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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
2019 - English
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.
Keywords:
adipose tissue-derived stem cells; fibrin assemblies; growth factors; heart valves
Available at various institutes of the ASCR
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart ...
Polymeric nanofibrous scaffolds reinforced with diamond and ceramic nanoparticles for bone tissue engineering
Bačáková, Lucie; Pařízek, Martin; Staňková, Ľubica; Novotná, Katarína; Douglas, T.E.L.; Brady, M. A.; Kromka, Alexander; Potocký, Štěpán; Stránská, D.
2015 - English
Three types of nanofibrous scaffolds were prepared by electrospining: (1) poly(lactide-co-glycoside) (PLGA) scaffolds reinforced with 23 wt.% of diamond nanoparticles (DNPs), (2) poly(L-lactide) (PLLA) scaffolds with DNPs in concentration ranging from from 0.4 wt.% to 12.3 wt.%, and (3) PLLA scaffolds with 5 wt.% or 15 wt.% of hydroxyapatite (HAp) nanoparticles. The diameter of the nanofibers ranged between 160 and 729 nm. The nanofibers with nanoparticles were thicker and the void spaces among them were smaller. Mechanical properties of the nanoparticle-loaded scaffolds were better, as demonstrated by a rupture test in scaffolds with DNPs and by a creep behavior test in scaffolds with HAp. On PLGA scaffolds with DNPs, the human osteoblast-like MG-63 cells adhered in similar numbers and grew with similar kinetics as on pure PLGA scaffolds. Human bone marrow mesenchymal stem cells grew faster and reached higher population densities on PLGA-DNP scaffolds. However, on PLLA-based scaffolds, the activity of mitochondrial enzymes and concentration of osteocalcin in MG-63 cells decreased with increasing DNP concentration. On the other hand, the metabolic activity of MG-63 cells and content of osteocalcin in these cells were positively correlated with the HAp concentration in PLLA scaffolds. Thus, PLGA nanofibers with 23 wt% of DNPs and PLLA nanofibers with 5 and particularly 15 wt.% of HAp seem to be promising for bone tissue engineering.
Keywords:
material nanostructure; nanofibers; osteogenic cells; bone implants; regenerative medicine
Available at various institutes of the ASCR
Polymeric nanofibrous scaffolds reinforced with diamond and ceramic nanoparticles for bone tissue engineering
Three types of nanofibrous scaffolds were prepared by electrospining: (1) poly(lactide-co-glycoside) (PLGA) scaffolds reinforced with 23 wt.% of diamond nanoparticles (DNPs), (2) poly(L-lactide) ...
Growth and differentiation of human osteoblast-like cells on TI-6AL-4V alloy modified with anodization
Doubková, Martina; Bačáková, Lucie; Pařízek, Martin; Vandrovcová, Marta; Musílková, Jana; Lisá, Věra; Gabor, R.; Marvan, J.
2015 - English
Titanium and its alloys are widely used as hard tissue implants for their high biocompatibility and suitable physical properties. Along with other surface treatment methods, anodization technique is known to enhance osseointegration. The aim of this study is to evaluate the adhesion, growth and osteogenic differentiation of human osteoblast-like SAOS-2 cells on Ti-6Al-4V samples anodized in electrolytes composed of a stable volume of KOH (336.48 g/l) and variable volumes of liquid glass (124.47 g/l, 84,12 g/l and 37.38 g/l; samples s5, s6 and s7, respectively). Non-anodized Ti-6Al-4V samples, cell culture polystyrene (PS) and microscopic glass coverslips served as control materials. On days 2 and 4 after seeding, the cell number did not differ significantly among the tested samples. However, on day 7, the cell number on s6 samples reached the lowest values, which could be attributed to a non-homogeneous TiO2 film on s6 samples formed during anodization. Nevertheless, the osteogenic differentiation, estimated by the intensity of fluorescence of collagen I in cells grown in a differentiation medium, was the highest on s6 samples. On s5 samples, coated with homogeneous TiO2 films, both cell numbers and intensity of fluorescence of collagen I was relatively high. The bone matrix mineralization, evaluated by Alizarin Red staining, was the highest on s5 samples in standard culture medium, and similar on all tested samples in differentiation medium. Thus, the surface modification of s5 samples could be considered the most suitable for application in bone implants.
Keywords:
Ti6-Al4-V; SAOS-2 cells; anodization; bone implants; collagen I; mineralization
Available at various institutes of the ASCR
Growth and differentiation of human osteoblast-like cells on TI-6AL-4V alloy modified with anodization
Titanium and its alloys are widely used as hard tissue implants for their high biocompatibility and suitable physical properties. Along with other surface treatment methods, anodization technique is ...
Case study of intracranial EEG records of patients with focal cortical dysplasia type I and II
Balach, J.; Ježdík, P.; Čmejla, R.; Kršek, P.; Jiruška, Přemysl
2015 - English
In this study we try to find out if it is possible to differentiate type of focal cortical dysplasia by features obtained from intracranial EEG. We compare occurrence and rates of three biomarkers present in epilepsy in patients with focal cortical dysplasia type I and II. Case study is made on long term night records of 6 pediatric patients. Detection of interictal epileptiform discharges and high-frequency oscillations is made by automated algorithms, delta brush are marked visually. Position of lesion and electrodes inside were obtained from MRI. In individual rates were not found difference on significant level. No major significance were found, but as promising seem to be ratio inside to outside rates of high-frequency oscillations and presence of delta brush, which were found only in patients with focal cortical dysplasia type II.
Keywords:
intracranial EEG; focal cortical dysplasia; IED; high frequency oscillations; delta brush
Available at various institutes of the ASCR
Case study of intracranial EEG records of patients with focal cortical dysplasia type I and II
In this study we try to find out if it is possible to differentiate type of focal cortical dysplasia by features obtained from intracranial EEG. We compare occurrence and rates of three biomarkers ...
Growth of human adipose-derived stem cells on Ti-6Al-4V alloy with various surface modifications
Kročilová, Nikola; Bačáková, Lucie; Pařízek, Martin; Havlíková, Jana; Motarjemi, H.; Molitor, M.; Gabor, R.; Marvan, J.
2015 - English
Adipose-derived stem cells (ASCs) are of a great importance for bone tissue engineering. We compared ASCs obtained by liposuction under two pressures (-200 mmHg and -700 mmHg). The number and proliferation activity of cells isolated under -700 mmHg (ASC-H) were higher than in cells isolated under -200 mmHg (ASC-L). However, the ASC-L was more active in osteogenic differentiation, as manifested by a higher intensity of fluorescence of alkaline phosphatase and osteocalcin in these cells. The adhesion and growth of ASCs were then studied on Ti-6Al-4V samples either unmodified (K, roughness parameter R-a = 280 nm) or modified by shot blasting and tarnishing A, R-a = 200 nm), vibratory finishing (B, R-a = 100 nm) and vibratory finishing, shot blasting and polishing (C, R-a = 80 nm). All modified samples were more wettable than the K samples. On day 1 after seeding, the size of cell spreading area on some modified samples was lower than on K samples, namely on B samples in ASC-L, on B and C in ASC-H and on A in control MG-63 cells. On day 3, the cell number on some modified samples became higher than on K samples, namely on C samples (ASC-L), on B (ASC-H) and on B and C s (MG-63 cells). On day 7, the numbers of ASC-H and MG-63 cells on all modified samples evened out and became significantly higher than on K samples. On ASC-L samples, the highest cell numbers were obtained on A samples. Thus, all studied modifications of Ti-6Al-4V enhanced growth of ASCs and human osteoblast-like MG-63 cells.
Keywords:
bone implants; bone tissue engineering; surface roughness; stem cells; liposuction; cell proliferation
Available at various institutes of the ASCR
Growth of human adipose-derived stem cells on Ti-6Al-4V alloy with various surface modifications
Adipose-derived stem cells (ASCs) are of a great importance for bone tissue engineering. We compared ASCs obtained by liposuction under two pressures (-200 mmHg and -700 mmHg). The number and ...
Analysis of high-frequency activity in electroencephalogram of animal epilepsy model
Havel, T.; Kudláček, J.; Jiruška, Přemysl; Ježdík, P.; Čmejla, R.
2015 - English
High frequency oscillations (HFO) are believed to be a new specific biomarker of epileptogenic tissue. According to the reported findings, we hypothesized that HFOs occur more specific to the epileptogenic tissue. To test this hypothesis, we analyzed intracranial electroencephalograms (iEEG) of three subjects of animal epilepsy model. Overall 180 minutes of iEEG records were processed by the automatic high frequency activity detector and further analyzed. The dominant frequency of each segment was determined and categorized as ripples (80-200 Hz) or fast ripples (200-1000 Hz). Even though overall number of HFO detections predominate in the hemisphere where epileptic focus is located, in comparison of each brain structure separately our hypothesis cannot be fully confirmed.
Keywords:
epilepsy; animal model; electroencephalogram (EEG); high-frequency oscillations (HFO)
Available at various institutes of the ASCR
Analysis of high-frequency activity in electroencephalogram of animal epilepsy model
High frequency oscillations (HFO) are believed to be a new specific biomarker of epileptogenic tissue. According to the reported findings, we hypothesized that HFOs occur more specific to the ...
MORPHOLOGICAL CLUSTERING OF INTERICTAL EPILEPTIFORM DISCHARGES IN INTRACRANIAL ELECTROENCEPHALOGRAPHY
Vlk, Pavel; Janča, R.; Čmejla, R.; Kršek, P.; Marusič, P.; Jiruška, Přemysl
2013 - English
To improve the localizing yield of interictal discharges, identification of specific features of the discharges generated only within epileptogenic region is required. We have developed self-clustering algorithm which discriminates distinct populations of interictal epileptiform discharges according to the morphology of their waveforms. Results demonstrate the ability of the algorithm to separate interictal epileptiform discharges according to their morphological features
Keywords:
epilepsy; interictal epiletiform discharges; morphological clustering
Available at various institutes of the ASCR
MORPHOLOGICAL CLUSTERING OF INTERICTAL EPILEPTIFORM DISCHARGES IN INTRACRANIAL ELECTROENCEPHALOGRAPHY
To improve the localizing yield of interictal discharges, identification of specific features of the discharges generated only within epileptogenic region is required. We have developed ...
ANALYSIS OF NON-ENZYMATIC POSTTRANSLATIONAL MODIFICATED (GLYCATED) ALBUMIN BY NANO-LC/MS/MS
Šťastná, Zdeňka; Pataridis, Statis; Sedláková, Pavla; Mikšík, Ivan
2012 - English
Posttranslational modifications of proteins are important reactions, which significantly affect the function of proteins in the organism. In principle, they can be divided into enzymatic and non-enzymatic modifications. Non-enzymatic reactions include glycation (earlier called nonezymatic glycosylation), which plays an important role in the development of chronic complications of diabetes mellitus, uremia, in the process of aging and degeneration of the brain.This work deals with the study of glycated albumins (human serum albumin and bovine serum albumin). Methodologically we used nano-liquid chromatography coupled to Q-TOF mass spectrometer. In vitro modified proteins were cleavaged by trypsin and arising peptides were separated on C18 nano column with trap-column. Peptides and their modifications were analysed by high-resolution Q-TOF mass spectrometer MaXis with precision determination of mass below 2 ppm. We found some modifications of proteins. Besides well known carboxymethyllysine new ones were determined - create mass shift 78, 132 and 218. Origin of these modifications is discussed and possible structure is presented. All found modifications were allocated to the structure of proteins and reactivity to various oxo-compounds was also examined
Keywords:
non-enzymatic glycation; serum albumin
Available at various institutes of the ASCR
ANALYSIS OF NON-ENZYMATIC POSTTRANSLATIONAL MODIFICATED (GLYCATED) ALBUMIN BY NANO-LC/MS/MS
Posttranslational modifications of proteins are important reactions, which significantly affect the function of proteins in the organism. In principle, they can be divided into enzymatic and ...
Application of morphology filters to compensation of lateral illumination inhomogeneities in confocal microscopy images
Michálek, Jan; Čapek, Martin; Mao, X. W.; Kubínová, Lucie
2010 - English
Due to multiple distortion effects, confocal laser scanning microscopy (CLSM) images of even homogeneous specimen regions suffer from irregular brightness variations. In this paper, a fast correction method based on estimating a spatially variable illumination gain, and multiplying acquired CLSM images by the inverse of the estimated gain, is presented. The method does not require any special calibration (reference) images since the gain estimate is extracted from the CLSM image being corrected itself. The proposed approach exploits two types of morphological filters: the median filter and a morphological operator called the upper Lipschitz cover
Keywords:
CLSM; illumination inhomogeneities
Available at various institutes of the ASCR
Application of morphology filters to compensation of lateral illumination inhomogeneities in confocal microscopy images
Due to multiple distortion effects, confocal laser scanning microscopy (CLSM) images of even homogeneous specimen regions suffer from irregular brightness variations. In this paper, a fast correction ...
Fitting geometrical models to 3D confocal microscopy images using graph cuts iteratively
Janáček, Jiří
2010 - English
A new iterative method for fitting triangulated surfaces and geometric graphs to surfaces and fibre-like structures is based on the calculation of the minimal graph cut in every iteration. The method was used for improvement of the geometric model of muscle fibres surfaces and capillaries in skeletal muscle from 3D confocal image
Keywords:
graph cut; skeletal muscle; confocal microscopy
Available at various institutes of the ASCR
Fitting geometrical models to 3D confocal microscopy images using graph cuts iteratively
A new iterative method for fitting triangulated surfaces and geometric graphs to surfaces and fibre-like structures is based on the calculation of the minimal graph cut in every iteration. The method ...
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