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Nanostructured Modifcation of Material Surfaces for Controlled Cell Cultivation
Kotelnikov, Ilya ; Proks, Vladimír (advisor) ; Chytil, Petr (referee) ; Šebestová Janoušková, Olga (referee)
Commercial media and surfaces for cell cultivation do not promote conditions for cell cultivation and proliferation with specific interactions cell-material surface. The aim of this thesis is developing surfaces for cell cultivation which mimic conditions in living tissues. The approach introduced in this thesis is based on applying biomimetic peptide ligands on inert supporting materials with non-fouling properties. Considering that a choice of a ligand sequence and distance between peptides can dramatically influence the outcome, a few model peptides with varying parameters were synthesized and investigated. The cell adhesive peptides were synthesized by solid phase peptide synthesis and scrambled peptides were synthesized and tested as well. Spatial deposition of peptides is another highly important point of study. The 'click'- reaction was used to successfully immobilize the peptides on produced surfaces. The distance between the peptide molecules on the surfaces was controlled by their concentration in a reaction mixture. The reference samples were immobilized with radiolabeled peptides for quantitative estimation of the peptides present. Then, the materials with different types of peptides and range of concentrations were examined via cultivation of cell cultures. The experiments were focused on...
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Deformation of thin self-standing mask at inhomogeneous irradiation.
Koláček, Karel ; Schmidt, Jiří ; Frolov, Oleksandr ; Štraus, Jaroslav ; Chalupský, Jaromír ; Choukourov, A.
Flatness of the mask is one of key features influencing the quality of image. Among factors that can affect mask flatness belongs inhomogeneous illumination. This does not apply to lithography, but to experiments that use only discrete parts of mask e.g. for nanostructuring or other type of material research. It is shown that even single EUV laser shot (laser wavelength ~46.9 nm, pulse duration ~1.5 ns, focused pulse energy ~20 .mu.J, peak fluency 48 J/cm2) not only deforms the mask, but also changes mask-substrate distance. In our case two kinds of grids (one circular with rectangular windows 7.5x7.5 μm and bars 5 micro m (period 12.5x12.5 micro m), other rectangular with rectangular windows 3.2x1.2 μm and bars 0.8 micro m (period 4x2 micro m)) were attached to PMMA substrate and exposed to one or five superimposed focused laser shots. The mask (grid) deformation was inferred from the changes of diffraction pattern engraved into PMMA.
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Applications of self-assembled 2D polystyrene nanosphere arrays
Domonkos, Mária ; Ižák, Tibor ; Demo, Pavel ; Kromka, Alexander
In this study nanosphere lithography (NSL) is demonstrated to be a low-cost, parallel and material independent fabrication process for creating periodic arrays of nanostructures using self-assembled nanospheres as templates. SA is the most feasible way to fabricate 2D or 3D colloidal crystals on large areas. After the mask preparation NSL uses different steps of plasma etching and deposition processes. The resulting patterned nanostructures have a wide range of applications in many important areas such as photonics, antireflection, surface wetting, biological and chemical sensing, solar cells, etc. This study focuses on an overview of applications of 2D colloidal crystals. First, structuring of substrate surfaces and the creation of various nano-objects (nanotips, nanopillars, nanocones) is shown. Next, direct growth of patterned structures (graphene nanomesh and diamond structures) is pointed out.
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Structuring of diamond films by reactive ion plasma etching
Domonkos, M. ; Ižák, Tibor ; Proška, J. ; Kromka, Alexander
In this study, two common strategies of diamond film structuring are described. Main focus is on the comparison of top-down and the bottom-up strategies. The top-down strategy is primary related to dry reactive ion etching through masking materials (or even without mask), while bottom-up strategy is based on selective area deposition of diamond film. Several methods of both strategies are demonstrated in details in the article, regarding to their properties and basic principles.
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