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71.
Michal Dziadek Barbara Zagrajczuk Elzbieta Menaszek Kinga Dziadek Katarzyna Cholewa-Kowalska 《Journal of Materials Science》2017,52(22):12960-12980
In contrast to currently used materials, membranes for the treatment of bone defects should actively promote regeneration of bone tissue beyond their physical barrier function. What is more, both material properties and biological features of membranes should be easily adaptable to meet the needs of particular therapeutic applications. Therefore, the role of preparation methods (non-solvent-induced phase separation and thermal-induced phase separation) of poly(ε-caprolactone)-based membranes and their modification with gel-derived bioactive glass (BG) particles of two different sizes (<45 and <3 μm) in modulating material morphology, polymer matrix crystallinity, surface wettability, kinetics of in vitro bioactivity and also osteoblast response was investigated. Both surfaces of membranes were characterised in terms of their properties. Our results indicated a possibility to modulate microstructure (pore size ranging from submicron to hundreds of micrometres), wettability (from hydrophobic to fully wettable surface) and polymer crystallinity (from 19 to 60%) in a wide range by the use of various preparation methods and different BG particle sizes. Obtained composite membranes showed excellent in vitro hydroxyapatite forming ability after incubation in simulated body fluid. Here we demonstrated that bioactive layer formation on the surface of membranes occurred through ACP–OCP–CDHA–HCA transformation, that mimic in vivo bone biomineralization process. Composite membranes supported human osteoblast proliferation, stimulated cell differentiation and matrix mineralization. We proved that kinetics of bioactivity process and also osteoinductive properties of membranes can be easily modulated with the use of proposed variables. This brings new opportunities to obtain multifunctional membranes for bone regeneration with tunable physicochemical and biological properties. 相似文献
72.
Lithography‐Free Fabrication of Silica Nanocylinders with Suspended Gold Nanorings for LSPR‐Based Sensing
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Anil Haraksingh Thilsted Jesper Yue Pan Kaiyu Wu Kinga Zór Tomas Rindzevicius Michael Stenbæk Schmidt Anja Boisen 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(48):6745-6752
Tunable plasmonic platforms are important for a variety of applications such as photovoltaics, LED's, optoelectronics, medical research, and biosensors. In particular, development of label‐free plasmonic biosensors is one of the key research areas that utilizes plasmonic nanostructures for detection of biologically relevant molecules at low concentrations. The authors have developed a cost‐effective, fast, and lithography‐free method to fabricate transparent fused silica nanocylinders. The technique allows tuning of nanocylinder height, diameter, and density and can be scaled to large surface areas, such as 8 in. wafers. The authors demonstrate that gold coated nanocylinders support localized surface plasmon resonances (LSPR) from visible to near infrared wavelengths. The plasmonic platform can be characterized as suspended gold nanorings and exhibits a sensitivity of 658 nm RIU–1 with a figure‐of‐merit of 10, comparable to other state‐of‐the‐art LSPR sensing platforms that utilize more complex nanofabrication pathways. It was observed that the LSPR peak positions can be controlled by varying the geometry of the nanocylinders. The authors illustrate surface functionalization, biosensing, and surface regeneration properties of the platform using thiols and detection of bovine serum albumin (BSA). The observed LSPR shifts for 11‐mercaptoundecanoic acid and BSA was 12 and 26 nm, respectively. 相似文献
73.
The accelerated development of technology over the last three decades has driven biological sciences to high-throughput profiling experiments, now broadly referred to as systems biology. The unprecedented improvement of analytical instrumentation has opened new avenues for more complex experimental designs and expands the knowledge in genomics, proteomics, and other omics fields. Despite the collective efforts of hundreds of researchers, gleaning all the expected information from omics experiments is still quite far. This paper summarizes what has been learned from high-throughput proteomics studies thus far, and what is believed should be done to reveal even more valuable information from such studies. It is drawn from the background in using proteomics to study human immunodeficiency virus 1 infection of macrophages and/or T cells, but it is believed that some conclusions will be more broadly applicable. 相似文献
74.
Kinga Kik Boena Bukowska Anita Krokosz Paulina Siciska 《International journal of molecular sciences》2021,22(9)
With the ongoing commercialization, human exposure to plastic nanoparticles will dramatically increase, and evaluation of their potential toxicity is essential. There is an ongoing discussion on the human health effects induced by plastic particles. For this reason, in our work, we assessed the effect of polystyrene nanoparticles (PS-NPs) of various diameters (29, 44 and 72 nm) on selected parameters of oxidative stress and the viability of human peripheral blood mononuclear cells (PBMCs) in the in vitro system. Cells were incubated with PS-NPs for 24 h in the concentration range of 0.001 to 100 µg/mL and then labeled: formation of reactive oxygen species (ROS) (including hydroxyl radical), protein and lipid oxidation and cell viability. We showed that PS-NPs disturbed the redox balance in PBMCs. They increased ROS levels and induced lipid and protein oxidation, and, finally, the tested nanoparticles induced a decrease in PBMCs viability. The earliest changes in the PBMCs were observed in cells incubated with the smallest PS-NPs, at a concentration of 0.01 μg/mL. A comparison of the action of the studied nanoparticles showed that PS-NPs (29 nm) exhibited a stronger oxidative potential in PBMCs. We concluded that the toxicity and oxidative properties of the PS-NPs examined depended to significant degree on their diameter. 相似文献
75.
Henry Man Kinga Kędziora Justyna Kulig Annika Frank Iván Lavandera Vicente Gotor-Fernández Dörte Rother Sam Hart Johan P. Turkenburg Gideon Grogan 《Topics in Catalysis》2014,57(5):356-365
Alcohol dehydrogenases (ADHs) are applied in industrial synthetic chemistry for the production of optically active secondary alcohols. However, the substrate spectrum of many ADHs is narrow, and few, for example, are suitable for the reduction of prochiral ketones in which the carbonyl group is bounded by two bulky and/or hydrophobic groups; so-called ‘bulky–bulky’ ketones. Recently two ADHs, RasADH from Ralstonia sp. DSM 6428, and SyADH from Sphingobium yanoikuyae DSM 6900, have been described, which are distinguished by their ability to accept bulky–bulky ketones as substrates. In order to examine the molecular basis of the recognition of these substrates the structures of the native and NADPH complex of RasADH, and the NADPH complex of SyADH have been determined and refined to resolutions of 1.5, 2.9 and 2.5 Å, respectively. The structures reveal hydrophobic active site tunnels near the surface of the enzymes that are well-suited to the recognition of large hydrophobic substrates, as determined by modelling of the bulky–bulky substrate n-pentyl phenyl ketone. The structures also reveal the bases for NADPH specificity and (S)-stereoselectivity in each of the biocatalysts for n-pentyl phenyl ketone and related substrates. 相似文献
76.
77.
Attempts to develop new technologies of reduction of NOx emission are still carried out all around the world. However, most of them as literature survey suggests is focused on NOx emission control from power plants and mobile vehicles. Fewer investigations are conducted on the NOx emission abatement from the chemical industry. One of the relatively new approaches is the application of ozone injection into exhaust gas stream followed by an absorption process. Ozone is used to transform NOx to higher nitrogen oxides that are more soluble in water, and therefore the higher yield of nitric acid is expected. The main objective of this article is to present results of our studies in which the effectiveness of the ozonation process, as well as the dependence of the conversion rate and the selectivities of NO ozonation into NO2, N2O5 and HNO3 on the residence time of reagents in the reactor space were studied. Results of laboratory investigations were confirmed during ozonation experiments with real exhaust gases from a nitric acid pilot plant in Fertilizers Research Institute in Pulawy, Poland. 相似文献
78.
Pyrolysed 3D‐Carbon Scaffolds Induce Spontaneous Differentiation of Human Neural Stem Cells and Facilitate Real‐Time Dopamine Detection
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Letizia Amato Arto Heiskanen Claudia Caviglia Fozia Shah Kinga Zór Marc Madou Lauge Gammelgaard Rasmus Hansen Emma G. Seiz Milagros Ramos Alberto Martínez‐Serrano Stephan S. Keller Jenny Emnéus 《Advanced functional materials》2014,24(44):7042-7052
Structurally patterned pyrolysed three‐dimensional carbon scaffolds (p3D‐carbon) are fabricated and applied for differentiation of human neural stem cells (hNSCs) developed for cell replacement therapy and sensing of released dopamine. In the absence of differentiation factors (DF) the pyrolysed carbon material induces spontaneous hNSC differentiation into mature dopamine‐producing neurons and the 3D‐topography promotes neurite elongation. In the presence and absence of DF, ≈73–82% of the hNSCs obtain dopaminergic properties on pyrolysed carbon, a to‐date unseen efficiency in both two‐dimensional (2D) and 3D environment. Due to conductive properties and 3D environment, the p3D‐carbon serves as a neurotransmitter trap, enabling electrochemical detection of a significantly larger dopamine fraction released by the hNSC derived neurons than on conventional 2D electrodes. This is the first study of its kind, presenting new conductive 3D scaffolds that provide highly efficient hNSC differentiation to dopaminergic phenotype combined with real‐time in situ confirmation of the fate of the hNSC‐derived neurons. 相似文献
79.
Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions. 相似文献
80.
The results presented in this study were concerned with microstructures and mechanical properties of polycrystalline Cu subjected to plastic deformation by a compression with oscillatory torsion process. Different deformation parameters of the compression with oscillatory torsion process were adopted to study their effects on the microstructure and mechanical properties. The deformed microstructure was characterized quantita- tively by electron backscattered diffraction (EBSD) and scanning transmission electron microscopy (STEM). Mechanical properties were determined on an MTS QTest/10 machine equipped with digital image correlation. From the experimental results, processes performed at high compression speed and high torsion frequency are recommended for refining the grain size. The size of structure elements, such as average grain size (D) and subgrain size (d), reached 0.42 μm and 0.30 μm, respectively, and the fraction of high angle boundaries was 35% when the sample was deformed at a torsion frequency f = 1.6 Hz and compression rate v = 0.04 mm/s. These deformation parameters led to an improvement in the strength properties. The material exhibited an ultimate tensile strength (UTS) of 434 MPa and a yield strength (YS) of 418 MPa. These values were about two times greater than those of the initial state. 相似文献