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od 2020-09-20 |
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1. |
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Effect of calcium ions on structure and stability of the C1q-like domain of otolin-1 from human and zebrafish Otolin-1 is a collagen-like protein expressed in the inner ear of vertebrates. It provides an organic scaffold for otoliths in fish and otoconia in land vertebrates. In this study, the expression and purification procedure of C1q-like domain of otolin-1 from human and zebrafish was developed. The structure and stability of the proteins were investigated. The results of sedimentation velocity analytical ultracentrifugation and small-angle X-ray scattering indicated that the C1q-like domain of otolin-1 forms stable trimers in solution in the presence of calcium ions. It was also observed that calcium ions influenced the secondary structure of the proteins. C1q-like domains were stabilized by the calcium ions. The human variant was especially affected by the calcium ions. The results indicate the importance of the C1q-like domain for the assembly of the organic matrix of otoliths and otoconia.
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FEBS Journal, 284(24), 4278-4297, (2017) |
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Overall conformation of covalently stabilized domain-swapped dimer of human cystatin C in solution Human cystatin C (HCC), a small protein, plays a crucial role in inhibition of cysteine proteases. The most common structural form of human cystatin C in crystals is a dimer, which has been evidenced both for the native protein and its mutants. In these structures, HCC dimers were formed through the mechanism of domain swapping. The structure of the monomeric form of human cystatin C was determined for V57N mutant and the mutant with the engineered disulfide bond (L47C)–(G69C) (known as stab1-HCC). On the basis of stab1-HCC, a number of covalently stabilized oligomers, including also dimers have been obtained. The aim of this study was to analyze the structure of the covalently stabilized dimer HCC in solution by the small angle X-ray scattering (SAXS) technique and synchrotron radiation. Experimental data confirmed that in solution this protein forms a dimer, which is characterized by the radius of gyration RG = 3.1 nm and maximum intramolecular distance Dmax = 10.3 nm. Using the ab initio method and program DAMMIN, we propose a low resolution structure of stabilized covalently cystatin C in solution. Stab-HCC dimer adopts in solution an elongated conformation, which is well reconstructed by the ab initio model.
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 411, 136-140, (2017) |
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Preliminary results of human PrPC protein studied by spectroscopic techniques Neurodegenerative diseases are one of the malfunctions of human nervous system, being a class of complex and prominent pathologies. The human prion Protease Resistant Protein (PrP) is protein regulating copper metabolism in mammalian cells through binding of Cu(II) ions to specific fragments. Nowadays misfolding of this protein is associated with development of prion diseases. Therefore, it is crucial to obtain structural information about coordination of Cu(II) by PrP protein. Herein, we report X-ray absorption spectroscopy (XAS) measurements, carried out on SuperXAS beamline (SLS, PSI Villigen) on PrPC-Cu(II) complexes. Obtained results were compared with theoretical predictions done by FEFF 9.6 software. Complementary to XAS data, Atomic Force Microscopy (AFM) measurements were conducted to obtain low resolution structural information about prepared sample that allow to develop protocol of fixing PrPC molecules on solid substrate used for further experiments. It has been established that folded C-terminal domain of PrPC protein has around 5 nm in diameter. Presented results showed that both XAS and AFM methods are useful tools in detailed examination of complexes of human PrPC either with Cu(II) or with other divalent metal ions.
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 411, 121-128, (2017) |
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Structural studies of degradation process of zirconium dioxide tetragonal phase induced by grinding with dental bur Zirconium dioxide has been widely used in dental prosthetics. However, the improper mechanical treatment can induce changes in the microstructure of zirconium dioxide. From the viewpoint of mechanical properties and performance, the phase transitions of ZrO2 from the tetragonal to the monoclinic phase induced by mechanical processing, are particularly undesirable. In this study, the phase transitions of yttrium stabilized zirconium dioxide (Y-TZP) induced by mechanical treatment are investigated by the scanning electron microscopy (SEM), atomic force microscopy (AFM) and powder diffraction (XRD). Mechanical stress was induced by different types of drills used presently in dentistry. At the same time the surface temperature was monitored during milling using a thermal imaging camera. Diffraction analysis allowed determination of the effect of temperature and mechanical processing on the scale of induced changes. The observed phase transition to the monoclinic phase was correlated with the methods of mechanical processing.
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 411, 85-93, (2017) |
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Proceedings of the XIII international school and symposium on synchrotron radiation in natural science 2016, Ustroń-Jaszowiec, Poland This special issue of Nuclear Instruments and Methods in Physics Research Section B of Nuclear Instruments and Methods in Physics Research was prepared to present recent achievements in synchrotron radiation science and mark the 25th anniversary of the Polish Synchrotron Radiation Society (PSRS) which fell in 2016. It presents selected papers submitted after the 13th International School and Symposium on Synchrotron Radiation in Natural Science (ISSRNS 2016) which was organized by PSRS in cooperation with the Adam Mickiewicz University. It is worth noting that PSRS is probably one of the earliest founded scientific societies focused on promoting the use of synchrotron radiation research (for details visit the PSRS home page: http://www.synchrotron.org.pl/). Since 2002 the Society has been regularly publishing its own journal-bulletin dedicated to synchrotron research – Synchrotron Radiation in Natural Science, and so far 17 volumes have been published. The first idea of constructing a synchrotron in Poland was proposed by the members of PSRS, and now the Society strongly supports the construction of this facility – National Centre of Synchrotron Radiation “Solaris” (http://www.synchrotron.uj.edu.pl/), which is located in Kraków (Poland) and it was put into operation in September 2015. Members of our Society are also involved in designing and construction of beamlines for “Solaris”. Recent photos of synchrotron experimental hall and beamlines are presented in Fig. 1. A review of the current status of Polish synchrotron is presented in this issue by Wawrzyniak et al.
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 411, 1-3, (2017) |
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6. |
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Self-organizing silver and ultrasmall iron oxide nanoparticles prepared with ginger rhizome extract: Characterization, biomedical potential and microstructure analysis of hydrocolloids Multimodal nanoparticles (NPs) that may be used for therapies and diagnostics is the most promising trend for efficient therapy. We demonstrate that nanocomposite based on self-organizing silver and ultrasmall magnetic iron oxide NPs (MAg) produced in one-step synthesis revealed unique combination of fluorescence, bactericidal, fungicidal properties and have a potential as magnetic resonance imaging (MRI) contrast agent. Using the green chemistry approach, ginger (Zingiber officinale) rhizome extract was applied as capping agent for MAg synthesis, providing also additional fluorescent properties of NPs and inducing hydrocolloids structuring. The MAg were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive microanalysis (EDS), fluorescence microscopy, cryo-SEM, dynamic light scattering (DLS) techniques, Fourier transforminfrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopies. MAg dispersions in water and some biological media are very stable which is important for biomedical application. The existence of microstructure inMAg hydrocolloids was proved. The hierarchical character and high ordering of this microstructure were discovered and its level-by-level building blocks were investigated. The microstructure was found to be responsible for fluorescence emittance of MAg hydrocolloids. The properties as well as potential application of the MAg hydrocolloids is yet to be discovered. © 2017 Elsevier Ltd. All rights reserved.
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Materials & Design, 133, 307-324, (2017) |
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7. |
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Size-controlled synthesis of anatase nanobrush structures with higher crystal density Titanium dioxide was synthesized in multistep process applying of AAO (Anode Aluminum Oxide) as a template. The TiO2 nanowires were obtained by deposition of titanium precursors inside the pores of AAO membranes (non-hydrolytic sol-gel technique), calcined at 875 K with subsequent removal of alumina matrix by leaching it with phosphoric acid. During the AAO synthesis, it was proved that the electrical work can serve as the unified factor influencing the amount of formed AAO. The diameters of obtained titania nanowires were consequence of used AAO membranes. The higher density of titania elementary cell was observed for all synthesized nanostructures. It was confirmed by XRD and SAED measurements. The TiO2 nanowires attached vertically to polymer disc (50 mm diameter) were used in photocatalytic decomposition of methyl orange. All nanomaterials showed ten times higher photo catalytic activity than P-25. High photoactivity of obtained material is related to external area of vertically aligned titania nanowires. © 2017 Elsevier Ltd. All rights reserved.
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Materials Research Bulletin, 94, 335-341, (2017) |
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8. |
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Second harmonic generation response in thermally reconstructed multiferroic beta '-Gd-2(MoO4)(3) thin films Gd-2(MoO4)(3) (GMO) is a well-studied multiferroic material that exhibits full ferroelectric and ferroelastic behavior at room temperature. However, its difficult stabilization in thin films has prevented the study and exploitation of its multiferroic properties in different architectures. Here, we report on the study of GMO thin films deposited on Si(001) substrates by Pulsed Laser Deposition (PLD). The physicochemical properties of the films are discussed and studied. Results obtained by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution transmission microscopy and second harmonic generation show that the orthorhombic (beta'-GMO) multiferroic phase can be stabilized and homogenized by post deposition thermal reconstruction. Finally, the reconstruction process takes place via a complex surface mechanism with a clear leaf-like behavior
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Scientific Reports, 7, 11800, (2017) |
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9. |
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Molecular dynamics study of polystyrene-b-poly(ethylene oxide) asymmetric diblock copolymer systems Two polystyrene-b-poly(ethylene oxide) (PS-b-PEO) diblock copolymers differing in molecular mass (49 and 78 kDa), but possessing the same PEO cylindrical morphology, are examined to elucidate their molecular dynamics. Of particular interest here is the molecular motion of the PEO blocks involved in the rigid amorphous fraction (RAF). Analysis of complementary thermal calorimetry and X-ray scattering data confirm the presence of a microphase-separated morphology, as well as semi-crystalline structure, in each copolymer. Molecular motion within the copolymer systems is monitored by dielectric and nuclear magnetic resonance spectroscopies. Results reported herein reveal the existence of two local, Arrhenius-type processes attributed to non-cooperative local motion of PEO segments involved in fully amorphous and rigid amorphous PEO microphases. In both systems, two structural relaxations governed by glass transition phenomena are identified and assigned to cooperative segmental motion in the fully amorphous phase (the αc process) and the RAF (the αc process). We measure the temperature dependence of the dynamics associated with all the processes mentioned above and propose that these local processes are associated with corresponding cooperative segmental motion in both copolymer systems. In marked contrast to the thermal activation of the αc process as discerned in both copolymers, the αc process appears to be a sensitive probe of the copolymer nanostructure. That is, the copolymer with shorter PEO blocks exhibits more highly restricted cooperative dynamics of PEO segments in the RAF, which can be explained in terms of the greater constraint imposed by the glassy PS matrix on the PEO blocks comprising smaller cylindrical microdomains.
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Langmuir, 33(36), 8856-8868, (2017) |
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10. |
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Corrigendum to “MWCNT based matrices as a platform for adhesion and growth of cells” [Compos. Sci. Technol. 136 (2016) 29-38] The authors regret that the author Anna Baranowka-Korczyc is actually Anna Baranowska-Korczyc.
The authors would like to apologise for any inconvenience caused. |
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Composites Science and Technology, 149, 305-305, (2017) |
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11. |
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EPR oximetry sensor-developing a TAM derivative for in vivo studies Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment. Triaryl methyl (TAM) derivative radicals are commonly used in electron paramagnetic resonance (EPR) as sensors for quantitative spatial tissue oxygen mapping. They are also known as magnetic resonance imaging (MRI) contrast agents and fluorescence imaging compounds. We report the properties of the TAM radical tris(2,3,5,6-tetrachloro-4-carboxy-phenyl)methyl, (PTMTC), a potential multimodal (EPR/fluorescence) marker. PTMTC was spectrally analyzed using EPR and characterized by estimation of its sensitivity to the oxygen in liquid environment suitable for intravenous injection (1mM PBS, pH=7.4). Further, fluorescent emission of the radical was measured using the same solvent and its quantum yield was estimated. An in vitro cytotoxicity examination was conducted in two cancer cell lines, HT-29 (colorectal adenocarcinoma) and FaDu (squamous cell carcinoma) and followed by uptake studies. The stability of the radical in different solutions (PBS pH=7.4, cell media used for HT-29 and FaDu cells culturing and cytotoxicity procedure, full rat blood and blood plasma) was determined. Finally, a primary toxicity test of PTMTC was carried out in mice. Results of spectral studies confirmed the multimodal properties of PTMTC. PTMTC was demonstrated to be not absorbed by cancer cells and did not interfere with luciferin-luciferase based assays. Also in vitro and in vivo tests showed that it was non-toxic and can be freely administrated till doses of 250 mg/kg BW via both i.v. and i.p. injections. This work illustrated that PTMTC is a perfect candidate for multimodal (EPR/fluorescence) contrast agent in preclinical studies.
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Cell Biochemistry and Biophysics, 1-10, (2017) |
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12. |
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Hybrid ZnPc@TiO2 nanostructures for targeted photodynamic therapy, bioimaging and doxorubicin delivery In this study ZnPc@TiO2 hybrid nanostructures, both nanoparticles and nanotubes, as potential photosensitizers for the photodynamic therapy, fluorescent bioimaging agents, as well as anti-cancer drug nanocarriers, were prepared via zinc phthalocyanine (ZnPc) deposition on TiO2. In order to provide the selectivity of prepared hybrid nanostructures towards cancer cells they were modified with folic acid molecules (FA). The efficient attachment of both ZnPc and FA molecules was confirmed with dynamic light scattering (DLS), zeta potential measurements and X-ray photoelectron spectroscopy (XPS). It was presented that ZnPc and FA attachment has a strong effect on fluorescence emission properties of TiO2 nanostructures, which can be further used for their simultaneous visualization upon cellular uptake. ZnPc@TiO2 and FA/ZnPc@TiO2 hybrid nanotubes were then employed as doxorubicin nanocarriers. It was demonstrated that doxorubicin can be easily loaded on these hybrid nanostructures via an electrostatic interaction and then released. In vitro cytotoxicity and photo-cytotoxic activity studies showed that prepared hybrid nanostructures were selectively targeting to cancer cells. Doxorubicin loaded hybrid nanostructures were significantly more cytotoxic than un-loaded ones and their cytotoxic effect was even more severe upon irradiation. The cellular uptake of prepared hybrid nanostructures and their localization in cells was monitored in vitro in 2D cell culture and tumor-like 3D multicellular culture environment with fluorescent confocal microscopy. These hybrid nanostructures preferentially penetrated into human cervical cancer cells (HeLa) than into normal fibroblasts (MSU-1.1) and were mainly localized within the cell cytoplasm. HeLa cells spheroids were also efficiently labelled by prepared hybrid nanostructures. Fluorescent imaging of Hela cells treated with doxorubicin loaded hybrid nanostructures showed that doxorubicin was effectively delivered into cells, released and evenly distributed in the cytoplasm. In conclusion, prepared hybrid nanostructures exhibit high potential as selective bioimaging agents next to their photodynamic activity and drug delivery ability.
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Materials Science & Engineering C: Materials for Biological Applications, 78, 1072-1085, (2017) |
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13. |
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The impact of adsorption on the localization of spins in graphene oxide and reduced graphene oxide, observed with electron paramagnetic resonance We report the observations of electronic properties of graphene oxide and reduced graphene oxide, performed with electron paramagnetic resonance technique in a broad temperature range. Both materials were examined in pure form and saturated with air, helium, and heavy water molecules. We show that spin localization strongly depends on the type and amount of molecules adsorbed at the graphene layer edges (and possible in-plane defects). Physical and chemical states of edges play crucial role in electrical transport within graphene-based materials, with hopping as the leading mechanism of charge carrier transport. Presented results are a good basis to understand the electronic properties of other carbon structures made of graphene-like building blocks. Most active carbons show some degree of functionalization and are known of having good adsorptive properties; thus, controlling both phenomena is important for many applications. Sample treatment with temperature, vacuum, and various adsorbents allowed for the observation of a possible metalinsulator transition and sorption pumping effects. The influence of adsorption on the localization phenomena in graphene would be very important if to consider the graphene-based material as possible candidates for the future spintronics that works in ambient conditions. Published by AIP Publishing
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Applied Physics Letters, 111(8), 084102, (2017) |
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14. |
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Tailoring of the electronic properties of ZnO-polyacrylonitrile nanofibers: Experiment and theory We report the study of ZnO-polyacrylonitrile (ZnO-PAN) nanofibers fabricated by the combination of electrospinning and atomic layer deposition. The latter technique enables us to control the size of the surface of ZnO 1D nanostructures and hence its effectiveness for energy and biosensor applications. We observe the tendency of ZnO to form nanograins with increase of the layer thickness, and investigate the influence of the grain size on the electronic properties of the nanofibers. It is demonstrated that the ZnO work function (Phi) is strongly affected by surface band bending in the ZnO layer. The observed change of Phi in ZnO layers results from the curvature of the grain surface as well as the presence of the hydroxyl and oxygen groups, adsorbed on ZnO surface and is in a good agreement with theoretical prediction.
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Applied Surface Science, 411, 494-501, (2017) |
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15. |
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EPR and impedance measurements of graphene oxide and reduced graphene oxide We report the observations of electron paramagnetic resonance and impedance measurements of graphene oxide and reduced graphene oxide performed in the wide temperature range in order to get insight into the electronic properties of graphene-based materials and the role of oxygen functionalities in the charge carrier transport phenomena. In such systems the strong spin localization, hopping charge carrier transport as well as the formation of adsorption layers are observed, all the phenomena changing significantly after the heavily oxidized graphene is reduced.
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Acta Physica Polonica A, 132(1), 81-85, (2017) |
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16. |
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Wetting of nanostructurized sapphire and gold surfaces We present the results of preliminary experiments regarding research on the contact angle measurements of various liquids on solid surfaces with different morphology. The aim was to get insight into the dependence of wetting phenomena on the nanoscale surface roughness. Flat and nanostructurized surfaces of gold and sapphire were used in the experiments. Four liquids - bromobenzene, water, mercury, and gallium - covering a broad range of surface tension values were used to check how varying roughness influences wetting in the systems with different adhesion/cohesion ratio. Structurization was anisotropic, which resulted in the very interesting behaviour of the examined liquids on the selected surfaces. Significant change of the wetting properties was observed as well as a strong dependence on the surface morphology.
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Acta Physica Polonica A, 132(1), 185-188, (2017) |
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17. |
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European Biophysics Journal with Biophysics Letters, 46(S1), S177-S177, (2017) |
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(Pobrane: 2018-04-03) |
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18. |
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Dispersion of water proton spin-lattice relaxation rates in aqueous solutions of multiwall carbon nanotubes (MWCNTs) stabilized via alkyloxymethylimidazolium surfactants Carbon nanotubes and a number of other carbon nanomaterials have a tendency to aggregate, which often resulted in difficulties of dispersion of these nanomaterials in aqueous solutions. The ability of dicationic (gemini) surfactants to disperse multiwall carbon nanotubes in water and the dynamic processes taking place at the water-MWCTs interface are studied. Stable dispersions of multi-wall carbon nanotubes with selected gemini surfactants (1,1’-(1,6-hexanediyl)bis(3-alkyloxymethylimidazolium) dichlorides) were prepared and characterized by nuclear magnetic relaxation dispersion (NMRD), NMR diffusometry, scanning and transmission electron microscopy, and Fourier transform infrared spectroscopy. The addition of multiwall carbon nanotubes to aqueous solutions of studied gemini surfactants leads to significant paramagnetic enhancement of the spin-lattice relaxation processes, which gets more pronounced with increasing concentration of well-dispersed MWNTs in water. The dominant role of outer sphere (OS) relaxation mechanism in total observed R1, governed by two-dimensional diffusion of water on the carbon nanotube surface in the vicinity of paramagnetic centers incorporated in the MWCNTs side-walls (mainly of iron origin), was assumed to explain NMRD data. The NMR diffusion experiments confirm the existence of restricted water diffusion in the studied supernatants. The NMR diffusion results are consistent with the FTIR and NMR proton spin-lattice relaxation dispersion in which the more effective R1 dispersion noticed for the sample with IMIC6C12 was ascribed to the better accessibility of water molecules to the surface of the MWCNTs.
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The Journal of Physical Chemistry, 121(21), 11839-11850, (2017) |
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19. |
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The study of complexation between dicationic surfactants and the DNA duplex using structural and spectroscopic methods Dicationic (also known as gemini or dimeric) bis-alkylimidazolium surfactants belong to a group of non-viral transfection systems proposed for the successful introduction of different types of nucleic acids (i.e., siRNA, DNA oligomers, and plasmid DNA) into living cells. Our studies reveal the formation of complexes composed of dicationic (gemini) surfactants, 3,3′-[α,ω-(dioxaalkane)]bis(1-dodecylimidazolium)chlorides, and 21 base pair deoxyribonucleic acid duplexes (dsDNA). The studied dsDNA and its complex formation process was analysed by small-angle X-ray scattering (SAXS), molecular modelling (dsDNA), agarose gel electrophoresis (AGE) and circular dichroism spectroscopy (CD). We observed the formation of stable complexes for charge ratio values of p/n > 2. Moreover, we noted conformational changes similar to those observed during the transition of B-DNA to C-DNA, X-DNA, and Z-DNA in several spatial structures (i.e., micellar, hexagonal and cubic) formed in mixtures. The surfactants used in this study were investigated for the influence of dioxaalkane spacer length and the presence of an imidazolium moiety on the complexation process. The complexes formed were stable, and the complexation process was reproducible and efficient. Toxicity tests done on HeLa cells allowed for the determination of non-toxic concentrations of studied surfactants. Transfection tests have confirmed that the studied surfactant systems are effective DNA carriers.
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RSC Advances, 7(42), 26006-26018, (2017) |
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20. |
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Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode - effect of nitro peripheral groups on electrochemical properties We report on the synthesis, MS, UV-vis, NMR, HPLC and electrochemical characterization of magnesium sulfanyl porphyrazine with 2-[2-(4-nitrophenoxy) ethoxy] ethylsulfanyl substituents in the periphery. The electrochemical properties of novel macrocycle were studied by cyclic voltammetry and differential pulse voltammetry in non-aqueous electrolyte. The experimental data indicated the occurrence of clearly defined four redox couples corresponded to one-electron reactions of the pi-conjugated porphyrazine ring and substituents in the periphery. Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on a glassy carbon electrode allowed for the evaluation of the effect of nitro peripheral groups on the electrochemical properties. The electrochemical behavior of immobilized nitro porphyrazine was consistent with the reduction mechanism for the various arylnitro compounds in aqueous media, with two processes characteristic of the redox transitions of the arylnitro group to the corresponding arylhydroxylamine and/or arylhydroxylamine-arylnitroso groups.
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Journal of Porphyrins and Phthalocyanines, 21(46) SI, 295-301, (2017) |
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21. |
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Seeded growth synthesis of Au-Fe3O4 heterostructured nanocrystals: Rational design and mechanistic insights Multifunctional hybrid nanoparticles comprising two or more entities with different functional properties are gaining ample significance in industry and research. Due to its combination of properties, a particularly appealing example is Au-Fe3O4 composite nanoparticles. Here we present an indepth study of the synthesis of Au-Fe3O4 heterostructured nanocrystals (HNCs) by thermal decomposition of iron precursors in the presence of preformed 10 nm Au seeds. The role of diverse reaction parameters on the HNCs formation was investigated using two different precursors: iron pentacarbonyl (Fe(CO)(5)) and iron acetylacetonate (Fe(acac)(3)). The reaction conditions promoting the heterogeneous nucleation of Fe3O4 onto Au seeds were found to significantly differ depending on the precursor chosen, where Fe(acac)(3) is considerably more sensitive to the variation of the parameters than Fe(CO)(5) and more subject to homogeneous nucleation processes with the consequent formation of isolated iron oxide nanocrystals (NCs). The role of the surfactants was also crucial in the formation of well-defined and monodisperse HNCs by regulating the access to the Au surface. Similarly, the variations of the [Fe]/[Au] ratio, temperature, and employed solvent were found to act on the mean size and the morphology of the obtained products. Importantly, while the optical properties are rather sensitive to the final morphology, the magnetic ones are rather similar for the different types of obtained HNCs. The surface functionalization of dimer-like HNCs with silica allows their dispersion in aqueous media, opening the path to their use in biomedical applications.
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Chemistry of Materials, 29(9), 4022-4035, (2017) |
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22. |
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Synthesis and singlet oxygen generation of pyrazinoporphyrazines containing dendrimeric aryl substituents Pyrazinoporphyrazines and tribenzopyrazinoporphyrazines were synthesized and studied towards their potential applications in photodynamic therapy. The macrocycles were obtained via Linstead macrocyclization with good yields. The expansion of the porphyrazine periphery with hyperbranched aryl substituents was beneficial in terms of purification and isolation of compounds, effectively hampering their aggregation tendency in different concentrations. The obtained macrocycles were assessed for their singlet oxygen generation quantum yields and revealed far better efficacies for tribenzopyrazinoporphyrazines than pyrazinoporphyrazines. A comparison of the crystal packing of two 2,3-dicyanopyrazine derivatives revealed that the recurring motif of the supramolecular architecture is a dimer formed by pi-pi stacking interactions between aromatic pyrazine and phenyl rings of the inversion center related molecules.
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Colloids and Surfaces B: Biointerfaces, 41(9), 3586-3594, (2017) |
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23. |
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Release and cytotoxicity studies of magnetite/Ag/antibiotic nanoparticles: An interdependent relationship Though the cytotoxic properties of magnetite nanoparticles (NPs) are rather well investigated and known to be dose dependent and rather low, surface functionalization can drastically change their properties. To determine whether the cytotoxicity of magnetite/Ag/antibiotic NPs may be associated, among other things, with iron, silver and antibiotic release, this study investigates the release profiles and cytotoxicity of magnetite/Ag/rifampicin and magnetite/Ag/doxycycline NPs compares it similar profiles from magnetite, magnetite/Ag NPs and antibiotics. It was established that the studied NPs released not only water-soluble substances, such as antibiotics, but also poorly-soluble ones, such as iron and silver. The deposition of silver on the magnetite surface promotes the release of iron by the formation of a galvanic couple. Antibiotic adsorbed on the magnetite/Ag surface plays a dual role in the galvanic corrosion processes: as a corrosion inhibitor for iron oxides and as a corrosion promoter for silver. Magnetite/Ag/rifampicin and magnetite/Ag/doxycycline. NPs were found to have greater cytotoxicity towards the HEK293T cell line than magnetite NPs. These results were attributed to the combined toxic action of the released iron, silver ions and antibiotics. Intensive and simultaneous release of the NP components caused cell stress and suppressed their growth.
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Colloids and Surfaces B: Biointerfaces, 152, 85-94, (2017) |
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24. |
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An enhanced electrochemical nanohybrid sensing platform consisting of reduced graphene oxide and sulfanyl metalloporphyrazines for sensitive determination of hydrogen peroxide and L-cysteine Sulfanyl porphyrazine with isophthaloxyalkyl substituents was metallated with copper(II), cobalt(II) and iron(II) metal ions. New macrocycles were characterized using MS, UV-Vis and NMR spectroscopy. Compounds were carefully purified by column chromatography and their purity was analyzed by HPLC. According to the voltammetric analysis data, the copper(II), cobalt(II) and iron(II) sulfanyl porphyrazine complexes exhibited good electrochemical reversibility. Well-defined metal ion centered redox processes were observed for cobalt(II) and iron(II) derivatives. These compounds were considered as the electrocatalytically active complexes and immobilized by pi-pi stacking forces within the matrix of electrochemically reduced graphene oxide. The porphyrazine-graphene hybrids revealed stronger electrocatalytic performance than their separately analyzed counterparts. The electrocatalytic properties of the investigated materials were attributed to the contributions from both the reduced graphene oxide conducting matrix, and the faradaic reactions provided by porphyrazine metal complex immobilized on the electrodes. In the presence of 1 mM of L-cysteine or hydrogen peroxide, the electrocatalytic oxidation coupled with higher catalytic current with reduced overpotential, was observed at the glassy carbon/ reduced graphene oxide modified electrode. It was found that the glassy carbon/reduced graphene oxide/porphyrazine electrodes can assay L-cysteine in the linear range between 1.0 and 660 mu M (LOD of 0.79 mu M) and hydrogen peroxide in the linear range between 4.5 and 460 mu M (LOD of 4.0 mu M). The formation of the metalled porphyrazine/reduced graphene oxide hybrid is a valuable strategy in obtaining synergetic effects between the redox active macrocyclic complex and a highly conducting carbon support which has potential value for the development of advanced electrodes for electrocatalytic applications
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Dyes and Pigments, 138, 190-203, (2017) |
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25. |
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C-60 fullerenes as contrast agents - structural, spectroscopic and nano-toxicity studies Recently, C60 fullerenes have been proposed as contrast agents for MRI method [1]. Especially promising for in vitro and in vivo NMR imaging are their complexes with gadolinum (containing Gd3+ ions entrapped inside the fullerene cage) known also as gadofullerenes [2].
The general problem of carbon nanomaterials is their toxicity towards living cells [3]. The aim of our study is to devise fullerene-based suspensions characterized with low toxicity, which could later be developed into metallofullerene contrast agents. We want to achieve that goal using C60 fullerenes, pluronics to lower the toxicity and phosphatidylcholine derivatives (DMPC or DPPC) to enhance biocompatibility of fullerenes and to stimulate the cellular absorption. In this work we would like to present results of toxicity studies of C60 fullerene systems pluronic modified C60 fullerene systems towards HeLa cells, along with results of structural analyses by AFM and SEM microscopies, FTIR and SAXS. This study was supported by Ministry of Science and Higher Education (Poland), within the project, Najlepsi z najlepszych!”
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Biophysical Journal, 112(3) S1, 593A, (2017) |
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26. |
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Interactions of carbon nanotubes stabilized by selected gemini surfactants with model biomembranes Thanks to the extraordinary mechanical strength and high electrical conductivity multiwalled carbon nanotubes are currently used in electronics, medicine (as biomedical sensors, transporters or drugs) as well as in the production of lightweight and durable construction. The aim of this study was to determine the possibility to use different cationic gemini surfactants with different spacer lengths or alkyl chain lengths in more efficient systems for dispersing nanostructures in aqueous solutions. The most important advantages of these systems are their non-immunogenic, biocompatible properties and generally low toxicity . Therefore nanotubes, surrounded by surfactants, have the potential to interact with biological membranes. For this purpose we studied the influence of dispersed CN solution on the phase behavior of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) - a phospholipid most often present in membranes of nerve cells. The microstructure of the stable suspension of carbon nanotubes was investigated using high-resolution Transmission Electron Microscopy and Atomic Force Microscopy. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) were used to analyze the influence of surfactants studied, used for CN dispersion, on the phase behavior of DMPC bilayers. A series of measurements of toxicity of these systems were performed in HeLa and fibroblast cell cultures. This work was supported by the Ministry of Science and Higher Education, within the project “Najlepsi z najlepszych!” dec.
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Biophysical Journal, 112(3) S1, 77A, (2017) |
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27. |
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Spectroscopic and SAXS studies of human prion protein variants complexed with divalent cations Neurodegenerative diseases are probably the most difficult diseases to find for them a successful treatment strategy. The discovery of new potential drugs, which can be useful in the treatment of neurodegenerative diseases, require full structural characterization of all proteins involved in development of these diseases. One of the human neurodegenerative disorders is Creutzfeldt-Jakob disease (CJD). This disease is caused by misfolded (pathogenic) form of prion protein (PrP), which is a membrane protein exposed into synaptic cleft [1]. So far, the structures of several variants of prion proteins from various organisms (hamster, bovine or human) have been solved by protein crystallography and NMR. The molecule of cellular form of human PrP protein is composed of two domains: unstructured and flexible N-terminal domain containing four tandem octarepeats and structured C-terminal domain [2]. The aim of our study was to obtain the structural information for several complexes of the human prion protein. As an object of the study presented here we have chosen the cellular form of human prion protein PrPC (23-231) and its mutant form (H61A). The low resolution structures of both forms complexed with divalent cations were characterized by SAXS technique. The conformational changes of proteins studied were also detected by spectrofluorimetry, circular dichroism and NMR. This work was supported by the funds from the National Science Centre (Poland) granted on the basis of decision no. No. 2014/15/B/ST4/04839
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Biophysical Journal, 112(3) S1, 190A, (2017) |
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28. |
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Dicationic and tricationic surfactants as transgene carriers - comparison of their ability to dsdna and siRNA binding In last decades, many different compounds have been tested as potential delivery systems of nucleic acids in gene therapy. Compounds subjected for delivery of nucleic acids should be characterized by low toxicity and high ability to form stable complexes with nucleic acids. In practice they should support efficient transfer of therapeutic material (transgene) to the pathological cells. Introduced transgene by interaction with the corresponding cellular genome induce a permanent curative effect. Our previous study indicated, that good transfection properties, have three-dimensional structures formed by self-organized compounds which are structurally similar to the natural lipids. Particularly, new oligomeric amphiphiles, dicationic and tricationic surfactants, seems to be quite promising. The physicochemical properties of these compounds promote their ability to create a stable, biocompatible complexes with dsDNA and siRNA. In this work we present results of structural studies of the complexes formed on the basis of selected novel dicationic or tricationic surfactants with short nucleic acid oligomers (dsDNA and siRNA, 21 bp). These systems were examined by the use of atomic force microscopy (AFM), small angle scattering of synchrotron radiation (SR-SAXS), circular dichroism (CD) and gel electrophoresis. We performed also toxicity tests on HeLa cells. Studies have shown formation of stable systems with the desired biological and chemical properties.
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Biophysical Journal, 112(3) S1, 214A, (2017) |
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29. |
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Carbon nanostructures of different spatial geometry: their dispersion and influence on model biological systems The discovery of carbon nanostructures (CN) in the last century has revolutionized science, opening new research opportunities in biophysics, material sciences, biomedicine and pharmacology [1]. Unfortunately, carbon nanomaterials show a strong tendency towards aggregation and poor stability in solutions. Such properties, especially the suspension stability, are critical for bio-applications of carbon nanostructures [2]. Surface functionalization of nanocarbons improves the dispersing properties in water solutions but it may also influence their physicochemical properties [3]. For preparation of biocompatible CN samples we used novel dicationic surfactant (gemini) with imidazole head groups. Nanocarbon suspensions were investigated in the context of their anticancer activity, as well as their application as multimodal contrast/drug delivery agents. Different spatial geometries of CN may be of key importance for designing of the efficient anti-cancer system. Such systems were subjected to the cytotoxicity tests on HeLa cell cultures. The structural properties of selected, the most effective systems based on CN suspensions were characterized by the use of SEM, AFM and NMR methods. This study was supported by the Ministry of Science and Higher Education (Poland), within the project “Najlepsi z najlepszych!”
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Biophysical Journal, 112(3) S1, 156A, (2017) |
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30. |
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The influence of surfactant structure and geometry on nanotoxicity and dispersion of carbon nanotubes Graphene, nanotubes and fullerenes, also known as carbon nanomaterials (CN), because of the their unique properties have potential applications not only in preparation of new composite materials or in electronics, but they can be also components of drug delivery systems. However, the applications of CN in life sciences or biomedicine require stable dispersions of these materials in water. The hydrophobic nature of CN causes serious problems with their separation in water solutions. Our study is aimed to find a way of dispersing such CN systems in water, by the use of non-covalent surface modification via different surfactants. In this work we focused on the use of trimeric, dimeric and monomeric surfactants fornon-covalent surface modification of selected carbon nanotubes. The toxicity of these systems (aqueous solutions of CN with surfactants and surfactants solutions) towards selected cell cultures (e. g. HeLa cells) was also tested. The surfactants studied can interact with carbon nanotubes in a number of different modes: hydrophobic interactions (surfactant chains with CN side walls) or π-π interactions (aromatic rings of surfactants with CN surface). Infrared spectroscopy and atomic force microscopy were used for characterization of the systems studied. Finally, we focused on mechanical properties of cells exposed to surfactants and CN. This study was supported by the Ministry of Science and Higher Education (Poland), within the project “
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Biophysical Journal, 112(3) S1, 156A, (2017) |
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31. |
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Influence of silver content on rifampicin adsorptivity for magnetite/Ag/rifampicin nanoparticles Magnetite nanoparticles (NPs) decorated with silver (magnetite/Ag) are intensively investigated due to their application in the biomedical field. We demonstrate that the increase of silver content on the surface of nanoparticles improves the adsorptivity of antibiotic rifampicin as well as antibacterial properties. The use of ginger extract allowed to improve the silver nucleation on the magnetite surface that resulted in an increase of silver content. Physicochemical and functional characterization of magnetite/Ag NPs was performed. Our results show that 5%-10% of silver content in magnetite/Ag NPs is already sufficient for antimicrobial properties against Streptococcus salivarius and Staphylococcus aureus. The rifampicin molecules on the magnetite/Ag NPs surface made the spectrum of antimicrobial activity wider. Cytotoxicity evaluation of the magnetite/Ag/rifampicin NPs showed no harmful action towards normal human fibroblasts, whereas the effect on human embryonic kidney cell viability was time and dose dependent.
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Nanotechnology, 28(5), 055603, (2017) |
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32. |
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Nucleoplasmin-like domain of FKBP39 from Drosophila melanogaster forms a tetramer with partly disordered tentacle-like C-terminal segments Nucleoplasmins are a nuclear chaperone family defined by the presence of a highly conserved N-terminal core domain. X-ray crystallographic studies of isolated nucleoplasmin core domains revealed a β-propeller structure consisting of a set of five monomers that together form a stable pentamer. Recent studies on isolated N-terminal domains from Drosophila 39-kDa FK506-binding protein (FKBP39) and from other chromatin-associated proteins showed analogous, nucleoplasmin-like (NPL) pentameric structures. Here, we report that the NPL domain of the full-length FKBP39 does not form pentameric complexes. Multi-angle light scattering (MALS) and sedimentation equilibrium ultracentrifugation (SE AUC) analyses of the molecular mass of the full-length protein indicated that FKBP39 forms homotetrameric complexes. Molecular models reconstructed from small-angle X-ray scattering (SAXS) revealed that the NPL domain forms a stable, tetrameric core and that FK506-binding domains are linked to it by intrinsically disordered, flexible chains that form tentacle-like segments. Analyses of full-length FKBP39 and its isolated NPL domain suggested that the distal regions of the polypeptide chain influence and determine the quaternary conformation of the nucleoplasmin-like protein. These results provide new insights regarding the conserved structure of nucleoplasmin core domains and provide a potential explanation for the importance of the tetrameric structural organization of full-length nucleoplasmins.
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Scientific Reports, 40405, (2017) |
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33. |
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The severe impact of in vivo-like microfluidic flow and the influence of gemini surfactants on amyloid aggregation of hen egg white lysozyme The formation of amyloid plaques is being intensively studied, as this process underlies severe human diseases, including Alzheimer's disease, and the exact mechanism of this specific aggregation has not been resolved yet. The investigation of its formation is accompanied by the search for substances inhibiting this aggregation process. Here we studied the process of hen egg white lysozyme (HEWL) amyloid aggregation process in bulk solution within a time scale of about a week. We also examined the influence of four dicationic (gemini) surfactants, including 3,3′-[1,6-(2,5-dioxahexane)]bis-(1-dodecylimidazolium) dichloride (oxyC2), as well as selected reference sulfobetaines, on the aggregation process and found that at certain concentrations gemini surfactants remarkably inhibited amyloidogenesis. A microfluidic system was designed to mimic the in vivo-like conditions of flow in order to assess the influence of flow on the amyloid formation process. The flow was found to induce severe amyloid formation in just a few hours of exposition to the conditions which without flow would induce amyloidogenesis within a few days. The results shed light on the mechanisms responsible for the amyloid aggregation process and make an important contribution to understanding of the process.
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RSC Advances, 7, 10973-10984, (2017) |
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34. |
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Plant epigenetics This book presents, in 26 chapters, the status quo in epigenomic profiling. It discusses how functional information can be indirectly inferred and describes the new approaches that promise functional answers, collectively referred to as epigenome editing. It highlights the latest important advances in our understanding of the functions of plant epigenomics and new technologies for the study of epigenomic marks and mechanisms in plants. Topics include the deposition or removal of chromatin modifications and histone variants, the role of epigenetics in development and response to environmental signals, natural variation and ecology, as well as applications for epigenetics in crop improvement. Discussing areas ranging from the complex regulation of stress and heterosis to the precise mechanisms of DNA and histone modifications, it presents breakthroughs in our understanding of complex phenotypic phenomena.
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Diagnostics. Book Series: RNA Technologies, Rajewski N., Jurga S., Barciszewski J. (Eds.),, V-VII, Springer-Verlag Berlin, Heidelberger Platz 3, d-14197 Berlin, Germany, (2017) |
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35. |
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Synthesis of G0 aminopolyol and aminosugar dendrimers, controlled by NMR and MALDI TOF mass spectrometry Organic compounds designed to serve as stable dendrimer cores were developed. A series of aminosugar and amino polyol containing G0 dendrimers were synthesized. The reaction mixture composition was checked by MALDI TOF mass spectrometry, while that of purified products - by H-1 and C-13 NMR combined with 2D NMR spectroscopy as well as MALDI TOF MSMS mass spectra. Mass spectrometric fragmentation experiments were performed in positive ion mode in order to determine common fragmentation patterns of [M+H](+) ions.
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Designed Monomers and Polymers, 20, 144-156, (2017) |
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Zaktualizowano: podstrony 2021-06-21 / bazę danych: 2024-04-23 by Webmaster: Zbigniew Fojud