|
|
Vliv síťování na denaturaci kolagenových vzorků z různých živočišných zdrojů
Ladický, Peter ; Muchová, Johana (oponent) ; Sedláček, Petr (vedoucí práce)
Diplomová práca sa zaoberá prípravou, sieťovaním a charakterizáciou kolagénových filmov z rôznych živočíšnych zdrojov. Na prípravu kolagénových filmov bol použitý kolagén z prasaťa, Tilapie, koňa, kravy a krokodýla. Na sieťovanie pripravených filmov boli použité chemické sieťovadlá EDC/NHS a Lyofix. V experimentálnej časti bola optimalizovaná metóda diferenčnej kompenzačnej kalorimetrie (DSC), pomocou ktorej bola následne stanovená teplota denaturácie jednotlivých kolagénových filmov pred a po sieťovaní. Ďalej bola analyzovaná schopnosť filmov botnať a degradovať. Pomocou infračervenej spektroskopie bola overená prítomnosť charakteristických skupín vyskytujúcich sa v štruktúre kolagénu. Morfólogia vzoriek bola skúmaná pomocou metódy skenovacej elektrónovej kryomikroskopie (kryo-SEM). Z výsledkov vyplýva, že EDC/NHS je v porovnaní s Lyofix lepším sieťovadlom kolagénu. Najlepším zdrojom na prípravu termálne stabilných filmov je prasací kolagén, ktorého teplota denaturácie po sieťovaní EDC/NHS bola približne 69 C a predstavuje viac ako adekvátnu náhradu kravského kolagénu, ktorý je v súčasnosti najviac využívaný či už v oblasti tkanivového inžinierstva alebo potravinárskeho priemyslu.
|
|
|
Preparation and characterization of nanostructured resorbable substitutes for accelerated skin healing
Kacvinská, Katarína ; Muchová, Johana (oponent) ; Vojtová, Lucy (vedoucí práce)
Together with the increasing demands on the quality of treatment in the field of burn and plastic surgery, there is the possibility of applying new technological solutions in the treatment of defects with full loss of skin thickness. This thesis deals with a preparation of a nanostructured bilayer scaffold for skin tissue engineering, which substitutes a skin dermis (lower porous layer) and a basal membrane (upper nanofibrous thin layer)). The porous layer is based on collagen, which is also characterized in presence of different polysaccharide additives: chitosan, oxidized cellulose calcium salt (CaOC), carboxymethyl cellulose sodium salt (NaCMC)), as well as a dopamine and fibroblast growth factor (FGF) addition, in order to improve biomechanical properties, regulate and promote skin healing. Thin nanofibers layer consists of electrospun gelatin in combination with polycaprolactone (PCL) and CaOC. Two different fabrication mechanisms differing in cross-linking between the porous and nanofibrous layer are proposed. The scaffolds were evaluated in terms of biomechanical, structural and in-vitro properties. A uniaxial strain test has shown that the upper nanofibrous layer provides mechanical support, which is significantly enhanced with the polydopamine (PDA)-coated surface. Swelling test of porous layer showed adequate spaces to allow cells infiltration, what has been shown as decrease in presence of PDA. Degradation with collagenase and lysozyme has shown significant time prolongation and also proliferation and viability of the mouse fibroblast cells seeded on the scaffolds were significantly enhanced with PDA and FGF modification. Novel nanostructured bilayer scaffold possess good biomechanical properties and exhibis potential in skin tissue engineering by allowing cells to adhere, proliferate and generate expracellular matrix.
|
|
|
The effect of biologicaly active substances on the structure and properties of collagenous substrates
Muchová, Johana ; Michlovská, Lenka (oponent) ; Vojtová, Lucy (vedoucí práce)
The thesis deals with the preparation of 3D porous collagen scaffolds by freeze-drying and their modification with bioactive compounds. The natural polysaccharides, chitosan, calcium oxidized cellulose and chitin/chitosan-glucan complex for the modification have been used. The mechanical properties of the scaffolds have been enhanced by crosslinking process with carbodiimides. Growth factors have been delivered in the form of platelet lysate. The influence of biologically active additives, crosslinking agents, and enrichment with growth factors on the properties of the prepared scaffold and their bioactivity in tissues of living organisms have been investigated. Specifically, this study includes the morphological properties, structure, porosity, swelling stability, chemical composition, temperature of denaturation and biological properties. Scanning electron microscopy, infrared specktroscopy, differential scanning calorimetry and confocal microscopy have been used to the characterization. Prepared collagen substrates involving bioactive additive and platelet lysate could be used as scaffold for growing cells in systems with low mechanical loading and which has potential application in biomedicine.
|
|
|
Dynamický rozptyl světla a elektroanalytické metody ve studiu systémů hyaluronanu a aminokyselin
Muchová, Johana ; Kalina, Michal (oponent) ; Chytil, Martin (vedoucí práce)
Bakalářská práce se zabývá studiem interakcí mezi polysacharidem hyaluronanem (HA) o nízké a vysoké molekulové hmotnosti a protonizovanými amfifilními aminokyselinami lysinem a argininem. Interakce byly pozorovány v oblasti nízkých koncentrací v koncentračním rozmezí lysinu a argininu 0–15 mmoldm-3. K interakcím dochází mezi karboxylovou skupinou HA a aminoskupinou protonizované aminokyseliny. Prokázání těchto interakcí by umožnilo fyzikální modifikaci HA a následné využití jako cíleného nosiče léčiv. Byla zkoumána odolnost vůči iontové síle o koncentraci 0,015 a 0,15 moldm-3 NaCl. Z předešlých výsledků vyplývá, že systém s neprotonizovanými aminokyselinami se rozpadá již při nízkých koncentracích elektrolytu v roztoku. Interakce proto byly posíleny protonizací aminokyselin pomocí kyseliny chlorovodíkové. Pro negativní vliv chloridových aniontů byly aminokyseliny oproti úplné protonizaci protonizovány také do pH roztoku HA. K výzkumu interakcí byly použity metody měření pH, měření vodivosti a dynamického rozptylu světla.
|
|
|
The effect of organic and inorganic additives on the chemico-physical properties of biopolymer substrates for tissue engineering
Kohoutek, Martin ; Muchová, Johana (oponent) ; Brtníková, Jana (vedoucí práce)
This bachelor’s thesis deals with the preparation and characterization of composite collagenous scaffolds for possible applications in both bone and skin tissue engineering with an emphasis on their chemico-physical properties. In the theoretical part, the selected components for fabrication of the scaffolds are described and later were used to fabricate 3D porous composite scaffolds in the experimental part. Altogether, four different composite collagenous scaffold types and a reference pure collagen scaffold type were prepared using the freeze-drying fabrication technique. Two scaffold types were made by combining collagen with either oxidised cellulose (OC) or carboxymethyl cellulose (CMC). The other two types of scaffolds had the same biopolymeric origin enhanced with the addition of bioceramics based on the hydroxyapatite and tricalcium phosphates. The microstructure, porosity and pore size were assessed by the scanning electron microscopy. The highest porosity and pore size were achieved by the reference purely collagenous scaffolds, followed by the collagen composites with OC and CMC. Scaffolds with the content of bioceramics had the lowest porosity and pore size, especially those containing CMC. Swelling behaviour analysis and enzymatic degradation in vitro showed, that the hydrophilicity and mass loss in the degradation process correlate with each other. The scaffolds without bioceramics were more hydrophilic and achieved greater mass loss than the scaffolds containing bioceramics. The pure collagen was in the between the two groups. Scaffolds containing CMC achieved greater mass loss and hydrophilicity than their OC counterparts. In terms of mechanical properties, scaffolds with bioceramics achieved higher compressive strength in the wet state than the other three scaffold types. The mechanical properties were generally better for scaffolds with lower porosity and lower hydrophilicity.
|
|
|
Fotostabilization of biopolymeric materials for regenerative medicine
Izsák, Dávid ; Muchová, Johana (oponent) ; Brtníková, Jana (vedoucí práce)
Non-stabilized biopolymers often show poor mechanical properties. The stabilization and improvement of these properties could be accomplished by crosslinking, but the traditionally used crosslinking agents are rather cytotoxic and harmful for the human body. The aim of this work is to find a suitable non-toxic crosslinking method that would be efficient enough, but at the same time would not represent danger to any organism. The crosslinking method developed in the presented bachelor thesis should be comparatively efficient as traditionally used methods (e.g. chemical carbodiimide-based crosslinking) as well as potentially less cytotoxic by use of naturally derived substances. The proposed alternative crosslinking method should improve the strength and stability of the crosslinked biopolymers and enhance their biological functionality. Specifically, the presented work deals with the stabilization of collagen scaffolds using vitamin important for human metabolism followed by short- and long-wavelength irradiation. The theoretical part contains a general overview of possible non-toxic crosslinking agents, describes the structure of collagen and characterizes its properties and with the properties of used vitamin as a crosslinking agent. The experimental part deals with the preparation and crosslinking optimization of collagen scaffolds. Swelling, degradation and morphology of scaffolds as well as collagen secondary structure were evaluated. As a result, sufficiently strong crosslinked scaffolds were obtained.
|
|
|
Preparation and characterization of nanostructured resorbable substitutes for accelerated skin healing
Kacvinská, Katarína ; Muchová, Johana (oponent) ; Vojtová, Lucy (vedoucí práce)
Together with the increasing demands on the quality of treatment in the field of burn and plastic surgery, there is the possibility of applying new technological solutions in the treatment of defects with full loss of skin thickness. This thesis deals with a preparation of a nanostructured bilayer scaffold for skin tissue engineering, which substitutes a skin dermis (lower porous layer) and a basal membrane (upper nanofibrous thin layer)). The porous layer is based on collagen, which is also characterized in presence of different polysaccharide additives: chitosan, oxidized cellulose calcium salt (CaOC), carboxymethyl cellulose sodium salt (NaCMC)), as well as a dopamine and fibroblast growth factor (FGF) addition, in order to improve biomechanical properties, regulate and promote skin healing. Thin nanofibers layer consists of electrospun gelatin in combination with polycaprolactone (PCL) and CaOC. Two different fabrication mechanisms differing in cross-linking between the porous and nanofibrous layer are proposed. The scaffolds were evaluated in terms of biomechanical, structural and in-vitro properties. A uniaxial strain test has shown that the upper nanofibrous layer provides mechanical support, which is significantly enhanced with the polydopamine (PDA)-coated surface. Swelling test of porous layer showed adequate spaces to allow cells infiltration, what has been shown as decrease in presence of PDA. Degradation with collagenase and lysozyme has shown significant time prolongation and also proliferation and viability of the mouse fibroblast cells seeded on the scaffolds were significantly enhanced with PDA and FGF modification. Novel nanostructured bilayer scaffold possess good biomechanical properties and exhibis potential in skin tissue engineering by allowing cells to adhere, proliferate and generate expracellular matrix.
|
|
|
Vliv síťování na denaturaci kolagenových vzorků z různých živočišných zdrojů
Ladický, Peter ; Muchová, Johana (oponent) ; Sedláček, Petr (vedoucí práce)
Diplomová práca sa zaoberá prípravou, sieťovaním a charakterizáciou kolagénových filmov z rôznych živočíšnych zdrojov. Na prípravu kolagénových filmov bol použitý kolagén z prasaťa, Tilapie, koňa, kravy a krokodýla. Na sieťovanie pripravených filmov boli použité chemické sieťovadlá EDC/NHS a Lyofix. V experimentálnej časti bola optimalizovaná metóda diferenčnej kompenzačnej kalorimetrie (DSC), pomocou ktorej bola následne stanovená teplota denaturácie jednotlivých kolagénových filmov pred a po sieťovaní. Ďalej bola analyzovaná schopnosť filmov botnať a degradovať. Pomocou infračervenej spektroskopie bola overená prítomnosť charakteristických skupín vyskytujúcich sa v štruktúre kolagénu. Morfólogia vzoriek bola skúmaná pomocou metódy skenovacej elektrónovej kryomikroskopie (kryo-SEM). Z výsledkov vyplýva, že EDC/NHS je v porovnaní s Lyofix lepším sieťovadlom kolagénu. Najlepším zdrojom na prípravu termálne stabilných filmov je prasací kolagén, ktorého teplota denaturácie po sieťovaní EDC/NHS bola približne 69 C a predstavuje viac ako adekvátnu náhradu kravského kolagénu, ktorý je v súčasnosti najviac využívaný či už v oblasti tkanivového inžinierstva alebo potravinárskeho priemyslu.
|
|
|
The effect of biologicaly active substances on the structure and properties of collagenous substrates
Muchová, Johana ; Michlovská, Lenka (oponent) ; Vojtová, Lucy (vedoucí práce)
The thesis deals with the preparation of 3D porous collagen scaffolds by freeze-drying and their modification with bioactive compounds. The natural polysaccharides, chitosan, calcium oxidized cellulose and chitin/chitosan-glucan complex for the modification have been used. The mechanical properties of the scaffolds have been enhanced by crosslinking process with carbodiimides. Growth factors have been delivered in the form of platelet lysate. The influence of biologically active additives, crosslinking agents, and enrichment with growth factors on the properties of the prepared scaffold and their bioactivity in tissues of living organisms have been investigated. Specifically, this study includes the morphological properties, structure, porosity, swelling stability, chemical composition, temperature of denaturation and biological properties. Scanning electron microscopy, infrared specktroscopy, differential scanning calorimetry and confocal microscopy have been used to the characterization. Prepared collagen substrates involving bioactive additive and platelet lysate could be used as scaffold for growing cells in systems with low mechanical loading and which has potential application in biomedicine.
|
|
|
Dynamický rozptyl světla a elektroanalytické metody ve studiu systémů hyaluronanu a aminokyselin
Muchová, Johana ; Kalina, Michal (oponent) ; Chytil, Martin (vedoucí práce)
Bakalářská práce se zabývá studiem interakcí mezi polysacharidem hyaluronanem (HA) o nízké a vysoké molekulové hmotnosti a protonizovanými amfifilními aminokyselinami lysinem a argininem. Interakce byly pozorovány v oblasti nízkých koncentrací v koncentračním rozmezí lysinu a argininu 0–15 mmoldm-3. K interakcím dochází mezi karboxylovou skupinou HA a aminoskupinou protonizované aminokyseliny. Prokázání těchto interakcí by umožnilo fyzikální modifikaci HA a následné využití jako cíleného nosiče léčiv. Byla zkoumána odolnost vůči iontové síle o koncentraci 0,015 a 0,15 moldm-3 NaCl. Z předešlých výsledků vyplývá, že systém s neprotonizovanými aminokyselinami se rozpadá již při nízkých koncentracích elektrolytu v roztoku. Interakce proto byly posíleny protonizací aminokyselin pomocí kyseliny chlorovodíkové. Pro negativní vliv chloridových aniontů byly aminokyseliny oproti úplné protonizaci protonizovány také do pH roztoku HA. K výzkumu interakcí byly použity metody měření pH, měření vodivosti a dynamického rozptylu světla.
|
host ::
RSS.