National Repository of Grey Literature 45 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
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.
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
Photoactive Nafion membrane photogenerate reactive oxygen species
Nentvich, Daniel ; Mosinger, Jiří (advisor) ; Jindřich, Jindřich (referee)
Herein you found that transparent Nafion membrane can serve as a matrix for cationic photosensitizers photogenerating reactive O2(1 Δg). Moreover, was found that Nafion itself without photosensitizer in a presence Fe3+ is an effective source of reactive oxygen species upon activation by UV and or visible light. Keywords Reactive oxygen species; singlet oxygen; Nafion; photosensitizer
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...
The study of photogeneration of hydrogen peroxide by nanofibers with encapsulated photosensitizer
Perlík, Martin ; Mosinger, Jiří (advisor) ; Kubát, Pavel (referee)
This study is dedicated to characterisation of photosensitisation properties of polymeric nanofibres with encapsulated photosentisitiser. Main goal of thesis is demonstration and study of H2O2 photoproduction. Photosensitizer used in this study was 5,10,15,20-meso-tetrafenylporfyrin (TPP), studied were also its complexes with Cu2+ a Ni2+ . Properties of nanofibers were examined using UV-Vis molecular absorption spectroscopy, fluorescence spectroscopy and electron microscopy (SEM).
Synthesis of anionic phthalocyanines as potential photodynamic active photosensitizers
Kollár, Jan ; Zimčík, Petr (advisor) ; Mosinger, Jiří (referee) ; Zitko, Jan (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Mgr. Jan Kollar Supervisor: prof. PharmDr. Petr Zimcik, Ph.D. Advisor: doc. PharmDr. Veronika Novakova, Ph.D. Doctoral Thesis: Synthesis of anionic phthalocyanines as potential photodynamic active photosensitizers Phthalocyanines (Pcs) and their aza-analogues (e.g. tetrapyrazinoporphyrazines, TPyzPzs) represent a promising group of organic dyes with interesting photophysical properties (strong absorption in area 650-750 nm, strong singlet oxygen production) highly suitable for the use in photodynamic therapy (PDT) of cancer. However, they have also some drawbacks lowering their potential use in PDT (low solubility in water, strong tendency to aggregate). The topic of my dissertation thesis closely follows the topic of my diploma thesis, during which TPyzPz with sixteen carboxylate groups in rigid arrangement was prepared and in which we have disclosed strong negative effect of low pH and serum proteins on photodynamic activity. In the first part of this thesis I prepared new zinc TPyzPz with eight sulfonate groups on periphery, which was characterised by good solubility in water. Sulfonates were chosen as stronger acids than carboxylic groups, so they were...
Study of novel phthalocyanine and azaphthalocyanine photosensitizers for the photodynamic therapy of cancer
Macháček, Miloslav ; Šimůnek, Tomáš (advisor) ; Řezáčová, Martina (referee) ; Mosinger, Jiří (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of biochemical sciences Candidate Mgr. Miloslav Macháček Supervisor doc. PharmDr. Tomáš Šimůnek, Ph.D. Title of Doctoral Thesis Study of novel phthalocyanine and azaphthalocyanine photosensitizers for the photodynamic therapy of cancer. Photodynamic therapy (PDT) of cancer is non-invasive treatment modality for solid tumour treatment using three basic components - molecular oxygen, light and photosensitizer (PS). These elements are essentially non-toxic on their own, but in the combination they induce reactive oxygen species (ROS; singlet oxygen mainly) production, causing damage to cellular components and subsequent cell death. Type of cell demise is dependent mainly on the type of PS, length of irradiation and subcellular localization of the drug. Singlet oxygen is highly reactive and is capable of limited diffusion in biological environment. Apart from direct cytotoxic effect, vascular shutdown (oxygen and nutrition deprivation) and activation of immune system are involved in tumour eradication. Combination of effective compound with delivery system, conjugation with targeting substances or synthesis of highly effective non-aggregating water soluble compounds are the main pathways in design of modern PSs. In our...
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...
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.
Polystyrene photoactive nanomaterials producing singlet oxygen
Henke, Petr ; Mosinger, Jiří (advisor) ; Dědic, Roman (referee) ; Kolářová, Hana (referee)
The increasing number of multidrug-resistant strains of bacteria call for alternatives to antibiotic therapy and, more generally, for the antimicrobial material as a component of prevention. Of particular interest is the photodynamic inactivation of bacteria and other pathogens caused by photogenerated singlet oxygen. This work is focused on the field of photoactive polymer nanofiber membranes and nanoparticles, generating singlet oxygen, suitable for medical applications. We prepared different types of photoactive modified polystyrene nanofiber membranes with encapsulated or externally bound porphyrin photosensitizers. These materials efficiently produce highly reactive and cytotoxic singlet oxygen capable of restricted diffusion into to the external environment. Our results demonstrate the crucial role of wettability for materials of this type with a short diffusion length of generated singlet oxygen, illustrate the effect of temperature and indicate their potential use as multifunctional materials. Due to their antimicrobial properties, these materials are suitable alternative to antibiotics and local antiseptics. With good breathability and short diffusion length of singlet oxygen good results can be expect in in vivo tests. From these nanofiber materials we also prepared photoactive extremely...

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