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Cell-biomaterial interactions in hard and soft tissue engineering
Zárubová, Jana ; Bačáková, Lucie (vedoucí práce) ; Mikšík, Ivan (oponent) ; Slepička, Petr (oponent)
Tkáňové inženýrství je interdisciplinární obor, který se snaží vytvořit náhrady poškozených tkání kombinací dvou základních složek, buněk a biomateriálů. Buňky jsou velmi citlivé ke svému mikroprostředí, což umožnuje ovlivňovat jejich chování různými vnějšími faktory nebo změnou vlastností biomateriálů. Úspěšná integrace implantátu do tkáně tak může být podpořena vhodnou drsností povrchu, chemickým složením, hustotou adhezních ligandů, stejně jako dostupností růstových faktorů. Tato práce se zaměřuje především na vývoj ortopedických náhrad a vylepšení aktuálně používaných cévních protéz. Studiem interakcí kostních buněk s biomateriálem bylo prokázáno, že povrchy s kombinovanou nanodrsností a mikrodrsností podporují rozprostření, proliferaci a metabolickou aktivitu těchto buněk. Na příkladu biomateriálů určených pro ortopedické implantáty byl demonstrován vliv chemického složení na proliferaci osteoblastů. Vyšší hustota buněk byla pozorována na kompozitech s 5-15 obj. % nanočástic fosforečnanu vápenatého, zatímco koncentrace 25 obj. % nepodporovala proliferaci buněk, přestože jejich viabilita nebyla ovlivněna. In vivo testy pak odhalily rozdíly mezi kompozity obsahujícími hydroxyapatitové a β-trikalciumfosfátové nanočástice, kde intenzivnější tvorba kostní tkáně byla pozorována na vzorcích...
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3D-bioprinted Gelatin/Alginate loaded with Carbon Nanotubes for tissue engineering application
Partovi Nasr, Minoo ; Zumberg, Inna ; Chmelíková, Larisa ; Fohlerová, Zdenka ; Provazník, Valentine
The objective of utilizing 3D-bioprinted Gelatin/Alginate loaded with Carbon Nanotubes (CNTs) in tissue engineering applications is to create scaffolds that closely mimic the natural extracellular matrix (ECM), thereby enhancing cell growth, proliferation, and differentiation. Gelatin and Alginate, both biocompatible materials, have been widely researched for their potential in bioprinting due to their similarity to the ECM, offering a conducive environment for cell encapsulation and tissue regeneration. The addition of CNTs to these hydrogels significantly improves the mechanical properties and stability of the scaffolds, making them more suitable for supporting tissue development. CNTs, known for their unique properties such as high tensile strength and electrical conductivity, contribute to the development of scaffolds that not only support mechanical stability but also can influence cellular behavior and tissue formation. This integration aims at enhancing the functionality of 3D-bioprinted scaffolds, enabling them to better support the formation and maturation of engineered tissues. Furthermore, the electrical conductivity of CNTs-loaded scaffolds can be exploited to stimulate electrical activity in tissues, such as cardiac and neural tissues, promoting organized tissue development and functionality. The strategic combination of Gelatin/Alginate with CNTs in 3D bioprinting offers a promising approach to tissue engineering, aiming to address the critical challenge of replicating the complex structure and function of natural tissues. This innovative methodology not only enhances the mechanical and structural properties of the scaffolds but also introduces new possibilities in tissue engineering through the electrical stimulation of tissues, paving the way for the creation of more complex and functional tissue constructs.
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Cell transplantation methods in cardiology
Kukhta, Dziyana ; Hežová,, Reneta (oponent) ; Skopalík, Josef (vedoucí práce)
This master’s thesis is devoted to tissue engineering, notably to creation homogeneous, isotropic and planar cardiac muscle cell layer using two technologies scaffold-based and scaffold-free. Firstly it describes the histology of heart wall, cardiac muscle cells, and cells cultures. This is followed by a description of tissue engineering, which includes cell sheet technology and scaffold-based tissue engineering. And at the end of the theoretical part application of tissue engineering and cell visualisation assay are described. The practical part is dedicated to the creation of a planar cell layer from cardiomyocytes and fibroblasts, using information from the theoretical part.
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Poly(3-hydroxybutyrate) based materials for 3D printing in medical applications
Krobot, Štěpán ; Vojtová, Lucy (oponent) ; Přikryl, Radek (vedoucí práce)
This master's thesis deals with the preparation and testing of 3D printed scaffolds for bone tissue engineering. The aim of the thesis is laboratory preparation of polymer blends on the basis of poly(3-hydroxybutyrate), poly(lactic acid) and polycaprolactone and their processing into the form of 3D printing filaments. Three polymeric blends were prepared and processed into the form of 3D printing filaments. Differential scanning calorimetry was conducted to evaluate the thermal properties, followed by temperature tower test and warping test to determine the processing conditions for 3D printing. The lowest warping coefficient was 1.26 for a blend of poly(3-hydroxybutyrate) with polycaprolactone and plasticizer. Tensile test, three-point flexural test and compression test were used to study the mechanical properties of materials. Scaffolds with different surfaces for bone tissue engineering were 3D printed from prepared filaments to determine the most optimal surface for cell proliferation. To determine the surface properties and their influence on cell adhesion, optical contact angle measurement with the use of OWRK method to calculate surface energy was conducted. 3D printed surfaces were also subjected to roughness analysis by confocal microscopy to determine their roughness and its effect on contact angle with water and cell growth. Finally, in the last part, in vitro tests on scaffolds were conducted in collaboration with the Institute of Experimental Medicine (Czech Academy of Sciences) to find out whether the prepared materials are non-cytotoxic and how the surface of scaffold affects the cell growth and proliferation. In the end, two out of three materials were proven to be non-cytotoxic (both blends of poly(3-hydroxybutyrate) with polycaprolactone) and that their mechanical properties were comparable with human trabecular bone. The most optimal surface for cell growth is probably grid diameter 50 m with roughness along the perimeter 1.9 m, which corresponds with water contact angle 74.1°.
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Comparison of various amination methods of polycaprolactone concerning their effectivity in tissue engineering
Kováč, Ján ; Lehocký, Marián (oponent) ; Zajíčková, Lenka (vedoucí práce)
This diploma thesis dealt with the comparison of different methods of amination of polycaprolcatone in terms of their effectiveness for tissue engineering. A polycaprolactone membrane was prepared by an electrospinning method, which was subsequently modified by three different amination methods. Selected types of amination were plasma polymerization with cyclopropylamine monomer, hybrid modification using plasma and N-allylmethylamine monomer, and chemical amination using aminolysis with diaminohexane. Surface amines were subsequently characterized by electron scanning microscopy (SEM), X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared spectroscopy (ATR-FTIR) and contact angle measurement. A cell culture designated A375 (Human malignant melanoma cell lines A375® CRL-1619®) was cultured on the thus modified membranes, which was analyzed by optical microscopy, and a proliferation assay was performed by determining the relative amount of ATP. Based on the experimental results, we can confirm the success for all types of amination. In terms of efficiency for tissue engineering, the amination method by plasma polymerization with the monomer cyclopropylamine has the most satisfactory results.
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Modification of Biodegradable Polyurethanes by Biologically Active Substances
Kupka, Vojtěch ; Khunová, Viera (oponent) ; Pekař, Miloslav (oponent) ; Vojtová, Lucy (vedoucí práce)
Presented dissertation thesis is focused on novel preparation of biodegradable polyurethanes (PUs) and their modification by biologically active cellulose nanocrystals. Literary review deals with current state of bioresorbable PUs used in tissue engineering. Examples of prepared PU elastomers, scaffolds and injectable PUs, together with biodegradation pathways to non-toxic products are summarized. The last part of the literary review is targeting on nanocellulose, which has gained much attention for the use as biomedical material due to its remarkable physical (high specific surface area, mechanical reinforcement) and biological (biocompatibility, biodegradability and low toxicity) properties. Experimental part presents characterization of biodegradable amphiphilic polyurethane films (bio-PUs) synthesized by solvent free polyaddition reaction of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(e-caprolactone) (PCL) as macrodiols with hexamethylene diisocyanate. Prepared bio-PUs were characterized on one hand by means of different PEG/PCL ratio and on the other hand by changing the isocyanate ratio between NCO/OH groups. Abrupt enhancement of mechanical properties was observed when PEG/PCL weight ratio was equal to or less than 20/80 and was ascribed to the PCL ability to form crystalline domains. The increasing amount of PEG promoted the ability of bio-PUs to absorb water and enhance the rate of hydrolytic degradation. Whereas, reducing the ability of bio-PUs to absorb water and prolonged time of hydrolytic degradation was achieved with increasing the crosslink density by enhancing the isocyanate ratio. The last part deals with novel solvent free preparation of nanocomposite utilizing bio-PU as a matrix and cellulose nanocrystals either neat or surface grafted by PEG. Structural analysis demonstrated that the presence of rod-like nanoparticles causes the immobilization of the PU chains in matrix resulting in increased stiffness and rigidity of bio-PU/cellulose nanocomposite. By adjusting the PEG/PCL ratio, the amount of isocyanate or the presence of nanofiller, the novel bio-PU material with desirable mechanical (toughness, flexibility) and physical (swelling, degradation) properties can be obtained. Prepared solvent free bio-PUs may advantageously be used in regenerative medicine for soft tissue regeneration (e.g. as vascular grafts).
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Implantáty pro nervový systém
Kuruc, Lukáš ; Zatloukal, Miroslav (oponent) ; Sedlaříková, Marie (vedoucí práce)
Predkladaná bakalárska práca sa zaoberá problematikou implantátov pre nervovú sústavu. Prvá časť je zameraná na teoretický rozbor tejto problematiky. Zahŕňa oboznámenie čitateľa s vážnosťou poranenia miechy, možnosti jej liečenia a regenerácie pomocou hydrogélových implantátov. V druhej časti je popísaná experimentálna výroba implantátov, testovanie priechodnosti implantátov a zhrnutie ich vlastností.
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3D tisk kmenových buněk a analýza mikroskopických obrazů
Kandra, Mário ; Svoboda, Ondřej (oponent) ; Kolářová, Jana (vedoucí práce)
V tejto diplomovej práci sa venujeme využitiu 3D biotlače v tkanivovom inžinierstve. Popisujeme využitie biomateriálov pri stavbe tkanivových nosičov a aplikáciu kmeňových buniek v 3D biotlači. V závere teoretickej časti špecifikujeme najpoužívanejšie techniky 3D biotlače so zameraním sa na vytlačovaciu techniku. V praktickej časti navrhujeme metódu 3D biotlače cievneho tkaniva. Ďalej realizujeme prototyp tlačovej hlavy, jej ná- vrch a 3D tlač jednotlivých dielov. K mechanickej časti vytvárame riadiací systém pre kontrolu tlače. Na záver si pomocou programových modulov viazualizujeme usporiadanie buniek.
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Tiskové hlavy pro 3D tisk hydrogelů s nízkou viskozitou
Havlíček, Václav ; Harabiš, Vratislav (oponent) ; Jaroš,, Josef (vedoucí práce)
V této bakalářské práci se věnuji 3D biotisku v tkáňovém inženýrství a rozebírám používané materiály a technologie, které lze pro 3D biotisk využít. V práci je také obsažena diskuze vybavení pro 3D biotisk a současné výzvy 3D biotisku metodou extruze. V praktické části je navrženo řešení extruzivního 3D biotisku nízkoviskózních hydrogelů pomocí hydraulické pumpy, vlastní tiskové hlavy a chladícího okruhu.
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The effect of biologicaly active substances on the structure and properties of collagenous substrates
Muchová, Johana ; Michlovská, Lenka (oponent) ; Vojtová, Lucy (vedoucí práce)
The thesis deals with the preparation of 3D porous collagen scaffolds by freeze-drying and their modification with bioactive compounds. The natural polysaccharides, chitosan, calcium oxidized cellulose and chitin/chitosan-glucan complex for the modification have been used. The mechanical properties of the scaffolds have been enhanced by crosslinking process with carbodiimides. Growth factors have been delivered in the form of platelet lysate. The influence of biologically active additives, crosslinking agents, and enrichment with growth factors on the properties of the prepared scaffold and their bioactivity in tissues of living organisms have been investigated. Specifically, this study includes the morphological properties, structure, porosity, swelling stability, chemical composition, temperature of denaturation and biological properties. Scanning electron microscopy, infrared specktroscopy, differential scanning calorimetry and confocal microscopy have been used to the characterization. Prepared collagen substrates involving bioactive additive and platelet lysate could be used as scaffold for growing cells in systems with low mechanical loading and which has potential application in biomedicine.
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