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1.

Coy E., Yate L., Kabacińska Z., Jancelewicz M., Jurga S., Iatsunskyi I.

Topographic reconstruction and mechanical analysis of atomic layer deposited Al2O3/TiO2 nanolaminates by nanoindentation A novel method of nanomechanical testing of multilayered Al2O3/TiO2 nanolaminates was implemented by the nanoindentation technique. The indentation data were reconstructed and filtered by a statistical analysis algorithm and presented as a function of the penetration depth of the indenter. Results show the increment of mechanical properties on the laminates as a function of the amorphous interfaces of the individual layers and the effective control of the wear rate of the structures for further applications. The results presented show both important insights on the mechanical behavior of nanolaminates and the further applicability of the reconstruction model for error reduction on mechanical testing of nanolaminate samples.

Materials & Design, 111 , 584-591 (2016)

DOI: 10.1016/j.matdes.2016.09.030   (Pobrano:  aktualizowanie)


2.

Jaroszewski K., Chrunik M., Głuchowski P.Coy E., Maciejewska B., Jastrząb R., Majchrowski A., Kasprowicz D.

Photoluminescence properties of Pr3+ doped Bi2ZnOB2O6 microcrystals and PMMA-based composites Photoluminescence properties of red-emitting Pr3+-doped Bi2ZnOB2O6 microcrystalline powder and PMMA-based composite materials were reported. Bi2ZnOB2O6:Pr3+ powders were synthesized by means of the modified Pechini method. The morphology and crystallographic structure of Bi2ZnOB2O6:Pr3+ microcrystals were investigated by XRD and HRTEM. The PMMA-based composite materials were prepared by embedding of Bi2ZnOB2O6:Pr3+ powder in the PMMA matrix. The vibrational properties of the powder and composite systems were investigated by ?-Raman spectroscopy. Emission spectra of the samples were measured under blue (451.6 nm) and UV (320 nm) excitation. Both, the powder and composite samples show enhancement of red emission (1D2 ? 3H4) and quenching of greenish-blue luminescence from 3P0 level of Pr3+ ions after excitation in UV and VIS caused by the 3P0 ~ 1D2 non-radiative relaxation of Pr3+ ion by low-lying charge transfer state and non-radiative de-excitation through Pr3+-Bi3+ energy transfer. The response of the powder and composite samples to pulsed excitation at 451.6 nm was measured by monitoring emission from the 1D2 level (595 nm/3P0 ? 3H6 transition). The determined lifetimes ?1 and ?2 of the red emission at 595 nm (1D2 ? 3H4 transition) of the composite are significantly longer in comparison to powder samples. Moreover, because of the good nonlinear optical properties of the Bi2ZnOB2O6 crystals and effective luminescence of the Pr3+-doped Bi2ZnOB2O6 powders and composites, they can be very useful as bi-functional materials in the new generation of optoelectronic devices.

Optical Materials, 62 , 72-79 (2016)

DOI: 10.1016/j.optmat.2016.09.059   (Pobrano:  aktualizowanie)


3.

Warowicka A., Maciejewska B.M., Litowczenko J., Kościński M., Baranowska-Korczyc A., Jasiurkowska-Delaporte M., Kozioł K., Jurga S.

MWCNT based matrices as a platform for adhesion and growth of cells In this study we examine multiwall carbon nanotube (MWCNT) based nanosystems i.e. aligned MWCNT matrices, as potential scaffolds for cell growth and tissue engineering. We present the effect of samples purification and surface modification on the viability, adhesiveness and morphology of human normal gingival fibroblasts (HGF-1) and human osteosarcoma (U2OS) cell lines. We employ spectroscopic and analytical techniques (Scanning Electron Microscopy, Thermal Gravimetric Analysis, Atomic Force Microscopy, Raman and Fourier Transform Infrared Absorption Spectroscopy and Confocal Microscopy) in order to characterize the obtained structures. Furthermore, we analyze the expression level of selected cell adhesion-related genes by the quantitative real-time (qRT-PCR) method and the cell viability for MWCNT powders. We show that the surface structure of MWCNTs carpets contributes to the adhesion of cells. Additionally, we report the increased expression level of integrin, talin and fibronectin, proteins which are involved in cell attachment. We speculate that carbon nanotube based materials can be consider as potential candidates for biomedical purposes and as a biocompatible scaffold for cell growth

Composites Science and Technology, 136 , 29-38 (2016)

DOI: 10.1016/j.compscitech.2016.09.026   (Pobrano:  aktualizowanie)


4.

Shypylenko A., Pshyk A.V., Grześkowiak B., Medjanik K., Peplińska B., Oyoshi K., Pogrebnjak A., Jurga S., Coy E.

Effect of ion implantation on the physical and mechanical properties of Ti-Si-N multifunctional coatings for biomedical applications In the present work, multifunctional Ti-Si-N coatings have been deposited using CAVD method with the aim of studying their chemical, physical, structural and mechanical properties. Coatings of Ti-Si-N were modified by high-intensity ion implantation using copper ions with dose D = 2 x 10(17) ions/cm(2) and energy E = 60 keV. The results demonstrated that ion implantation has an effect on the grain size, hardness, and Young modulus of the Ti-Si-N coating. Additionally, the effect of Cu implantation on the bioactive properties of coatings was investigated by contact antimicrobial essay. The results show a high release of Cu ions in the cultivation liquid and the low efficiency of the <20% Cu doping towards E. coli bacteria. Our results bring understanding to the low dosage ion implantation of multifunctional surfaces towards applications and general drawbacks of ion implantation as bioactive tailoring method.

Materials & Design, 110 , 821-829 (2016)

DOI: 10.1016/j.matdes.2016.08.050   (Pobrano:  aktualizowanie)


5.

Falkowski M., Rębiś T., Piskorz J., Popenda Ł., Jurga S., Mielcarek J., Milczarek G., Gośliński T.

Improved electrocatalytic response toward hydrogen peroxide reduction of sulfanyl porphyrazine/multiwalled carbon nanotube hybrids deposited on glassy carbon electrodes We report on the synthesis, physico-chemical properties of magnesium sulfanyl porphyrazine derivatives with peripheral hyperbranched groups and their deposition on the multi-walled carbon nanotube surface. Sulfanyl porphyrazines containing bulky and dendrimeric peripheral benzyloxy units, mers, up to their second generation, were synthesized and characterized using MS, UV-Vis, FT-IR, NMR spectroscopy and HPLC. The morphology of the hybrid nanostructures was researched using SEM and AFM microscopy. Their potential for biomedicine and technology was assessed in an electrochemical study. The electrodes modified with dendrimeric sulfanyl porphyrazine/multiwalled carbon nanotube hybrids were utilized for electrocatalytic determination of hydrogen peroxide, which is an important compound generated in many enzymatic reactions. The strong synergistic effect between two nanostructural components, namely multi-walled carbon nanotubes and dendrimeric porphyrazines was evaluated in the electrochemical study. In the result a significant enhancement of electrochemical properties of the modified electrode was observed. The reversible redox couples derived from porphyrazine ring based electron transfer were responsible for the improvement of the electrocatalytic response of the modified electrode toward hydrogen peroxide reduction. According to the electrochemical results, multi-walled carbon nanotube - dendrimeric porphyrazine hybrids deposited on the surface of glassy carbon electrode constitute a valuable material for enzyme free biosensor development.

Dyes and Pigments, 134 , 569-579 (2016)

DOI: 10.1016/j.dyepig.2016.08.014   (Pobrano:  aktualizowanie)


6.

Szczeszak A., Ekner-Grzyb A., Runowski M., Szutkowski K., Mrówczyńska L., Kaźmierczak Z., Grzyb T., Dąbrowska K., Giersig M., Lis S.

Spectroscopic, structural and in vitro cytotoxicity evaluation of luminescent, lanthanide doped core@shell nanomaterials GdVO4:Eu(3+)5%@SiO2@NH2 The luminescent GdVO4:Eu(3+)5%@SiO2@NH2 core@shell nanomaterials were obtained via co-precipitation method, followed by hydrolysis and co-condensation of silane derivatives: tetraethyl orthosilicate and 3-aminopropyltriethoxysilane. Their effect on human erythrocytes sedimentation and on proliferation of human lung microvascular endothelial cells was examined and discussed. The luminescent nanopartides were synthesized in the presence of polyacrylic acid or glycerin in order to minimalize the agglomeration and excessive growth of nanostructures. Surface coating with amine functionalized silica shell improved their biocompatibility, facilitated further organic conjugation and protected the internal core. Magnetic measurements revealed an enhanced T-1-relaxivity for the synthesized GdVO4:Eu(3+)5% nanostructures. Structure, morphology and average grain size of the obtained nanomaterials were determined by X-ray diffraction, transmission electron microscopy and dynamic light scattering analysis. The qualitative elemental composition of the nanomaterials was established using energy-dispersive X-ray spectroscopy. The spectroscopic characteristic of red emitting core@shell nanophosphors was completed by measuring luminescence spectra and decays. The emission spectra revealed characteristic bands of Eu3+ ions related to the transitions D-5(0)-F-7(0,1,2,3,4) and D-5(1)-F-7(1). The luminescence lifetimes consisted of two components, associated with the presence of Eu3+ ions located at the surface of the crystallites and in the bulk.

Journal of Colloid and Interface Science, 481 , 245-255 (2016)

DOI: 10.1016/j.jcis.2016.07.025   (Pobrano:  aktualizowanie)


7.

Leszczyński B., Hadjipanayis G.C., El-Gendy A.A., Zaleski K., Śniadecki Z., Musiał A., Jarek M., Jurga S., Skumiel A.

The influence of oxidation process on exchange bias in egg-shaped FeO/Fe3O4 core/shell nanoparticles Egg-shaped nanoparticles with a core shell morphology were synthesized by thermal decomposition of an iron oleate complex. XRD and M(T) magnetic measurements confirmed the presence of FeO (wustite) and Fe3O4 (magnetite) phases in the nanoparticles. Oxidation of FeO to Fe3O4 was found to be the mechanism for the shell formation. As-made nanoparticles exhibited high values of exchange bias at 2 K. Oxidation led to decrease of exchange field from 2880 Oe (in as-made sample) to 330 Oe (in oxidized sample). At temperatures higher than the Neel temperature of FeO (200 K) there was no exchange bias. An interesting observation was made showing the exchange field to be higher than the coercive field at temperatures close to magnetite's Verwey transition.

Journal of Magnetism and Magnetic Materials, 416 , 269-274 (2016)

DOI: 10.1016/j.jmmm.2016.05.023   (Pobrano:  aktualizowanie)


8.

Masewicz Ł., Lewandowicz J., Le Thanh-Blicharz J., Kempka M., Baranowska H.M.

Diffusion of water in potato starch pastes The aim of the work was to describe water transport in two-component biopolymer-water systems on the basis of water activity measurements. Research material consisted oi physically (drum dried) and differently chemically modified starches (E1404, E1412, E1414, E1422). A phenomenological model was proposed which takes into consideration water transport in the gel and surface effects associated with evaporation. It was found, that water molecules in such systems undergo diffusion in two phases. Moreover, utilization of comprehensive results of water activity measurements as well as the model proposed in this study provide detailed analysis of water transport mechanism in starch gels.

Proceedings of the 12th International Conference on Polysacch arides-Glycoscience - Czech Chemical Society, , 193-195 (2016)

ISBN: 978-80-86238-59-3   (Pobrano:  2017-11-06)


9.

Przysiecka Ł., Michalska M., Nowaczyk G., Peplińska B., Jesionowski T., Schneider R., Jurga S.

iRGD peptide as effective transporter of CuInZnxS2+x quantum dots into human cancer cells In this paper, iRGD peptide-mediated quantum dots (QDs) delivery was studied. In the first step, dodecanethiol-capped CulnZn(x)S(2+x) (ZCIS) QDs were prepared and subsequently transferred into water using a standard and facile ligand exchange approach involving 3-mercaptopropionic acid (MPA). ZCIS@MPA nanocrystals possess a photoluminescence quantum yield (PL QY) of 25%, a PL emission centered at ca. 640nm and low distributions in size and shape. Next, the iRGD peptide was electrostatically associated to ZCIS@MPA QDs. After cytotoxicity evaluation, the tumor-targeting and penetrating activities of the iRGD/QD assembly were investigated by confocal microscopy. The experiments performed on various cancer cell lines revealed a high penetration ability of the assembly, while the bare QDs were not internalized. Additionally, imaging experiments were conducted on three-dimensional multicellular tumor spheroids in order to mimic the tumor microenvironment in vivo. iRGD/QD assemblies were found to be evenly distributed throughout the whole HeLa spheroid contrary to normal cells where they were not present. Therefore, iRGD/QD assemblies have a great potential to be used as targeted imaging agents and/or nanocarriers specific to cancer cells.

Colloids and Surfaces B: Biointerfaces, 146 , 9-18 (2016)

DOI: 10.1016/j.colsurfb.2016.05.041   (Pobrano:  aktualizowanie)


10.

Coy E., Yale L., Kabacińska Z., Jancelewicz M., Jurga S., Iatsunskyi I.

Topographic reconstruction and mechanical analysis of atomic layer deposited Al2O3/TiO2 nanolaminates by nanoindentation A novel method of nanomechanical testing of multilayered Al2O3/TiO2 nanolaminates was implemented by the nanoindentation technique. The indentation data were reconstructed and filtered by a statistical analysis algorithm and presented as a function of the penetration depth of the indenter. Results show the increment of mechanical properties on the laminates as a function of the amorphous interfaces of the individual layers and the effective control of the wear rate of the structures for further applications. The results presented show both important insights on the mechanical behavior of nanolaminates and the further applicability of the reconstruction model for error reduction on mechanical testing of nanolaminate samples.

Materials and Design, 111 , 584-591 (2016)

DOI: 10.1016/j.matdes.2016.09.030   (Pobrano:  aktualizowanie)


11.

Kolonko M., Ożga K., Hołubowicz R., Taube M., Kozak M., Ożyhar A., Greb-Markiewicz B.

Intrinsic disorder of the C-terminal domain of drosophila methoprene-tolerant protein Methoprene tolerant protein (Met) has recently been confirmed as the long-sought juvenile hormone (JH) receptor. This protein plays a significant role in the cross-talk of the 20-hydroxyecdysone (20E) and JH signalling pathways, which are important for control of insect development and maturation. Met belongs to the basic helix-loop-helix/Per-Arnt-Sim (bHLH-PAS) family of transcription factors. In these proteins, bHLH domains are typically responsible for DNA binding and dimerization, whereas the PAS domains are crucial for the choice of dimerization partner and the specificity of target gene activation. The C-terminal region is usually responsible for the regulation of protein complex activity. The sequence of the Met C-terminal region (MetC) is not homologous to any sequence deposited in the Protein Data Bank (PDB) and has not been structurally characterized to date. In this study, we show that the MetC exhibits properties typical for an intrinsically disordered protein (IDP). The final averaged structure obtained with small angle X-ray scattering (SAXS) experiments indicates that intrinsically disordered MetC exists in an extended conformation. This extended shape and the long unfolded regions characterise proteins with high flexibility and dynamics. Therefore, we suggest that the multiplicity of conformations adopted by the disordered MetC is crucial for its activity as a biological switch modulating the cross-talk of different signalling pathways in insects.

PloS ONE, 11(9) , 598-606 (2016)

DOI: 10.1371/journal.pone.0162950   (Pobrano:  aktualizowanie)


12.

Coy E. Yateb L., Kabacińska Z., Jancelewicz J., Jurga S., Iatsunskyi I.

Topographic reconstruction and mechanical analysis of atomic layerdeposited Al2O3/TiO2nanolaminates by nanoindentation A novel method of nanomechanical testing of multilayered Al2O3/TiO2 nanolaminates was implemented by the nanoindentation technique. The indentation data were reconstructed and ?ltered by a statistical analysis algorithm and presented as a function of the penetration depth of the indenter. Results show the increment of mechanical properties on the laminates as a function of the amorphous interfaces of the individual layers and the effective control of the wear rate of the structures for further applications. The results presented show both important insights on the mechanical behavior of nanolaminates and the further applicability of the reconstruction model for error reduction on mechanical testing of nanolaminate samples. boratory efficiencies of dye-sensitized

Materials and Design, 111 , 584-591 (2016)

DOI: 10.1016/j.matdes.2016.09.030   (Pobrano:  aktualizowanie)


13.

Pogrebnjak A.D., Bondar O.V., Abadias G., Ivashchenko V., Sobol O.V., Jurga S., Coy E.

Structural structural and mechanical properties of NbN and Nb-Si-N films: Experiment and molecular dynamics simulations The structural and mechanical properties of NbN and Nb-Si-N films have been investigated both experimentally and theoretically, in their as-deposited and annealed states. The films were deposited using magnetron sputtering at substrate bias (U-B) between 0 and -70 V. While NbN films were found to crystallize in the cubic delta-NbN structure, Nb-Si-N films with Si content of 11-13 at% consisted of a two phases nanocomposite structure where delta-NbN nanocrystals were embedded in SiNx amorphous matrix. Films deposited at U-B = 0 V were highly (001)-textured. Application of substrate bias potential led to a depletion of light atoms, and caused a grain size refinement concomitantly with the increase of (111) preferred orientations in both films. The maximum hardness was 28 GPa and 32 GPa for NbN and Nb-Si-N films, respectively. NbN and Nb-Si-N filais deposited at U-B = -70 V exhibited compressive stress of -3 and -4 GPa, respectively. After vacuum annealing, a decrease in the stress-free lattice parameter was observed for both films, and attributed to alteration of film composition. To obtain insights on interface properties and related mechanical and thermal stability of Nb-Si-N nanocomposite films, first principles molecular dynamics simulations of NbN/SiNx heterostructures with different structures (cubic and hexagonal) and atomic configurations were carried out. All the hexagonal heterostructures were found to be dynamically stable and weakly dependent on temperature. Calculation of the tensile strain-stress curves showed that the values of ideal tensile strength for the delta-NbN(111)- and epsilon-NbN(001)-based heterostructures with coherent interfaces and Si3N4-like Si2N3 interfaces were the highest with values in the range 36-65 GPa, but lower than corresponding values of bulk NbN compound. This suggests that hardness enhancement is likely due to inhibition of dislocation glide at the grain boundary rather than interfacial strengthening due to Si-N chemical bonding. (C) 2016 Elsevier Ltd and Techna Group S.r.l.

Ceramics International, 42(10) , 11743-11756 (2016)

DOI: 10.1016/j.ceramint.2016.04.095   (Pobrano:  aktualizowanie)


14.

Gurzęda B., Florczak P., Wiesner M., Kempiński M., Jurga S., Krawczyk P.

Graphene material prepared by thermal reduction of the electrochemically synthesized graphite oxide In the present work we demonstrate a simple and effective way to produce bulk quantities of graphene material. For the first time, graphite oxide (GO), synthesized by electrochemical treatment of natural graphite in HClO4 aqueous solution, was used to obtain thermally exfoliated-reduced graphite oxide (TRGO). Herein, GO was thermally exfoliated and reduced at 500 degrees C in air, giving the final product of TRGO. Due to shock treatment, the volume of the synthesized TRGO drastically increased compared to the starting GO. Furthermore, the exfoliation process resulted in a significant decrease in the concentration of oxygen functionalities. The choice of GO exfoliation temperature was preceded by thermogravimetric analysis (TGA). TRGO was characterized using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis.

RSC Advances, 6(67) , 63058-63063 (2016)

DOI: 10.1039/c6ra10903a   (Pobrano:  aktualizowanie)


15.

Andrzejewska W., Pietralik Z., Skupin M., Kozak M.

Structural studies of the formation of lipoplexes between siRNA and selected bis-imidazolium gemini surfactants Dicationic (gemini) surfactants are agents that can be used for the preparation of stable complexes of nucleic acids, particularly siRNA for therapeutic purposes. In this study, we demonstrated that bis-imidazolium gemini surfactants with variable lengths of dioxyalkyl linker groups (from dioxyethyl to dioxydodecyl) and dodecyl side chains are excellent for the complexation of siRNA. All of these compounds effectively complexed siRNA in a charge ratio range (p/n) of 1.5-10. The low resolution structure of siRNA oligomers was characterised by small angle scattering of synchrotron radiation (SR-SAXS) and ab initio modelling. The structures of the formed complexes were also analysed using SR-SAXS, circular dichroism studies and electrophoretic mobility tests. The most promising agents for complexation with siRNA were the surfactants that contained dioxyethyl and dioxyhexyl spacer groups.

Colloids and Surfaces B: Biointerfaces, 146 , 598-606 (2016)

DOI: 10.1016/j.colsurfb.2016.06.062   (Pobrano:  2016-10-11)


16.

Pavlenko M., Myndrul V., Iatsunskyi I., Jurga S., Smyntyna V.

Study on structural and optical properties of TiO2 ALD coated silicon nanostructures Structural and optical properties of TiO2 ALD coated silicon nanostructures were investigated. The morphology and chemical composition of TiO2 coated silicon nanopillars and porous silicon were studied by using methods of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Optical characteristics were studied using measurements of reflectance and luminescence spectra. Detailed analysis of morphological features and photoluminescence mechanisms were provided. Peculiarities of reflectance spectra were discussed. It was shown the possible application of these structures as antireflectance coatings.

Proceedings of SPIE - Nanophotonics VI, ISBN: 9781510601291, 9884 , 98842H (2016)

DOI: 10.1117/12.2227122   (Pobrano:  aktualizowanie)


17.

Jastrzębska K., Felcyn E., Kozak M., Szybowicz M., Buchwald T., Pietralik Z., Jesionowski T., Mackiewicz A., Dams-Kozłowska H.

The method of purifying bioengineered spider silk determines the silk sphere properties Bioengineered spider silks are a biomaterial with great potential for applications in biomedicine. They are biocompatible,biodegradable and can self-assemble into films, hydrogels, scaffolds, fibers, capsules and spheres. A novel, tag-free, bioengineered spider silk named MS2(9x) was constructed. It is a 9-mer of the consensus motif derived from MaSp2- the spidroin of Nephila clavipes dragline silk. Thermal and acidic extraction methods were used to purify MS2(9x). Both purification protocols gave a similar quantity and quality of soluble silk; however, they differed in the secondary structure and zeta potential value. Spheres made of these purified variants differed with regard to critical features such as particle size, morphology, zeta potential and drug loading. Independent of the purification method, neither variant of the MS2(9x) spheres was cytotoxic, which confirmed that both methods can be used for biomedical applications. However, this study highlights the impact that the applied purification method has on the further biomaterial properties.

Scientific Reports, 6 , 28106, 1-15 (2016)

DOI: 10.1038/srep28106   (Pobrano:  aktualizowanie)


18.

Reyes Y.C., Coy L.E., Yate L., Jurga S., Gonzalez E.E.

Nanostructured and selective filter to improve detection of arsenic on surface plasmon nanosensors The development of a pretreatment system to assist surface plasmon sensor-based measurement of arsenic in water is described. The system proposed addresses important issues, regarding the reliable in situ detection of arsenic in water. This system uses a primary filter made of nonactivated cotton fibers for particulate matter and chemical retention agents without modifying the arsenic concentration in the water sample. A secondary filter was designed for retention of mercury, lead, and other heavy metals without alteration of the arsenic concentration in the collected water samples to be sensed. This filter was made with amino-functionalized carbon nanotubes. The results of the operational assessment of this filter show a retention efficiency of 98% for suspended solids, 96% for mercury ions, and 2% for arsenic, a remarkable improvement toward the accurate detection and quantification of arsenic in contaminated waters.

ACS Sensors, 1(6) , 725-731 (2016)

DOI: 10.1021/acssensors.6b00211   (Pobrano:  aktualizowanie)


19.

Skupin M., SobczaK, K., Zieliński R., Kozak M.

The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid-A structural and spectroscopic study Systems suitable for the effective preparation of complexes with siRNA (small interfering RNA) are at the center of interest in the area of research work on the delivery of the RNA-based drugs (RNA-therapeutics). This article presents results of a study on the structural effects associated with siRNA complexation by a surfactant comprising a lactose group (N-(3-propanesulfone)-N-dodecyl-amino-beta-D-lactose hydrochloride, LA12). The double stranded siRNA oligomer (21 base pairs) used in this study is responsible for silencing a gene that can be important in the therapy of myotonic dystrophy type 1. The obtained siRNA/LA12 lipoplexes were studied using the methods of small angle scattering of synchrotron radiation, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, and electrophoretic mobility tests. Lipoplexes form in solution stable lamellar or cubic phases. The surfactant selected for the study shows much lower cytotoxicity and good complexation abilities of siRNA than dicationic or polycationic surfactants.

Applied Physics Letters, 108 , 213701 (2016)

DOI: 10.1063/1.4952589   (Pobrano:  aktualizowanie)


20.

Pietralik Z., Skrzypczak A., Kozak M.

Dicationic surfactants with glycine counter ions for oligonucleotide transportation Gemini surfactants are good candidates to bind, protect, and deliver nucleic acids. Herein, the concept of amino acids (namely glycine) as counter ions of gemini surfactants for gene therapy application was explored. This study was conducted on DNA and RNA oligomers and two quaternary bis-imidazolium salts, having 2,5-dioxahexane and 2,8-dioxanonane spacer groups. The toxicity level of surfactants was assessed by an MTT assay, and their ability to bind nucleic acids was tested through electrophoresis. The nucleic acid conformation was established based on circular dichroism and infrared spectroscopic analyses. The structures of the formed complexes were characterized by small-angle scattering of synchrotron radiation. Both studied surfactants appear to be suitable for gene therapy; however, although they vary by only three methylene groups in the spacer, they differ in binding ability and toxicity. The tested oligonucleotides maintained their native conformations upon surfactant addition and the studied lipoplexes formed a variety of structures. In systems based on a 2,5-dioxahexane spacer, a hexagonal phase was observed for DNA-surfactant complexes and a micellar phase was dominant with RNA. For the surfactant with a 2,8-dioxanonane spacer group, the primitive cubic phase prevailed.

ChemPhysChem, 17 , 2424-2433 (2016)

DOI: 10.1002/cphc.201600175   (Pobrano:  aktualizowanie)


21.

Młynarczyk D.T., Lijewski S., Falkowski M., Piskorz J., Szczółko W., Sobotta Ł., Stolarska M., Popenda Ł., Jurga S., Konopka K., Duzgunes N., Mielcarek J., Goślinski T,

Dendrimeric sulfanyl porphyrazines: synthesis, physico-chemical characterization, and biological activity for potential applications in photodynamic therapy Sulfanyl porphyrazines substituted at their periphery with different dendrimeric moieties up to their first generation were synthesized and characterized by photochemical and biological methods. The presence of a dendrimeric periphery enhanced the spectral properties of the porphyrazines studied. The singlet-oxygen-generation quantum yield of the obtained macrocycles ranged from 0.02 to 0.20 and was strongly dependent on the symmetry of the compounds and the terminal groups of the dendritic outer shell. The in vitro biological effects of three most promising tribenzoporphyrazines were examined; the results indicated their potential as photosensitizers for photodynamic therapy (PDT) against two oral squamous cell carcinoma cell lines derived from the tongue. The highest photocytotoxicity was found for sulfanyl tribenzoporphyrazine that possessed 4-[3,5-di(hydroxymethyl) phenoxy] butyl substituents with nanomolar IC50 values at 10 and 42 nm against CAL 27 and HSC-3 cell lines, respectively.

ChemPlusChem, 81(5) , 460-470 (2016)

DOI: 10.1002/cplu.201600051   (Pobrano:  aktualizowanie)


22.

Baranowska-Korczyc A., Jasiurkowska-Delaporte M., Maciejewska B.M., Warowicka A., Coy L.E., Zalewski T., Kozioł K.K., Jurga S.

PEG-MWCNT/Fe hybrids as multi-modal contrastagents for MRI and optical imaging This study examines the use of oxidized multi-walled carbon nanotube/iron (O-MWCNT/Fe) nanohybrids modified with polyethylene glycol (PEG) as multifunctional cellular imaging agents for magnetic resonance imaging (MRI) and fluorescence microscopy. The PEGylated MWCNTs with embedded iron particles were investigated as T2-weighted contrast agents for MRI. The number of PEG molecules attached to the MWCNT surface was calculated. The PEG-MWCNT/Fe complex was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared and Raman spectroscopies. Covalent surface modification of the MWCNTs improves their solubility and enables the attachment of further biomolecules to their surface. The PEGylated nanostructures were labeled with the MDC organic dye and internalized inside HeLa cells for cellular imaging. Additionally, the minima cytotoxic effect of PEGylated complexes in comparison to non-PEGylated samples was measured Rusing the WST-1 test and an In Cell Analyzer. A confocal microscopy study of the organelle morphology also confi rmed that the HeLa cell morphology was unchanged after treatment with PEGylated MWCs.

RSC Advances, 6(55) , 49891-49902 (2016)

DOI: 10.1039/c6ra09191a   (Pobrano:  aktualizowanie)


23.

Grześkowiak B., Hryhorowicz M., Tuśnio K., Grzeszkowiak M., Zaleski K., Lipiński D., Zeyland J., Mykhaylyk Olga., Słomski R., Jurga S., Woźniak A.

Generation of transgenic porcine fibroblast cell lines using nanomagnetic gene delivery vectors The transgenic process allows for obtaining genetically modified animals for divers biomedical applications. A number of transgenic animals for xenotransplantation have been generated with the somatic cell nuclear transfer (SCNT) method. Thereby, efficient nucleic acid delivery to donor cells such as fibroblasts is of particular importance. The objective of this study was to establish stable transgene expressing porcine fetal fibroblast cell lines using magnetic nanoparticle-based gene delivery vectors under a gradient magnetic field. Magnetic transfection complexes prepared by self-assembly of suitable magnetic nanoparticles, plasmid DNA, and an enhancer under an inhomogeneous magnetic field enabled the rapid and efficient delivery of a gene construct (pCD59-GFPBsd) into porcine fetal fibroblasts. The applied vector dose was magnetically sedimented on the cell surface within 30min as visualized by fluorescence microscopy. The PCR and RT-PCR analysis confirmed not only the presence but also the expression of transgene in all magnetofected transgenic fibroblast cell lines which survived antibiotic selection. The cells were characterized by high survival rates and proliferative activities as well as correct chromosome number. The developed nanomagnetic gene delivery formulation proved to be an effective tool for the production of genetically engineered fibroblasts and may be used in future in SCNT techniques for breeding new transgenic animals for the purpose of xenotransplantation.

Molecular Biotechnology, 58(5) , 351-61 (2016)

DOI: 10.1007/s12033-016-9934-1   (Pobrano:  aktualizowanie)


24.

Robak E., Coy E., Kotkowiak M., Jurga S., Zaleski K., Drozdowski H.

The effect of Cu doping on the mechanical and optical properties of zinc oxide nanowires synthesized by hydrothermal route Zinc oxide (ZnO) is a wide-bandgap semiconductor material with applications in a variety of fields such as electronics, optoelectronic and solar cells. However, much of these applications demand a reproducible, reliable and controllable synthesis method that takes special care of their functional properties. In this work ZnO and Cu-doped ZnO nanowires are obtained by an optimized hydrothermal method, following the promising results which ZnO nanostructures have shown in the past few years. The morphology of as-prepared and copper-doped ZnO nanostructures is investigated by means of scanning electron microscopy and high resolution transmission electron microscopy. X-ray diffraction is used to study the impact of doping on the crystalline structure of the wires. Furthermore, the mechanical properties (nanoindentation) and the functional properties (absorption and photoluminescence measurements) of ZnO nanostructures are examined in order to assess their applicability in photovoltaics, piezoelectric and hybrids nanodevices. This work shows a strong correlation between growing conditions, morphology, doping and mechanical as well as optical properties of ZnO nanowires.

Nanotechnology, 27(17) , 175706 (2016)

DOI: 10.1088/0957-4484/27/17/175706   (Pobrano:  aktualizowanie)


25.

Wieczorek E., Gierszewski M., Popenda Ł., Tykarska E., Gdaniec M., Jurga S., Sikorski M., Mielcarek J., Piskorz J., Gośliński T.

Synthesis, characterization and photophysical properties of novel 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles Three 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles with bulky 2-(3,5-dibromophenyl)ethenyl, 2-(4-tert-butylphenyl)ethenyl and 2-(3,5-dibenzyloxyphenyl)ethenyl substituents were synthesized and characterized using UV-Vis, MS ES, elemental analysis and NMR spectroscopy. NMR data indicated that diazepine rings of all obtained compounds adopted 6H-tautomeric form. In addition, trans-isomerism within styryl substituents was observed. Experimental data for diazepine derivative containing 2-(4-tertbutylphenyl)ethenyl substituents were verified by X-ray crystallography. The obtained compounds were subjected to photophysical studies. In the UV-Vis absorption spectra two characteristic bands were found. In the solvatochromic study, the first band maxima were located in the range of 384-418 nm, whereas second band maxima in the range of 313-345 nm. Fluorescence intensity of novel diazepine derivatives was rather low in all solvents used with the values of fluorescence quantum yield Phi(F) (=) 10(-4) for 2-(3,5-dibromophenyl)ethenyl, and 10(-5) for 2-(4-tert-butylphenyl)ethenyl and 3,5-(dibenzyloxyphenyl)ethenyl 1,4-diazepine-2,3-dicarbonitriles. (C) 2016 Elsevier B.V. All rights reserved.

Journal of Molecular Structure, 110 , 208-214 (2016)

DOI: 10.1016/j.molstruc.2016.01.032   (Pobrano:  aktualizowanie)


26.

Michalska M., Florczak A., Dams-Kozłowska H., Gapiński J., Jurga S., Schneider R.

Peptide-functionalized ZCIS QDs as fluorescent nanoprobe for targeted HER2-positive breast cancer cells imaging In this paper, the synthesis of alloyed CuInZnxS2+x quantum dots (ZCIS QDs), their transfer into aqueous solution via a polymer coating technique, and the use of these nanocrystals to selectively target HER2-positive cells, are reported. By optimizing first the ZnS shell deposition process onto the CuInS2 core, and next the encapsulation of the dots with the amphiphilic poly(maleic anhydride-alt-1-octadecene) (PMAO) polymer, water-dispersible ZCIS QDs were successfully prepared. The nanocrystals with a photoluminescence quantum yield of 35% were purified via centrifugation and ultracentrifugation and high quality nanoparticles with narrow size distributions and surface charges were obtained. After verifying the biocompatibility of PMO-coated ZCIS QDs, we coupled these nanocrystals with the LTVSPWY peptide and demonstrated via MTT assay that both bare and the peptide-linked QDs exhibit low cytotoxicity. The HER2-mediated delivery of the peptide-linked QDs was confirmed by confocal microscopy. This study indicates that as engineered QDs can efficiently be used as fluorescent nanoprobes for selective labelling of HER2-positive SKBR3 cancer cells. Copyright 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Acta Biomaterialia, 35 , 293-304 (2016)

DOI: 10.1016/j.actbio.2016.02.002   (Pobrano:  aktualizowanie)


27.

Tillo A., Stolarska M., Kryjewski M., Popenda Ł., Sobotta Ł., Jurga S., Mielcarek J., Gośliński T.

Phthalocyanines with bulky substituents at non-peripheral positions - Synthesis and physico-chemical properties Three novel phthalocyanine derivatives equipped with bulky substituents at non-peripheral positions were synthesized and their physico-chemical properties were analyzed. Singlet oxygen generation as well as the aggregation properties of the phthalocyanines with different sizes of peripheral substituents were thoroughly studied. An insertion of benzyloxy or 3,5-bis(benzyloxy)benzyloxy groups to the non peripheral positions of phthalocyanines increased the singlet oxygen generation efficacy compared with a phthalocyanine substituted with 2-propoxy groups. (C) 2015 Elsevier Ltd. All rights reserved.

Dyes and Pigments, 127 , 110-115 (2016)

DOI: 10.1016/j.dyepig.2015.12.017   (Pobrano:  aktualizowanie)


28.

Gurzęda B., Florczak P., Kempiński M., Peplińska B., Krawczyk P., Jurga S.

Synthesis of graphite oxide by electrochemical oxidation in aqueous perchloric acid In this research a graphite oxide (GO) was synthesized by electrochemical oxidation of natural graphite in aqueous solution of perchloric acid. The process of anodic oxidation of graphite was performed by linear sweep voltammetry (LSV) from the rest potential of electrode to 1.4 V. In consequence of the electrochemical treatment graphite was fully transformed yielding GO. Formation of GO was proved by X-ray diffraction (XRD) and Raman spectroscopy analysis. The synthesis product was also characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). (C) 2016 Elsevier Ltd. All rights reserved.

Carbon, 100 , 540-545 (2016)

DOI: 10.1016/j.carbon.2016.01.044   (Pobrano:  aktualizowanie)


29.

Viter R., Iatsunskyi I., Fedorenko V., Tumenas S., Balevicius Z., Ramanayicius A., Balme S., Kempinski M., Nowaczyk G., Jurga S., Bechelany M.

Enhancement of electronic and optical properties of zno/al2o3 nanolaminate coated electrospun nanofibers Nanolaminates are new class of promising nanomaterials with outstanding properties. Here we explored on the tuning of structural properties and the enhancement of electronic and optical properties of 1D PAN ZnO/Al2O3 nanolaminates designed by atomic layer deposition (ALD) and electrospinning. The influence of ZnO/Al2O3 bilayer thicknesses on the fundamental properties of 1D PAN ZnO/Al2O3 nanolaminates has been investigated. Due to the quantum confinement effect, the shift of XPS peaks to higher energies has been observed. Work function of Al2O3 was mostly independent of the bilayers number, whereas the ZnO work function decreased with an increase of the bilayer number. Photoluminescence of the 1D PAN ZnO/Al2O3 nanolaminates corresponded to emission bands in ZnO nanolayers. Due to quantum confinement and surface band bending, no excitonic peaks were observed. The defect emission band was affected by the band bending and defect concentration. The enhanced photoluminescence of the 1D PAN ZnO/Al2O3 nanolaminates allows applications in optical (bio)sensing field.

Journal of Physical Chemistry C, 120(9) , 5124-5132 (2016)

DOI: 10.1021/acs.jpcc.5b12263   (Pobrano:  aktualizowanie)


30.

Adrjanowicz K., Kamiński K., Tarnacka M., Szutkowski K., Popenda Ł., Barbara G., Paluch M.

The effect of hydrogen bonding propensity and enantiomeric composition on the dynamics of supercooled ketoprofen - dielectric, rheological and NMR studies The aim of this work is to analyze in details the role of small hydrogen bonding (HB) structures and enantiomeric composition on the dynamics of glass-forming liquid ketoprofen. For that purpose dielectric relaxation, rheological and NMR studies were performed. Investigated samples are racemic ketoprofen, single enantiomer of ketoprofen and racemic ketoprofen methyl ester with no tendency to form dimeric hydrogen bonding aggregates. Combination of complementary experimental techniques enable us to show that the macroscopic viscosity ? and structural relaxation time ?? have nearly the same dependencies, whereas the relation between the rotational mobility and translational self-diffusion violates Stokes-Einstein law already at high temperature. Additionally, based on dielectric relaxation studies performed on increased pressure we were able to identify similarities and key differences in the supercooled liquid dynamics of investigated materials affected by their various tendency to form HB cyclic dimers. This includes the effect of pressure on the glass transition temperature Tg, changes in the fragility parameter m and activation volume ?V, the role of thermal energy and density fluctuations in governing the viscous liquid dynamics (Ev/Ep ratio). Finally, we have also demonstrated that the dynamic behaviour of single enantiomer and racemic mixture of the same compound are very much alike. Nevertheless, some slight differences were observed, particurarly in the ?? dependences measured in vinicity of the glass transition both at ambient and elevated pressure.

Physical Chemistry Chemical Physics, 18(15) , 10585-10593 (2016)

DOI: 10.1039/C6CP00578K   (Pobrano:  aktualizowanie)


31.

Skupin M., Kozak M.

Study of molecular mechanisms of amyloid beta-peptid variants aggregation in presence of surfactants It is estimated that in 2050 at least 1.25 % of population might have Alzheimer's disease. It is supposed that the most critical changes relevant for the progress of this disease are related to development and deposition of amyloid plaque whose main components are amyloid ?-peptides (A?).
The aim of this study was characterization of the structure and conformational changes of ?-amyloid peptides in the presence of a wide group of surfactants. The kinetic study of the aggregation behavior of different peptides in solution was also undertaken. Four groups of surfactants (cationic, dicationic, tricationic and zwitterionic) and different ?-amyloid peptides were selected for the study. The surfactant concentration effect was tested on 1-42 A? peptide and its shorter variants (N-terminal with hydrophilic properties and hydrophobic C-terminal fragment).
Analysis of the secondary structure of A? peptide in the presence of different concentrations of surfactants as well as a function of temperature, was carried out using FTIR spectroscopy and circular dichroism method. The kinetics of aggregation processes of the peptides and formation of plaques was studied using fluorescence spectroscopy and Thioflavin T assay. The size distribution of aggregates of A? peptide was evaluated on the basis of gel electrophoresis.
Results of our study showed different impact of surfactants studied on the conformations of beta-amyloid peptides. Preliminary examination of the cytotoxicity of selected surfactants on HeLa cells was conducted in order to verify their suitability for therapeutic purposes.

Biophysical Journal, 110(3) S1 , 533a-534a (2016)

DOI: 10.1016/j.bpj.2015.11.2855   (Pobrano:  aktualizowanie)


32.

Pietralik Z., Murawska M., Szymańska A., Kumita J.R., Dobson C.M., Kozak M.

Structural studies of the oligomerization process of human cystatin C variants Human cystatin C (HCC), an inhibitor of cysteine proteases, is also involved in amyloidogenic processes within the human body. In the crystal structure, as in solution, wild-type (WT) cystatin C dimerizes via a domain swapping mechanism. The same process has also been shown to be important for protein oligomerization. Aggregation of HCC results in a heterogeneous mixture of species, both oligomeric and fibrillar, with varying shapes, sizes and molecular weights.
The goal of our study was to characterize the assembly process of potentially neurotoxic oligomers of WT and variant HCC in solution. The oligomerization processes of several point mutation variants of HCC (V57N, V57P, V57D, V57G and L68V), with specific dimerization properties [3], were compared to the WT protein. Prepared oligomers were purified by size-exclusion chromatography and using TEM and AFM studies, we observed characteristic donutlike structures along with fibrils and we determined the size distribution of cystatin C oligomers obtained from the WT and variant forms. Independently, the oligomerization process was analyzed by fluorescence spectroscopy and visualized by native electrophoresis. Additionally, induced secondary structure changes were characterised by circular dichroism (CD) and infrared (FTIR) spectroscopies. Finally, the structural studies were supplemented with the modelling of the larger HCC oligomers using molecular dynamics simulations, allowing the identification of the most stable oligomeric forms of HCC to be determined.

Biophysical Journal, 110(3) S1 , 26a (2016)

DOI: 10.1016/j.bpj.2015.11.205   (Pobrano:  2017-12-08)


33.

Andrzejewska W.J., Skupin M., Skrzypczak A., Kozak M.

Structural characterization of dsDNA nanocomplexes based on ammonium gemini surfactants One of the most intensively studied groups of chemical compounds are gemini surfactants, because of their specific and attractive properties, especially the capability of stable binding of the nucleic acids, formation of spatial structures with high symmetry and relatively low cytotoxicity. They have found a broad range of applications in medicine, chemical technology, pharmaceutical industry. These complexes can be applied as nonviral transfection delivery systems in gene therapy, a novel and most promising method for the treatment of a broad range of genetic diseases. Dicationic surfactants allow introduction of a transgene without inducing natural immunological response, and release it undamaged inside the cell. However, the successful completion of this process is difficult, because of the need for many studies in order to determine all necessary parameters.
In our study we analysed nanocomplexes of cationic gemini surfactants(1,n-dodecanebis[(oxymethyl)alkyldimethylammonium]chlorides) with DNA oligomers using synchrotron radiation of small angle X-ray scattering, circular dichroism spectroscopy, agarose gel electrophoresis, polarization microscopy and transmission electron microscopy. We also analysed the cytotoxicity of our systems using MTT colorimetric assay on model cell cultures.
We observed the formation of complexes, their morphology, spatial nanostructure, conformation of nucleic acid inside them and influence on the cells. The systems studied were found to be stable and the process of their formation was reproducible.

Biophysical Journal, 110(3) S1 , 403a-404a (2016)

DOI: 10.1016/j.bpj.2015.11.2178   (Pobrano:  aktualizowanie)


34.

Ivashchenko O., Jurga-Stopa J., Coy E., Peplińska B., Pietralik Z., Jurga S.

Fourier transform infrared and Raman spectroscopy studies on magnetite/Ag/antibiotic nanocomposites This article presents a study on the detection of antibiotics in magnetite/Ag/antibiotic nanocomposites using Fourier transform infrared (FTIR) and Raman spectroscopy. Antibiotics with different spectra of antimicrobial activities, including rifampicin, doxycycline, cefotaxime, and ceftriaxone, were studied. Mechanical mixtures of antibiotics and magnetite/Ag nanocomposites, as well as antibiotics and magnetite nanopowder, were investigated in order to identify the origin of FTIR bands. FTIR spectroscopy was found to be an appropriate technique for this task. The spectra of the magnetite/Ag/antibiotic nanocomposites exhibited very weak (for doxycycline, cefotaxime, and ceftriaxone) or even no (for rifampicin) antibiotic bands. This FTIR “invisibility” of antibiotics is ascribed to their adsorbed state. FTIR and Raman measurements show altered C—O, C=O, and C—S bonds, indicating adsorption of the antibiotic molecules on the magnetite/Ag nanocomposite structure. In addition, a potential mechanism through which antibiotic molecules interact with magnetite/Ag nanoparticle surfaces is proposed.
© 2015 Elsevier B.V. All rights reserved.

Applied Surface Science, 364 , 400-409 (2016)

DOI: 10.1016/j.apsusc.2015.12.149   (Pobrano:  2017-12-08)


35.

Tadyszak K., Boś-Liedke A., Jurga J., Baranowski M., Mrówczynski R., Chlewicki W., Jurga S., Czechowski T.

Overmodulation of projections as signal-to-noise enhancement method in EPR imaging A study concerning the image quality in electron paramagnetic resonance imaging in two-dimensional spatial experiments is presented. The aim of the measurements was to improve the signal-to-noise ratio (SNR) of the projections and the reconstructed image by applying modulation amplitude higher than the radical electron paramagnetic resonance linewidth. Data were gathered by applying four constant modulation amplitudes, where one was below 1/3 (Amod=0.04 mT) of the radical linewidth (ΔBpp=0.14 mT). Three other modulation amplitude values were used in this experiment, leading to undermodulated (Amod < 1/3 ΔBpp), partially overmodulated (Amod ∼ 1/3 ΔBpp) and fully overmodulated (Amod >> 1/3 ΔBpp) projections. The advantages of an applied overmodulation condition were demonstrated in the study performed on a phantom containing four shapes of 1.25 mM water solution of 2, 2, 6, 6-tetramethyl-1-piperidinyloxyl. It was shown that even when the overmodulated reference spectrum was used in the deconvolution procedure, as well as the projection itself, the phantom shapes reconstructed as images directly correspond to those obtained in undermodulation conditions. It was shown that the best SNR of the reconstructed images is expected for the modulation amplitude close to 1/3 of the projection linewidth, which is defined as the distance from the first maximum to the last minimum of the gradient-broadened spectrum. For higher modulation amplitude, the SNR of the reconstructed image is decreased, even if the SNR of the measured projection is increased.
Copyright © 2015 John Wiley & Sons, Ltd.

Magnetic Resonance in Chemistry, 54(2) , 136-142 (2016)

DOI: 10.1002/mrc.4330   (Pobrano:  2017-12-07)


36.

Zalewski P., Skibiński R., Szymanowska-Powałowska D., Piotrowska H., Kozak M., Pietralik Z., Bednarski W., Cielecka-Piontek J.

The radiolytic studies of cefpirome sulfate in the solid state The possibility of applying radiation sterilization to cefpirome sulfate was investigated. The lack of changes in the chemical structure of cefpirome sulfate irradiated with a dose of 25 kGy, required to attain sterility, was confirmed by UV, FT-IR, Raman, DSC and chromatographic methods. Some radical defects with concentration no more than over a several dozen ppm were created by radiation. The antibacterial activity of cefpirome sulfate for two Gram-positive and three Gram-negative strains was changed. The radiation sterilised cefpirome sulfate was not in vitro cytotoxic against fibroblast cells.

Journal of Pharmaceutical and Biomedical Analysis, 118 , 410-416 (2016)

DOI: 10.1016/j.jpba.2015.11.008   (Pobrano:  aktualizowanie)


37.

Sikorska E., Wyrzykowski D., Szutkowski K., Greber K., Lubecka E.A., Zhukov I.

Thermodynamics, size, and dynamics of zwitterionic dodecylphosphocholine and anionic sodium dodecyl sulfate mixed micelles The thermodynamic properties of micellization for dodecylphosphocholine (DPC), sodium dodecyl sulfate (SDS), and their mixtures were studied using isothermal titration calorimetry. NMR relaxation measurements were used to explore molecular mobility of the DPC-containing micelles, whereas the diffusion measurements were taken to determine the micelle size. The DPC/SDS mixed systems reveal a tendency to form two kinds of micelles in buffered solution at lower temperatures. An increase in temperature as well as the transfer of the DPC/SDS mixed micelles from buffered to unbuffered solution results in only a single-step micellization process. The average size of the DPC-containing micelles is only slightly dependent on the SDS fraction. Examination of the data of spin-spin relaxation (T2) shows that methylene protons on the polar headgroup of DPC and methylene protons (H1) on the hydrocarbon chain in the micellar systems studied reveal a heterogeneous dynamic behavior reflected in a two-component T2 relaxation in the whole temperature range. The latter is the main constituent of the rigid interfacial layer core protecting the penetration of water into the hydrophobic interior.

Journal of Thermal Analysis and Calorimetry, 123(1) , 511-523 (2016)

DOI: 10.1007/s10973-015-4918-0   (Pobrano:  aktualizowanie)


38.

Baranowska-Korczyc A., Warowicka A., Jasiurkowska-Delaporte M., Grześkowiak B., Jarek M., Maciejewska B.M., Jurga-Stopa J., Jurga S.

Antimicrobial electrospun poly(epsilon-caprolactone) scaffolds for gingival fibroblast growth This study discusses the value of polymer electrospun materials in three-dimensional (3D) scaffolds and antibacterial wound dressings for potential dental applications. Polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers were used as bases for gingival fibroblast (HGF-1 cell line) growth. HGF-1 cells cultured on both types of nanofibers were found to have normal morphology and growth by selective staining of the nuclei and cytoskeleton. The nanofibers were synthesized on different collectors to obtain a random or parallel alignment. Cell growth was observed along the nanofibers. In addition, antibiotics were incorporated within the nanofibers and studied by means of Raman spectroscopy and differential scanning calorimetry. The release profile of the antibiotics was determined by broad band dielectric measurements. The drug was found to be released by Fickian diffusion. The WST-1 test found PCL and PCL/ampicillin nanofibers to have minimal cytotoxicity. The antibacterial activity of materials containing ampicillin was evaluated by zone inhibition against a selected oral strain of Streptococcus sanguinis. The bacterial growth was inhibited by antibiotic release from PCL/ampicillin mats.

RSC Advances, 6(24) , 19647-19656 (2016)

DOI: 10.1039/c6ra02486f   (Pobrano:  aktualizowanie)


39.

Mrówczyński R., Jurga-Stopa J., Markiewicz R., Coy L.E., Jurga S., Woźniak A.

Assessment of polydopamine coated magnetic nanoparticles in doxorubicin delivery Magnetic nanoparticles (MNP) coated with bioinspired polydopamine (PDA) were obtained via a co-precipitation method and oxidative polymerization of dopamine. Nanoparticles were investigated by FTIR, TEM and SQUID. Loading capacity of anticancer drug doxorubicin was determined by UV-Vis spectroscopy. The nanocomposites exhibit a high drug loading capacity of 0.46 mg mg(-1). Anticancer activity of the nanocomposites was proved in profound in vitro tests on HeLa cells. Cytotoxicity and internalization of nanoparticles were checked using various method, i.e. proliferation assay (WST-1), a two-colour fluorescence cell viability assay, and fluorescent and confocal microscopy.

RSC Advances, 6(7) , 5936-5943 (2016)

DOI: 10.1039/c5ra24222c   (Pobrano:  aktualizowanie)


40.

Jurga S., Erdmann V.A., Barciszewski J.

Modified Nucleic Acids in Biology and Medicine This volume is comprised of 18 chapters, covering various aspects of DNA modification and RNA modified bases. It also discusses in detail circular RNA, therapeutic oligonucleotides and their different properties. The chemical nature of DNA, RNA, protein and lipids makes these macromolecules easily modifiable, but they are also susceptible to damage from both endogenous and exogenous agents. Alkylation and oxidation show a potential to disrupt the cellular redox equilibrium and cause cellular damage leading to inflammation and even chronic disease. Furthermore, DNA damage can drive mutagenesis and the resulting DNA sequence changes can induce carcinogenesis and cancer progression. Modified nucleosides can occur as a result of oxidative DNA damage and RNA turnover, and are used as markers for various diseases. To function properly some RNA needs to be chemically modified post-transcriptionally. Dysregulation of the RNA-modification pattern or of the levels of the enzymes that catalyze these modifications alters RNA functionality and can result in complex phenotypes, likely due to defects in protein translation. While modifications are best characterized in noncoding ribonucleic acids like tRNA and rRNA, coding mRNAs have also been found to contain modified nucleosides. This book is a valuable resource, not only for graduate students but also researchers in the fields of molecular medicine and molecular biology.

Diagnostics. Book Series: RNA Technologies, Erdmann V.A., Jurga S., Barciszewski J. (Eds.), , Springer-Verlag Berlin, Heidelberger Platz 3, d-14197 Berlin, Germany (2016)

ISBN: 978-3-319-34175-0   (Pobrano:  aktualizowanie)


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