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Optimization of the skin barrier model with isolated ceramides of human stratum corneum
Dulanská, Lucia ; Pullmannová, Petra (advisor) ; Zbytovská, Jarmila (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author: Lucia Dulanská Supervisor: Mgr. Petra Pullmannová, Ph.D Title of thesis: Optimization of the skin barrier model with isolated ceramides of human Stratum corneum Stratum corneum (SC), the uppermost layer of the skin, regulates transcutaneous water loss and protects against outer conditions and harmful substances. It consists of cornified cells - corneocytes and extracellular lipid matrix, which is responsible for the barrier functions. Corneocytes are covered with covalently bound lipids creating the corneocyte lipid envelope (CLE). CLE is considered to interconnect the extracellular lipids with corneocytes and to have a templating effect. We aimed to optimize a skin lipid model simulating also the presence of CLE. The lipidic part of the model was prepared from an equimolar mixture of isolated human skin ceramides (hCer), cholesterol and free fatty acids (FFA, either protonated or deuterated) with 5 weight % of cholesteryl sulfate. hCer were extracted from the isolated human SC and purified by the column chromatography. The composition of hCer was determined by the high- performance thin-layer chromatography. The reverse-phase and normal phase silica gel particles served as the CLE...
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Study of substances affecting permeability of the skin barrier
Nováčková, Anna ; Zbytovská, Jarmila (advisor) ; Cvačka, Josef (referee) ; Doležal, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Department of Pharmaceutical Technology Candidate Mgr. Anna Nováčková Supervisor doc. Mgr. Jarmila Zbytovská, Dr. rer. nat. Title of Doctoral Thesis Study of substances affecting permeability of the skin barrier The skin barrier plays a vital role in protecting the human body and enables mammals' life on dry land. The epidermis has the primary barrier function due to several cells' layers, which gradually differentiate to their final stage, the stratum corneum (SC). SC is formed by stratified keratinocytes (known as corneocytes) surrounded by a lipid matrix. This intercellular matrix consists of an approximately equimolar ratio of ceramides, free fatty acids and cholesterol. These are particular substances formed in the epidermis from their precursors during the keratinocyte's differentiation, and their arrangement into the multilamellar structure is essential for the impermeability of the skin barrier. However, some substances or factors can disrupt the skin barrier. It is usually an undesirable process of lipid disbalance resulting in disorders or diseases of the skin barrier. On the other hand, specific substances have been developed for a reversible disruption of the skin barrier (so-called enhancers) to allow drug...
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Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
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Study of substances affecting permeability of the skin barrier
Nováčková, Anna ; Zbytovská, Jarmila (advisor) ; Cvačka, Josef (referee) ; Doležal, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Department of Pharmaceutical Technology Candidate Mgr. Anna Nováčková Supervisor doc. Mgr. Jarmila Zbytovská, Dr. rer. nat. Title of Doctoral Thesis Study of substances affecting permeability of the skin barrier The skin barrier plays a vital role in protecting the human body and enables mammals' life on dry land. The epidermis has the primary barrier function due to several cells' layers, which gradually differentiate to their final stage, the stratum corneum (SC). SC is formed by stratified keratinocytes (known as corneocytes) surrounded by a lipid matrix. This intercellular matrix consists of an approximately equimolar ratio of ceramides, free fatty acids and cholesterol. These are particular substances formed in the epidermis from their precursors during the keratinocyte's differentiation, and their arrangement into the multilamellar structure is essential for the impermeability of the skin barrier. However, some substances or factors can disrupt the skin barrier. It is usually an undesirable process of lipid disbalance resulting in disorders or diseases of the skin barrier. On the other hand, specific substances have been developed for a reversible disruption of the skin barrier (so-called enhancers) to allow drug...
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Preparation of pharmaceutical formulations based on polymeric and lipid carriers
Kubačková, Jana ; Zbytovská, Jarmila (advisor) ; Panáček, Aleš (referee) ; Štěpánek, František (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate Mgr. Jana Kubačková Supervisor Assoc. Prof. Jarmila Zbytovská, Mgr., Dr. rer. nat. Co-supervisor PharmDr. Ondřej Holas, PhD. Title of Doctoral Thesis Preparation of pharmaceutical formulations based on polymeric and lipid carriers Nanomedicine allows application of nanoscaled drug delivery carriers to achieve a therapy that can be tailored in terms of e.g. controlled release, site-specific delivery and protection of an active substance. From multiple nanoplatforms available for drug delivery, advantage was taken of biocompatible and biodegradable polymers and lipids to enable targeted intracellular delivery, delivery of a poorly water-soluble drug and delivery of a sensitive macromolecule. In the study with biodegradable polymeric nanomaterial we worked with experimental poly(lactic-co-glycolic acid) (PLGA) polymers. The formulations were optimised for targeting to phagocytic macrophages - of size up to 300 nm and negative surface charge. For this purpose, two linear and one branched PLGA were screened in combination with one of four surfactants in low concentrations (0.1-1%). These PLGA polymers were formulated into nanoparticles and loaded with a hydrophilic fluorescent dye Rhodamine B...
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Optimization of the skin barrier model with isolated ceramides of human stratum corneum
Dulanská, Lucia ; Pullmannová, Petra (advisor) ; Zbytovská, Jarmila (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Author: Lucia Dulanská Supervisor: Mgr. Petra Pullmannová, Ph.D Title of thesis: Optimization of the skin barrier model with isolated ceramides of human Stratum corneum Stratum corneum (SC), the uppermost layer of the skin, regulates transcutaneous water loss and protects against outer conditions and harmful substances. It consists of cornified cells - corneocytes and extracellular lipid matrix, which is responsible for the barrier functions. Corneocytes are covered with covalently bound lipids creating the corneocyte lipid envelope (CLE). CLE is considered to interconnect the extracellular lipids with corneocytes and to have a templating effect. We aimed to optimize a skin lipid model simulating also the presence of CLE. The lipidic part of the model was prepared from an equimolar mixture of isolated human skin ceramides (hCer), cholesterol and free fatty acids (FFA, either protonated or deuterated) with 5 weight % of cholesteryl sulfate. hCer were extracted from the isolated human SC and purified by the column chromatography. The composition of hCer was determined by the high- performance thin-layer chromatography. The reverse-phase and normal phase silica gel particles served as the CLE...
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In vitro models of skin barrier
Šimek, Matěj ; Zbytovská, Jarmila (advisor) ; Pullmannová, Petra (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Matěj Šimek Consultant: doc. Dr. rer. nat. Mgr. Jarmila Zbytovská Title of thesis: In vitro models of skin barrier The aim of this work is to summarize information about various types of skin models which are used for testing of permeability, toxicity, irritability and other aspects of drugs, through professional, verified and reviewed literature. These characteristics are necessary to know in order to grant optimal safety, effectiveness nad quality of transdermally administered drugs. Transdermal administration of drugs has got lots of benefits in contrast with classic peroral administration. An administration of drugs through this way is quite simple and it can be interrupted quite easily. We can also easily change a place of administration in which a drug is released and the risk of overdosing is very low. Furthermore, transdermal administration makes possible to maintain constant plasmatic concentration of drug in a blood stream and also to prolong the duration of effect of drugs with small halftime thanks to constant releasing of drug. And primarily, transdermally administered drug normally avoids the "first-pass" effect of liver, so the dose of drug can be lowered. The risk of drug...
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Study of transdermal and dermal absorption of 2,6-diaminopurine acyclic nucleoside phosphonates
Diblíková, Denisa ; Vávrová, Kateřina (advisor) ; Zbytovská, Jarmila (referee)
Acyclic nucleoside phosphonates (ANP) are broad-spectrum antivirals highly effective against herpes-, retro- and hepadnaviruses. They also exhibit cytostatic, antiparasitic, immunomodulatory activities. Their transdermal delivery offers an attractive and advantageous route of administration, but is limited due to the polar character of their phosphonate moiety. The aim of this work was to study the possibility of both transdermal and dermal application of a series of 2,6-diaminopurine derivatives including (R)-PMPDAP and (S)-PMPDAP, (S)-HPMPDAP, (S)-8-azaHPMPDAP, cyclic (S)-HPMPDAP and lysolipid prodrugs, i.e., hexadecyloxypropyl (HDP) esters of (R)-HDP-PMPDAP and (S)-HDP- HPMPDAP. Ability of ANP to penetrate trough the skin by themselves is generally very low. For this reason the influence of permeation enhancer dodecylester of 6- (dimethylamino)hexanoic acid (DDAK) through and into human skin was investigated. The evaluation was performed in vitro by using Franz diffusion cells and human skin. The results of this work confirm that ANP (60 mM in 60 % propylene glycol) delivery through the skin is very low (flux 0.53-1.40 nmol/cm2 /h), except for the lysolipid prodrugs (R)-HDP-PMPDAP and (S)-HDP-HPMPDAP), which were not detected in the acceptor phase at all. 1 % DDAK enhanced transdermal flux of...
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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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Nanocarriers for dermal and transdermal drug administration
Girgel, Josef ; Zbytovská, Jarmila (advisor) ; Holas, Ondřej (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Josef Girgel Consultant: Doc. Dr. rer. Nat. Mgr. Jarmila Zbytovská Title of thesis: Nanocarriers for dermal and transdermal drug delivery The aim of this work was to map the literature and the most logically divide it and to elucidate the mechanisms of the carrier's interaction with the skin, the degree of their ability to penetrate the skin and to evaluate their potential to the next years. Skin administration appears to be more advantageous way than others, mainly due to higher patient's compliance, avoiding the first pass effect of the liver, ensuring a stable blood concentration during transdermal administration and reducing adverse effect of the drug. However, the skin serves as an effective barrier to the external environment, especially its outermost layer called stratum corneum. In a recent year, the interest of many research groups has focused on nanocarriers which are expected to deliver more efficient transport to and through the skin barrier due to their size ranging from tens to hundreds of nanometers. It has been confirmed that some of these carriers are able to permeate the skin. For metallic nanoparticles, their permeation is primary associated with toxicity and they are...
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