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Methodological detection solution scaffolds response to mechanical stress, depending on the degree of hydration
Mejzlíková, Kateřina ; Jelen, Karel (advisor) ; Kubový, Petr (referee)
Title: Methodological detection solution scaffolds response to mechanical stress, depending on the degree of hydration Objectives: Determining the extent of lateral deformation u scaffolds made of PVA polymer electrospinning technique. Identify the extent of differences in transverse deformation for different groups of nanofiber scaffolds made of PVA polymer electrospinning technique. Methods: Research scaffolds, we used a measuring device μ-tester, which has two jaws. For the measurement, we chose uniaxial tension test in -tester and record the fluorescence microscope was used with HD camera Olympus 320 for online video recording. Results: The results of this study showed that the ratio of the samples U: L and crosslinking time affects the degree of lateral deformation of the samples scaffolds. Samples scaffolds are compressible, some groups even reached the limits of incompressibility 0.5 Poisson's ratio. Keywords: Poisson, Poisson's ratio, scaffold, nanofiber scaffold, scaffold hydrated, electrospun scaffold, lateral deformation
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Kompozitní pěnové nosiče pro tkáňové inženýrství kostí
Kuntová, Henrieta ; Rampichová, Michala (advisor) ; Krulová, Magdaléna (referee)
The goal of my work was to introduce the fast pacing field of tissue engineering with focus on bone regeneration. Tissue engineering could be a future alternative to the currently used conventional approaches that suffer from healing failures. Due to increasing demand for bone tissue replacement damaged by degenerative diseases or injuries, many laboratories have attempted to come up with solutions in a form of artificial constructs. In the present light of interest are composite scaffolds usually made of polymer and ceramic combinations. Their main advantage is that they combine elasticity and tensile strength of a polymer with bioactivity and mechanical hardness of a ceramic, while removing drawbacks of each material. Powered by TCPDF (www.tcpdf.org)
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Use of biological materials for tissue substitution in plastic surgery
Měšťák, Ondřej ; Sukop, Andrej (advisor) ; Brychta, Pavel (referee) ; Dražan, Luboš (referee)
Užití biologických materiálů k náhradě tkání v plastické chirurgii ! Abstrakt v angličtině Background: Biological meshes are biomaterials consisted of extracellular matrix and used in surgery particularly for hernia treatment or thoracic wall reconstruction. They are capable of vascularization, that decreases risk of infection, expecially when used in contaminated fields. This study compared the strength of incorporation and biocompatibility of two porcine-derived grafts (cross-linked and non-cross-linked) in a rat hernia model. In addition, we hypothesized that combination of extracellular matrices with autologous mesenchymal stem cells used for hernia repair would result in increased vascularization and increased strength of incorporation. Methods: Standardized 2 x 4 cm fascial defect was created in 42 Wistar rats and repaired with a cross-linked or a non-cross-linked graft either enriched or non-enriched with stem cells. The rats were sacrificed 3, 6 and 12 months later. The strength of incorporation, vascularization, cellular invasion, foreign body reaction and capsule formation were evaluated. Results: Comparison of stem cell enriched and non-enriched groups showed no significant differences in the capsule thickness, foreign body reaction, cellularization or vascularization. In the non-cross-linked...
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Biomechanical response of scaffold on mechanical loading
Anděrová, Jana ; Jelen, Karel (advisor) ; Amler, Evžen (referee)
The purpose of this work is to identify the parameters of scaffold's mechanical properties by observing/monitoring their response to defined external mechanical strain. The first part of the work is summarizing the knowledge about the required properties of scaffolds, their production and the factors influencing production. The practical part of the work concerns itself with measurement, analysis and evaluation of data based on proprietary methodology. Based on the results at this stage of the research, we can confirm, that scaffolds have viscoelastic, or viscoplastic character and its response depends on the magnitude of deformation, state of hydration, ratio of solutions and period of networking. Keywords: scaffod, tensile test, rheologic model
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3D Printing of Ceramic Bone Grafts with Different Internal Architecture
Novotná, Lenka ; Sekora, Jiří (referee) ; Provazník, Ivo (advisor)
Bioceramics in the form of scaffolds hold great promise in bone tissue regeneration. While the scaffold composition is important for biocompatibility, the internal architecture plays a key role in allowing proper cell penetration, nutrient diffusion, bone ingrowth, vascularization as well as mechanical properties. A solid freeform fabrication is a promising processing technique, allowing to study structural parameters independently. This bachelor thesis is focused on ceramic bone replacements with different internal structure. The thesis is divided into 8 chapters. The first four chapters briefly summarize the current state of the art in the following fields: bone structure, requirements for synthetic bone replacements, scaffold architecture, and fabrication methods with an emphasis on 3D printing. The next chapters deal with experimental part. The image analysis of mouse skeleton was performed. On the basis of the measured pore size (50 200 m) and according to the literature search, 16 structures with various shape, curvature and pore size were designed. The CAD models were printed by a stereolithography from a tricalcium phosphate dispersion. Sintered ceramic scaffolds exhibited an ideal structure for application in bone tissue engineering. Scaffolds contained both interconnected macro- and micropores of optimal sizes up to 500 m and about 3 m, respectively. The results confirm that stereolithography is suitable, and compared to others, precise method for preparing scaffolds having different internal structures. The individual structural characteristics influencing the scaffold behaviour will be possible to study independently to each other. And thus improve the scientific knowledge in the field of treatment of large segmental bone defects.
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Histomorphological Changes in Normal and Pathological Cartilage Tissues and after their Experimental and Clinical Transplantation
Kaňa, Radim ; Nečas, Emanuel (advisor) ; Slípka, Jaroslav (referee) ; Ludvíková, Marie (referee)
1 Abstract Introduction Autologous transplants of the cartilage tissue from the pinna is commonly used in reconstructive surgery of the nasal skeleton. The present study used animal models to elucidate responses of the auricular cartilage to its damage or transplantation to ectopic sites. Histomorphological analysis of changes observed in auricular cartilage including immunohistochemical study of different isoforms of actin and S-100 proteins was performed. Human articular cartilage prepared by in vitro cultivation using artificial scaffolds was also studied after its transplantation. Aims of the study The aim was to study histological changes and expression of chondrocytic markers (α- SMA and S-100 proteins) in intact, artificially traumatised, or in a human auricular cartilage cultivated in culture medium. An attempt to grow human auricular cartilage chondrocytes implanted in vitro into various types of three dimensional scaffolds aimed at testing chondrocyte survival and phenotype both in the culture and after transplantation to immunodeficient mice. A human auricular cartilage transplanted into the nasal skeleton of patients during a reconstruction surgery should be submitted to a histomorphological examination. Research assumed also comparison of the auricular cartilage responses to a damage,...
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The effect of biologicaly active substances on the structure and properties of collagenous substrates
Muchová, Johana ; Michlovská, Lenka (referee) ; Vojtová, Lucy (advisor)
Diplomová práce se zabývá přípravou 3D porézních kolagenových skafoldů metodou lyofilizace a jejich modifikací bioaktivními látkami. K modifikaci byly použity přírodní polysacharidy – chitosan, vápenatá oxidovaná celulóza a chitin/chitosan-glukanový komplex. Mechanické vlastnosti skafoldů byly upraveny síťováním pomocí karbodiimidů. Růstové faktory byly dodány formou destičkového lyzátu. Byl zkoumán vliv biologicky aktivních aditiv, siťovacího činidla a obohacení růstovými faktory na vlastnosti připravených skaffoldů a jejich bioaktivitu v tkáních živých organismů. Konkrétně byly studovány morfologické vlastnosti, struktura, porozita, botnání, stabilita, chemické složení, teplota denaturace a biologické vlastnosti. K charakterizaci byly použity metody rastrovací elektronová mikroskopie, infračervená spektroskopie, diferenční kompenzační kalorimetrie a konfokální mikroskop. Připravené kolagenové substráty obohaceny bioaktivním aditivem a destičkovým lyzátem mohou být využity v biomedicíně jako skafoldy pro růst buněk v systémech s nízkou mechanickou zátěží.
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Bioceramic Materials for Advanced Medical Applications
Novotná, Lenka ; Lapčík,, Lubomír (referee) ; Drdlíková, Katarina (referee) ; Cihlář, Jaroslav (advisor)
Cílem disertační práce bylo připravit trojrozměrné biokeramické podpůrné systémy („skafoldy“), které by v budoucnu mohly pomoci při rekonstrukci a regeneraci poškozených kostních tkání. Porézní keramické pěny byly připraveny dvěma způsoby – replikační technikou a polymerizací in situ. Co se složení týče, byly studovány keramické materiály zejména na bázi oxidu hlinitého, zirkoničitého a kalcium fosfátů. Byl studován jednak vliv procesních parametrů jako je složení suspenzí a jejich viskozit, dále pak vliv tepelného zpracování na strukturu a výsledné vlastnosti připravených materiálů. U slinutých pěn byla pomocí rastrovací elektronové mikroskopie hodnocena zejména morfologie – velikost pórů, jejich propojenost a celková porozita, charakterizace mikrostruktury nebyla opomenuta. Dále bylo stanoveno fázové složení a pevnost v tlaku. Z biologických vlastností byla testována a diskutována bioaktivita a cytotoxicita materiálů. Disertační práce je členěna do několika částí. V literární rešerši je popsána stavba a vlastnosti kosti, požadavky kladené na kostní náhrady, výhody a nevýhody současně používaných materiálů a způsoby přípravy keramických pěn. Následuje experimentální část, kde byly nejprve studovány pěny připravené replikační technikou. Všechny takto vyrobené pěny měly propojené póry o velikostech 300 až 2000 m, celková porozita se pohybovala v rozmezí 50 – 99 %. Pevnost pěn na bázi kalcium fosfátů – 0,3 MPa (při celkové porozitě 80%) byla nedostatečná pro kostní náhrady, kde je požadována pevnost větší než 2 MPa. Kalcium fosfátové keramiky byly tedy zpevněny buďto inertním jádrem na bázi oxidu hlinitého nebo ATZ (oxidem zirkoničitým zhouževnatělým oxidem hlinitým). Dále byl přípraven částicový kompozit, ve kterým byl hydroxyapatit pojený oxidem křemičitým. Pevnost pěn se podařilo zvýšit až na více než 20 MPa. V poslední kapitole experimentální části byly studovány keramické pěny pěněné in situ, kde byly póry vytvářeny oxidem uhličitým unikajícím během reakce mezi diisokyanátem a polyalkoholem. Po vypálení polymerního pojiva měly pěny propojené póry o průměrné velikosti 80 až 550 m. Celková porozita se pohybovala v rozmezí 76 – 99%. Výhodou oproti replikační technice byly plné trámečky bez velké středové dutiny vznikající vypálením polymerní předlohy. Žádný ze studovaných materiálů nebyl pro buňky toxický, navíc všechny studované pěny vykazovaly bioaktivní chování. Z hlediska kostního tkáňového inženýrství se jako nejslibnější jeví kompozitní materiál zpevněný oxidem křemičitým.
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Residence Erasmus - preparation, implementation and project management
Dokoupil, Jan ; Brno,, Alexander Lazar, IMOS (referee) ; Hrazdil, Václav (advisor)
This diploma thesis deals with the construction of a residential building The Erasmus Residence. This work includes a technical report of the issue solved, construction site installations of three phases of construction, which are groundwork, rough top construction and finishing. The work includes drawings of construction site installations for all these stages. The thesis also includes technological specification for thermal insulation systems including scaffolding construction, timing of construction, inspection and quality test plan and itemized budget.
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Ceramic materials applied in medicine - challenges and opportunities
Vitásek, Ladislav ; Sláma, Martin (referee) ; Novotná, Lenka (advisor)
This thesis deals with ceramic materials applied in medicine, mainly in orthopaedics and dentistry. The first part is focused on requirements and current state of biomaterials in bone tissue engineering and their advantages and disadvantages. Composite materials, where ceramic material is one component at least, are mentioned in the next part. Dense ceramics based on alumina and toughened zirconia is described in the separate part. The main part of this thesis deals with porous ceramic materials based on calcium phosphates. There are also defined scaffolds requirements such as porosity, mechanical and biological properties and moreover processing methods. The experimental part of this thesis has been devoted to the preparation of bioactive porous ceramic material based on hydroxyapatite and silica with improved properties. Samples with different amount of silica in structure (6-21 wt%) were fabricated by polymer replica technique. Prepared scaffolds with structure similar to cancellous bone can be promising candidates for using in bone tissue engineering applications.
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