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|Preparation and characterization of micro- and nanoparticles with selected drugs
Sosková, Simona ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
The presented bachelor thesis is focused on the way to prepare combined micro- and nanoparticles containing some natural extracts with antioxidant effects, ibuprofen as the anti-inflammatory and analgetic agent and clotrimazole as the agent with an antifungal effect. The theoretical part contains an introduction of the methods of liposome preparation and a review of encapsulation techniques, methods of particles characterization, and analysis of active substances content. Furthermore, the yeasts of the genus Candida and the methods of the antimicrobial activity determination are described. The mentioned components were encapsulated into liposomes, alginate and chitosan particles. The antioxidant activity of the extracts was determined spectrophotometrically. The encapsulation effectivity of active substances into particles and the long-term stability of encapsulated components were determined and compared too. The HPLC method was used for measuring of the concentration of drugs and spectrophotometric method was used to quantify the content of polyphenols. Prepared particles were characterized with DLS method (size) and zeta- potential (stability). Finally, antibacterial properties of prepared particles and extracts using the test system Candida glabrata were studied. The antimycotic effect of particles, disturbed liposomes and extracts was compared. Finally, potential utilization of prepared liposomes in a cosmetic or pharmaceutical product is proposed.
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Characterization and application of some plant antimicrobial substances
Bendová, Agáta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The main goal of this bachelor thesis was the study of antioxidant and antibacterial effects of natural plant extracts and liposomes. The theoretical part was focused on description of natural antimicrobial and antioxidant substances from selected herbs and spices. Also bacterial resistance and methods used in work were described. In the experimental part basic characteristics of extracts from 12 kinds of herbs and spices (oil, alcohol and aqueous) were analyzed. Mainly content of polyphenols, flavonoids and the total antioxidant activity were determined. All extracts were also encapsulated into liposomes and the encapsulation effectivity, long-term stability and size and stability of liposomes were determined. The size of prepared liposomes was in range of 100 nm to 200 nm. Stability of the liposome particles was measured using a zeta potential and all prepared particles exhibited very good stability, but in term of long term stability were liposomes relatively unstable. Antibacterial activity was tested against Gram-positive Micrococcus luteus and Gram-negative Serratia marcescens. Encapsulation of extracts into liposome particles has greatly increased their antimicrobial effect and liposomes containing oil extracts from the goat, nutmeg and pepper and liposomes containing alcoholic extracts from star anise and cloves were the most effective against both strains. The prepared liposomes could be used as alternative to antibiotics and could be found application in the form of various antimicrobial gels for the cosmetic or pharmaceutical industry.
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Use of genotoxicity tests to characterization of some natural substances and particles
Tilšarová, Kamila ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
In production of drugs, cosmetics, in food industry and other biotechnologies, testing of genotoxicity (that are changes in genetic information which are not inhereted) is one of the common steps in the process before distribution to the market. This bachelor´s thesis is focused on the characterization of extracts from chosen natural substances with respect to the content of polyfenols, flavonoides and antioxidant activity. These extracts were encapsulated into liposomes and chitosan particles. The aim was testing possible genotoxicity of whole extracts and particles on possible genotoxicity on the basis of SOS Chromotest performed on bacteria E. coli. This genotoxic assay did not show genotoxic effect of neither pure extracts nor tested liposomes.
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Encapsulation of plant extracts containing phenolic compounds into nanoparticles and nanofibers
Petrželková, Markéta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis was focused on the encapsulation of extracts containing phenolic substances in order to apply these materials in cosmetics. At work were prepared aqueous, ethanol and lipid extracts of coffee and cocoa. All extracts were characterized on the content of all polyphenols and flavonoids. Their antioxidant aktivity and SPF were also determined. Then the selected extracts were encapsulated into liposomes and polyhydroxybutyrate nanofibres. The basic characteristics of the prepared liposomes were also observed and also their SPF and antioxidant aktivity were monitored. The highest antioxidant aktivity and SPF had liposome particles containing ethanol cocoa extracts. The liposome particles were applied to cosmetic emulsion. These creams evince high antioxidant acitivity and stability determined by analytical centrifugation. Also the prepared nanofibres had high antioxidant aktivity and confirmed the gradual release of the active substances. In conclusion the test cytotoxicity on human keratinocytes confirmed the safety of prepared nanomaterials using the MTT test, which are therefore suitable for cosmetic applications.
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PREPARATION AND APPLICATION OF SOME BIOPOLYMERS, NANOPARTICLES AND NANOFIBRES FOR COSMETICS AND FOOD
Bokrová, Jitka ; Pekař, Miloslav (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on preparation of nanoparticles and nanofibers with natural active ingredient and testing their biological effects. Modern types of application forms were prepared from biomaterials based on one or more natural polymers. Chitosan particles were prepared from cross-linked polymer using ultrasonication. A mixture of soy lecithin and cholesterol was used for preparation of liposomes. Poly-3-hydroxybutyrate was used for preparation of combined liposomes, too. All liposome particles were prepared by ultrasonication. Nanofibers were obtained from polyhydroxybutyrate using electrospinning. Mixtures of low-molecular antioxidants obtained by extraction from natural sources were used as active ingredients. Different types of teas, barks, herbs, spices, fruits and vegetables were selected as sources of natural antioxidants. Total phenolic and flavonoid content and total antioxidant activity of extracts were determined using spectrophotometrical methods. Obtained natural extracts were subsequently used for encapsulation. Prepared application forms were characterized in terms of their physicochemical properties. Particle size was monitored by dynamic light scattering. Colloidal stability of particles in suspension was determined using zeta potential. Spectrophotometry was used to evaluate the efficiency of encapsulation of active compounds into particles. The morphology of the new type of combined PHB liposomes was monitored by electron microscopy. Chromatography was used for quantification of individual components of particles. Morphology of nanofibers and incorporation of active agent into their structure were monitored using FTIR-ATR spectroscopy and electron microscopy. Afterwards, antimicrobial, cytotoxic and genotoxic effects of preparations were evaluated. It was found that the most suitable types of extracts for liposome preparation are aqueous and lipid extracts of natural antioxidants. Prepared particles showed excellent stability and good encapsulation efficiency. The study confirmed that incorporation of polydroxybutyrate into liposome structure does not reduce neither the colloidal stability of the particle, nor the efficiency of encapsulation process. Antimicrobial and antimycotic effect of preparations against model microorganisms Micrococcus lutues, Serratia marcescens and Candida glabrata was detected. It was found that process of encapsulation increases the inhibitory effect of natural extracts of antioxidants. The safety of preparations was assessed using two human cell cultures: epidermal keratinocytes and HaCaT cell line. Assays of cell viability and plasma membrane integrity were used to determine cytotoxicity of preparations. Low toxicity of liposome particles was confirmed by a series of cytotoxic tests. Obtained data showed that association of phospholipid with PHB polymer does not cause a significant increase in cytotoxicity in human skin cells. Genotoxicity testing on model procaryotic organism confirmed zero genotoxic potential of preparations. The new type of combined particles and polymeric fibers cant thus be used as a carrier for active ingredients, complex natural extracts, antimicrobial agents and many others.
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Interaction of PHA-based particles and fibres with human cells
Tarageľ, Matej ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation and characterization of PHA based nanoparticles and nanofibers and their subsequent influence on the living human skin cell. Theoretical part is aimed at polyhydroxyalkanoates, preparation of PHA based nanoparticles and nanofibers and methods of their physical, biological and chemical characterization. Further, the theory of liposomes, their clasification, preparation and physical and chemical properties are discussed too. Next, the theoretical part focuses on the cultivation of human cells and general information on selected cell lines. The experimental part is focused on the optimalization of the preparation of liposomes and fibers enriched by PHA. Further, characterization of stability and interactions of these nanomaterials with human HaCaT cells was proved. Cytotoxic and genotoxic tests were performed and determination of concentration of phospholipids in prepared particles was realized too.
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Encapsulation of plant extracts containing phenolic compounds into nanoparticles and nanofibers
Petrželková, Markéta ; Bokrová, Jitka (referee) ; Skoumalová, Petra (advisor)
The presented bachelor thesis was focused on the encapsulation of extracts containing phenolic substances in order to apply these materials in cosmetics. At work were prepared aqueous, ethanol and lipid extracts of coffee and cocoa. All extracts were characterized on the content of all polyphenols and flavonoids. Their antioxidant aktivity and SPF were also determined. Then the selected extracts were encapsulated into liposomes and polyhydroxybutyrate nanofibres. The basic characteristics of the prepared liposomes were also observed and also their SPF and antioxidant aktivity were monitored. The highest antioxidant aktivity and SPF had liposome particles containing ethanol cocoa extracts. The liposome particles were applied to cosmetic emulsion. These creams evince high antioxidant acitivity and stability determined by analytical centrifugation. Also the prepared nanofibres had high antioxidant aktivity and confirmed the gradual release of the active substances. In conclusion the test cytotoxicity on human keratinocytes confirmed the safety of prepared nanomaterials using the MTT test, which are therefore suitable for cosmetic applications.
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Active components of technical cannabis and their application in cosmetics
Kubáčková, Eliška ; Bokrová, Jitka (referee) ; Němcová, Andrea (advisor)
Hemp is unique plant with many therapeutic effects thanks to its large content of substances. This bachelor thesis brings information about characterization of main biological active substances in cannabis sativa, which are described in theoretical part of this thesis and determined in experimental part of this thesis. As a main active substance were determined antioxidants and cannabinoids for which the liquid chromatography method was optimized. This bachelor thesis also describes the antimicrobial effect of active cannabis substances for which it is used in the cosmetic industry. This antimicrobial activity has been studied in terms of the effect against dandruff, which is primarily caused by the high incidence of Malassezia yeasts on the skin of human hair. For the experimental part, the extracts of the technical hemp and more specific varieties of Bialobrzeskie and Finola were tested, which were further used for the preparation of the anti-dandruff shampoo. By analyzing the active substances in hemp extracts, the uniform result was obtained - the highest content of antioxidants and cannabinoids was reached by preparing of extract from dried hemp flowers. In the last part of the thesis, the antimicrobial effect of hemp extracts and prepared hemp shampoos was determined on selected strains of microorganisms and it was observed antimicrobial activity in extracts and shampoos againts Malassezia furfur yeast.
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Use of antimicrobial products of animal origin in cosmetics
Puškárová, Radka ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
The Bachelor thesis deals with characterization a whey in free and encapsulated form and its application to cosmetic industry. The theoretical part is focused on characterization of whey, especially on its antimicrobial properties, and use of this effect in selected cosmetics preparatives. Further, methods of encapsulation and particles characterization were described. In the experimental part, antimicrobial properties of whey were tested by two different methods. Whey was encapsulated into three different types of particles: liposomes, alginate and chitosan. Long-term colloid stability of particles during one and three weeks of storage in model conditions was tested. Further, particles were added into model skin creams. Long-term sedimentation stability of these emulsions was analyzed by analytical centrifuge.
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Viability of probiotic bacteria in some foods
Pokorná, Martina ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on viability od probiotic bacteria in some foods and looking for optimal food and beverages, that exhibited a minimal negative effect on the growth and viability of probiotic bacteria. Lactobacillus acidophilus, Bifidobacterium breve and commercially complex of probiotics were tested. In the practical part, probiotics were incubated in the environment of selected types of model and real foods. Further, incubation in model gastrointestinal juices to simulate human digestion was performed. Model foods with a moderate value of concentrations of sugar, protein and alcohol were shown the best alternative for growth of bacteria and their lowest mortality. For salt, the smallest concentration was shown as the most suitable. The chicken broth, chicken and beef meat were evaluated as the best environment for the capsule with complex probiotics. The vegetables and vegetable broth were stated like the best for Lactobacillus acidophilus and Bifidobacterium breve. According to the preliminary results we can conclude that the probiotics should be preferably consumed during meals and with the sufficient amount of liquids for the activation of all cells.
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