National Repository of Grey Literature 89 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
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
Encapsulation of vitamins and provitamins into nanoparticles
Martinusíková, Katarína ; Wikarská, Monika (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis is focused on the encapsulation of vitamins in liposomes and the subsequent observation of the properties of this form. The theoretical part is focused on the history of vitamins, their classification into groups, but mainly the general characterization of all vitamins. It describes their function in the human body, the consequences of their deficiencies and also the sources of their income. It also describes the technique of encapsulation in liposomes and their characterization and use in the food industry. The experimental part is focused on the preparation of specific liposomes of vitamins and their mixtures. These prepared liposomes are subsequently characterized by properties such as size, stability and encapsulation efficiency. Long-term stability of prepared liposome particles over 2 and 5 weeks were also investigated. In the conclusion of this thesis are summarized all the results of observations and the subsequent suggestion of the possible use of this technique in food products.
The use of aromatic herbs in the production of white sausages
Havlíková, Michaela ; Skoumalová, Petra (referee) ; Mikulíková, Renata (advisor)
The aim of the bachelor thesis is to compare the sensory properties of white sausages with the addition of different concentrations and types of herbs. Selected were basil, thyme and lavender. The aim was also to assess the microbial activity of selected herbs. The theoretical part describes the Czech legislation that controls the production and composition of sausages, the characteristics of raw materials that are used in the production of white sausages and the technological process of production. The theoretical part also deals with the theory of sensory analysis and microbiological determination of antimicrobial properties of used herbs. The experimental part describes the preparation of samples, sensory analysis and microbial test. In the sensory analysis, the evaluators assessed the different properties of the submitted samples by comparing only the concentrations of one herb. Next was a test performed to compare one concentration of all herbs against each other. Aqueous and organic herb extracts were prepared for the microbial test and the absorbance values on the microtiter plate were subsequently measured.
Monitoring of lipophilic vitamins and provitamins in children 's products and possibilities of their fortification
Maráčková, Adéla ; Hoová, Julie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis deals with the study of lipophilic vitamins with a focus on children's food supplements. It designs own food supplement in the form of gum confectionery with a vitamin mixture encapsulated in liposomes. The theoretical part focuses mainly on the characterization of lipophilic vitamins and their monitoring in the market. The experimental part is focused on their determination in real food supplements (Marťánci, Vibovit Dino and Vitamin Code Kids). Extraction in chloroform and enzymatic methods were chosen as suitable methods of determination, both methods being evaluated chromatographically (HPLC). Finally, liposomes were prepared and characterized. Liposomes prepared in the same way were later added to the preparation of gum confectionery. Finally, several types of dietary supplements with liposomes were proposed, into which lipophilic vitamins were encapsulated. Design of the food supplement itself was in the form of a gum confectionery (in the shape of a gummy bear and a coffee bean) made of gelatin or a mixture of agar and alginate. The proposed dietary supplement was subjected to sensory analysis and its organoleptic properties were evaluated.
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.
Encapsulation of active substances and possibilities of their application in anti-aging products
Horváthová, Iveta ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The aims of this thesis were encapsulation of selected active substances and their possible application in cosmetic products with anti-aging effects. 6 kinds of active substances were studied – lipophilic vitamin E and vitamin A, hydrophilic vitamin B1 and vitamin B2, and phenolic compounds ferulic acid and chlorogenic acid. In theoretocal part, the general characteristics of active compounds and their use are described. It also includes the description of used methods. Practical part was focused on characterisation of active compounds from the perspective of antioxidant activity and encapsulation into liposomes from soy and sunflower lecithin. Encapsulation effectivity, size, stability and long-term stability of liposomes after four weeks were determined. The most suitable liposomes with active compounds were also tested for safety on human skin cells using the MTT test of cytotoxicity on keratinocytes HaCaT. Furthernore, 3 types of cosmetic products were prepared – day cream, night cream and skin serum. Each kind of cosmetic product was devided into 4 types – the product without any active compounds, the product containing free active compounds, the product with liposomes with active compouds and the product containing empty liposomes. As active compounds all our tested substances were used. Final products were tested 14 days on 15 female volunteers. Before and after products usage parametres of their skin were measured to analyze effect of products on skin rejuvenation. Volunteers were also rating sensory analysis of cosmetic products. The part of this thesis was also creating an online questionnaire about anti-aging cosmetics for publicity to find out the popularity of this kind of cosmetics.
Gold nano systems for the detection of molecules using surface-enhanced Raman scattering (SERS)
Benešová, Markéta ; Bernatová,, Silvie (referee) ; Skoumalová, Petra (advisor)
This diploma thesis was focused on the production and use of gold nanosystems to enhance Raman scattering. Metal nanoparticles, when interacting with electromagnetic radiation, form so-called localized plasmons, which can enhance Raman scattering. SERS (surface-enhanced Raman scattering) is a non-destructive analytical technique used in this work to measure the concentration and chemical changes in the rhodamine B molecule. Rhodamine B was subjected to photocatalytic degradation using two types of photocatalysts before measurement: TiO2-(H) and TiO2-(H)-Ag. The quantitative dependence of rhodamine B photodegradation on the presence of photocatalysts in a given period time was sought using photodegradation processes. The results of measurements using the SERS method were compared with the results obtained by UV-VIS spectroscopy. From the measured data, it was found that the photocatalysts significantly accelerate the photodegradation processes, because the Raman signal of rhodamine B decreased, while the signal decrease was most pronounced for the catalyst with added TiO2-(H)-Ag, less prominent but still statistically significant signal decrease was observed for the TiO2-(H) catalyst. In the control sample without the addition of photocatalyst, no decrease in signal was observed. In the next phase of the thesis, a sandwich immunoassay was designed that uses SERS to detect E. coli bacteria or other specific microorganisms in the sample. The first component of the sandwich immunoassay is gold nanoparticles, which carry a so-called Raman reporter, which has a clear Raman response in the spectrum, and gold nanoparticles amplify this signal, and antibodies, thanks to which the particles specifically bind to the microorganism. Another component is either gold layered slides or magnetic nanoparticles, which are modified with antibodies and serve to immobilize microorganisms. This system can be a fast and very accurate way to identify a given microorganism in a sample.
Preparation of nanoparticles and nanofibers with antimicrobial components
Kubišová, Veronika ; Slaninová, Eva (referee) ; Skoumalová, Petra (advisor)
This thesis addresses the problem of inadequate current wound therapy and presents a solution in the form of nanomaterial-based wound dressings (coverings). Specifically, it focuses on the development and characterization of various nanofibrous materials with integrated liposome particles that could serve as a source of therapeutic agents and be useful specifically in the field of a wound therapy. The review in the introductory part of the thesis first focused on the mentioned problem, which describes the shortcomings of existing conventional dressing materials. A description of human skin from an anatomical and functional point of view was not omitted, nor was the wound healing process itself. Different types of covering materials were also presented. However, a large part was focused on nanomaterials and their use in the field of the skin wound therapy. The nanomaterials mentioned were mainly liposome particles and nanofibres, as the experimental part of the work was focused on these structures. The description dealt with the characterization of these structures as well as the biopolymers used for their preparation. However, the aim was to prepare nanofibers with liposome content, so the method of forming such systems was described. Various therapeutic agents are also an integral part of the covering materials, especially those that suppress the development of infection and reduce wound pain; therefore, the search focused on the antibiotic ampicillin and the analgesic ibuprofen. The experimental part was devoted to the actual production of nanofibers with liposomes and also to the qualitative demonstration of the presence of liposomes in electrostatically prepared nanofibers. The selected polymeric components of these systems were polyhydroxybutyrate (PHB) and gelatine. However, the nanofibers and liposome particles (as well as combined liposomes with PHB) were first prepared in their own form and characterized mainly in terms of the gradual release of the drug substances. The results obtained were then compared with those of therapeutic drug delivery via combined nanofibrous structures with liposomes. For these combined structures, the aim was to achieve synergy in drug delivery between these systems. The aim of this work was to create a biomaterial covering with the controlled drug release. The drugs contained in these materials were the aforementioned ampicillin and ibuprofen. An important part of the work was then to determine the safety of the prepared materials which were tested for cytotoxicity, where the tests performed were MTT test and LDH test. And the actual wound healing ability of the nanofibers was then monitored in a scratch test or a "wound healing" test. At the end of the paper, recommendations for future work on this topic are given.
Preparation and characterization of enzyme-containing wound dressings
Jurová, Bronislava ; Szotkowski, Martin (referee) ; Skoumalová, Petra (advisor)
This diploma thesis is focused on the study and characterization of nanofiber wound dressings from natural biopolymers. Proteolytic enzymes, specifically collagenase and bromelain, were incorporated into these nanofiber covers. The theoretical part deals with a brief description of skin wounds, their healing and skin covers. There are also methods for preparing these covers and the methods used to characterize them. The practical part deals with the optimization of the preparation of nanofiber coatings based on polyhydroxybutyrate, gelatin, alginate and chitosan. These nanofibers were then enriched with active substances and their gradual release into the model environment was monitored. Finally, their proteolytic activity was determined for these substances.
Encapsulation of active substances into nanofibers and possibilities of their application
Procházková, Lucie ; Pernicová, Iva (referee) ; Skoumalová, Petra (advisor)
The master thesis was based on the optimization of the production of nanofiber covers and to gaine the product for subsequent functional use. The production of nanofiber covers was made by electrospinning and forcespinning from selected materials. Polyhydroxybutyrate, gelatin, chitosan and alginate were used as starting materials. After successful optimization, these materials were enriched with active ingredients ampicillin and ibuprofen for the functionalized use of covers for more effective wound healing. The theoretical part was focused on the issue of skin, healing processes, types of wounds and nanofibers, the characterization of selected starting materials for the formation of nanofibers was also mentioned. The practical part was based on the lengthy optimization of the preparation of fiber covers and later enriched with active ingredients. Furthermore, combined covers made of different materials with contents of both active ingredients were designed. This was followed by the characterization of all prepared covers from the point of view of stability in the short and long term. The gradual release of active ingredients was determined spectrophotometrically and by hifh performance liquid chromatography. It was also important to determine the antimicrobial activity of selected active substances. At the end of all testing, combined coatings containing both active ingredients were used for safety testing with human keratinocyte cells (HaCaT). Safety testing was based on determining the viability of human cells using the MTT test, to verify the LDH test. A scratch test was also performed, a wound healing test after the application of devised combined covers.

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