|
|
Isolation of active compounds from algae and their application in cosmetic products
Nováková, Laura ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis is dedicated to the study of active substances and antioxidant effects of cultivated microalgae. We compared the results with a commercial alga that is freely available. In the theoretical part we focused on description of algal metabolites in cosmetics and a brief description of the methods used in their testing. In the experimental part there were analyzed three types of extracts (aqueous, alcohol and oil) from 4 species of algae. It is mainly the content of polyphenols, flavonoids and antioxidant activity that is determined. According to the results, the highest content of active substances was found in oil extracts. All extracts were encapsulated into liposomes. The average size of the nanoparticles was in range of 200 nm to 300 nm. The particles were stable enough also for long-term stability. The largest decrease was observed in the oil extract of the cultivated algae Chlorella vulgaris. The cytotoxicity of oil extracts was realized by MTT test on human cell cultures HaCaT. Finally, we concluded that the prepared liposomal particles could be used for anti-aging cosmetics.
|
|
|
Characterization of some natural substances with antimycotic effect
Plachá, Monika ; Hlaváček, Viliam (referee) ; Márová, Ivana (advisor)
The introduced bachelor thesis is focused on investigation of the effects of natural substances with potential antimycotic effects and characterization of their constituents. As a part of this work, an overview of mycosis, antimycotics and constituents of natural substances were introduced. Moreover, antifungal susceptibility and genus Candida were described. In the end of the theoretical part the liposomes and their characterization were described. In the experimental part general characteristics of some natural substances and antimycotic test were analyzed. Aqueous, ethanol, methanol and DMSO extracts were tested on yeast strain Candida glabrata. Aqueous extract of the cloves, cloves oil and their combination were encapsulated into liposomes. The encapsulation effectivity, long-term stability and their antifungal activity were determined too. Characterization of liposomes was identified by DLS. Finally, application of liposomes to a preparation of pharmaceutical and cosmetic preparations were presented.
|
|
|
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.
|
|
|
Encapsulation of active components and their applications in food industry
Malčíková, Hana ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The Diploma thesis is focused on encapsulation of bioactive compounds which are contained in selected superfoods for the purpose of application to childrens nutrition supplements. In view of the nature of selected samples, which are seaweed, walnuts, hemp seed and flax seed, the emphasis is put on the content of omega-3 and omega-6 acids. The theoretical part introduces topic of children food, further it describes the nature of selected superfoods and last but not least it contains screening of available childrens food supplements containing omega-3 fatty acids on the market. In the experimental part, an optimization of the appropriate type of extract was made. A 24 hour aqueous macerate and 20% ethanol macerate were selected for next analyzes. Samples were characterized by content of polyphenols, flavonoids and the antioxidant activity and they were used to forming of extracts were encapsulated into liposomes for which their encapsulation efficiency, stability and long-term stability have been tested. Hexan extracts were also prepared for the same reasons. It was found that liposomes of selected superfoods should not be stored for 12 weeks. The samples were used analyzed for the carbohydrate content by the duboise method, a protein content by the Kjeldahl method and the determination of the fatty acid profile by gas chromatography. Furthermore, the content of carotenoids and chlorophylls in algae samples was determined by spectrophotometry and this analysis was verified by high-performance liquid chromatography. The technique of high-performance liquid chromatography was also used to verified a content of polyphenols in the algae samples. Finally, a sensory analysis of prepared alginate supplements containing algae and cold-pressed oils was performer in combinations to achieve a higher omega-3 and omega-6 fatty acid content. The F01-labeled sample containing wakame algae was evaluated as the best one.
|
|
|
Characterization and stabilization of pancreatin
Wurstová, Agáta ; Němcová, Andrea (referee) ; Obruča, Stanislav (advisor)
This work focuses on a study of enzyme mixture pancreatin, its characterization and subsequent encapsulation into liposomes. As a reference proteins bovine serum albumin and trypsin were used. Characterization of pancreatin consisted of two parts. The first part focuses on optimization of methods for the concentration determination by absorption spectrophotometry using basic methods for identifying proteins (Biuret method, Hartree-Lowry method and Bradford method). Moreover, UV spectrums of the protein were measured. As a method for identification of protein´s molecular weight, SDS-PAGE was used. To identify components of pancreatin, LPLC was employed in two modifications, ion-exchange chromatography and size exclusion chromatography. The second part is dedicated to the characterization of pancreatin as enzyme in terms of pH and temperature optimum for the enzyme activities of protease (pH 9, 8 and 50 °C), amylase (pH 7 and 40 °C) and lipase (pH 7 and 50 °C). The last part of this work aimed at an encapsulation of pancreatin into liposomes and DLS analysis of distribution of particles and their zeta potential. Liposomes did not spontaneously release encapsulated enzyme. To confirm that proteins were successfully entrapped into liposomes, their structure was disrupted by application of phospholipase D. In conclusion, liposomes can be utilized as delivery systems for native enzymes.
|
|
|
Development of a new type of energy drinks containing natural active components
Vysoká, Marie ; Němcová, Andrea (referee) ; Skoumalová, Petra (advisor)
The aim of this thesis is the development and preparation of a new energy drink. The theoretical part of the thesis focuses on the comparison of the drinks available in market, the presentation of the main active ingredients and the proposal of enriching the new energy drink. It also describes the possibility of using an encapsulation and the method used to determine specific compound in energy drink or encapsulated particles. In the experimental part of the work, at the beginning, the main content of energy drinks were characterized, for instance caffeine, sugar, polyphenol and vitamin C. Subsequently the energy drink based on selected types of loose teas that were enriched with the encapsulated extract of acai, acerola, maca, goji and ginseng was designed. All extracts contained large amounts of polyphenols and antioxidants. In addition, acerola extracts contained very high amounts of vitamin C. Two types of particles, alginate particles and liposomes were prepared for encapsulation. For all particles, encapsulation efficiency, size, stability, and antioxidant activity were determined. Long-term stability was then monitored within three months. The particles were also exposed to artificial gastric, pancreatic and bile juice. All tested particles showed very good encapsulation efficiency. In terms of long-term storage stability in an aqueous environment. Particularly liposome particles, which also showed high stability by zeta potential measurement, were suitable. On the contrary, in case of alginate particles, when stored in an aqueous medium, the release of active substances occurred. Finally, an energy drink was created and subjected to sensory analysis. The best energy drink was based on black or green tea with alginate particles acai, goji and ginseng.
|
|
|
Use of some encapsulation techniques to controlled release of active substances in food and cosmetics products.
Skoumalová, Petra ; Rittich, Bohuslav (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on preparation, characterization and application of organic micro- and nanoparticles as transport systems for active components and some their complex natural sources. Active component were packed into liposomes and polysaccharide particles. As active components were used caffeine, some drugs – clotrimazole and ibuprofen, further antioxidants and vitamins. Antimicrobial herbs and spices extract, antimicrobial peptides lysozyme, nisin and other antimicrobial ingredients were encapsulated too. Encapsulation of selected hydrolytic enzymes was tested, too. Particles were also used for encapsulation of probiotic strains Bifidobacterium breve and Lactobacillus acidophilus and prebiotic components. These prebiotics were co-encapsulated into capsules with probiotic cells. Natural extracts were encapsulated e.g. extracts of guarana, ginseng, goji, green barley, propolis, black, green and white tea, coffee, fruit and vegetable extracts. The efficiency of encapsulation was determined by HPLC/PDA and by spectrophotometry. Long-term stability of particles and amount of released component in model/real foods, in model cosmetic conditions and in a model physiological environment were monitored too. Size of prepared liposomes and polysaccharide particles was determined by dynamic light scattering and by light microscopy and electron microscopy, respectively. Stability of the particles was measured using a zeta potential. Also, analytical centrifugation was used to measurement of sedimentation velocity and stability of the prepared particles. The antimicrobial activity were tested using two Gram-positive (Bacillus subtilis, Micrococcus luteus), two Gram-negative (Escherichia coli, Serratia marcescens) bacteria and one fungal strains (Candida glabrata). For determining the antimicrobial properties of active component and prepared particles two the most widely used methods were used - agar diffusion method and broth dilution method. The viability of probiotic strains were performed using flow cytometry and fluorescence microscopy. Encapsulation of active component was successful in all types of particles. Liposome showed a very good long-term stability mainly in water conditions with neutral pH and polysaccharide particles were stable in acidic conditions. Prepared particles showed a very good stability in model stomach environment, while in model intestines environments particles were disintegrated and active component were released. Prepared particles with encapsulated caffeine as well as other tested antioxidants and vitamins could be used to modern types of energy drinks, food supplements and also for some cosmetics applications. Encapsulated antimicrobial components could be used for food application as well as for cosmetics and pharmaceutical application like antimicrobial wound formulation. Encapsulated enzymes can be used for controlled release of proteases in wound healing, as delivery systems in digestive tract and as a part of pharmaceutical preparative and food supplements for enzyme therapy. The study revealed that encapsulation of probiotics and also co-encapsulation of probiotics with prebiotics exhibited longer stability of particles and survival bacterial cells. So, prepared particles are suitable for use to food product with beneficial effects on the human body.
|
|
|
Antimicrobial materials based on nanostructures with enzymes
Jurová, Bronislava ; Vysoká, Marie (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis is focused on the preparation and characterization of antimicrobial gels and coatings containing antimicrobial components and enzymes. The theoretical part deals with a brief description of antimicrobial substances, their structure and mainly enzymes with antimicrobial effect. The methods used in the testing are also listed here. The practical part deals with testing the antimicrobial effects of extracts from cinnamon and cloves, clove essential oil, lysozyme and bromelain against Micrococcus luteus, Serratia marcescens and Candida glabrata. Various types of extracts were prepared from the selected spices, namely aqueous and ethanol extracts in different percentages. The individual extracts were characterized and, according to the total proportion of phenolic substances, the best ones were selected for encapsulation in liposome particles and gels. Extracts and enzymes were also added to the hydrogel and non-fibrous covers. A solution of sodium alginate and chitosan was used to prepare non-fibrous covers. A broth dilution method was used to test the antimicrobial effects on the given microorganisms. Furthermore, nanofibers based on PHB were prepared using the forcespinning method. These nanofibers were enriched with clove essential oil and their antioxidant activity was monitored.
|
|
|
Use of nanofluidic mixing for preparation of liposome carriers stained by gadolinium for contrast imaging by magnetic resonance (MRI)
Velínská, Kamila ; Mašek,, Josef (referee) ; Turánek, Jaroslav (advisor)
This diploma thesis focuses on the preparation of the liposomes, containing lipids with gadolinium, which are used for a contrast magnetic resonance imaging. The liposomes were prepared by the lipid film hydration followed by an extrusion and also by a new nanofluid mixing method on the NanoAssemblr Benchtop. The preparation technology has been optimized for parameters such as the composition of lipids, the flow rate ratio and total flow rate. The method of modification of the liposomes surface by gadolinium complexes has been developed. This method is using a conjugation reaction between the lipids containing cyanuric acid and Gd-DOTA. Prepared Gd-liposomes, which contain gadolinium, were complexly defined by the characterization techniques of DLS and NTA. The morphology of liposomes was observed by TEM and cryo-TEM. Methods for the determination of phospholipid content (Stewart test) and residual water in the lyophylisates of liposomes (Karl-Fischer titration) were used. Gadolinium in liposomal preparations was determined by ICP-OES. Using MR, the concept of gadolinium liposomes was verified and designed for MRI imaging of thrombi. The concept describing the mechanism of liposomes formation based on the experimentally proven existence of a phospholipid bilayer fragment has been developed. This concept is based on the experimentally proven existence of a phospholipid bilayer fragment.
|
|
|
Inverse FCS in colloidal systems research
Richterová, Veronika ; Venerová, Tereza (referee) ; Mravec, Filip (advisor)
This diploma thesis is focused on the study of inverse fluorescence correlation spectroscopy, especially with the regard for the usage of different fluorescent probes and different sized analysed particles. At first, the proper concentration of fluorescent probes was determined. In this concentration is the probe considered as a medium surrounding the analysed particles. Based on this concentration, which was determined as 400 M, several sets of samples were prepared. This samples contained different concentration of polystyrene particles of 100 and 500 nm diameter and multilamellar liposomes. Then, the FCS curves of samples with different fluorescent probes were measured. Fluorescein, rhodamine 6G and Atto 488 were used as fluorescent probes. As a result from experiments, it was found, that particles with 100 nm diameter cannot be analysed with none of the fluorescent probes. Inverse FCS method can be applied to systems, that contains particles with 500 nm diameter and fluorescein. Systems with rhodamine 6G have the same behaviour as typical FCS measurement. It is caused by dimerization of this probe and it cannot be used for 500 nm particles. Liposome samples can be established with iFCS method, but the results are biased by random distribution of liposomes size.
|
guest ::
