National Repository of Grey Literature 95 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Development of new type of energy drinks based on coffee with active substances
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with development and preparation of new energy drinks with active plant component in free and encapsulated form. The theoretical part is focused on characterization of the energy drinks, their components and properties. The experimental part deals with the preparation of plant extracts, their characterization and subsequent encapsulation into liposome particles. All particles were determined for size, colloidal stability, long-term stability, antioxidant activity and encapsulation efficiency. Energy drinks based on various types of coffee were prepared and enriched with free or encapsulated guarana, goji, matcha or cocoa extract. In prepared energy drinks the content of caffeine, sugar, phenolics and antioxidant aktivity was monitored. Finally, selected energy drinks were subjected to sensory analysis, where appearance, color, smell and taste were evaluated.
Use of algae extracts in cosmetics
Plášková, Anna ; Rapta, Marek (referee) ; Márová, Ivana (advisor)
This thesis is focused on a preparation of extracts from selected species of algal and cyanobacterial strains, their characterization, a cytotoxicity testing and a use in cosmetic products. The theoretical part contains the review of a taxonomic classification and parameters of algae and cyanobacteria and basic information about used organisms. There is a description of the most significant factors influencing the algae cultivation and production of biomass. Further, active substances of algae and cyanobacteria, which could be used in cosmetic products as UV protective substances, were described. An overview of extraction techniques, encapsulation of active substance into liposomes and particles characterization, antioxidant activity analysis, and cytotoxicity tests is given too. In experimental part, antioxidant activity of algal extracts and chlorophyll a and carotenoid content were determined spectrophotometrically. The long-term stability of extracts was monitored for three weeks. Liposomes were prepared by sonification and encapsulation activity was analysed. The Dynamic Light Scattering method (DLS) was used for analysis of polydispersity and size of liposomes. Colloid stability of particles was determined by zeta potential. Cytotoxicity tests were performed using MTT assay. The prepared extracts, particles and lyophilized biomass of algal and cyanobacterial strain were further used as active substances in the formulation of cosmetic products (type o/w). These creams were tested on human skin.
Preparation and characterization of biomaterials with natural UV filtres
Pavelková, Renata ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This presented diploma thesis is focuses on preparation and characterization of biomaterials with natural UV filters. The theoretical part is aimed at effects of sunlight on the skin and how to avoid these effects by using cosmetic products. The materials and methods for extraction of lipid part of the selected vegetable and microorganism species and methods for preparation and characterization of nanoparticles and emulsions were characterized. The practical part deals with extraction of lipid part of selected vegetable and microorganism species. The liposome particles with encapsulated active compounds were prepared. The particle size, polydispersity index, colloidal stability, encapsulation efficiency, SPF, antioxidant capacity, phospholipid content and cytotoxic effect on human keratinocytes were observed. These particles were used for preparation of the resulting emulsions. Their protection level on UV light were set and stability were tested by using analytical centrifugation.
Preparation of edible antimicrobial packaging
Kozubová, Petra ; Dzurická, Lucia (referee) ; Skoumalová, Petra (advisor)
This bachelor’s thesis is focused on preparation and characterization of eatable packaging. Eatable packaging consists of two components, antimicrobial component and base of packaging. The task of eatable packaging is to protect product against antimicrobial attack and to extend durability of the product. As antimicrobial components were used water and oil extracts of several herbs (mint, nettle, lavender, cinnamon, cloves, vanilla, ginger and rhinoceros). Oil extracts were also encapsulated into liposomes for better application. Firstly, concentrations of polyphenoles and antioxidants of extracts were determined. Oil extract of clove contained the highest concentration of both determined substances. Encapsulation efficiency, stability and size of liposomes were tested too. All prepared liposomes were stable and relatively of the same size. Also high encapsulation efficiency was observed. Next, antimicrobial activity of prepared extracts and liposome particles against yeast Candida glabrata and two bacteria strains Escherichia coli and Staphycococcus epidermidis was tested and the high antimicrobial activity reported mainly all tested liposomes. Then alginate, chitosan and carboxymethylcellulose and their combinations respectively were used as bases of packaging. Created film had to meet several parameters, especially suitable sensory properties such as pleasant taste and smell, as well as invisibility, gloss, affordability and suitable manipulability. Combination of 2% carboxymethylcellulose and 1% alginate in a ration of 2:1 with liposomes of mint as antimicrobial component achieved the best results.
Preparation and use of selected nanoparticles in cosmetics
Hoová, Julie ; Němcová, Andrea (referee) ; Márová, Ivana (advisor)
The Bachelor thesis is focused on preparation and use of selected nanoparticles in cosmetics. The theoretical part deals with general characterization and use of caffeine, phenolics and vitamin C in cosmetics. Further, characterization of liposomes and possibilities of encapsulation of active substances gained from natural sources were introduced. In experimental part liposomes with encapsulated active substances were prepared by three different techniques. Encapsulation efficiency was determined by HPLC/PDA, phenolics spectrophotometrically and vitamin C by titration. Prepared particles were monitored for size and stability by dynamic light scattering. Furthermore, long-term stability of liposomes in model conditions was evaluated as the amount of the active substances released during incubation. In this work was found out that from all tested samples co-encapsulated liposomes are probably the best application form which can be used in face lotion or gel. Co-encapsulated liposomes exhibited relatively high encapsulation efficiency, good stability and thanks to quality of active substances they meet customer’s requirements of cosmetic industry.
Isolation and characterization of natural antimycotics and their potential applications
Dvořáková, Eva ; Hoová, Julie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on preparation and characterization of products containing natural antimycotic ingredients. The theoretical part summarizes the current issue of increased presence of mycoses and yeast diseases in connection with the extension of the problem of reduced immunity. Furthermore, the problem of synthetic drugs and antimycotics compared to alternatives of natural origin was described. In the experimental part, selected extracts (aqueous, ethanolic and lipidic) were prepared, characterized and subsequently encapsulated into liposomes. The content of polyphenols, flavonoids and the total antioxidant activity of extracts was measured. In liposomes, the encapsulation efficiency, size, stability and long-term stability were measured. In addition, the antimycotic activity of individual extracts and liposomes against Candida glabrata was studied. For comparison, the antifungal activity of the commercial drug clotrimazole was also tested. Lipidic extracts showed highest antimycotic activity from all of the prepared extracts, which is why these extracts were used to prepare antifungal gels and suppositories. More specifically, lipidic extracts of nasturcium, cinnamon, ginger and liposomes containing them were used. Their antimycotic activity was also tested and confirmed for these preparations. Finally, the cytotoxicity test on the HaCaT human cell line showed that used extracts and liposome particles are safe and that the prepared products could thus serve as an alternative to synthetically prepared antimycotics in the future.
Application of nanoparticles and nanofibers with active compound in cosmetics
Pavelková, Renata ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on application of nanoparticles and nanofibers with active compound in cosmetics. The theoretical part is aimed at effect of UV radiation on the skin and compounds that are used in photo protection of the skin. The materials and methods used in nanoparticle and nanofiber preparing were characterized. The experimental part deals with preparing of liposomes and marinosomes with active compound. Particles size, stability measured using zeta potential and stability in model environment were observed. Finally, pilot experiments of optimization of nanofibers preparation using electrospinning were carried out.
Preparation and Characterization of Complex Nanoparticles by Field-Flow Fractionation and Advanced Spectroscopic Methods
Kotouček, Jan ; Krejsek,, Jan (referee) ; Skládal, Petr (referee) ; Turánek,, Jaroslav (advisor)
Liposomes are versatile biocompatible and biodegradable carriers for a variety of medical applications. As the first nanoparticles, they have been approved for pharmaceutical use so far, and many liposome-based preparations are in clinical trials. Classical methods of liposome preparation represent potential limitations in technology transfer from laboratory to industrial scale. New, microfluidic techniques overcome these limitations and offer new possibilities for controlled, continuous preparation of liposomal particles in a laboratory and industrial scale. An important element in the development of new nanoparticle systems is their complex characterization and purification. In addition to the established chromatographic techniques, the Field flow fractionation technique, in particular the Asymmetrical flow Field-flow fractionation, is described. This relatively new technique in conjunction with the MALS/DLS/DAD-UV/dRI online detectors enables the purification and characterization of complex samples. The main advantage of this technique lies in the possibility of separation under native conditions, which plays an important role in the separation of biopolymers in particular. Separation in the “empty” channel then eliminates sample degradation due to unwanted interactions at the stationary phase-sample interface. The theoretical part of this thesis describes the possibilities of preparation, modification, and characterization of liposomal nanoparticles. For this purpose, optical methods based on dynamic light scattering, multi-angle dynamic light scattering and nanoparticle tracking analysis techniques are described, as well as a non-optical method using "particle by the particle" analysis, tunable resistive pulse sensing method. A separate chapter of the theoretical part is dedicated to the technique Asymmetrical flow Field-flow fractionation in connection with the above-mentioned detectors. Important results associated with this work are summarized in the attached scientific paper, together with the result summaries and the author's contributions.
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.
Use of cell cultures to test cytotoxicity of natural substances
Blažková, Veronika ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This thesis is aimed on study of cell cultures, primarily on introduction of techniques for cultivation of human cells and optimization of their usage in cytotoxicity tests. The thesis is aimed preferably on natural substances and liposomes that are suitable to be used in cosmetics. Theoretical part contains literature review focused on overview of cell cultures, appropriate cultivation conditions for in vitro testing and summary of cytotoxicity tests. Experimental part contains characteristics of natural extracts with antimicrobial effect in terms of content of polyphenols, flavonoids and antioxidant activity. Further, these extracts were encapsulated into the liposomes. Encapsulation effectivity was determined. Distribution of particles size by dynamic light scattering and finally also stability of prepared particles were also determined. Long-term stability in water and gel environment was tested too. This thesis also contains study of optimization of cell culture of human skin keratinocytes cultivation and use of those cells for testing cytotoxicity of selected natural substances by MTT method.

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