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Physical factors influencing the development of corneal damage by UV rays
Čejka, Čestmír ; Rosina, Jozef (advisor) ; Štípek, Stanislav (referee) ; Amler, Evžen (referee) ; Salminen, Lotta (referee)
Purpose: The purpose of the Thesis "Physical factors influencing the development of corneal damage by UV rays" was a) to determine the light absorption properties in the rabbit cornea irradiated with UVB rays by measuring of physical values of absorbance A and transmittance T as functions of wavelength ; b) To investigate the absorption coefficient as a function of wavelength ; c) To evaluate the importance of this coefficient for corneal light absorption properties; d) To determine the light absorption properties in the rabbit cornea irradiated with UVA by measuring of physical values of absorbance A and transmittance T as functions of wavelength (to compare the effect of UVA with UVB rays). Material and Methods: To achieve individual aims, the new spectrohotometrical method was developed and following experimets were performed: a) Repeted irradiation of the rabbit cornea with UVB rays (daily dose 1.01 J/cm2 during 5 days); b) Repeated irradiation of the rabbit cornea with UVA rays (daily dose 1.01 J/cm2 or 2.02 J/cm2) during five days; c) Repeated irradiation of the rabbit cornea with the daily dose of 1.01 J/cm2 during 4 days and in individual time intervals investigation of corneal light absorption and hydration changes; d) The anti-UV efficacy of UV filter (actinoquinol combined with hyaluronic acid,...
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Effect of plasma modified nanofiber surface on mesenchymal stem cell adhesion, viability and proliferation.
Lukášová, Věra ; Amler, Evžen (advisor) ; Svoboda, Ondřej (referee)
This work summarizes information about the interactions between the plasma modified nanofibres surfaces and mesenchymal stem cells. Knowledge of mechanisms of cell specific adhesion could be used for a development of artificial scaffolds which will support a growth of the particular cell type. Nanofibrous materials mimic the morphology of the extracellular matrix and serve as cell scaffolding materials. However, the cell adhesion to the material surface is often not sufficient for efficient tissue regeneration. Plasma modification of nanofiber scaffolds leads to an improvement of surface characteristics. Changes in wettability, surface energy, roughness and chemical composition occur in various extents according to the type of utilized plasma. Such modifications could lead to improvement of cell adhesion and could enhance the potential of scaffold application for biomedical use.
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Application of nanofiber scaffolds for vesel regeneration
Bezděková, Dagmar ; Amler, Evžen (advisor) ; Holzerová, Kristýna (referee)
Although plenty of systems for vessel regeneration have been developed, no system is successful in small diameter (under 6 mm) vessel replacement yet. Synthetic materials, such as Dacron and ePTFE, have good results in large vessels replacement, but they cause thrombosis in small vessels. In addition, they are not degradable and do not allow a natural remodeling of the vessel system. Furthemore, endothelial cells, which are essential for creating natural antithrombogenic endothelium, do not adhere on these materials, as well as smooth muscle cells. Decellularized xenogenic material is the non-synthetic alternative for vessel regeneration. Appropriate detergent removes donor's cells and only extracellular matrix remains, which is able to host acceptor's cells. The main disadvantages of this system are difficulties with animal's nurture and structure violations after detergent is used. It appears that electrospun materials are the best alternative. The relatively simple process can be modified in many ways and provides then a scaffold, which mimics extracellular matrix. A big advantage of this process is the possibility to incorporate bioactive substances into a fiber. The substances serve there as an attractant for blood cells or as an anticoagulation factor. In combination with the progenitor cells seems...
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Nanofibrous scaffolds in controlled delivery of autologous growth factors
Buzgo, Matej ; Amler, Evžen (advisor) ; Gášková, Dana (referee)
Platelet preparations are a source of various autologous growth factors and have numerous applications in tissues engineering. The aim of this work was to development electrospun nanofiber scaffolds with platelet preparations. Scaffolds based on the adhesion of platelets on nanofiber meshes were developed. The scaffolds were able to enhance chondrocyte proliferation in vitro. The main disadvantage of this system is the burst release of growth factors immediately after adhesion. To overcome this, we developed coaxially electrospun scaffolds with incorporated alpha granules. Alpha granules are novel platelet preparations with high amounts of growth factors. This system was able to stimulate chondrocyte proliferation and maintain TGF- 1 concentrations for 7 days. Additionally, a novel drug delivery system with coaxially incorporated liposomes was developed. Liposomes incorporated into nanofibers remain intact and can be used for the delivery of various molecules. The ability to maintain HRP activity was compared to systems based on coaxial electrospinning with liposomes, coaxial electrospinning without liposomes and blend electrospinning. When compared to other systems, coaxial electrospinning with liposomes preserves enzyme activity twice as long. These results clearly indicate the potential of...
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Enhanced biomechanical characteristics of connective tissues and development of artificial implants
Varga, Ferdinand ; Amler, Evžen (advisor) ; Rosina, Jozef (referee) ; Daniel, Matej (referee) ; Sabo, Ján (referee)
(english) Hyaline cartilages are designed to enable smooth life-long articular move- ment. They serve also substantial role in load bearing, being loaded especially in normal compression. Eventual deterioration of articular cartilage tissue therefore has crucial consequences for affected individ- ual. Characterization of native articular cartilage and application of gained knowledge in reconstructive cartilage treatment is therefore de- sired. Mechanical characteristics are of prime importance. Blunt impact testing method in pendulum setup was developed to characterize cartilage tissue under physiological values of dynamic com- pressive loading. Information on impact process was simultaneously read by piezoelectric accelerometer and laser doppler vibrometer. Acquired data were processed to form loading diagrams and to evaluate standard mechanical quantities. The method was found to be consistent, reliable and effective way of mechanical characterization. Introduced technique was used for qualitative and quantitative de- scription of native articular cartilage, correlation of its condition with mechanical properties, assessment of tissue engineered materials quality and approval of newly designed artificial materials suitability. Consider- ing native cartilage status, dissipated energy was found to be...
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Cartilage regeneration using peroral supplementation and artificial scaffolds
Filová, Eva ; Amler, Evžen (advisor) ; Jebavý, Lukáš (referee) ; Otáhal, Stanislav (referee) ; Tománková, Kateřina (referee)
Cartilage can regenerate only in a limited extend. The aim of the study was to enhance hyaline cartilage regeneration using peroral supplementation of glycosaminoglycans (GAGs) and antioxidants, or using artificial scaffolds seeded with autologous cells. Scaffolds seeded with chondrocytes or mesenchymal stem cells (MSCs) have a potential for treatment of cartilage defects. For the complex characterization of biomechanical properties of scaffold, we developed the novel shock dynamic method. Subsequently, the composite hyaluronate-type I collagen-fibrin scaffold with the viscoelastic properties and dynamic loading response similar to the native cartilage was developed. The composite scaffold was then used for osteochondral regeneration and physeal cartilage regeneration. The effect of peroral supplementation of GAGs and antioxidants (vitamin E/selenium) on the regeneration of osteochondral defects was investigated in rabbits. After introduction of defined osteochondral defects in the knee joint, groups of ten animals were given a GAG/vitamin E/selenium mixture or a placebo (milk sugar) for 6 weeks. The amount of sulfated GAGs in the osteochondral regenerates was significantly higher in the GAG group. In both groups, the GAG amount in the cartilage of the operated knee was significantly higher than in the...
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