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Effect of the number of lipid layers on the properties of thin films as skin barrier models.
Bělochová, Šárka ; Pullmannová, Petra (advisor) ; Paraskevopoulou, Anna (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Mentor: Mgr. Petra Pullmannová, Ph.D. Student: Šárka Bělochová Title of Thesis: Effect of the number of lipid layers on the properties of thin films as skin barrier models The uppermost layer of the skin, the stratum corneum (SC), primarily serves a barrier function that is essential for human survival on dry land. The SC is composed of flattened dead cells, corneocytes, which are surrounded by an extracellular lipid matrix. The composition and arrangement of SC lipids are closely related to the proper structure and function of the skin, and their disruption can lead to the development of certain skin diseases. The study aimed to determine the effect of the number of lipid layers on the properties of thin films as skin barrier models. The method used for the preparation of the models was the deposition of thin films by the Langmuir-Blodgett technique. Mono-, tri- and five-layer models were prepared. The deposited sample was a mixture simulating the composition of skin lipids and containing ceramides, cholesterol and a mixture of fatty acids in a molar ratio of 1:0.45:1. These models were then evaluated by atomic force microscopy (AFM) and Raman microspectroscopy. During the experiments,...
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The effect of ceramide structure on the behavior of thin films modeling the skin barrier.
Šustrová, Terezie ; Pullmannová, Petra (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Student: Terezie Šustrová Mentor: Mgr. Petra Pullmannová, Ph.D. Title of Diploma Thesis: The effect of ceramide structure on the behavior of thin films modeling the skin barrier The skin barrier is essential for human survival on dry land, it is located in the uppermost layer of the skin, in the stratum corneum (SC). SC consists of corneocytes that are surrounded by an oligolamellar lipid matrix. The main components of the SC lipids are ceramides (Cer), fatty acids (FFA) and cholesterol (Chol). They are found in the SC in a ratio of 1:1:1. This ratio is essential for epidermal homeostasis. Any change in this ratio may lead to disruption of the barrier function, e.g. to the development of atopic dermatitis or psoriasis. These lipids prevent excessive loss of water from the body and the entry of undesired substances from the external environment into the body. The lipid matrix forms a typical lamellar arrangement in the skin. Lipids form structures with a long periodicity phase - LPP (d ~ 13 nm), with a short periodicity phase - SPP (d ~ 6 nm) and a separated Chol phase (d ~ 3,4 nm). The molecules are organized with each other in a lateral arrangement that can be orthorhombic, hexagonal, or...
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Study of the interaction of hyaluronan and biocompatible amphiphilic substances
Cigánková, Hana ; Krouská, Jitka (referee) ; Mravec, Filip (advisor)
This thesis focuses on the study of the interactions between hyaluronan and selected phospholipids and their mixtures in water or buffer. First, the aggregation behavior of these lipids was measured, afterwards the influence of hyaluronan was studied. This behavior was investigated by fluorescence spectoscopy using pyrene as fluorescence probe. The Critical Agregation Concentration of the lipids before and after addition of hyaluronan was determined. The measurements revealed that the addition of hyaluronan has an observable influence on the aggregate behavior of the selected lipids and their mixtures.
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Mixed lipids and their interaction with biopolymers
Cigánková, Hana ; Smilek, Jiří (referee) ; Mravec, Filip (advisor)
This thesis focuses on the study of interactions between hyaluronan and lipid DOTAP and its mixtures with DPPC in water. First, the aggregation behavior of the lipid itself and its mixtures was measured, afterwards the influence of hyaluronan in different concentration was studied. Further the fluorescence anisotropy of fluorescence probe DPH in these mixtures and influence of cholesterol was measured. These properties were investigated by fluorescence spectoscopy using pyrene and DPH as fluorescence probes. The measurements revealed that the addition of hyaluronan has observable influence on the aggregation behavior of the lipid DOTAP and its mixtures with DPPC and that cholesterol influences liposomes fluidity.
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Phospholipids as the basis of biodegradable delivery systems
Burdíková, Jana ; Čeppan, Michal (referee) ; Mravec, Filip (advisor)
This thesis is focused on investigation of phospholipid-hyaluronan system. First, appropriate method for preparation of bulk solution of phospholipid/lipid and suitable fluorescence probe were chosen. Sonification was selected as a method for preparation of bulk solution and pyrene was chosen as a fluorescence probe. From the group of phospholipids lecithin was selected. Next to phospholipid, lipid with no phosphate group (DPTAP) was utilized for comparison, alternatively a mixture of lipid (DPTAP) and phospholipid (DPPC). Instead of hyaluronan another polyelectrolytes (sodium polystyrene sulfonate, sodium alginate) were used too. Measurements were performed in water environment and in phosphate buffer saline (PBS). All investigation was accomplished by fluorescence spectroscopy and dynamic light scattering.
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The human skin barrier model containing stripped stratum corneum
Soukupová, Romana ; Pullmannová, Petra (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author: Romana Soukupová Supervisor: Mgr. Petra Pullmanová, Ph.D. Title of diploma thesis: The human skin barrier model containing stripped stratum corneum The uppermost layer of the epidermis, the stratum corneum, acts as a protective skin barrier. It contains a lipid matrix, which is made up of ceramides, cholesterol, and free fatty acids. The composition and arrangement of these lipids are necessary for the proper function of the skin barrier. Corneocytes, which do not have nuclei, are distributed in the lipid matrix. They are surrounded by insoluble proteins with covalently bound lipids on their surface, creating the corneocyte lipid envelope. The aim of this diploma thesis was to prepare models of the human skin barrier using an isolated stratum corneum with a preserved corneocyte lipid envelope and without a preserved corneocyte lipid envelope, and then monitor and compare the lipid arrangements in these models. Obtaining the stratum corneum from the skin samples was necessary to prepare the models. Human skin lipids were extracted from isolated stratum corneum and part of this delipidated stratum corneum was saponified. Skin lipids were purificated by column chromatography, and their...
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Preparation of the human skin barrier model using thin lipid film deposition
Suciu-Šubert, Karina ; Pullmannová, Petra (advisor) ; Opálka, Lukáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Student: Karina Suciu-Šubert Supervisor: Mgr. Petra Pullmannová, Ph.D. Title of diploma thesis: Preparation of the human skin barrier model by using thin lipid film deposition The uppermost part of the human skin - the stratum corneum, which protects the body from the external environment, is made up of cornified cells - corneocytes, which are surrounded by the extracellular matrix of highly ordered lipids: ceramides (Cer), fatty acids and cholesterol. The protective barrier is constantly renewed with so-called keratinocytes, which differentiate to corneocytes and finally desquamate from skin to surface. The corneocyte envelope replaces plasma membrane of corneocytes. It consists of proteins (eg. involucrin) and a lipid monolayer consisting mainly of ω-hydroxyceramides which are attached to the protein segments by covalent bonds. The task of this diploma thesis was the preparation of the human skin barrier model by using thin lipid film deposition. Two different lipid mixtures were based on Cer NS or Cer EOS and NS. The mixtures were applied on the hydrophilic or hydrophobic substrate by spraying with Linomat V. The amount of lipids and consequently the number of theoretical lipid layers on the...
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The human skin barrier model containing stripped stratum corneum
Soukupová, Romana ; Pullmannová, Petra (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author: Romana Soukupová Supervisor: Mgr. Petra Pullmanová, Ph.D. Title of diploma thesis: The human skin barrier model containing stripped stratum corneum The uppermost layer of the epidermis, the stratum corneum, acts as a protective skin barrier. It contains a lipid matrix, which is made up of ceramides, cholesterol, and free fatty acids. The composition and arrangement of these lipids are necessary for the proper function of the skin barrier. Corneocytes, which do not have nuclei, are distributed in the lipid matrix. They are surrounded by insoluble proteins with covalently bound lipids on their surface, creating the corneocyte lipid envelope. The aim of this diploma thesis was to prepare models of the human skin barrier using an isolated stratum corneum with a preserved corneocyte lipid envelope and without a preserved corneocyte lipid envelope, and then monitor and compare the lipid arrangements in these models. Obtaining the stratum corneum from the skin samples was necessary to prepare the models. Human skin lipids were extracted from isolated stratum corneum and part of this delipidated stratum corneum was saponified. Skin lipids were purificated by column chromatography, and their...
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Artificial phospholipid membranes - method of prepatation, properties and their usage
Hryzáková, Klára ; Fišer, Radovan (advisor) ; Sýkora, Michal (referee)
Heterogenita biologických membrán vedla ke vzniku širokého spektra zjednodušených modelových systémů, jejichž uspořádání, velikost a tvar se dají přizpůsobovat různým aktuálním požadavkům. Existují dva rozdílné přístupy k vytváření umělých fosfolipidových membrán. První z nich je založen na vzniku membrán ve vodném prostředí. Do této skupiny patří černé lipidické membrány, dvojvrstvy na pevném podkladu, dvojvrstvy vzniklé z monovrstev na rozhraní vody a vzduchu a liposomy. Ve druhém případě vznikají dvojvrstevné membrány v množství organické fáze metodou dvojvrstev na kapičkovém rozhraní. Každý typ umělých membrán má své experimentální výhody a nevýhody, což se používá ke studiu různých problémů sahajících od chování jednotlivých fosfolipidů a proteinů až po fúze membrán. Umělé fosfolipidové membrány jsou vhodným nástrojem pro elektrickou charakterizaci dvojvrstev a nebo membránových proteinů. Tato práce je ucelený přehled nejpoužívanějších metod vhodných pro vznik umělých fosfolipidových membrán. Klíčová slova: membrána, lipid, fosfolipidová dvojvrstva, liposom, černá lipidová membrána, dvojvrstvy na pevném podkladu, dvojvrstva na kapičkovém rozhraní Abstract The heterogeneity of biological membranes has led to development of a wide spectrum of simplified model systems whose composition, size and...
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Antioxidanty v potravinářském průmyslu
Tomková, Monika
This bachelor thesis is focused on antioxidants used in the food industry. The content is general description of antioxidants within their mechanical effect (primary, secundary) and their origin (natural, synthetic). Next part is about antioxidants themseves. Within clarification of problematics about oxidation are decsribed oxidation mechanisms of main food nutriens (lipids, proteins, carbohydrates). Ordinarily is determined total antioxidant capacity or individual antioxidants contains of food in practice. For this purpose are used differnt methods desribed in separate chapter in this thesis.
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