National Repository of Grey Literature 26 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Filová, Elena ; Trávníčková, Martina ; Knitlová, Jarmila ; Matějka, Roman ; Kučerová, Johanka ; Riedelová, Zuzana ; Brynda, Eduard ; Bačáková, Lucie
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart valve prostheses, re-seeded with autologous cells, i.e. Adipose tissue-derived cells (ASCs) and endothelial cells, could have longer durability and biocompatibility. In order to improve the adhesion of cells and their ingrowth into decellularized pericardium, various fibrin (Fb) layers were developed, i.e. Fb, Fb with covalently bound heparin (H), Fb with either vascular endothelial growth factor (VEGF) or fibroblast growth factor 2 (FGF) in various concentrations (1 ng/ml, 10 ng/ml, 100 ng/ml) or with both VEGF and FGF (100 ng/ml). Growth factors were attached onto Fb via heparin or were adsorbed. ASCs were seeded on theses layers in a DMEM medium supplemented with 2 % of fetal bovine serum, TGFβ1 and BMP-4 (both 2.5 ng/ml), and with ascorbic acid. Cell adhesion and growth/viability was assessed by counted cell number/MTS evaluation. ASCs were stained for differentiation markers of smooth muscle cells, such as alpha-actin, calponin, and myosin heavy chain. On day 7, ASCs on Fb-H-VEGF layers produced both calponin and alpha-actin. An increased FGF concentration caused reduced calponin staining of ASCs. Lack of heparin in fibrin assemblies with growth factors inhibited the production of both alpha-actin and calponin in ASCs. The highest ASCs density/viability was found on Fb-H-VEGF-FGF layer. The proper formulation of fibrin coatings could be favorable for ASCs growth and differentiation and could subsequently support endothelialization of cardiovascular prostheses with endothelial cells.
Histology and micro-CT study of diamond-coated metal bone implants
Potocký, Štěpán ; Ižák, Tibor ; Dragounová, Kateřina ; Kromka, Alexander ; Rezek, Bohuslav ; Mandys, V. ; Bartoš, M. ; Bačáková, Lucie ; Sedmera, David
A conformal coating of a thin diamond layer on three-dimensional metal bone implants was shown directly on stainless steel and TiAl6V4 cortical screw implant using ultrasonic and composite polymer pretreatment method. The best conformation coverage was achieved in the case of the WO3 interlayer for both stainless steel and TiAl6V4 screws. The process of osteointegration of the screw implants into rabbit femurs is evidenced by the formation of a bone edge via desmogenous ossification around the screws in less than six months after implantation. A detailed evaluation of the tissue reaction around the implanted screws shows good biocompatibility of diamond-coated metal bone implants.
Optimizing and Evaluating the Biocompatibility of Fiber Composites with CaP Additives
Suchý, Tomáš ; Sucharda, Zbyněk ; Balík, Karel ; Sochor, M. ; Bačáková, Lucie
Composite materials based on a polyamide fabric (aramid) and a polydymethyl-siloxane (PDMS) matrix were designed for application in bone surgery. In order to increase the bioactivity, 2, 5, 10, 15, 20 and 25 vol. % of nano/micro hydroxyapatite (HA) and tricalcium phosphate (TCP) were added. The effect of the additives on the biocompatibility was studied. It appears that nano additives have a more favorable effect than micro particles on mechanical properties. For final application of the composites as substitutes for bone tissues, 15 vol. % of nano hydroxyapatite additives is an optimum amount: in this case both the mechanical properties and the biological properties are optimized without distinct changes in the inner structure of the composite.
Adhesion, growth and differentiation of osteoblast-like cells on materials for bone implants
Doubková, Martina ; Bačáková, Lucie (advisor) ; Filová, Eva (referee)
This thesis focuses on testing and improving Ti-6Al-4V ELI biomaterials, which are currently one of the most used titanium alloys in biomedicine (predominantly in orthopaedics and dentistry), in cooperation with research institutions and private companies developing and producing such materials. The metallic samples were previously modified by plasma electrolytic oxidation (PEO) with use of electrolytes of a different composition to induce development of a homogeneous TiO2 layer on its surface. In vitro interactions of human osteoblast-like cell line Saos-2 with the surface of Ti-6Al-4V ELI alloy samples are investigated. Initial cell attachment, spreading, morphology, cell population density, viability, calcium deposition and expression of selected osteogenic markers, e.g. collagen type I, alkaline phosphatase and osteocalcin, were evaluated on cultured cells. The cells behavior were then correlated with physicochemical properties of the material surface, such as its topography, roughness, wettability, surface layer chemical composition etc. The results are also compared with those obtained in cells cultured on control samples of untreated alloys as well as microscopic glass coverslips and bottom of standard polystyrene cell culture wells. The aim of this thesis is to select the most promising...
Adhesion, growth and differentiation of skin cells on nanofibrous polymer membranes
Pajorová, Júlia ; Bačáková, Lucie (advisor) ; Eckhardt, Adam (referee)
Our study contributes to the tissue engineering, mainly to the construction of appropriate scaffolds for regeneration of damaged skin. Simultaneously, it brings valuable insights for basic research in the field of molecular mechanisms of adhesion, proliferation and phenotypic maturation of cells and the control of the cell behavior through the cell extracellular matrix (ECM), represented by synthetic nanofibrous material. Nanofibrous polylactic-co-glycolic acid (PLGA) membranes were prepared by needle-less electrospinning technology. These membranes were further modified with cell adhesion-mediating biomolecules, e.g. collagen, fibronectin and fibrin in order to increase their affinity to colonizing cells. Adhesion, growth and differentiation of keratinocytes (HaCaT) and fibroblasts, i.e. major cell types of epidermis and dermis, were evaluated on these nanofibrous membranes. The results show that the membrane modification using fibrin structures improved adhesion and proliferation of human dermal fibroblasts. The collagen structure on the surface of membranes improved the adhesion and proliferation of human HaCaT keratinocytes. Furthermore, fibrin structure stimulated fibroblasts to produce collagen, which is a major component of ECM in the natural skin dermis. Fibronectin enhanced cell attachment...
The Growth of vascular and skin cells on polymer materials for tissue engineering
Bačáková, Markéta ; Bačáková, Lucie (advisor) ; Smetana, Karel (referee) ; Daniel, Matej (referee)
The ideal vascular or skin substitute is able to simulate the functions of original vascular or skin tissue. To reach this goal, the tissue substitute should be based on a biomaterial scaffold of an appropriate structure and desirable physical and chemical properties. These properties strongly influence successful implantation of the substitute to the patient's organism, substitute durability in the organism, and the desired colonization of the scaffolds with cells. These properties have a great impact on the adhesion, proliferation, differentiation, and desired phenotypic maturation of cells. Most of the biomaterials used for constructing clinically used tissue substitutes do not have appropriate properties for sufficient cell colonization, and thus their surface modification is needed. This thesis focuses on the improvement of biomaterial surface properties for successful cell colonization by plasma treatment, or by grafting and coating biomaterials with bioactive substances and extracellular matrix proteins. The modification of polyethylene (PE) foils by Ar+ plasma discharge showed a positive effect on the spreading, proliferation, and phenotypic maturation of vascular smooth muscle cells (VSMC). Subsequent grafting of the plasma-activated surface with bioactive substances further influenced cell...
Role of endothelial and vascular smooth muscle cells in the origin, progression and therapy of vascular diseases
Chlupáč, Jaroslav ; Bačáková, Lucie (advisor) ; Piťha, Jan (referee) ; Sedmera, David (referee)
Introduction: Vascular surgery for atherosclerosis is confronted by the lack of a suitable bypass material. Synthetic vascular prostheses include polyethylene terephthalate (PET) and expanded polytetrafluoroethylene (ePTFE). However, these materials become thrombosed in small-caliber applications (<6 mm) because of the lack of an endothelium. The objectives of this study were to make modifications to clinically-used PET vascular prostheses with tissue-engineered surfaces to improve their bio-compatibility towards vascular smooth muscle cells (VSMC) and endothelial cells (EC). Methods: Blood coagulation protein fibrin (Fb) and extracellular matrix proteins collagen (Co), laminin (LM) and fibronectin (FN) were used. Cell adhesive assemblies were prepared: Co, Co/LM, Co/FN, Co/Fb, Co/Fb/FN. Cell culture experiments were performed: (1) planar static, (2) planar dynamic with simulation of blood flow, (3) tubular dynamic, and (4) animal porcine implantation. Results: The growth of EC and VSMC on commercial prostheses (ePTFE, PET and PET/Co) was low. The growth of both cell types was lower on PET/Co than on PET. After modification with protein assemblies, the highest numbers of EC were reached on PET/Co and on PET/Co +Co/Fb. There was no difference in the densities of VSMC among various assemblies. The...
Application of the stem cells in bone tissue engineering
Kročilová, Nikola ; Bačáková, Lucie (advisor) ; Eckhardt, Adam (referee)
Problems with musculoskeletal system, such as of developmental disorders, fractures or damage of the bone by age, inflammatory or tumor diseases, are still increasing in orthopaedics. Sometimes the bone tissue is not capable to completely regenerate to exert its physiological function in the organism. For this reason, using the bone replacements is necessary and common nowadays. Despite of an intensive research and testing of a wide range of the potential biomaterials and their combinations, the usage of metal materials for construction of the bone implants, still remains to be the gold standard. Ti-6Al-4V alloy is one of the commercialy used metal materials, which is known for the high mechanical and chemical resistance and a good biocompatibility. For a good biological response of the patient's organism for the bone implant, is an ability of osteointegration into the surrounding bone tissue, the key. This ability can be influenced in the case of the metals, by their surface structure. As it is known from earlier studies, the surface topography of the material is very important for the adhesion and proliferation of the bone cells, which are able to discriminate, very sensitively, between various stages of the material surface roughness. For this reason we have focused on studying of an influence...

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