microscopy, absorption and emission spectra, including time-resolved emission spectra. The sensitivity of the sensors was optimized in different polymer matrices, concentrations of porphyrin sensor molecules, and the thickness of the nanofibrous sensor layer. Furthermore, the photogeneration of singlet oxygen and the resulting antibacterial properties of the sensor nanofiber membrane were demonstrated. Key words Photoactive, nanofiber, oxygen, singlet oxygen, optical sensor
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Nanofiber membranes with encapsulated photoactive molecules simultaneously generating NO and 1O2 species
Liška, Vojtěch ; Mosinger, Jiří (advisor) ; Kubíček, Vojtěch (referee)
This thesis focuses on the preparation and study of a new type of photoactive polycaprolactone nanofibrous membrane with encapsulated NO photodonor 4-(N- (aminopropyl)-3-(trifluoromethyl)-4-nitrobenzenamine)-7-nitrobenzofurazan and photosensitizer chlorin e6. The electrospun nanofibrous membrane exhibits efficient photogeneration of NO and singlet oxygen molecules, which initiate facial and space photoantibacterial properties. The structure of the prepared NO photodonor was studied by NMR spectroscopy and UV-VIS absorption spectroscopy measurements. The resulting nanofibrous material was studied by scanning electron microscopy, and the successful encapsulation of both photoactive species was studied by absorption and fluorescence spectroscopy. Photogeneration of the NO molecule was studied by direct amperometric detection of NO and by reaction with a chemical substrate. The photogeneration of singlet oxygen O2( Δg 1 ) was studied by time-resolved spectroscopy and by reaction with a chemical substrate. Significant photoantibacterial properties were demonstrated on the bacterial strain Escherichia coli DH5α. Both antibacterial effects were studied by monitoring the number of colony forming units (CFU) using image analysis, and the facial effect by scanning electron microscopy. Keywords: singlet...
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Self-cleaning ability of organic photo-active layers
Těthal, Vít ; Vala, Martin (referee) ; Veselý, Michal (advisor)
In this paper, methodes of determination of singlet oxygen (decolorization methodes, luminiscence detection, reaction with anorganic compounds, electon paramagnetic resonation, detecting of singlet oxygen luminiscence, detecting of absorption in IR region) and determination of efectivity of photoactive layers (photobleaching of dye aqueous solution, photodegradation of a solid fatty deposit, photoreduction of an organic dye, photooxidation of sodium salt of terephtalic acid, degradation of 1,3-diphenylisobenzofuran (DPIBF), degradation of diketopyrrolopyrrole (DPP), degradation of acridine orange) are summarized, including principle and procedure. In experimental part, 2 of these methodes (DPIBF and DPP degradation) were chosen and tested. Reaction rate constant and conversion were measured. It was found out that DPIBF methode is quick, reliable and reproducable.
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Nanofiber materials simultaneously photogenerating NO and 1O2 species; Reversible NO binding on boron-containing clusters
Dolanský, Jiří ; Mosinger, Jiří (advisor) ; Klán, Petr (referee)
This project is concerned with the preparation of electrospun polystyrene (PS) nanofiber materials with covalently bonded NO-photodonor and electrostatically attached tetracationic porphyrinoid photosensitizers. These photofunctional nanofiber materials exhibit effective simultaneous photogeneration of small antibacterial NO and O2(1 ∆g) species under irradiation with daylight creating an antibacterial surface and near surrounding. NO species can be also generated just by gentle heating. Nanofiber materials were analyzed with SEM, FTIR, emission and UV/vis spectroscopy and time-resolved emission and absorption spetroscopy. The antibacterial effect was tested on Escherichia coli. The dual antibacterial action, in combination with the nanoporous character of the material that detains pathogens like bacteria on its surface, is ideal for any application where a sterile environment is neces- sary. The known bimetallic cluster system [(PMe2Ph)4Pt2B10H10] that possesses the propen- sity to reversibly bind small gaseous molecules (O2, SO2, CO) was synthesized in good yields for NO reversible binding investigation. Seven new monometallic precursors (Pt, Pd and Ni) to new bimetallic species were succesfully synthesized with the aim of future study of NO reversible binding. All new compounds were purified by...
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Photooxidative and photodisinfective polymeric nanofabrics: The effect of oxygen permeability
Jesenská, Soňa ; Mosinger, Jiří (advisor) ; Lang, Kamil (referee)
The diploma thesis compares the photophysical, photooxidative and photocytotoxic properties of four polymer nanofabrics with encapsulated 5,10,15,20 - meso - tetraphenylporphyrin (TPP). The main focus of the work lies especially in the study of the effect of polymer oxygen permeability on the ability of nanofabrics to produce singlet oxygen and the utilization of nanofabrics for measurement of the polymer oxygen permeability and polymer oxygen diffusion coefficients. A possible application of nanofabrics in the framework of oxygen detection, photooxidation of substrates and photodesinfection has been studied as well.
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