IR Studies of Ethoxy Groups on CeO2.

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.

Ethoxy Groups on ZrO2, CuO, CuO/ZrO2 Al2O3, Ga2O3, SiO2 and NiO: Formation and Reactivity.

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.

On the Role of Protonic Acid Sites in Cu Loaded FAU31 Zeolite as a Catalyst for the Catalytic Transformation of Furfural to Furan.

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.

IL-4 and SDF-1 Increase Adipose Tissue-Derived Stromal Cell Ability to Improve Rat Skeletal Muscle Regeneration.

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.

Physicochemical and Biological Characterisation of Diclofenac Oligomeric Poly(3-hydroxyoctanoate) Hybrids as ß-TCP Ceramics Modifiers for Bone Tissue Regeneration.

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.

Adipose Tissue-Derived Stromal Cells in Matrigel Impacts the Regeneration of Severely Damaged Skeletal Muscles.

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.

Silencing of gelatinase expression delays myoblast differentiation in vitro.

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.

Inflammatory response during slow- and fast-twitch muscle regeneration.

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.

The role of TGF-ß1 during skeletal muscle regeneration.

The injury of adult skeletal muscle initiates series of well-coordinated events that lead to the efficient repair of the damaged tissue. Any disturbances during muscle myolysis or reconstruction may result in the unsuccessful regeneration, characterised by strong inflammatory response and formation of connective tissue, that is, fibrosis. The switch between proper regeneration of skeletal muscle and development of fibrosis is controlled by various factors. Amongst them are those belonging to the transforming growth factor ß family. One of the TGF-ß family members is TGF-ß1, a multifunctional cytokine involved in the regulation of muscle repair via satellite cells activation, connective tissue formation, as well as regulation of the immune response intensity. Here, we present the role of TGF-ß1 in myogenic differentiation and muscle repair. The understanding of the mechanisms controlling these processes can contribute to the better understanding of skeletal muscle atrophy and diseases which consequence is fibrosis disrupting muscle function.

[Matrix metalloproteinase in development, physiology and degenerative processes of skeletal muscles]. / Metaloproteinazy macierzy zewnatrzkomórkowej w rozwoju, fizjologii i procesach degeneracyjnych miesni szkieletowych.

Matrix metalloproteinase (MMP) are a large family of enzymes, active in both physiological and pathological processes of many tissues. These proteases are able to selectively degrade components of the Extracellular Matrix (ECM). In skeletal muscle enzymes included in the MMP family are involved in tissue remodeling process, playing a key role in myogenesis as well as in tissue remodeling and regeneration of muscle. This paper describes the role of this group of enzymes in the conversion of skeletal muscle extracellular environment both in physiological processes in skeletal muscle and in the context of regeneration of the tissue.

Nuclear MMP-9 role in the regulation of rat skeletal myoblasts proliferation.

BACKGROUND INFORMATION: Matrix metalloproteinases (MMPs) are the key enzymes responsible for the remodelling of extracellular matrix. Two of them, namely MMP-2 and MMP-9 (gelatinases A and B, respectively), are expressed in skeletal muscles and are involved in their regeneration after the injury. Although MMPs are primarily known to act extracellularly, recent studies have shown that some of them are also found within the cell. In this study, we examine intracellular localisation of gelatinases during myoblasts differentiation in vitro, focussing the impact of MMPs inhibition on the myoblasts proliferation and function. RESULTS: We show that MMP-9 localises within the S-phase nuclei of in vitro differentiating myoblasts. The inhibition of MMPs activity achieved by either doxycycline (a non-competitive inhibitor of collagenases), TIMP-1 (tissue inhibitor of metalloproteinases 1) or neutralising anti-MMP-9 antibody affects nuclear localisation of this gelatinase, and impacts at myoblasts proliferation. CONCLUSIONS: During myoblasts differentiation, MMP-9 that is localised in nuclei might be involved in the processes regulating cell cycle progression.

Modulating the Release Kinetics of Natural Product Actinomycin from Bacterial Nanocellulose Films and Their Antimicrobial Activity.

The present study aimed to create a more sustainable and controlled delivery system based on natural biopolymer bacterial nanocellulose (BNC) and bacterial natural product actinomycin (Act), with the applicative potential in the biomedical field. In order to provide improved interaction between BNC and the active compound, and thus to modulate the release kinetics, the TEMPO oxidation of BNC support was carried out. A mix of actinomycins from bacterial fermentation (ActX) were used as natural antimicrobial agents with an established bioactivity profile and clinical use. BNC and TEMPO-oxidized BNC films with incorporated active compounds were obtained and analyzed by FTIR, SEM, XPS, and XRD. The ActX release profiles were determined in phosphate-buffer solution, PBS, at 37 °C over time. FTIR analysis confirmed the improved incorporation and efficiency of ActX adsorption on oxidized BNC due to the availability of more active sites provided by oxidation. SEM analysis indicated the incorporation of ActX into the less-dense morphology of the TEMPO-oxidized BNC in comparison to pure BNC. The release kinetics of ActX were significantly affected by the BNC structure, and the activated BNC sample indicated the sustained release of active compounds over time, corresponding to the Fickian diffusion mechanism. Antimicrobial tests using Staphylococcus aureus NCTC 6571 confirmed the potency of this BNC-based system for biomedical applications, taking advantage of the capacity of modified BNC to control and modulate the release of bioactive compounds.

Physicochemical, structural and biological characterisation of poly(3-hydroxyoctanoate) supplemented with diclofenac acid conjugates - Harnessing the potential in the construction of materials for skin regeneration processes.

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.

Sdf-1 (CXCL12) improves skeletal muscle regeneration via the mobilisation of Cxcr4 and CD34 expressing cells.

BACKGROUND INFORMATION: The regeneration of skeletal muscles involves satellite cells, which are muscle-specific precursor cells. In muscles, injured either mechanically or as a consequence of a disease, such as muscular dystrophy, local release of the growth factors and cytokines leads to satellite cells activation, proliferation and differentiation of the resulting myoblasts, followed by the formation of new myofibres. Various cell types, such as stem and progenitor cells, originating from other tissues different than the muscle, are also able to follow a myogenic program. Participation of these cells in the repair process depends on their precise mobilisation to the site of the injury. RESULTS: In this study, we showed that stromal-derived factor-1 (Sdf-1) impacts on the mobilisation of CXC chemokine receptor (Cxcr)4-positive cells and improves skeletal muscle regeneration. Analysis of isolated and in vitro cultured satellite cells showed that Sdf-1 did not influence myoblasts proliferation and expression of myogenic regulatory transcription factors but induced migration of the myoblasts in Cxcr4-dependent ways. This phenomenon was also associated with the increased activity of crucial extracellular matrix modifiers, i.e. metalloproteases Mmp-2 and Mmp-9. CONCLUSIONS: Thus, positive impact of Sdf-1 on muscle regeneration is related to the mobilisation of endogenous cells, that is satellite cells and myoblasts, as well as non-muscle stem cells, expressing Cxcr4 and CD34.

Improvement of La0.8Sr0.2MnO3-δ Cathode Material for Solid Oxide Fuel Cells by Addition of YFe0.5Co0.5O3.

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.

Utilisation of soybean post-production waste in single- and double-layered films based on furcellaran to obtain packaging materials for food products prone to oxidation.

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.

Variously Prepared Zeolite Y as a Modifier of ANFO.

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.

Aluminum Doped Titania as a Support of Copper Catalysts for SCR of Nitrogen Oxides.

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.

Active Double-Layered Films Enriched with AgNPs in Great Water Dock Root and Pu-Erh Extracts.

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.

Anodic Electrodeposition of Chitosan-AgNP Composites Using In Situ Coordination with Copper Ions.

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.