Samples of linear (additionally crosslinked) p(HEMA) with different amounts of fibrillar collagen were implanted into the popliteal region of rats. After 3 month, the implanted materials were harvested and examined by SEM. The implants underwent marked structural or morphological changes. While the fibrillar collagen was readily resorbed by invading cells, the synthetic constituent persisted to biodegradation. The p(HEMA) residues were shaped into spherical particles, approx. 1-15 microns in diameter. The possible fate of these microparticles in the host organism is discussed.

• MeSH
• bérec MeSH
• biodegradace MeSH
• biokompatibilní materiály * MeSH
• inbrední kmeny potkanů MeSH
• kolagen * ultrastruktura   MeSH
• krysa rodu rattus MeSH
• mikroskopie elektronová rastrovací MeSH
• polyhydroxyethylmethakrylát * chemie   MeSH
• protézy a implantáty * MeSH
• složené pryskyřice MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

Background: Platelets are small anucleated blood particles that play a key role in the control of bleeding. Platelets need to be activated to perform their functions and participate in hemostasis. The process of activation is accompanied by vast protein reorganization and posttranslational modifications. The goal of this study was to identify changes in proteins in platelets activated by different agonists. Platelets were activated by three different agonists - arachidonic acid, collagen, and thrombin. 2D SDS-PAGE (pI 4-7) was used to separate platelet proteins. Proteomes of activated and resting platelets were compared with each other by Progenesis SameSpots statistical software; and proteins were identified by nanoLC-MS/MS. Results: 190 spots were found to be significantly different. Of these, 180 spots were successfully identified and correspond to 144 different proteins. Five proteins were found that had not previously been identified in platelets: protein CDV3 homolog, protein ETHE1, protein LZIC, FGFR1 oncogene partner 2, and guanine nucleotide-binding protein subunit beta-5. Using spot expression profile analysis, we found two proteins (WD repeat-containing protein 1 and mitochondrial glycerol-3-phosphate dehydrogenase) that may be part of thrombin specific activation or signal transduction pathway(s). Conclusions: Our results, characterizing the differences within proteins in both activated (by various agonists) and resting platelets, can thus contribute to the basic knowledge of platelets and to the understanding of the function and development of new antiplatelet drugs.

• MeSH
• aktivace trombocytů MeSH
• hemostáza MeSH
• kolagen MeSH
• kyselina arachidonová MeSH
• lidé MeSH
• proteom * agonisté   analýza   MeSH
• trombin MeSH
• trombocyty fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

Collagen composite scaffolds have been used for a number of studies in tissue engineering. The hydration of such highly porous and hydrophilic structures may influence mechanical behaviour and porosity due to swelling. The differences in physical properties following hydration would represent a significant limiting factor for the seeding, growth and differentiation of cells in vitro and the overall applicability of such hydrophilic materials in vivo. Scaffolds based on collagen matrix, poly(DL-lactide) nanofibers, calcium phosphate particles and sodium hyaluronate with 8 different material compositions were characterised in the dry and hydrated states using X-ray microcomputed tomography, compression tests, hydraulic permeability measurement, degradation tests and infrared spectrometry. Hydration, simulating the conditions of cell seeding and cultivation up to 48 h and 576 h, was found to exert a minor effect on the morphological parameters and permeability. Conversely, hydration had a major statistically significant effect on the mechanical behaviour of all the tested scaffolds. The elastic modulus and compressive strength of all the scaffolds decreased by ~95%. The quantitative results provided confirm the importance of analysing scaffolds in the hydrated rather than the dry state since the former more precisely simulates the real environment for which such materials are designed.

• MeSH
• biokompatibilní materiály chemie   MeSH
• fosforečnany vápenaté chemie   MeSH
• kolagen chemie   MeSH
• kyselina hyaluronová chemie   MeSH
• mechanické jevy MeSH
• modul pružnosti MeSH
• pevnost v tlaku MeSH
• polyestery chemie   MeSH
• poréznost MeSH
• rentgenová mikrotomografie MeSH
• testování materiálů MeSH
• tkáňové inženýrství metody   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• voda chemie   MeSH
• vysoušení * MeSH
• Publikační typ
• časopisecké články MeSH

Nanocomposite scaffolds which aimed to imitate a bone extracellular matrix were prepared for bone surgery applications. The scaffolds consisted of polylactide electrospun nano/sub-micron fibres, a natural collagen matrix supplemented with sodium hyaluronate and natural calcium phosphate nano-particles (bioapatite). The mechanical properties of the scaffolds were improved by means of three different cross-linking agents: N-(3-dimethylamino propyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide in an ethanol solution (EDC/NHS/EtOH), EDC/NHS in a phosphate buffer saline solution (EDC/NHS/PBS) and genipin. The effect of the various cross-linking conditions on the pore size, structure and mechanical properties of the scaffolds were subsequently studied. In addition, the mass loss, the swelling ratio and the pH of the scaffolds were determined following their immersion in a cell culture medium. Furthermore, the metabolic activity of human mesenchymal stem cells (hMSCs) cultivated in scaffold infusions for 2 and 7 days was assessed. Finally, studies were conducted of cell adhesion, proliferation and penetration into the scaffolds. With regard to the structural stability of the tested scaffolds, it was determined that EDC/NHS/PBS and genipin formed the most effectively cross-linked materials. Moreover, it was discovered that the genipin cross-linked scaffold also provided the best conditions for hMSC cultivation. In addition, the infusions from all the scaffolds were found to be non-cytotoxic. Thus, the genipin and EDC/NHS/PBS cross-linked scaffolds can be considered to be promising biomaterials for further in vivo testing and bone surgery applications.

• MeSH
• analýza selhání vybavení MeSH
• biokompatibilní materiály chemická syntéza   MeSH
• buněčná adheze fyziologie   MeSH
• design vybavení MeSH
• kolagen chemie   MeSH
• kostní matrix chemie   MeSH
• kostní náhrady chemická syntéza   MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   fyziologie   MeSH
• nanokompozity chemie   ultrastruktura   MeSH
• proliferace buněk fyziologie   MeSH
• reagencia zkříženě vázaná chemie   MeSH
• testování materiálů MeSH
• tkáňové podpůrné struktury * MeSH
• transplantace mezenchymálních kmenových buněk přístrojové vybavení   metody   MeSH
• velikost částic MeSH
• viabilita buněk fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Collagen I-based foams were modified with calcined or noncalcined hydroxyapatite or calcium phosphates with various particle sizes and pores to monitor their effect on cell interactions. The resulting scaffolds thus differed in grain size, changing from nanoscale to microscopic, and possessed diverse morphological characteristics and resorbability. The materials' biological action was shown on human bone marrow MSCs. Scaffold morphology was identified by SEM. Using viability test, qPCR, and immunohistochemical staining, we evaluated the biological activity of all of the materials. This study revealed that the most suitable scaffold composition for osteogenesis induction is collagen I foam with calcined hydroxyapatite with a pore size of 360 ± 130 μm and mean particle size of 0.130 μm. The expression of osteogenic markers RunX2 and ColI mRNA was promoted, and a strong synthesis of extracellular protein osteocalcin was observed. ColI/calcined HAP scaffold showed significant osteogenic potential, and can be easily manipulated and tailored to the defect size, which gives it great potential for bone tissue engineering applications.

• MeSH
• buněčná diferenciace MeSH
• hydroxyapatit * chemie   farmakologie   MeSH
• kolagen typu I genetika   MeSH
• kultivované buňky MeSH
• lidé MeSH
• osteogeneze * MeSH
• tkáňové inženýrství metody   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The combination of long-term hypercapnia and hypoxia decreases pulmonary vascular remodeling and attenuation of right ventricular (RV) hypertrophy. However, there is limited information in the literature regarding the first stages of acclimatization to hypercapnia/hypoxia. The purpose of this study was to investigate the effect of four-day hypoxia (10% O2) and hypoxia/hypercapnia (10% O2 + 4.4% CO2) on the protein composition of rat myocardium. Expression of the cardiac collagen types and activities of matrix metalloproteinases (MMPs) and of their tissue inhibitor TIMP-1 were followed. The four-day hypoxia changed protein composition of the right ventricle only in the hypercapnic condition; remodeling was observed in the extracellular matrix (ECM) compartments. While the concentrations of pepsin-soluble collagenous proteins in the RV were elevated, the concentrations of pepsin-insoluble proteins were decreased. Furthermore, the four-day hypoxia/hypercapnia increased the synthesis of cardiac collagen due to newly synthesized forms; the amount of cross-linked particles was not affected. This type of hypoxia increased cardiac collagen type III mRNA, while cardiac collagen type I mRNA was decreased. MMP-2 activity was detected on the zymographic gel through appearance of two bands; no differences were observed in either group. mRNA levels for MMP-2 in the RV were significantly lower in both the hypoxic and hypoxic/hypercapnic animals. mRNA levels for TIMP-1 were reduced in the RV of both the hypoxic and hypoxic/hypercapnic animals. Hypoxia with hypercapnia increased the level of mRNA (6.5 times) for the atrial natriuretic peptide (ANP) predominantly in the RV. The role of this peptide in remodeling of cardiac ECM is discussed.

• MeSH
• atriální natriuretický faktor biosyntéza   MeSH
• časové faktory MeSH
• extracelulární matrix - proteiny genetika   metabolismus   MeSH
• financování organizované MeSH
• hyperkapnie metabolismus   MeSH
• hypoxie metabolismus   MeSH
• kolagen typ III biosyntéza   MeSH
• kolagen typu I biosyntéza   MeSH
• krysa rodu rattus MeSH
• matrixové metaloproteinasy biosyntéza   MeSH
• myokard enzymologie   ultrastruktura   MeSH
• peptidové mapování MeSH
• potkani Wistar metabolismus   MeSH
• remodelace komor genetika   MeSH
• stanovení celkové genové exprese MeSH
• tkáňový inhibitor metaloproteinasy 1 biosyntéza   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• srovnávací studie MeSH

Bioapatite ceramics produced from biogenic sources provide highly attractive materials for the preparation of artificial replacements since such materials are not only more easily accepted by living organisms, but bioapatite isolated from biowaste such as xenogeneous bones also provides a low-cost material. Nevertheless, the presence of organic compounds in the bioapatite may lead to a deterioration in its quality and may trigger an undesirable immune response. Therefore, procedures which ensure the elimination of organic compounds through bioapatite isolation are being subjected to intense investigation and the presence of remaining organic impurities is being determined through the application of various methods. Since current conclusions concerning the conditions suitable for the elimination of organic compounds remain ambiguous, we used the mass spectrometry-based proteomic approach in order to determine the presence of proteins or peptides in bioapatite samples treated under the most frequently employed conditions, i.e., the alkaline hydrothermal process and calcination at 500 °C. Since we also investigated the presence of proteins or peptides in treated bioapatite particles of differing sizes, we discovered that both calcination and the size of the bioapatite particles constitute the main factors influencing the presence of proteins or peptides in bioapatite. In fact, while intact proteins were detected even in calcinated bioapatite consisting of particles >250 µm, no proteins were detected in the same material consisting of particles <40 µm. Therefore, we recommend the use of powdered bioapatite for the preparation of artificial replacements since it is more effectively purified than apatite in the form of blocks. In addition, we observed that while alkaline hydrothermal treatment leads to the non-specific cleavage of proteins, it does not ensure the full degradation thereof.

• MeSH
• apatity chemie   MeSH
• biokompatibilní materiály chemie   MeSH
• femur patologie   MeSH
• hmotnostní spektrometrie MeSH
• keramika chemie   MeSH
• kolagen typu I chemie   MeSH
• kosti a kostní tkáň chemie   MeSH
• organické látky chemie   MeSH
• peptidy chemie   MeSH
• proteomika MeSH
• skot MeSH
• teplota MeSH
• tkáňové inženýrství metody   MeSH
• tlak MeSH
• velikost částic MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The modification of implant surface situated in the area of peri-implant sulcus has important role in bacterial and cell adhesion. Six different chemically and physically modified titanium discs were prepared: glazed (Tis-MALP), unglazed (Tis-O), unglazed and alkali-etched (Tis-OA), unglazed and coated with ZrN (Tis-OZ), unglazed, sand blasted, and acid etched (Tis-OPAE), and unglazed, sand blasted, acid, and alkali etched (Tis-OPAAE). Analysis of surface topography was determined using scanning electron microscopy and atomic force microscopy (AFM). Biocompatibility of gingival fibroblasts was characterized by the production of tumor necrosis factor alpha, collagen I, matrix metalloproteinase 2 (MMP-2) after 24 and 72 h and expression of α3 β1 integrin and vinculin using enzyme-linked immunosorbent assay (ELISA) or modified ELISA after 6 and 24 h. Microorganism adhesion (five bacterial strains) and biofilm formation was also evaluated. The adhesion of bacteria and gingival fibroblasts was significantly higher on titanium disc Tis-OPAAE and biofilm formation on the same surface for Streptococcus mutans, Streptococcus gordonii, and Streptococcus intermedius. The gingival fibroblasts on Tis-OPAAE disc had also significantly lower production of MMP-2. The collagen production was significantly lower on all surfaces with roughness higher than 0.2 μm. This study confirmed that the titanium disc with the surface roughness 3.39 μm (Tis-OPAAE) supported the adhesion of bacterial strains as well as gingival fibroblasts.

• MeSH
• bakteriální adheze účinky léků   MeSH
• biofilmy účinky léků   růst a vývoj   MeSH
• biokompatibilní materiály farmakologie   MeSH
• buněčná adheze účinky léků   MeSH
• fibroblasty cytologie   účinky léků   mikrobiologie   MeSH
• fokální adheze účinky léků   metabolismus   MeSH
• gingiva cytologie   MeSH
• integrin alfa3beta1 metabolismus   MeSH
• kolagen typu I biosyntéza   MeSH
• lidé MeSH
• matrixová metaloproteinasa 2 biosyntéza   MeSH
• mikroskopie atomárních sil MeSH
• mikroskopie elektronová rastrovací MeSH
• spektrometrie rentgenová emisní MeSH
• Streptococcus cytologie   účinky léků   fyziologie   MeSH
• testování materiálů * MeSH
• titan farmakologie   MeSH
• TNF-alfa biosyntéza   MeSH
• vinkulin metabolismus   MeSH
• zubní implantáty mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

This paper deals with the problem of chromium recovery from chrome-tanned waste and thus with reducing the environmental impact of the leather industry. Chrome-tanned waste was transformed by alkaline enzymatic hydrolysis promoted by magnesium oxide into practically chromium-free, commercially applicable collagen hydrolysate and filtration cake containing a high portion of chromium. The crude and magnesium-deprived chromium cakes were subjected to a process of thermal decomposition at 650°C under oxygen-free conditions to reduce the amount of this waste and to study the effect of magnesium removal on the resulting products. Oxygen-free conditions were applied in order to prevent the oxidation of trivalent chromium into the hazardous hexavalent form. Thermal decomposition products from both crude and magnesium-deprived chrome cakes were characterized by high chromium content over 50%, which occurred as eskolaite (Cr2O3) and magnesiochromite (MgCr2O4) crystal phases, respectively. Thermal decomposition decreased the amount of chrome cake dry feed by 90%. Based on the performed experiments, a scheme for the total control of chromium in the leather industry was designed.

• MeSH
• chrom * chemie   MeSH
• difrakce rentgenového záření MeSH
• hydrolýza MeSH
• koncentrace vodíkových iontů MeSH
• koželužství metody   MeSH
• nakládání s odpady metody   MeSH
• průmyslový odpad * MeSH
• spektrometrie rentgenová emisní MeSH
• Publikační typ
• časopisecké články MeSH

Dexamethasone (DEX) is known to induce diabetes and dyslipidemia. We have compared fasting triacylglycerol and cholesterol concentrations across 20 lipoprotein fractions and glucose tolerance in control (standard diet) and DEX-treated 7-month-old males of two rat strains, Brown Norway (BN) and congenic BN.SHR-(Il6-Cd36)/Cub (BN.SHR4). These two inbred strains differ in a defined segment of chromosome 4, originally transferred from the spontaneously hypertensive rat (SHR) including the mutant Cd36 gene, a known target of DEX. Compared to BN, the standard-diet-fed BN.SHR4 showed higher cholesterol and triacylglycerol concentrations across many lipoprotein fractions, particularly in small VLDL and LDL particles. Total cholesterol was decreased by DEX by more than 21% in BN.SHR4 contrasting with the tendency to increase in BN (strain*DEX interaction p = 0.0017). Similar pattern was observed for triacylglycerol concentrations in LDL. The LDL particle size was significantly reduced by DEX in both strains. Also, while control BN and BN.SHR4 displayed comparable glycaemic profiles during oral glucose tolerance test, we observed a markedly blunted DEX induction of glucose intolerance in BN.SHR4 compared to BN. In summary, we report a pharmacogenetic interaction between limited genomic segment with mutated Cd36 gene and dexamethasone-induced glucose intolerance and triacylglycerol and cholesterol redistribution into lipoprotein fractions.

• MeSH
• antigeny CD36 nedostatek   genetika   MeSH
• cholesterol metabolismus   MeSH
• chromozomy metabolismus   MeSH
• dexamethason farmakologie   MeSH
• farmakogenetika MeSH
• krysa rodu rattus MeSH
• lipoproteiny chemie   MeSH
• mutace MeSH
• omezení příjmu potravy MeSH
• porucha glukózové tolerance MeSH
• potkani inbrední SHR MeSH
• triglyceridy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH