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Laboratory Measurements of Skin Conductance
Slouka, Petr ; Harabiš, Vratislav (referee) ; Sekora, Jiří (advisor)
This thesis contains an introduction to anatomy and physiology of the skin highlighting its barrier function. The barrier function of the skin enables it to separate internal organism from external environment. thermore, the electrical properties of the skin are described and possibilities of skin conductance measurement are discussed. The thesis presents a design of a device for the skin conductance measurement as the method of evaluation for barrier function. Alternating current is used for measurement during iontophoresis for evaluation of skin conductance. Circuit design and circuit board are included with a list of parts. The designed device was realized and in the end it was tested and the results were discussed.
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Experimental study and modelling of the transdermal penetration of active species from gels
Palanová, Veronika ; Opatřilová, Radka (referee) ; Sedláček, Petr (advisor)
This diploma thesis deals with design and experimental study of transdermal transport of pharmaceutically active agents from gel matrices, which contain humic substance in its structure. A model absorption membrane was represented by the skin of pig´s earlobes. The study of the release of active substances and Lignohumte was performed due to the vertical diffusion cells. The amount of released humic substance was characterized by UV-VIS method and the amount of released active agent from gel matrix was determined by HPLC-DAD. The most interesting finding of this diploma thesis was that Lignohumate enhances transdermal transport of active agents and supports their release from gel samples to the particular environment.
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Study of penetration of selected substances from elderberry extracts through biological membrane
Škubalová, Zuzana ; Němcová, Andrea (referee) ; Vespalcová, Milena (advisor)
This Diploma thesis focuses on the study of penetration of selected phenolic substances contained in extract from black elder (Sambucus nigra) via modelling systems represented by two types of synthetic membranes and a real system represented by a biological membrane. As a biological membrane, we have chosen skin from pig´s earlobe. Experiments of transdermal absorption and absorption through synthetic membranes were conducted through vertical (Franz´s) cells. Selected substances contained in the extract from black elder were rutin and chlorogenic acid. The main focus of this work was to determine how readily, or if at all, these two selected phenolic substances penetrate the skin and selected synthetic membranes. The percentage of absorbed amount of the substance was determined by HPLC analysis.
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Study and Evaluation of Topically Applied Ceramides onto Disrupted Skin Barrier
Svobodová, Marie ; Kováčik, Andrej (advisor) ; Vraníková, Barbora (referee)
Department of Pharmaceutical Technology Author: M S b S , Ph.D. Title of diploma thesis: Study and Evaluation of Topically Applied Ceramides onto Disrupted Skin Barrier Skin is the largest organ of the human body and serves several key functions, such as protection against external influences and regulation of body temperature. Healthy skin is able to maintain the integrity and stability of the organism due to its complex structure. The skin is composed of several layers of cells, including the stratum corneum (SC), which forms the main protective barrier. Ceramides (CER) are one of the main types of barrier lipids found in the SC. These lipid molecules, along with other lipids, create a hydrophobic matrix that protects the skin from dehydration and other external influences. The lack of CER in the skin barrier leads to the disruption of its function and the worsening of the skin condition. This is associated with many diseases, such as dermatitis, psoriasis, and others. The study of CER in the SC is important to understand the mechanisms of skin protection and to develop new therapeutic approaches for the treatment of skin diseases. Topical administration of barrier lipids, especially CER, is one possible treatment route for skin diseases. Therefore, the aim of this work was to prepare...
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Interaction of PAMAM dendrimers with the human stratum corneum
Žofková, Kateřina ; Paraskevopoulou, Anna (advisor) ; Svačinová, Petra (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Supervisor: PharmDr. Anna Paraskevopoulou, Ph.D. Author: Kateřina Žofková Title of the thesis: Interaction of PAMAM dendrimers with human stratum corneum Dendrimers are highly branched, monodisperse macromolecules. On the basis of the degree of branching, can be distinguished different generations of dendrimers that arise as the dendrimers expand. Higher generations of dendrimers form spherical structures with an internal cavity, where molecules such as a drug can be encapsulated. Due to their structure, which can be specifically and controllably modified, dendrimers are investigated for their use in biomedicine. One of the most widely used groups of dendrimers are polyamidoamine (PAMAM) dendrimers, based on an ethylenediamine core, branched amide and amine units, and terminal functional groups. PAMAM dendrimers with amine groups have proven useful in the past as skin penetration enhancers of different drugs. However, the mechanism how these molecules affect skin barrier function is not yet known. Therefore, in this work was investigated the mechanism of interaction of PAMAM dendrimers with lipids of stratum corneum (SC), the uppermost skin layer where the skin barrier is found. Second, third and...
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Influence of cholesterol concentration on permeability and microstructure of model skin barrier lipid membranes
Červená, Martina ; Vávrová, Kateřina (advisor) ; Zbytovská, Jarmila (referee)
Cholesterol is a substance of a steroidal nature that has a number of functions in the human body. One of them is also an irreplaceable role in the proper functioning of the skin barrier. Cholesterol is an integral part of the lipid matrix, together with ceramides and free fatty acids in an equimolar ratio (1: 1: 1), and 5% cholesterol sulfate, which fills the intercellular space between stratum corneum cells and is responsible for the barrier properties of the skin. Cholesterol is therefore necessary for epidermal homeostasis, but its role in SC permeability is unknown. The aim of this work was to study the influence of cholesterol concentration on the permeability and microstructure of model lipid membranes of the skin barrier. Eight sets of model membranes with decreasing cholesterol concentrations (100%, 80%, 70%, 60%, 40%, 20%, 0%) and cholesterol alone were studied for which permeability and microstructure were monitored.The study of permeability of membranes was carried out in the Franz diffusion cells by measuring four permeation parameters: water loss, electrical impedance measurement, and the cumulative amount of two model drugs (theophylline and indomethacin). The microstructure of these model membranes was verified by X-ray powder diffraction. X-ray powder diffraction measurements...
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Study and Evaluation of Topically Applied Ceramides onto Disrupted Skin Barrier
Svobodová, Marie ; Kováčik, Andrej (advisor) ; Vraníková, Barbora (referee)
Department of Pharmaceutical Technology Author: M S b S , Ph.D. Title of diploma thesis: Study and Evaluation of Topically Applied Ceramides onto Disrupted Skin Barrier Skin is the largest organ of the human body and serves several key functions, such as protection against external influences and regulation of body temperature. Healthy skin is able to maintain the integrity and stability of the organism due to its complex structure. The skin is composed of several layers of cells, including the stratum corneum (SC), which forms the main protective barrier. Ceramides (CER) are one of the main types of barrier lipids found in the SC. These lipid molecules, along with other lipids, create a hydrophobic matrix that protects the skin from dehydration and other external influences. The lack of CER in the skin barrier leads to the disruption of its function and the worsening of the skin condition. This is associated with many diseases, such as dermatitis, psoriasis, and others. The study of CER in the SC is important to understand the mechanisms of skin protection and to develop new therapeutic approaches for the treatment of skin diseases. Topical administration of barrier lipids, especially CER, is one possible treatment route for skin diseases. Therefore, the aim of this work was to prepare...
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Study of Topical Ceramide Application
Kulhánková, Roksolana ; Kováčik, Andrej (advisor) ; Vraníková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Author: Roksolana Kulhánková Supervisor: doc. PharmDr. Andrej Kováčik, Ph.D. Title of diploma thesis: Study of topically administred ceramides The human stratum corneum (SC) is the uppermost layer of the epidermis, which is made up of several layers of corneocytes. The space between the corneocytes is filled with barrier lipids, i.e., ceramides, cholesterol, and fatty acids, which are represented in an equimolar ratio. The arrangement of intercellular lipids has a significant effect on the barrier properties of the skin. Damaged skin barrier (e.g., in atopic dermatitis) is associated with a lack of lipids in the SC lipid matrix, which is reflected in increased trans-epidermal water loss and deterioration of skin quality (e.g., severe dryness, flaking, and cracks). One of the potential ways to restore the skin barrier is the topical administration of barrier lipids, especially ceramides (Cer). The goal of this work was to study the effect of topically administered Cer (very long-chain Cer AP alone or in combination with ultra-long-chain Cer EOS) on model-damaged SC and their effect in the process of restoring barrier function. Several topically administered formulations (creams) were prepared, which...
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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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Synthesis of fluorinated serine derivatives and study of their effect on skin barrier function
Župina, Richard ; Vávrová, Kateřina (advisor) ; Opálka, Lukáš (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Supervisor: Prof. PharmDr. Kateřina Vávrová, Ph.D. Consultant: Dr. Georgios Paraskevopoulos, Ph.D. Author: Richard Župina Title of the thesis: Synthesis of fluorinated serine derivatives and study of their effect on skin barrier function The human skin serves as a barrier against physical, chemical and microbial injury. When the skin barrier is perturbed, there is a possibility of microbial infiltration and biochemical damage. Ceramides, as essential components of the skin lipid layer, help to maintain the barrier integrity. Decreased content of skin ceramides in epidermis is connected with skin diseases such as atopic dermatitis and psoriasis. Previous findings of our research group proved that a ceramide analogue with similar steric and hydrophobic parameters to skin ceramides could selectively supplement the recovery of perturbed human skin barrier. The goal of this study was to design a convenient synthesis of ceramide analogues derived from L-serine with two long aliphatic chains. The first chain is amidically bound lignoceric acid and the second chain is either a 10 or a 14 carbon polyfluorinated chain conjugated with the rest of the molecule by an ester bond. Furthermore, the aim of this...
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