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Application of the stem cells in bone tissue engineering
Kročilová, Nikola ; Bačáková, Lucie (advisor) ; Eckhardt, Adam (referee)
Problems with musculoskeletal system, such as of developmental disorders, fractures or damage of the bone by age, inflammatory or tumor diseases, are still increasing in orthopaedics. Sometimes the bone tissue is not capable to completely regenerate to exert its physiological function in the organism. For this reason, using the bone replacements is necessary and common nowadays. Despite of an intensive research and testing of a wide range of the potential biomaterials and their combinations, the usage of metal materials for construction of the bone implants, still remains to be the gold standard. Ti-6Al-4V alloy is one of the commercialy used metal materials, which is known for the high mechanical and chemical resistance and a good biocompatibility. For a good biological response of the patient's organism for the bone implant, is an ability of osteointegration into the surrounding bone tissue, the key. This ability can be influenced in the case of the metals, by their surface structure. As it is known from earlier studies, the surface topography of the material is very important for the adhesion and proliferation of the bone cells, which are able to discriminate, very sensitively, between various stages of the material surface roughness. For this reason we have focused on studying of an influence...
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The biocompatibility and potential cytotoxicity of materials for joint replacement manufacturing and coating
Kopová, Ivana ; Bačáková, Lucie (advisor) ; Hubálek Kalbáčová, Marie (referee) ; Jendelová, Pavla (referee)
Currently used prostheses for total joint replacement still have numerous disadvantages: extreme stiffness or elastic modulus of the bulk metallic material; insufficient integration of the implant into the host bone; and a high wear and corrosion rate, which causes an accumulation of mostly metallic or polymeric wear debris. Because of these reasons, many patients experience increasing local pain, swelling, allergic reactions, and inflammation resulting in bone loss and the aseptic loosening of the implant leading to the need for painful and expensive revision surgery. To address the mechanical issues of commonly used orthopaedic alloys, this thesis presents the development of the new β-type titanium alloy Ti-35Nb-7Zr-6Ta-2Fe-0.5Si with a relatively low elastic modulus (up to 85 GPa), increased tensile strength (880 MPa), and enhanced biocompatibility and osteoconductivity. Considering the generally low osteoinductivity of metallic implants, various surface modifications and coatings have been developed to improve the cell-material interaction, e.g. carbon-based coatings. Among these coatings, C60 fullerene layers have emerged as a great candidate for coating orthopaedic implants due to their therapeutic potential in arthritis. The potential cytotoxicity and DNA damage response of fullerenes have...
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Cell-biomaterial interactions in hard and soft tissue engineering
Zárubová, Jana ; Bačáková, Lucie (advisor) ; Mikšík, Ivan (referee) ; Slepička, Petr (referee)
Tissue engineering is an interdisciplinary field which aims to create substitutes of damaged tissues by combining cells with biomaterials. Cells are extremely sensitive to their microenvironment and so the cell response to biomaterials can be regulated by different extrinsic stimuli and alterations of biomaterial properties. Successful implant integration into the tissue can therefore be promoted by appropriate surface roughness, chemical composition, adhesion ligand density, as well as the availability of growth factors. This thesis mainly focuses on the development of orthopedic replacements and the improvement of the currently used blood vessel prostheses. Through the study of cell-biomaterial interactions, it was demonstrated that superimposed topography with features ranging from the nano to micro scale promotes cell spreading, proliferation, and the metabolic activity of osteoblast-like cells. Moreover, when comparing the chemical composition of biomaterials for orthopedic implants, higher osteoblast densities were observed on composites with 5-15 vol. % of calcium phosphate nanoparticles, while concentrations of 25 vol. % did not support cell proliferation. Cell viability, however, was not affected. In vivo, a more intensive formation of new bone tissue, was found on samples containing...
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Cell growth on biomaterials for skin replacements and wound dressings
Kudláčková, Radmila ; Bačáková, Lucie (advisor) ; Rösel, Daniel (referee) ; Eckhardt, Adam (referee)
Tissue engineering is an emerging interdisciplinary field developing new ways of treatment of patient's tissue defects using artificial substitutes. Skin tissue engineering is developing skin substitutes and wound dressings that would replace current treatment using autologous, allogeneic or xenogenic substitutes. There are high demands on materials which should serve as a scaffolds for dermal fibroblasts and keratinocytes. They must be non-cytotoxic and biodegradable with a rate proportional to formation of a new tissue. The materials should support adhesion and proliferation of the cells and even they could release growth factors and antimicrobial substance to enhance healing and new tissue formation. In this master thesis, the cell adhesion and proliferation were evaluated on sodium carboxymethyl cellulose (Hcel® NaT), poly-ε-caprolactone (PCL), poly-L-lactide-co-ε-caprolactone (PLA/PCL) and cellulose acetate (AC) nanofiber membranes. Primary human dermal fibroblasts and HaCaT cell line keratinocytes were selected for evaluation. The cell adhesion was observed by fluorescent microscopy, the proliferation was determined by metabolic assay (WST-1) and the material cytotoxicity was evaluated in xCELLigence® system. Materials did not show cytotoxic effects on the cells. However, the materials did...
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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...
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Adhesion, growth and potential immune activation of cells on metallic materials for bone implants.
Straňavová, Lucia ; Bačáková, Lucie (advisor) ; Filová, Elena (referee)
The contemporary orthopaedics and traumatology of the musculoskeletal system and stomatology have been witnessing a substantial increase in the number of surgeries using metallic implants. The issue of reconstruction of bone defects covers a large area of study, where the surface properties of the implants are extremely important. Bone defects often occur as a result of open fractures, radical cancer treatment or limb lengthening, which is very common in paediatric orthopaedics. In the treatment of these conditions, the surface of the applied materials should provide a favorable environment for bone cells and support bone formation. In endoprosthetics it is highly desirable to achieve the strongest possible fixation between the implant surface and the bone. During the surgery, primary stability of the implant fixation is ensured by the proper positioning of the implant, based on the appropriate shape of the implant and the quality of bone cut. The initial stability is only temporary, being estimated to last approximately three months. After this period, the secondary stability starts, determined by the bone ingrowth into the implant surface structure. Osteogenic differentiation and extracellular matrix (ECM) mineralization can be enhanced by the presence of bone morphogenetic proteins (BMPs),...
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Interaction of bone and vascular cells with materials constructed for tissue replacement and drug delivery system
Vandrovcová, Marta ; Bačáková, Lucie (advisor) ; Smetana, Karel (referee) ; Jirka, Ivan (referee)
Interactions between biomaterials and cells play an important role in tissue engineering. It has been repeatedly shown that the cell behaviour strongly depends on physical and chemical properties of the material surface. In our study we focused on materials used for the construction of bone implants and replacements to support cell adhesion, growth and osteogenic diferenciation and to lead to an integration between an implant and a bone tissue. First we tested an influence of different micrpattern of fullerens' C60 and composites' C60/Ti films to adhesion of bone cells MG 63, their initial spreading, growth, viability and formation of cytosceletal protein actin. Some of these films were additionally iradiated with Au+ ions, which led to the conversion of some C60 molcules into amorphous carbon (a-C). We confirmed that pattern influenced the distribution of cells without decrease viability. Thus, the production of patterns could be used to direct cell adhesion. In the second study, we also observed the influence of the thickness of coated layer. We found that more selective cell growth can be achieved by depositing of thicker fullerens' film. Our study with osteoblast-like MG 63 cells cultured on PLGA films revealed, that surface coated with chosen components of extracellular matrix (colagen I and...
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Nanofibrous materials in bone tissue engineering
Zajdlová, Martina ; Bačáková, Lucie (advisor) ; Míčová, Petra (referee)
This thesis focuses on nanofibrous materials which are highly promising regarding they application in a modern interdisciplinary scientific field - tissue engineering. Through the years there have been developed various strategies for creating materials usable in tissue engineering. The earliest materials that were made did not allow any cell adhesion on their surfaces (so-called "bioinert" materials), whereas nowadays there is an effort to create hybrid bioartificial organs. Especially in bone tissue engineering do polymeric materials in the form of a nanofibrous network, such as polylactide or polycaprolactone with the addition of inorganic particles (for example nanocrystalic hydroxyapatite), show great potential. Such materials mimic the natural bone tissue and stimulate the adhesion, proliferation and differentiation of cells into desirable a cell type. In the experimental part of this thesis one of these promising nanomaterials was tested for its biocompatibility in vitro. Polylactide in the form of nanofibrous networks with 0, 5 and 15 % of nanocrystallic hydroxyapatite was provided by Elmarco s.r.o, Liberec. Human osteoblast-like cells MG 63 were cultivated on these materials for 1, 3 and 7 days. The results show the convenience of hydroxyapatite particles which stimulate the cells to the...
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Carbon nanoparticles as promising components of materials for bone tissue engineering
Grausová, Ľubica ; Bačáková, Lucie (advisor) ; Mikšík, Ivan (referee) ; Balík, Karel (referee)
Recently, nanotechnology in tissue engineering has become a very irnportant field of study. Many different materials of nanoscale roughness have been studied for their potential use in the regeneration of various tissues. The reason is that nallostructured materials imitate the architecture of natural extracellular matrix and thus support cell adhesion, growth and differentiation. Our investigations were focused on the influence of fullerene layers, carbon nanotube-terpolymer composites and nanocrystalline diamond layers on the adhesion. growth and differentiation of human osteoblast-like MG 63 cells. Each of these materials supported colonization with cells. On continuous fullerene C6s layers, deposited on composites with the carbon matrir reinforced with carbon fibres, the cell population density was lower than on non-coated composites. but MG 63 cells were well-spread w'ith rvell-developed vinculin-containing focal adhesiort plaques and a beta- actin cy'toskeleton. On contposites of carbon naliotubes u ith a terpolymer of poll.tetrafluoroethvlene. poly propy lene and polyvinyldifluoride, the adhesion, spreading. formation oť tbcal adhesion plaques and actin cytoskeleton, viability and cell grouth u ere markedly improved in comparison with pure terpolymer. At the same time, these cells did not...
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Vascular and osseous cells in polymer structures for tissue engineering
Filová, Elena ; Bačáková, Lucie (advisor) ; Maxová, Hana (referee) ; Motlík, Jan (referee) ; Kromka, Alexander (referee)
Artificial vascular and bone prostheses are engineered as bioinert, not allowing cell attachment and growth. Our aim was to prepare materials based on natural and synthetic polymers that could modify the surface or create the bulk material of prostheses, and test their bioactivity in vitro. We prepared fibrin assemblies of various thicknesses and evaluated the adhesion, growth and differentiation of endothelial cells (EC) on these layers. We observed increased cell spreading on twodimensional fibrin assemblies and improved cell growth and maturation on thick fibrin gels. Fibrin coated with collagen I, or fibronectin, increased the adhesion area and the proliferation activity of vascular smooth muscle cells (VSMC). Synthetic polymers were based on an inert block copolymer of poly(DL-lactide) and polyethylene oxide (PDLLA-b-PEO) in which 5% or 20% of the PEO chains were grafted with Gly-Arg-Gly-Asp-Ser-Gly oligopeptide, a ligand for cell adhesion receptors. Grafting oligopeptide peptide to the cell non-adhesive copolymer restored adhesion and growth of VSMC, even in a serum-free medium. Synthetic polymers could therefore serve as artificial extracellular matrix analogues for vascular tissue repair and regeneration. Our study with human osteoblast-like MG 63 cells cultured in poly(lactic-co-glycolic acid)...
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