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Study of azaphthalocyanines as fluorescence quenchers in oligodeoxynucleotide probes
Demuth, Jiří ; Nováková, Veronika (advisor) ; Hocek, Michal (referee) ; Vávrová, Kateřina (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Mgr. Jiří Demuth Supervisor: doc. PharmDr. Veronika Nováková, Ph.D. Consultant: prof. PharmDr. Petr Zimčík, Ph.D. Doctoral Thesis: Study of azaphthalocyanines suitable for quenching of fluorescence in oligodeoxynucleotide probes Phthalocyanines (Pcs) and azaphthalocyanines (AzaPcs) are planar macrocyclic compounds. These synthetic compounds are derived from naturally occurring dyes - porphyrins. Pcs and AzaPcs have very interesting photophysical properties due to their extensive 18 -electron conjugated system. They are used in electrotechnics, material industry or in medicinal applications. Octaalkylamino substituted tetrapyrazinoporphyrazines (TPyzPzs), which belong to AzaPc family, can quench fluorescence of other molecules due to the ultrafast intramolecular charge transfer. This thesis studies this quenching ability of TPyzPzs with the aim to develop efficient fluorescence probes. Such probes could find application in a variety of experiments across scientific disciplines i.e. - biochemistry, forensic or genetic analysis. Synthetic part of dissertation thesis is a continuation of previous investigation of TPyzPzs in our research group. It describes...
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Study of cholesterol depletion in human skin barrier
Audrlická, Pavla ; Vávrová, Kateřina (advisor) ; Nováková, Veronika (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Pavla Audrlická Supervisor: prof. PharmDr. Kateřina Vávrová, Ph.D. Title of diploma thesis: Study of cholesterol depletion in human skin barrier Barrier function of human skin barrier dwells in intercellular lipid membranes of the uppermost skin layer, the stratum corneum (SC), composed of equimolar mixture of ceramides (Cer), free fatty acids (FFA) and cholesterol (Chol).1 Chol is required for proper lipid organization of SC, however, it stays unclear, why is it present in an amount so high that it separates from other lipids.2 Experiments using synthetic model membranes with decreased Chol content suggested that molar ratio of Cer:FFA:Chol 1:1:0,4 is sufficient for lipid barrier formation and its complex functionality.3 The aim of this work was to manipulate Chol content directly in human SC and to study the effects of decreased Chol content on the SC permeability and microstructure. Ex vivo SC obtained from healthy donors was extracted by methyl-β-cyclodextrin (MCD) to reduce natural Chol content. The extracted SC did not show significant changes in Cer or FFA whilst the amount of Chol was lowered to 78 %. SC barrier properties were evaluated by measurements of transepidermal water loss...
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Synthesis and evaluation of transdermal drug permeation enhancers
Kopečná, Monika ; Vávrová, Kateřina (advisor) ; Doležal, Pavel (referee) ; Hampl, František (referee)
Penetration enhancers are compounds that facilitate transdermal drug delivery, which is an advantageous pathway of drug administration (compared to conventional methods). However, skin acts as formidable barrier enabling terrestrial life by protecting the inner body from the environmental conditions, microbes and substances. Thus, for drug administration via this pathway, some approach to temporary increase the skin permeability (e.g. permeation enhancer) should be employed. Despite the existence of many enhancer classes, there is still a need for new compounds enhancing broader spectrum of drugs, with reversible mode of action and better safety profile. One of the promising approaches is to explore natural compounds with low toxicity and irritation potential. In this thesis, I first studied various glucose and galactose derivatives bearing structural fragments that were responsible for enhancing activity of previously studied enhancers (e.g. amino acid derivatives, fatty acids and alcohols, modified ceramides). A detailed examination of these sugar- based compounds revealed potent glucoside and galactoside enhancers (12Glc6N and A15) comparable to or better than Span 20 with reversible mode of action and acceptable toxicity on keratinocyte and fibroblast cell lines. Another part of my work builds...
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Study of barrier lipids in the skin and skin models
Sochorová, Michaela ; Vávrová, Kateřina (advisor) ; Zimčík, Petr (referee) ; Salavec, Miloslav (referee)
1 Abstract Charles University, Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Candidate: Mgr. Michaela Sochorová Supervisor: prof. PharmDr. Kateřina Vávrová, Ph.D. Title of doctoral thesis: Study of barrier lipids in the skin and skin models The barrier lipids are found in the intercellular spaces of the uppermost layer of epidermis - stratum corneum (SC). These lipids comprise an approximately equimolar mixture of ceramides (Cer), fatty acids (FA) and cholesterol (Chol). The composition and organization of the lipid mixture is unique and provides a barrier, which protects organism against harmful effects from the surroundings and, at the same time, it protects body from excessive water loss and contributes to homeostasis maintenance. Skin barrier disruption, including altered barrier lipid composition and organization, was described in many skin diseases, for example atopic dermatitis, psoriasis or skin cancer. Study and therapy of these diseases are limited by their complex pathophysiology and a lack of biological material (human skin). Therefore, skin models are appropriate and useful tools for study of skin diseases. The skin models differ in their simplicity/complexity and their preparation therefore they can provide different information. Model lipid membranes are...
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Study of barrier lipids in the skin and skin models
Sochorová, Michaela ; Vávrová, Kateřina (advisor) ; Zimčík, Petr (referee) ; Salavec, Miloslav (referee)
1 Abstract Charles University, Faculty of Pharmacy in Hradec Králové Department of Organic and Bioorganic Chemistry Candidate: Mgr. Michaela Sochorová Supervisor: prof. PharmDr. Kateřina Vávrová, Ph.D. Title of doctoral thesis: Study of barrier lipids in the skin and skin models The barrier lipids are found in the intercellular spaces of the uppermost layer of epidermis - stratum corneum (SC). These lipids comprise an approximately equimolar mixture of ceramides (Cer), fatty acids (FA) and cholesterol (Chol). The composition and organization of the lipid mixture is unique and provides a barrier, which protects organism against harmful effects from the surroundings and, at the same time, it protects body from excessive water loss and contributes to homeostasis maintenance. Skin barrier disruption, including altered barrier lipid composition and organization, was described in many skin diseases, for example atopic dermatitis, psoriasis or skin cancer. Study and therapy of these diseases are limited by their complex pathophysiology and a lack of biological material (human skin). Therefore, skin models are appropriate and useful tools for study of skin diseases. The skin models differ in their simplicity/complexity and their preparation therefore they can provide different information. Model lipid membranes are...
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Synthesis and evaluation of transdermal drug permeation enhancers
Kopečná, Monika ; Vávrová, Kateřina (advisor) ; Doležal, Pavel (referee) ; Hampl, František (referee)
Penetration enhancers are compounds that facilitate transdermal drug delivery, which is an advantageous pathway of drug administration (compared to conventional methods). However, skin acts as formidable barrier enabling terrestrial life by protecting the inner body from the environmental conditions, microbes and substances. Thus, for drug administration via this pathway, some approach to temporary increase the skin permeability (e.g. permeation enhancer) should be employed. Despite the existence of many enhancer classes, there is still a need for new compounds enhancing broader spectrum of drugs, with reversible mode of action and better safety profile. One of the promising approaches is to explore natural compounds with low toxicity and irritation potential. In this thesis, I first studied various glucose and galactose derivatives bearing structural fragments that were responsible for enhancing activity of previously studied enhancers (e.g. amino acid derivatives, fatty acids and alcohols, modified ceramides). A detailed examination of these sugar- based compounds revealed potent glucoside and galactoside enhancers (12Glc6N and A15) comparable to or better than Span 20 with reversible mode of action and acceptable toxicity on keratinocyte and fibroblast cell lines. Another part of my work builds...
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Connection between completion of weight loss program and self efficacy in obese people
Vávrová, Kateřina ; Hrachovinová, Tamara (advisor) ; Rodriguez Manchola, Mabel Virginia (referee)
The thesis deals with connections between completion of reduced course and self-efficacy of obese people. The theoretical part deals with definition of obesity, its prevalence and aspects of its treatment. A chapter of the theoretical part focuses on self-efficacy and its connections to obesity and physical activity. The last part is about general self-efficacy. The empirical part describes physical activity of obese respondents, changes in their physical activity self-efficacy and their general self-efficacy after completion of reduced course. The questionnaires about the level of physical activity and physical activity self-efficacy were created by author of the thesis. General self-efficacy was measured by General self-efficacy scale. Data were obtained in the first and last lesson of reduced courses. A paired-samples t-test was conducted to compare changes in both areas of self-efficacy. It has been found that frequency of respondents physical activity was insufficient. The results suggest that connection between completion of reduced course and general self-efficacy exist. On the other hand there was not significant difference between individual's physical self-efficacy before reduced course and after its completion. Keywords: obesity, self-efficacy, physical activity self-efficacy, general...
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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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Synthesis and study of 1-O-acylceramides
Jon, Vojtěch ; Vávrová, Kateřina (advisor) ; Opálka, Lukáš (referee)
The extracellular matrix of the uppermost layer of the skin, the stratum corneum (SC), consists of ceramides (Cer), cholesterol (Chol), free fatty acids (FFA) and cholesteryl sulfate (CholS). Cer play an important role in the correct barrier function of mammalian epidermis. A new type of sphingolipids, i.e., 1-O-acyl-Cer, have been found in human SC very recently; however, their role in the SC is unknown. These Cer species contain sphingosine (S) that is N- acylated with non-hydroxylated or α- hydroxylated fatty acid, and moreover, hydroxyl group at C1 in sphingosine is esterified by an additional fatty acid (lignoceric acid, C24 or palmitic acid, C16). Because 1-O-acyl-Cer are not commercially available, we aimed to synthesize physiological 1-O-acyl Cer, i.e., Cer-24NS16, Cer-16NS16 and Cer-24AS16. Moreover, we aimed to study their behaviour on permeability and microstructure of model skin lipid membranes. The 1-O-acyl-Cer were synthesized by an acylation of Cer-NS16 or Cer-AS16 with palmitic or lignoceric acid using N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide and 4- dimethylaminopyridine. Cer-AS16 was prepared by α-bromination of palmitic acid, substitution of bromine by hydroxyl and N-acylation of sphingosine by the prepared acid in the presence N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide...
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Study of Effect of Ceramide Hydroxylation on Permeability and Microstructure of Model Lipid Membranes
Kováčik, Andrej ; Vávrová, Kateřina (advisor) ; Uhriková, Daniela (referee) ; Šklubalová, Zdeňka (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Department of Organic and Bioorganic Chemistry Candidate Mgr. Andrej Kováčik Supervisor prof. PharmDr. Kateřina Vávrová, Ph.D. Title of Doctoral Thesis Study of Effect of Ceramide Hydroxylation on Permeability and Microstructure of Model Lipid Membranes Ceramides (Cer) occur in intracellular spaces of the stratum corneum, the outermost mammalian epidermal layer, where they along with other lipids (free fatty acids, cholesterol) form a skin lipid barrier. Besides sphingosine- (Cer NS) and dihydrosphingosine-based Cer (Cer NdS), in the healthy mammalian epidermis some polar Cer are present, i.e., Cer based on phytosphingosine (with hydroxyl group in position 4, i.e., phytoceramides) and Cer based on 6-hydroxysphingosine (with hydroxyl group in position 6, i.e., 6- hydroxyceramides). However, the role of phytoceramides (Cer NP) and 6 hydroxyceramides (Cer NH) in the skin barrier function has not been clarified. Moreover, 6 hydroxyceramides are not commercially available. Therefore, the first aim of this work was to synthesize physiological 6-hydroxyceramides. The synthesis of 6- hydroxylated Cer, i.e., Cer NH with long (C24:0) and Cer EOH with ultralong acyl with ester-linked linoleic acid is reported. The triple bond was reduced...
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