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1.
Int J Biol Macromol ; 268(Pt 1): 131476, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38614181

RESUMO

This study involved creating oligomeric conjugates of 3-hydroxy fatty acids and diclofenac, named Dic-oligo(3HAs). Advanced NMR techniques confirmed no free diclofenac in the mix. We tested diclofenac release under conditions resembling healthy and chronic wound skin. These oligomers were used to make P(3HO) blends, forming patches for drug delivery. Their preparation used the solvent casting/porogen leaching (SCPL) method. The patches' properties like porosity, roughness, and wettability were thoroughly analysed. Antimicrobial assays showed that Dic-oligo(3HAs) exhibited antimicrobial activity against reference (S. aureus, S. epidermis, S. faecalis) and clinical (Staphylococcus spp.) strains. Human keratinocytes (HaCaT) cell line tests, as per ISO 10993-5, showed no toxicity. A clear link between material roughness and HaCaT cell adhesion was found. Deep cell infiltration was verified using DAPI and phalloidin staining, observed under confocal microscopy. SEM also confirmed HaCaT cell growth on these scaffolds. The strong adhesion and proliferation of HaCaT cells on these materials indicate their potential as wound dressing layers. Additionally, the successful diclofenac release tests point to their applicability in treating both normal and chronic wounds.

2.
Molecules ; 28(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37110696

RESUMO

The reaction of ethanol with surface OH groups on ZrO2, CuO/ZrO2, CuO, Al2O3, Ga2O3, NiO, and SiO2 was studied by IR spectroscopy. The basicity of oxides was followed by CO2 adsorption, and their ability to oxidize was investigated by H2-TPR. It has been found that ethanol reacts with surface OH groups forming ethoxy groups and water. Some oxides: ZrO2, CuO/ZrO2, Al2O3, and Ga2O3 contain several kinds of OH groups (terminal, bidentate, and tridentate) and terminal hydroxyls react with ethanol in the first order. Two kinds of ethoxyls are formed on these oxides: monodental and bidental ones. On the other hand, only one kind of ethoxy group is formed on CuO and NiO. The amount of ethoxy groups correlates with the basicity of oxides. The biggest amount of ethoxyls is produced on the most basic: ZrO2, CuO/ZrO2, and Al2O3, whereas the smallest amount of ethoxyls is produced on CuO, NiO, and Ga2O3, i.e., on oxides of lower basicity. SiO2 does not form ethoxy groups. Above 370 K ethoxy groups on CuO/ZrO2, CuO, and NiO are oxidized to acetate ions. The ability of oxides to oxidize ethoxyl groups increases in the order NiO < CuO < CuO/ZrO2. The temperature of the peak in the H2-TPR diagram decreases in the same order.

3.
Molecules ; 28(3)2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36770916

RESUMO

The reaction of ethanol with a surface of CeO2 was studied using IR spectroscopy. In some experiments, CeO2 was pretreated in a vacuum at 820 K which caused a partial reduction. In other experiments, CeO2 was reduced with hydrogen at 770 K. We also used CeO2 oxidized by oxygen treatment at 670 K. At low coverages, ethoxy groups and new surface OH groups were formed and water was not produced. On the other hand, at higher loading surfaces, Ce-OH was consumed and ethoxy groups and water were formed. Three kinds of ethoxyls were found on CeO2: monodentate, bidentate, and tridentate ones. They were characterized by various frequencies of symmetrical, asymmetrical, and combinational bands of C-C-O units. The reduction of CeO2 increased the contribution of tridentate ethoxyls and the oxidation increased the contribution of monodentate ones. At higher temperatures, ethoxy groups were oxidized to acetate ions with the formation of new surface OH groups. Monodentate ethoxyls were the most reactive and tridentate ones were the least reactive during oxidation. The amounts of acetate species were the highest for the oxidized CeO2.

4.
Materials (Basel) ; 15(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36079238

RESUMO

In the presented research, we investigated Ammonium Nitrate Fuel Oil (ANFO), with the addition of variously modified zeolite Y as an attractive explosive. Analysis of both blasting tests and thermodynamic models of blasting properties led to the conclusion that the addition of zeolite Y enhanced the detonation properties of such prepared ANFO via the growth of the detonation pressure, temperature, compression energy, and heat of the explosion. Generally, the modification of ANFO with variously prepared zeolite Y also reduced the volume of (COx + NOx) post-blast fumes. Furthermore, it was found that the ANFO's velocity of detonation (VOD) could be controlled by the choice of the way of zeolite Y modification. Namely, for zeolite Y without Mg, as well as Mg-Y prepared via the impregnation method, the VOD rose. The opposite effect was observed when ANFO was modified with Mg-Y, obtained from the deposition of Mg over zeolite Y via the ultrasonic-assisted procedure.

5.
Food Chem ; 387: 132883, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35421651

RESUMO

Single-layered films, based on furcellaran and protein hydrolysates from soybean bran (1st layer), were obtained. Moreover, a procedure for the preparation of double-layered films was developed, in which an ethanol extract from soybean bran was deposited onto the 1st layer. It was checked how the addition of the 2nd layer affects the functional properties of the film. The addition of the 2nd layer increased the thermal properties, modulus of elasticity and antioxidant activity, while decreases were noted for tensile strength and elongation at break parameters. The films were used as packaging materials for storing butter and the active films did not extend the quality of butter during storage, however, they behaved in the same way as synthetic films. Therefore they have the potential to be used as packaging material instead of a synthetic film.


Assuntos
Embalagem de Alimentos , Glycine max , Alginatos , Manteiga , Embalagem de Alimentos/métodos , Gomas Vegetais , Resistência à Tração
6.
Materials (Basel) ; 15(2)2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35057359

RESUMO

The high efficiency of solid oxide fuel cells with La0.8Sr0.2MnO3-δ (LSM) cathodes working in the range of 800-1000 °C, rapidly decreases below 800 °C. The goal of this study is to improve the properties of LSM cathodes working in the range of 500-800 °C by the addition of YFe0.5Co0.5O3 (YFC). Monophasic YFC is synthesized and sintered at 950 °C. Composite cathodes are prepared on Ce0.8Sm0.2O1.9 electrolyte disks using pastes containing YFC and LSM powders mixed in 0:1, 1:19, and 1:1 weight ratios denoted LSM, LSM1, and LSM1, respectively. X-ray diffraction patterns of tested composites reveal the presence of pure perovskite phases in samples sintered at 950 °C and the presence of Sr4Fe4O11, YMnO3, and La0.775Sr0.225MnO3.047 phases in samples sintered at 1100 °C. Electrochemical impedance spectroscopy reveals that polarization resistance increases from LSM1, by LSM, to LSM2. Differences in polarization resistance increase with decreasing operating temperatures because activation energy rises in the same order and equals to 1.33, 1.34, and 1.58 eV for LSM1, LSM, and LSM2, respectively. The lower polarization resistance of LSM1 electrodes is caused by the lower resistance associated with the charge transfer process.

7.
Materials (Basel) ; 14(22)2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34832324

RESUMO

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for AgNPs+KB and 440.8 nm for AgNPs+PE was observed via spectral analysis of UV absorbance. In this study, double-layered biopolymer films (FUR/CHIT+HGEL) with AgNPs incorporated in KB solution (AgNPs+KB) and AgNPs in PE solution (AgNPs+PE), were successfully prepared using the casting method. The SEM, XRD, zeta potential and size analyses confirmed the presence of AgNP in the films. The addition of AgNPs in plant extracts improved antimicrobial and antioxidant activity and thermal stability, whereas WVTR experienced a decrease. The nanocomposite films' orange-brown colour may aid in the protection of food products against UV rays. The composite films demonstrated antibacterial activity against food-borne pathogens and may offer potential in food packaging applications.

8.
Materials (Basel) ; 14(20)2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34683612

RESUMO

Aluminum doped titania samples were synthesized as supports of copper oxide catalysts for NO reduction with ammonia. Samples were prepared by the sol-gel method with various ratios of aluminum to titanium. Their thermal stability was examined by TG/DSC methods which revealed that precursors were decomposed at 450 °C. The XRD measurements showed that aluminum caused the diminishing of titania crystallites and was built into the anatase structure or formed an amorphous phase. The admixture of aluminum in titania resulted in a significant increase in specific surface area of mesoporous supports as determined by low temperature sorption of nitrogen. Results of the catalytic tests over copper/aluminum-titania samples obtained by impregnation pointed out that the addition of aluminum broadened the temperature window of high catalytic activity. The increase in Al concentration shifted the temperature of maximum activity to higher values, and at the same time lowered nitrous oxide formation as well. Better catalytic efficiency could result from high copper dispersion on the catalysts surface, as well as the synergistic interaction between Ti and Cu causing reduction in CuO species as confirmed by XPS measurements. It was shown that copper was present as Cu+ species mainly, forming Cu-O-Ti bonds on the catalysts surface.

9.
Materials (Basel) ; 14(11)2021 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-34071001

RESUMO

Chitosan is an attractive material for biomedical applications. A novel approach for the anodic electrodeposition of chitosan-AgNP composites using in situ coordination with copper ions is proposed in this work. The surface and cross-section morphology of the obtained coating with varying concentrations of AgNPs were evaluated by SEM, and surface functional groups were analyzed with FT-IR spectroscopy. The mechanism of the formation of the coating based on the chelation of Cu(II) ions with chitosan was discussed. The antibacterial activity of the coatings towards Staphylococcus epidermidis ATCC 35984/RP62A bacteria was analyzed using the live-dead approach. The presented results indicate that the obtained chitosan-AgNP-based films possess some limited anti-biofilm-forming properties and exhibit moderate antibacterial efficiency at high AgNP loads.

10.
Molecules ; 26(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33916185

RESUMO

The aim of the present paper is to study the speciation and the role of different active site types (copper species and Brønsted acid sites) in the direct synthesis of furan from furfural catalyzed by copper-exchanged FAU31 zeolite. Four series of samples were prepared by using different conditions of post-synthesis treatment, which exhibit none, one or two types of active sites. The catalysts were characterized by XRD, low-temperature sorption of nitrogen, SEM, H2-TPR, NMR and by means of IR spectroscopy with ammonia and CO sorption as probe molecules to assess the types of active sites. All catalyst underwent catalytic tests. The performed experiments allowed to propose the relation between the kind of active centers (Cu or Brønsted acid sites) and the type of detected products (2-metylfuran and furan) obtained in the studied reaction. It was found that the production of 2-methylfuran (in trace amounts) is determined by the presence of the redox-type centers, while the protonic acid sites are mainly responsible for the furan production and catalytic activity in the whole temperature range. All studied catalysts revealed very high susceptibility to coking due to polymerization of furfural.

11.
Int J Mol Sci ; 21(24)2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33322564

RESUMO

Nowadays, regenerative medicine faces a major challenge in providing new, functional materials that will meet the characteristics desired to replenish and grow new tissue. Therefore, this study presents new ceramic-polymer composites in which the matrix consists of tricalcium phosphates covered with blends containing a chemically bounded diclofenac with the biocompatible polymer-poly(3-hydroxyoctanoate), P(3HO). Modification of P(3HO) oligomers was confirmed by NMR, IR and XPS. Moreover, obtained oligomers and their blends were subjected to an in-depth characterisation using GPC, TGA, DSC and AFM. Furthermore, we demonstrate that the hydrophobicity and surface free energy values of blends decreased with the amount of diclofenac modified oligomers. Subsequently, the designed composites were used as a substrate for growth of the pre-osteoblast cell line (MC3T3-E1). An in vitro biocompatibility study showed that the composite with the lowest concentration of the proposed drug is within the range assumed to be non-toxic (viability above 70%). Cell proliferation was visualised using the SEM method, whereas the observation of cell penetration into the scaffold was carried out by confocal microscopy. Thus, it can be an ideal new functional bone tissue substitute, allowing not only the regeneration and restoration of the defect but also inhibiting the development of chronic inflammation.


Assuntos
Fosfatos de Cálcio/química , Cerâmica/química , Diclofenaco/química , Poli-Hidroxialcanoatos/química , Animais , Regeneração Óssea/efeitos dos fármacos , Linhagem Celular , Cerâmica/farmacologia , Camundongos , Microscopia Eletroquímica de Varredura , Medicina Regenerativa/métodos , Engenharia Tecidual/métodos
12.
Carbohydr Polym ; 240: 116244, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475550

RESUMO

Graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) were added to furcellaran films (FUR). Silver nanoparticles (AgNPs) were prepared by reducing AgNO3 using a FUR matrix as the stabilising agent. The structure and surface morphology of nanocomposite films were obtained using FTIR, SEM and XRD. The molecular weights of furcellaran chains were estimated using HPSEC-MALLS-RI. Characterisation of the films was undertaken to analyse their physical, mechanical and structural properties. SEM analysis revealed that GO, MWCNTs and AgNPs were evenly distributed throughout the FUR surface. FUR + AgNP films showed antimicrobial activity against bacteria and fungi. P. aeruginosa, E. faecalis and S. aureus were the most affected with effective growth inhibition using the disc diffusion method. In the study, the effect of nanofillers on the structural, thermal, mechanical and antimicrobial properties of furcellaran films as potential materials for food packaging is presented.


Assuntos
Alginatos/química , Antibacterianos/química , Biopolímeros/química , Nanocompostos/química , Gomas Vegetais/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Grafite/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Prata/química
13.
Int J Mol Sci ; 21(9)2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32392778

RESUMO

Skeletal muscle regeneration depends on the satellite cells, which, in response to injury, activate, proliferate, and reconstruct damaged tissue. However, under certain conditions, such as large injuries or myopathies, these cells might not sufficiently support repair. Thus, other cell populations, among them adipose tissue-derived stromal cells (ADSCs), are tested as a tool to improve regeneration. Importantly, the pro-regenerative action of such cells could be improved by various factors. In the current study, we tested whether IL-4 and SDF-1 could improve the ability of ADSCs to support the regeneration of rat skeletal muscles. We compared their effect at properly regenerating fast-twitch EDL and poorly regenerating slow-twitch soleus. To this end, ADSCs subjected to IL-4 and SDF-1 were analyzed in vitro and also in vivo after their transplantation into injured muscles. We tested their proliferation rate, migration, expression of stem cell markers and myogenic factors, their ability to fuse with myoblasts, as well as their impact on the mass, structure and function of regenerating muscles. As a result, we showed that cytokine-pretreated ADSCs had a beneficial effect in the regeneration process. Their presence resulted in improved muscle structure and function, as well as decreased fibrosis development and a modulated immune response.


Assuntos
Tecido Adiposo/citologia , Quimiocina CXCL12/farmacologia , Interleucina-4/farmacologia , Músculo Esquelético/lesões , Regeneração , Células Estromais/transplante , Tecido Adiposo/efeitos dos fármacos , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Modelos Animais de Doenças , Camundongos , Músculo Esquelético/fisiologia , Ratos , Células Estromais/citologia , Células Estromais/efeitos dos fármacos , Cicatrização
14.
Ultrason Sonochem ; 60: 104785, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31539732

RESUMO

In this study, the sonochemical-assisted desilication method was applied as a special and innovative way of preparing hierarchical zeolites. The physicochemical properties of the hierarchical zeolites prepared using the sonochemical route were compared with those prepared using the conventional desilication method. Commercial zeolite with FAU-type structure was desilicated with a sodium and tetrabutylammonium hydroxide aqueous solution (NaOH/TBAOH) for 30 min. The ultrasound treatment process was performed using a QSonica Q700 sonicator (Church Hill Rd, Newtown, CT, USA) equipped with a ½â€³ diameter horn. The average power of sonication was 60 W, and the frequency was 20 kHz. During the sonication procedure, the alkaline solution with the catalyst precursor and sonicator probe were placed in an ice bath to keep them at room temperature. The prepared catalyst samples were examined by ICP-OES, XRD, SEM, NMR, and nitrogen sorption techniques. The acidic properties of the prepared hierarchical zeolite samples were assessed by means of IR spectroscopy with ammonia and carbon monoxide sorption as probe molecules. All catalysts were studied in the decarbonylation of furfural into furan. Independently of the application of ultrasonic irradiation, desilication of zeolites with an NaOH/TBAOH mixture extracts comparable amounts of silicon, resulting in comparable crystallinity and acidity. On the other hand, the samples prepared in the presence of ultrasounds revealed higher both mesoporosity and enhanced catalytic properties in the reaction of decarbonylation of furfural into furan in comparison with their counterparts prepared using the conventional method.

15.
Stem Cell Res Ther ; 10(1): 343, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31753006

RESUMO

BACKGROUND: Satellite cells, a population of unipotent stem cells attached to muscle fibers, determine the excellent regenerative capability of injured skeletal muscles. Myogenic potential is also exhibited by other cell populations, which exist in the skeletal muscles or come from other niches. Mesenchymal stromal/stem cells inhabiting the bone marrow do not spontaneously differentiate into muscle cells, but there is some evidence that they are capable to follow the myogenic program and/or fuse with myoblasts. METHODS: In the present study we analyzed whether IGF-1, IL-4, IL-6, and SDF-1 could impact human and porcine bone marrow-derived mesenchymal stromal/stem cells (hBM-MSCs and pBM-MSCs) and induce expression of myogenic regulatory factors, skeletal muscle-specific structural, and adhesion proteins. Moreover, we investigated whether these factors could induce both types of BM-MSCs to fuse with myoblasts. IGF-1, IL-4, IL-6, and SDF-1 were selected on the basis of their role in embryonic myogenesis as well as skeletal muscle regeneration. RESULTS: We found that hBM-MSCs and pBM-MSCs cultured in vitro in the presence of IGF-1, IL-4, IL-6, or SDF-1 did not upregulate myogenic regulatory factors. Consequently, we confirmed the lack of their naïve myogenic potential. However, we noticed that IL-4 and IL-6 impacted proliferation and IL-4, IL-6, and SDF-1 improved migration of hBM-MSCs. IL-4 treatment resulted in the significant increase in the level of mRNA encoding CD9, NCAM, VCAM, and m-cadherin, i.e., proteins engaged in cell fusion during myotube formation. Additionally, the CD9 expression level was also driven by IGF-1 treatment. Furthermore, the pre-treatment of hBM-MSCs either with IGF-1, IL-4, or SDF-1 and treatment of pBM-MSCs either with IGF-1 or IL-4 increased the efficacy of hybrid myotube formation between these cells and C2C12 myoblasts. CONCLUSIONS: To conclude, our study revealed that treatment with IGF-1, IL-4, IL-6, or SDF-1 affects BM-MSC interaction with myoblasts; however, it does not directly promote myogenic differentiation of these cells.


Assuntos
Células da Medula Óssea/metabolismo , Células-Tronco Mesenquimais/metabolismo , Fibras Musculares Esqueléticas/fisiologia , Mioblastos/metabolismo , Regeneração , Animais , Células da Medula Óssea/citologia , Fusão Celular , Linhagem Celular , Humanos , Células-Tronco Mesenquimais/citologia , Fibras Musculares Esqueléticas/citologia , Mioblastos/citologia , Suínos
16.
Int J Mol Sci ; 20(13)2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31284492

RESUMO

In case of large injuries of skeletal muscles the pool of endogenous stem cells, i.e., satellite cells, might be not sufficient to secure proper regeneration. Such failure in reconstruction is often associated with loss of muscle mass and excessive formation of connective tissue. Therapies aiming to improve skeletal muscle regeneration and prevent fibrosis may rely on the transplantation of different types of stem cell. Among such cells are adipose tissue-derived stromal cells (ADSCs) which are relatively easy to isolate, culture, and manipulate. Our study aimed to verify applicability of ADSCs in the therapies of severely injured skeletal muscles. We tested whether 3D structures obtained from Matrigel populated with ADSCs and transplanted to regenerating mouse gastrocnemius muscles could improve the regeneration. In addition, ADSCs used in this study were pretreated with myoblasts-conditioned medium or anti-TGFß antibody, i.e., the factors modifying their ability to proliferate, migrate, or differentiate. Analyses performed one week after injury allowed us to show the impact of 3D cultured control and pretreated ADSCs at muscle mass and structure, as well as fibrosis development immune response of the injured muscle.


Assuntos
Tecido Adiposo/citologia , Colágeno/farmacologia , Laminina/farmacologia , Músculo Esquelético/patologia , Proteoglicanas/farmacologia , Regeneração/efeitos dos fármacos , Animais , Anticorpos/farmacologia , Forma Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Combinação de Medicamentos , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/genética , Inflamação/patologia , Masculino , Camundongos Endogâmicos C57BL , Músculo Esquelético/efeitos dos fármacos , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Mioblastos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células Estromais/citologia , Células Estromais/efeitos dos fármacos , Células Estromais/transplante , Fator de Crescimento Transformador beta/metabolismo
17.
J Mech Behav Biomed Mater ; 98: 235-245, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31277039

RESUMO

Development of new composite materials for bone tissue engineering is a constantly growing field of medicine. Therefore there is a continuous need in creating novel materials that can not only regenerate the defected tissue but also nourish it while the healing process progresses. Here we present a novel type of composite material that fulfils these requirements. The study describes creation of a composite with macroporous bioceramic core that is infiltrated with a thin biopolymer layer. The ceramic component, namely tricalcium phosphate (TCP), due to its mechanistic and bioactive properties may promote new bone creation as shown through the in vitro studies. To the best of our knowledge the coating layer was created for the first time from a representative of bacterially derived medium chain length polyhydroxyalkanoate polymers (mcl-PHA), namely polyhydroxyoctanoate (PHO). This polymer layer not only profoundly changed the stress-strain characteristics of the bioceramic foam but also released (R)-3-hydroxyacids and their dimers/trimers to the investigated environment. In the manuscript we have in depth characterised these materials employing a set of basic procedures, through 3D structure reconstruction and finishing with prolonged in vitro experiments.


Assuntos
Osso e Ossos/citologia , Fosfatos de Cálcio/química , Engenharia Tecidual , Alicerces Teciduais/química , Materiais Biocompatíveis , Biomimética , Porosidade , Molhabilidade
18.
Polymers (Basel) ; 10(8)2018 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-30960790

RESUMO

The effect of synthesis parameters on the physicochemical properties of clay/ polydiallyldimethylammonium (PDDA)/Ru composites and their applicability in hydrogenation of 2-butanone under very mild conditions (room temperature, atmospheric pressure, and aqueous solution) was studied. Three synthetic procedures were employed, differing in the order of addition of components and the stage at which metallic Ru species were generated. The materials were characterized with XRD (X-ray diffraction), XRF (X-ray fluorescence), EDS (energy-dispersive spectroscopy), AFM (atomic force microscopy), TEM/HRTEM (transmission electron microscopy/high resolution transmission electron microscopy), and TG/DSC (thermal gravimetry/differential scanning microscopy techniques. The study revealed that the method of composite preparation affects its structural and thermal properties, and controls the distribution and size of Ru particles. All catalysts are active in hydrogenation of 2-butanone. For best catalytic performance (100% conversion within 30 min) both the size of Ru particles and the load of polymer had to be optimized. Superior catalytic properties were obtained over the composite with intermediate crystal size and intermediate PDDA load, prepared by generation of metallic Ru species in the polymer solution prior to intercalation. This method offers an easy way of controlling the crystal size by modification of Ru/PDDA ratio.

19.
Cell Biol Int ; 42(3): 373-382, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29193437

RESUMO

Skeletal muscle growth and regeneration relies on the activation of muscle specific stem cells, that is, satellite cells. The activation and differentiation of satellite cells into myoblasts, as well as their migration, proliferation, and fusion of mononuclear myoblasts into a functional multi-nucleated muscle fiber, are associated with extracellular matrix (ECM) protein synthesis and degradation. The extracellular environment is dynamically adapting to the changes accompanying skeletal muscle growth or repair. Enzymes engaged in many biological processes that involve ECM remodeling are matrix metalloproteinases (MMPs). Among metalloproteinases crucial for skeletal muscles are two gelatinases-MMP-9 and MMP-2. In the current study we test the effect of silencing the MMP-9 and MMP-2 expression on the proliferation and differentiation of in vitro cultured skeletal muscle myoblasts. We show that downregulating gelatinase MMP-9 expression results in a delayed myoblast differentiation.


Assuntos
Gelatinases/genética , Gelatinases/metabolismo , Mioblastos Esqueléticos/citologia , Animais , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Matriz Extracelular/metabolismo , Inativação Gênica , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/fisiologia , Metaloproteinase 9 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/fisiologia , Metaloproteinases da Matriz/metabolismo , Desenvolvimento Muscular/fisiologia , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Mioblastos Esqueléticos/patologia , Cultura Primária de Células , Ratos , Regeneração/fisiologia , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/fisiologia
20.
Muscle Nerve ; 55(3): 400-409, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27396429

RESUMO

INTRODUCTION: Skeletal muscles are characterized by their unique ability to regenerate. Injury of a so-called fast-twitch muscle, extensor digitorum longus (EDL), results in efficient regeneration and reconstruction of the functional tissue. In contrast, slow-twitch muscle (soleus) fails to properly reconstruct and develops fibrosis. This study focuses on soleus and EDL muscle regeneration and associated inflammation. METHODS: We determined differences in the activity of neutrophils and M1 and M2 macrophages using flow cytometry and differences in the levels of proinflammatory cytokines using Western blotting and immunolocalization at different times after muscle injury. RESULTS: Soleus muscle repair is accompanied by increased and prolonged inflammation, as compared to EDL. The proinflammatory cytokine profile is different in the soleus and ED muscles. CONCLUSIONS: Muscle repair efficiency differs by muscle fiber type. The inflammatory response affects the repair efficiency of slow- and fast-twitch muscles. Muscle Nerve 55: 400-409, 2017.


Assuntos
Inflamação/etiologia , Fibras Musculares de Contração Rápida/fisiologia , Fibras Musculares de Contração Lenta/fisiologia , Regeneração/fisiologia , Acetiltransferases/metabolismo , Animais , Citocinas/metabolismo , Citometria de Fluxo , Laminina/metabolismo , Macrófagos/metabolismo , Masculino , Doenças Musculares/complicações , Cadeias Pesadas de Miosina/metabolismo , Neutrófilos/metabolismo , Neutrófilos/patologia , Ratos , Fatores de Tempo , Proteína X Associada a bcl-2/metabolismo
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