National Repository of Grey Literature 65 records found  beginprevious31 - 40nextend  jump to record: Search took 0.00 seconds. 
The Growth of vascular and skin cells on polymer materials for tissue engineering
Bačáková, Markéta ; Bačáková, Lucie (advisor) ; Smetana, Karel (referee) ; Daniel, Matej (referee)
The ideal vascular or skin substitute is able to simulate the functions of original vascular or skin tissue. To reach this goal, the tissue substitute should be based on a biomaterial scaffold of an appropriate structure and desirable physical and chemical properties. These properties strongly influence successful implantation of the substitute to the patient's organism, substitute durability in the organism, and the desired colonization of the scaffolds with cells. These properties have a great impact on the adhesion, proliferation, differentiation, and desired phenotypic maturation of cells. Most of the biomaterials used for constructing clinically used tissue substitutes do not have appropriate properties for sufficient cell colonization, and thus their surface modification is needed. This thesis focuses on the improvement of biomaterial surface properties for successful cell colonization by plasma treatment, or by grafting and coating biomaterials with bioactive substances and extracellular matrix proteins. The modification of polyethylene (PE) foils by Ar+ plasma discharge showed a positive effect on the spreading, proliferation, and phenotypic maturation of vascular smooth muscle cells (VSMC). Subsequent grafting of the plasma-activated surface with bioactive substances further influenced cell...
Structure-function organization of the cell nucleus.Microscopical analysis of nuclear subcompartments.
Jůda, Pavel ; Cmarko, Dušan (advisor) ; Mokrý, Jaroslav (referee) ; Kučera, Tomáš (referee) ; Smetana, Karel (referee)
Pavel Jůda - Abstract The cell nucleus is a complex cellular organelle. The nucleus and nuclear processes are organized into functionally and morphologically separated nuclear subcompartments. This thesis is particularly concerned with the three following nuclear subcompartments: sites of DNA replication, Polycomb bodies and nuclear inclusions constituted of inosine monophosphate dehydrogenase 2 (IMPDH2). First, we examined the relationship between MCM proteins and DNA replication. Using immunofluorescent labeling of cells extracted prior fixation and applying cross-correlation function analysis, we showed that MCM proteins are present at the sites of active DNA synthesis. Our results contributed to the solving of the first part of so-called MCM paradox. Second, we studied the structural basis of the Polycomb bodies. Based on fluorescence microscopy studies, Polycomb bodies have been considered to be the nuclear subcompartments formed by the accumulation of Polycomb proteins in the interchromatin compartment. In our work, using correlative light electron microscopy and experimental changes in macromolecular crowding, we clearly showed that a Polycomb body is a chromosomal domain formed by an accumulation of heterochromatin structures, rather than a typical nucleoplasmic body. Third, we were interested in...
Healing wound as a model for the study of cell interactions
Gál, Peter ; Smetana, Karel (advisor) ; Motlík, Jan (referee) ; Brábek, Jan (referee)
Healing wound as a model for the study of cell interactions Abstract Galectins play an important role in the processes of cell proliferation, differentiation, migration and extracellular matrix formation. Furthermore, galectins are able to transfer cellular signals and to participate in cell interaction. It has been proven that galectins play an important role in the microenvironment formation of a tumor and/or healing wound. This study demonstrated significant role of galectins, in particular Galectin-1, in wound healing and cell interactions (endothelial cells, fibroblasts and keratinocytes) forming a part of the granulation tissue and tumor stroma. We have demonstrated that the extracellular matrix rich on Galectin-1 creates a suitable environment for the cultivation of keratinocytes. Galectin-1 also induces differentiation of fibroblasts into myofibroblasts. The knowledge of above mentioned processes is important to better understand the complexity of cancer biology and its parallel to wound healing. Key words: tissue repair, regeneration, galectin, tumor
Immunocompetent cells and their importance in immunopathological conditions
Podrazil, Michal ; Bartůňková, Jiřina (advisor) ; Reiniš, Milan (referee) ; Smetana, Karel (referee)
Pokroky v současné imunologii vedou k lepšímu porozumění interakcí mezi imunitním systémem a nádory, což vzbuzuje zájem o využití imunitního systému v léčbě nádorových onemocnění. V úvodní části práce jsou shrnuty teoretické poznatky o mechanismech protinádorové imunitní odpovědi a jednotlivých složkách imunitního systému podílejících se na tomto procesu. Ústřední úlohu v této interakci reprezentují dendritické buňky. Právě jejich využitím v klinické medicíně se dlouhodobě zabývá naše pracoviště. V této práci se věnuji několika dílčím cílům. První z nich je analýza zastoupení jednotlivých subpopulací imunokompetentních buněk v imunoterapeutickém léčivém přípravku na bázi dendritických buněk proti karcinomu prostaty- DCVAC/PCa vyvinutého na Ústavu imunologie, dále praktickým aspektům přípravy této formy aktivní buněčné imunoterapie a její optimalizaci za podmínek správné výrobní praxe. Výsledky této části byly součástí farmaceutické dokumentace, která vedla ke schválení výrobního postupu i zahájení klinických studií u pacientů s karcinomem prostaty regulačními autoritami. Dalším krokem bylo následné praktické testování imunoterapie DCVAC/PCa nejprve v pilotní "first-in-men" aplikaci u pacienta s pokročilým metastatickým karcinomem prostaty a následně klinické hodnocení tohoto preparátu v rámci 2...
Novel avenues for the preparation of antifouling scaffolds for tissue engineering
Kostina, Nina ; Michálek, Jiří (advisor) ; Smetana, Karel (referee) ; Vlček, Petr (referee)
Non-specific protein adsorption -protein fouling- is an adverse effect occurring at the surface of most artificial materials which come into contact with biological fluids, affecting various biomedical devices and tissue engineering scaffolds. In order to address this ubiquitous problem the preparation of scaffolds resistant to protein fouling (antifouling) was proposed. The main goal of this Thesis was the development of strategies for the preparation of antifouling scaffolds for tissue engineering. The work consisted of three steps: (i) the selection of monomers leading to antifouling properties by utilizing model system based on polymer brushes; (ii) preparation of antifouling hydrogels of different properties and architecture by copolymerization with zwitterionic carboxybetaine monomers, selected from model experiment; and (iii) modification of the surface of poly( -caprolactone) (PCL) nanofibers by growing four types of polymer brushes resistant to protein fouling. The scaffolds presented in this work showed variety of unique properties, such as hydration (up to 30000%), elongation (up to 1800%), self-healing, biodegradation, availability of functional groups and complex pore structure. Importantly, all scaffolds showed significant reduction of protein fouling and non-specific cell adhesion and can be...
Nanotechnology and biomaterials for application in cell therapy of spinal cord injury
Vaněček, Václav ; Haninec, Pavel (referee) ; Smetana, Karel (referee)
New approaches for the treatment of SCI use advances in the fields of nanotechnology, biomaterial science and cell therapy. The results presented in this thesis showed that superparamagnetic iron oxide nanoparticles coated with a stable dopamine-hyaluronane associate can be used for the safe and effective labeling of MSC. Cell labeling efficiency, viability and the relaxivity of the tested particles were significantly better than those obtained with the commercial particles Endorem®. The DPA-HA coated nanoparticles can be used for the noninvasive monitoring of cell therapy using MRI. Furthermore, we showed that SPION can be used for the targeted delivery of MSC to the site of a spinal cord lesion. The labeled cells can be concentrated in the lesion area by means of a magnetic implant. The process of cell targeting depends on the physical characteristics of the magnetic implant as well as on the biological features of the cells and nanoparticles, as we described with a proposed mathematical model. It is possible to modify the properties of the magnetic system, e.g. by changing the shape or size of the magnet, thus tuning the magnetic force distribution and the gradient of the magnetic field necessary for effective cell targeting. A promising therapeutic strategy for the treatment of spinal cord injury is the...
Immunocomplexes of IL-2 and anti-IL-2 mAbs as a novel class of selective and extremely potent immunostimulators
Tomala, Jakub ; Kovář, Marek (advisor) ; Smetana, Karel (referee) ; Špíšek, Radek (referee)
vi ABSTRACT IL-2 has been used in cancer therapy and also for other applications like treatment of chronic viral infections or as an adjuvant for vaccines. However, treatment with IL-2 is rather difficult due to its severe side effects. These toxicities, associated with high-dose treatment necessary for IL-2 to function, have been found the most limiting factor for IL- 2 applications. Further, particular anti-IL-2 monoclonal antibodies (mAb) can actually increase biological activity of IL-2 rather than block it. Binding of IL-2 to anti-IL-2 mAb creates a superagonistic immunocomplexes which have dramatically higher and selective biological activity in comparison to free IL-2 in vivo. Such approach may finally over- come the difficulties associated with administration of IL-2, thus opening brand new scopes for IL-2 and its application not only in the field of tumor therapy. We have shown that IL-2 immunocomplexes composed of IL-2 and anti-IL-2 mAb S4B6 (IL-2/S4B6) stimulate predominantly cells expressing CD122 and CD132 (dimeric IL-2 receptor), i.e. NK and MP CD8+ T cells, with Treg,  T and NKT cells being expanded as well. IL-2/S4B6 are able to drive the expansion of activated naive CD8+ T cells into functional memory-like CD8+ T cells. Moreover, these immunocomplexes exert therapeu- tical potential alone...
Glycobiology of the head and neck cancer
Valach, Jaroslav ; Smetana, Karel (advisor) ; Dřízhal, Ivo (referee) ; Říhová, Blanka (referee)
iii Abstract Glycobiology represents a very progressive subject of cell biology. Protein-saccharide interactions play not only supporting and cell organization role, but they also represent medium for information storage and its decoding. Galectins, group of animal lectins (saccharide-binding proteins), which have selective affinity to ß-galactosides, are multifactorial molecules. They participate in cell-cell and cell-matrix interaction, transmembrane signaling, apoptosis, pre- mRNA splicing and are also present in various types of carcinomas. High expression of galectin-1 has been detected in cancer stroma originated from squamous cell epithelium. In the previous study we established that the fibroblasts - myofibroblasts transition, apart from the known TGF- beta, is also induced by galectin-1. We compared relationship between galectin-1 expression, presence of myofibroblasts and gene expression in tissue samples from patients with head and neck squamous cell carcinoma. Cancer stroma with myofibroblasts was rich in galectin-1 expression in comparison with stroma without myofibroblasts. Moreover, we used microarray analysis (ILLUMINA) to compare the whole genome transcriptome from samples with and without presence of galectin-1. High expression of galectin-1 in tissue samples corresponded with expression...
Interactions of vascular and bone cells with bioactive polymers for construction of tissue replacements
Pařízek, Martin ; Bačáková, Lucie (advisor) ; Smetana, Karel (referee) ; Hrubý, Martin (referee)
This work deals with the interaction of cells with surface-modified existing or newly created materials developed for vascular and bone tissue engineering, and also for controlled drug delivery into implants. In the first part of this work, we modified the surface of the polyethylene foil by Ar plasma, and then we grafted them with bioactive molecules (glycine, polyethylene glycol, albumin) and with C or Au nanoparticles. These modifications improved the chemical and physical characteristics of the material for the adhesion and growth of vascular smooth muscle cells (VSMC), and also for their phenotypic maturation towards the contractile fenotype. In future, these modifications can be also used for material currently used for fabrication of clinically used vascular prostheses in order to increase their biocompatibility. The aim of the second part of this work was to develop a perivascular drug-delivery system that would release the antiproliferative drug Sirolimus. This perivascular system is designed to be wrapped around a venous graft, implanted to the arterial position, such as in the case of the aortocoronary bypass. The system comprises a polyester mesh, which ensures the mechanical stability of the system and of the venous wall, and a copolymer of L-lactide and ε-caprolactone (Purasorb), serving as a...
Nanotechnology and biomaterials for application in cell therapy of spinal cord injury
Vaněček, Václav ; Syková, Eva (advisor) ; Smetana, Karel (referee) ; Haninec, Pavel (referee)
New approaches for the treatment of SCI use advances in the fields of nanotechnology, biomaterial science and cell therapy. The results presented in this thesis showed that superparamagnetic iron oxide nanoparticles coated with a stable dopamine-hyaluronane associate can be used for the safe and effective labeling of MSC. Cell labeling efficiency, viability and the relaxivity of the tested particles were significantly better than those obtained with the commercial particles Endorem®. The DPA-HA coated nanoparticles can be used for the noninvasive monitoring of cell therapy using MRI. Furthermore, we showed that SPION can be used for the targeted delivery of MSC to the site of a spinal cord lesion. The labeled cells can be concentrated in the lesion area by means of a magnetic implant. The process of cell targeting depends on the physical characteristics of the magnetic implant as well as on the biological features of the cells and nanoparticles, as we described with a proposed mathematical model. It is possible to modify the properties of the magnetic system, e.g. by changing the shape or size of the magnet, thus tuning the magnetic force distribution and the gradient of the magnetic field necessary for effective cell targeting. A promising therapeutic strategy for the treatment of spinal cord injury is the...

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