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Flexible generators of electrical energy
Tesařová, Tereza ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bachelor thesis is focused on actual research part of energy harvesting technologies – flexible electrical generators, which mean the special generating of electricity using specific flexible materials. The net charge result is affected by the incidental mechanism to transform certain energy form into electrical power and is influenced of material range, which determines what will be harnessed as a source of energy. The energy harvesting is aiming at producing alternative and efficient ways instead of harmful and strained manufacture processing.
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Vliv proteinové korony na toxicitu částic
Jemelíková, Vendula
When foreign particles enter the organism, they come into contact with the physiological environment and subsequent adsorption of naturally occurring biomolecules on the surface of the particles. Protein corona is formed during the adsorption of proteins, which fundamentally changes the physico-chemical properties of the particles. The aim of this work was to focus on the change in properties and toxicity of particles caused by the formation of a protein corona around selected particles. The formation of protein corona around different particles based on hydroxyapatites (CaNPs), iron (FeNPs), platinum (PtNPs) and titanium (TiNPs), was characterized and proved using electrophoretic methods, and subsequently the change in size, zeta potential and cytotoxicity was monitored depending on the formation of a protein corona. Based on the results, it is possible to claim that in all cases particles with a protein corona were less toxic to breast tumor cells, than particles without a corona and CaNPs were the most cytotoxic. In general, it is possible to say that the formation of protein corona around the tested nanoparticles affects their properties and reduces cytotoxicity and oxidative stress.
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Combined preparatives with encapsulated antimicrobial component
Kneblová, Kateřina ; Bendová, Agáta (referee) ; Márová, Ivana (advisor)
The presented bachelor thesis deals with the preparation and characterization of liposome nanoparticles that have been functionalized by the active substance and subsequently tested for their synergistic effect against microorganisms. In the theoretical part, a research focused on an overview of antimicrobials agents and on encapsulation techniques. In the experimental part, the method of sonification was used to prepare liposomes. Natural and synthetic antimicrobial substances were encapsulated into the particles. The size, stability, encapsulation efficiency, antioxidant and antimicrobial activity were determined for the liposomes that were prepared. Antimicrobial activity was tested on the gram-negative strain Esterichia coli, the gram-positive bacteria Micrococcus luteus, and one fungual strains Candida glabrata. Subsequently, a synergistic effect of the active substances was observed, which was demonstrated both when combining a synthetic active substance with a natural one and when combining two natural active substances. The synergistic effect of the encapsulated substances was observed after a longer period of time than that of the synergy of the pure active substrances. Which could find its application in the pharmaceutical industry, in drug delivery, or in the food industry in preservation processes.
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The role of dispersion medium on nanoparticle aggregation and size in biological systems
Červená, Tereza ; Rössnerová, Andrea ; Závodná, Táňa ; Vrbová, Kristýna ; Sikorová, Jitka ; Topinka, Jan ; Rössner ml., Pavel
The use of nanomaterials (NMs) in different areas has been rising for more than a decade. Along with this growth, there is visible development of different testing tools and approaches for measuring the actual size of nanomaterials in biological systems. Test conditions during in vitro toxicological assays are different from the standard conditions under which nanomaterials are characterized and careful evaluation of results is needed. The unique properties and range variety of NMs require the close look how the NMs behave in different dispersion medium over time. In this study we present the results of five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size and shape. The hydrodynamic size and Zeta potentials in suspensions were measured using a dynamic light scattering technique (DLS) (Zetasizer Nano ZS, Malvern, UK). The DLS method is suitable for spherical particles, nevertheless, all samples were measured in order to obtain a rough insight into agglomerate formation in the medium. NM300, NM302, and NM200 aggregated rapidly in the media, thus the cells would be most likely exposed to settled big aggregates then small clusters or individual particles. More stable NMs (NM100 and NM103) showed slight grow along with cultivation time or concentration corresponding to cluster formation. Cells exposed to those NMs would be in contact with small clusters and aggregates of NMs. Measured zeta potentials fluctuated around the stability limit corresponding to observed aggregation.
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Biological characteristics of polysccharide based contrast agents for cancer diagnostics
Křivánková, Markéta
Despite all the progress made in the treatment of cancer in recent years, it is still necessary to continue with the research of more effective and specific drugs. In recent years, there has been a growing interest in personalized medicine and its application through drug delivery systems, which could help increase the specificity of cancer treatment and subsequently its effectiveness. Drug delivery systems can use different platforms for their design, whether they are liposomes, micelles, nano crystals or others. A very interesting platform for the construction of drug delivery systems are polysaccharides, which were, as carriers of contrast agents in order to effectively display tumours, characterized in this doctoral thesis. But polysaccharides are interesting for more reasons. Both by its availability, and by its biocompatibility and non-toxic character. In this doctoral thesis we deal with two types of polysaccharides conjugates with linked contrast agents for magnetic resonance and fluorescent imaging. The first type of polysaccharide is glycogen, the second is mannan. Both constructs - glycogen and mannan based, were synthesized in a version with and without polymethyloxazolin, which should prolong their circulation in the organism. Both types of polysaccharide conjugates used passive...
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Preparation and characterization of nanofiber wound dressings
Jiroušková, Pavla ; Uhlířová, Renata (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis deals with the preparation and characterization of nanofiber wound dressings. The materials used for the preparation of nanofibers were poly(3-hydroxybutyrate) and gelatin. Active substances, such as ampicillin and ibuprofen, were incorporated into the wound dressings. In the theoretical part of the work skin, wound healing, and nanofibers and their properties were described. This part also deals with the use of nanofibers as wound dressings. Additionally, it depicts materials suitable for the preparation of nanofiber wound dressings. Furthermore, this section contains a review focused on various methods of preparation of nanofibers, drugs that can be incorporated into the fibers and the subsequent determination of the safety of the prepared dressings. In the experimental part, nanofiber wound dressings containing ampicillin and ibuprofen were produced. The maximum possible amount of active substance feasible to be incorporated into the nanofibers has been determined. Subsequently, combined wound dressings were prepared to study the release rate of active substances into the model environments. The release in the time intervals was determined spectrophotometrically. Finally, antimicrobial activity assays were performed to test the effect of dressings containing ampicillin on selected strains of microbiirganism: S. Epidermidis, E. Coli and M. Luteus
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Biological characteristics of polysccharide based contrast agents for cancer diagnostics
Křivánková, Markéta ; Jirák, Daniel (advisor) ; Shapoval, Oleksandr (referee) ; Vannucci, Luca Ernesto (referee)
Despite all the progress made in the treatment of cancer in recent years, it is still necessary to continue with the research of more effective and specific drugs. In recent years, there has been a growing interest in personalized medicine and its application through drug delivery systems, which could help increase the specificity of cancer treatment and subsequently its effectiveness. Drug delivery systems can use different platforms for their design, whether they are liposomes, micelles, nano crystals or others. A very interesting platform for the construction of drug delivery systems are polysaccharides, which were, as carriers of contrast agents in order to effectively display tumours, characterized in this doctoral thesis. But polysaccharides are interesting for more reasons. Both by its availability, and by its biocompatibility and non-toxic character. In this doctoral thesis we deal with two types of polysaccharides conjugates with linked contrast agents for magnetic resonance and fluorescent imaging. The first type of polysaccharide is glycogen, the second is mannan. Both constructs - glycogen and mannan based, were synthesized in a version with and without polymethyloxazolin, which should prolong their circulation in the organism. Both types of polysaccharide conjugates used passive...
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Preparation and application of combined functionalized nanomaterials with antimicrobial effect in food and cosmetics
Vojteková, Vanesa ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The presented diploma thesis is focused on the preparation of combined nanomaterials that were functionalized with an antimicrobial ingredient. Liposomes were prepared without the addition of polyhydroxybutyrate but also with its addition. The nanofibers were obtained from gelatin solution by electrospinning. Thymol, eugenol, curcumin and vitamin E were used for functionalization. In the theoretical part, individual bioactive components, materials for the preparation of nanoparticles and nanofibers as well as methods of synthesis of these materials were characterized. The applications of the prepared nanoparticles as preservatives in the food industry and applications of nanofibers in wound healing and in the cosmetics industry have also been described. In the experimental part, the antioxidant activity of the active substances was determined. Two types of liposomes were prepared and evaluated for size, stability and encapsulation efficiency. Subsequently, the release rate of active substances from the prepared liposomes was monitored. Nanofibers with combinations of substances that were encapsulated in liposomes were prepared by electrospinning. The antimicrobial activity of the active ingredients, nanofibers and nanomaterials was monitored on three strains of microorganisms, namely Micrococcus luteus, Staphylococcus epidermidis and Escherichia coli. The individual substances in pure as well as encapsulated form were combined with each other to observe the possible synergistic effect. The prepared nanoparticles and nanofibers with antimicrobial components were tested for cytotoxicity on human keratinocytes. The nanofibers were also subjected to a scratch test, which simulates the wound healing process.
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Adhesion, growth and differentiation of osteoblasts and mesenchymal stromal cells on biocompatible nanomaterial surfaces
Brož, Antonín ; Hubálek Kalbáčová, Marie (advisor) ; Černý, Jan (referee) ; Kylián, Ondřej (referee)
The thesis is based on articles describing the fundamental research of carbon based nanomaterials for their possible utilization in biomedicine. The aim of this thesis was to describe the way how human osteoblasts (SAOS-2 cell line) and primary human mesenchymal stem cells (hMSC) adhere, grow and behave on surfaces made of several carbon allotropes - nanocrystalline diamond (NCD), single walled carbon nanotubes (SWCNTs) films and graphene. The utilization of carbon as the basic material promised good biocompatibility and possibility of useful surface modifications. The NCD had modified surface nanotopography (nanoroughness and nanostructuring prepared by dry ion etching). All the materials had modified surface atomic termination with oxygen and hydrogen which changes the surface electrical conductivity, surface charge and wettability. It was hypothesized that the surface termination can also influence the cell adhesion and growth. It turned out that all the studied materials were suitable as substrates for cultivation of mentioned cell types. Various nanoroughnesses of NCD surface had different effect on the cell adhesion and cell metabolic activity. Nanostructuring of the NCD influenced the formation of focal adhesions. The surface terminations of NCD and the other studied nanomaterials in...
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