Kiev, Ukraine
Kiev, Ukraine

Time filter

Source Type

Korsunska N.,Ukrainian Academy of Sciences | Baran M.,Ukrainian Academy of Sciences | Vorona I.,Ukrainian Academy of Sciences | Nosenko V.,Ukrainian Academy of Sciences | And 4 more authors.
Nanoscale Research Letters | Year: 2017

The influence of calcination temperature on copper spatial localization in Y-stabilized ZrO2 powders was studied by attenuated total reflection, diffuse reflectance, electron paramagnetic resonance, transmission electron microscopy, electron energy loss, and energy-dispersive X-ray spectroscopies. It was found that calcination temperature rise in the range of 500–700 °C caused the increase of copper concentration in the volume of ZrO2 nanocrystals. This increase was due to Cu in-diffusion from surface complexes that contained copper ions linked with either water molecules or OH groups. This copper in-diffusion led also to an enhancement of absorption band peaked at ~270 nm that was ascribed to the formation of additional oxygen vacancies in nanocrystal volume. Further increasing of calcination temperature from 800 up to 1000 °C resulted in outward Cu diffusion accompanied by a decrease of the intensity of the 270-nm absorption band (i.e., oxygen vacancies’ number), the transformation of ZrO2 tetragonal (cubic) phase to monoclinic one as well as the enhancement of absorption band of dispersed and crystalline CuO in the 600–900 nm range. © 2017, The Author(s).


Heffeter P.,Medical University of Vienna | Riabtseva A.,Lviv Polytechnic | Senkiv Y.,Medical University of Vienna | Senkiv Y.,Ukrainian Academy of Sciences | And 10 more authors.
Journal of Biomedical Nanotechnology | Year: 2014

Ruthenium anticancer drugs belong to the most promising non-platinum anticancer metal compounds in clinical evaluation. However, although the clinical results are promising regarding both activity and very low adverse effects, the clinical application is currently hampered by the limited solubility and stability of the drug in aqueous solution. Here, we present a new nanoparticle formulation based on polymer-based micelles loaded with the anticancer lead ruthenium compound KP1019. Nanoprepared KP1019 was characterised by enhanced stability in aqueous solutions. Moreover, the nanoparticle formulation facilitated cellular accumulation of KP1019 (determined by ICP-MS measurements) resulting in significantly lowered IC50 values. With regard to the mode of action, increased cell cycle arrest in G2/M phase (PI-staining), DNA damage (Comet assay) as well as enhanced levels of apoptotic cell death (caspase 7 and PARP cleavage) were found in HCT116 cells treated with the new nanoformulation of KP1019. Summarizing, we present for the first time evidence that nanoformulation is a feasible strategy for improving the stability as well as activity of experimental anticancer ruthenium compounds. Copyright © 2014 American Scientific Publishers All rights reserved.


Riabtseva A.,Lviv Polytechnic | Mitina N.,Lviv Polytechnic | Boiko N.,Ukrainian Academy of Sciences | Garasevich S.,Taras Shevchenko National University | And 4 more authors.
Chemistry and Chemical Technology | Year: 2012

Novel comb-like polymeric and oligomeric drug carriers combining backbone - copolymers of 5-tertbutylperoxy-5-methyl-1-hexene-3-yne (VEP) and glycidyl methacrylate (GMA) - and side PEG chains of various lengths were synthesized. Nanosized delivery systems containing conjugates of water soluble anticancer drug Doxorubicin were developed. The structures of copolymers and their conjugates with drugs were confirmed by IR-spectroscopy. Structural and colloidalchemical properties of water drug delivery systems were studied using photoluminescent (PL), UV-spectroscopy techniques, surface tension measurements and dynamic light scattering. The scheme of the immobilization of water soluble doxorubicin on developed PEGylated polymeric carriers was assumed. © Riabtseva A., Mitina N., Boiko N., Garasevich S., Yanchuk I., Stoika R., Slobodyanyuk O., Zaichenko A., 2012.


Soloviev A.,Ukrainian Academy of Sciences | Zholos A.,Taras Shevchenko National University | Ivanova I.,Ukrainian Academy of Sciences | Novokhatska .,Ukrainian Academy of Sciences | And 4 more authors.
Vascular Pharmacology | Year: 2015

Colloidal gold nanoparticles (AuNPs) of ~5nm core size and Zeta-potential of -35mV, having absorption maximum and plasmon resonance in the range of 510-570nm, were studied as a potential K+-channel opener in vascular smooth muscle (SM) cells. Experimental design of the study comprised SM contractile recordings. When externally applied to the organ bath, AuNPs (10-6-3×10-4M) led to decrease in amplitude of norepinephrine-induced contractions in a concentration-dependent and endothelium-independent manner in SM thoracic aorta, with mean value of pD2 (-log EC50) 4.2±0.03, Emax=55±4%. Being added to the bath solution in concentration of 10-4M, AuNPs significantly increased whole cell peak outward current at +70mV from 32±2pA/pF to 59±5pA/pF (n=14, P<0.05). External irradiation using a 5mW/532nm green laser, to facilitate plasmon resonance, led to an increment in the AuNPs-induced macroscopic outward potassium current (IK) from 59±5pA/pF to 74±1pA/pF (n=10, P<0.05). Paxilline (500nM), when added to the external bathing solution, significantly decreased AuNPs-induced increment of IK in SM cells. Single channel recordings provided a direct confirmation of BKCa activation by AuNPs at the single-channel level. Application of AuNPs to the bath potentiated BKCa activity with a delay of 1-2min, as was seen initially by more frequent channel openings followed by the progressive appearance of additional open levels corresponding to multiple openings of channels with identical single-channel amplitudes. Eventually, after 10-15min in the presence of AuNPs and especially when combined with the green laser illumination, there was a massive increase in channel activity with >10 channels evident. When irradiated by laser, AuNPs significantly increased the amplitude of maximal AuNPs-induced relaxation from 55±5% to 85±5% (n=10, P<0.05) while the sensitivity of SM to AuNPs was without changes.In summary, plasmonic AuNPs possess the ability to activate BKCa channel opening in vascular SM. Laser irradiation facilitates this effect due to local plasmon resonance that, in turn, further increases BKCa channel activity causing SM relaxation. © 2015 Elsevier Inc..


Tsymbaliuk O.V.,Taras Shevchenko National University | Naumenko A.M.,Taras Shevchenko National University | Skoryk M.A.,NanoMedTech LLC | Nyporko O.Y.,Taras Shevchenko National University | And 2 more authors.
Biopolymers and Cell | Year: 2016

Aim. To investigate the influence of titanium dioxide nanoparticles (TiO2) on histamine-, nicotine- (acetylcholine- nicotine)-stimulated modulations of mechanical activity in smooth muscles of caecum and stomach of rats. Methods. Electronic scanning microscopy; zeta-potential estimation; the isometric tension recordings; pharmacological and kinetic analysis. Results. Relaxation of smooth muscles stripes (SMS) of caecum stimulated by 10–5 mol/l nicotine on the background of histamine contraction was not affected by TiO2 (10–3 mg/ml); under the same conditions TiO2 reinforced the histamine-induced contractions. The cumulative increase in TiO2 concentration in the 10–6–10–4 mg/ml range was accompanied by inhibition of SMS contractions stimulated by histamine (10–5 mol/l) and nicotine (10–7 mol/l). Similar results were obtained on stomach SMS. The phase component of acetylcholine contraction modulated by nicotine was bound to be unaffected by TiO2 whereas the tonic component was inhibited. Conclusions. The suspension of TiO2 nanoparticles in conditions of cumulative effect modulates the mechanisms of neurotransmitter release from neurons of intramural plexuses of circular smooth muscle of the gastrointestinal tract which are activated by histamine and nicotine (10–7 mol/l). © 2016 O. V. Tsymbaliuk et al.


PubMed | Ukrainian Academy of Sciences, Taras Shevchenko National University and NanoMedTech LLC
Type: | Journal: Vascular pharmacology | Year: 2015

Colloidal gold nanoparticles (AuNPs) of ~5nm core size and Zeta-potential of -35mV, having absorption maximum and plasmon resonance in the range of 510-570nm, were studied as a potential K(+)-channel opener in vascular smooth muscle (SM) cells. Experimental design of the study comprised SM contractile recordings. When externally applied to the organ bath, AuNPs (10(-6)-310(-4)M) led to decrease in amplitude of norepinephrine-induced contractions in a concentration-dependent and endothelium-independent manner in SM thoracic aorta, with mean value of pD2 (-log EC50) 4.20.03, Emax=554%. Being added to the bath solution in concentration of 10(-4)M, AuNPs significantly increased whole cell peak outward current at +70mV from 322pA/pF to 595pA/pF (n=14, P<0.05). External irradiation using a 5mW/532nm green laser, to facilitate plasmon resonance, led to an increment in the AuNPs-induced macroscopic outward potassium current (IK) from 595pA/pF to 741pA/pF (n=10, P<0.05). Paxilline (500nM), when added to the external bathing solution, significantly decreased AuNPs-induced increment of IK in SM cells. Single channel recordings provided a direct confirmation of BKCa activation by AuNPs at the single-channel level. Application of AuNPs to the bath potentiated BKCa activity with a delay of 1-2min, as was seen initially by more frequent channel openings followed by the progressive appearance of additional open levels corresponding to multiple openings of channels with identical single-channel amplitudes. Eventually, after 10-15min in the presence of AuNPs and especially when combined with the green laser illumination, there was a massive increase in channel activity with >10 channels evident. When irradiated by laser, AuNPs significantly increased the amplitude of maximal AuNPs-induced relaxation from 555% to 855% (n=10, P<0.05) while the sensitivity of SM to AuNPs was without changes. In summary, plasmonic AuNPs possess the ability to activate BKCa channel opening in vascular SM. Laser irradiation facilitates this effect due to local plasmon resonance that, in turn, further increases BKCa channel activity causing SM relaxation.


Andryushina N.S.,Ukrainian Academy of Sciences | Stroyuk O.L.,Ukrainian Academy of Sciences | Yanchuk I.B.,NanoMedTech LLC | Yefanov A.V.,NanoMedTech LLC
Colloid and Polymer Science | Year: 2014

Evolution of the hydrodynamic size d HD of colloidal graphene oxide (GO) sheets in water induced by the photochemical GO reduction by UV light was studied by the dynamic light scattering spectroscopy. An increase of d HD at an initial stage of the photoreduction is caused by partial photoelimination of the functional groups of GO and breaking of the hydrogen bonds between the fragments of the GO particles resulting in the sheets' unfolding. At deeper photoreduction, a decrease of d HD is observed as a result of ππ stacking interaction between the aromatic areas of GO particles and crumpling of the GO sheets. Variations of pH affect strongly the d HD of the photoreduced GO. At pH lowering from 6-7 to 2-3, a drastic growth of d HD and the sheets' aggregation are observed, caused by the protonation of the carboxyl groups. At pH elevation to 11-12, on the contrary, a decrease of d HD is observed, which is more pronounced the longer the photochemical GO reduction. The observation reflects crumpling/scrolling of the the GO sheets to minimize the contact area between the aromatic components of the photoreduced GO particles and the dispersive medium. The changes of the photoreduced GO particle size in basic media were found to be reversible. © 2013 Springer-Verlag.


Lebyedyeva T.,Ukrainian Academy of Sciences | Kryvyi S.,Ukrainian Academy of Sciences | Lytvyn P.,Ukrainian Academy of Sciences | Skoryk M.,NanoMedTech LLC | Shpylovyy P.,Ukrainian Academy of Sciences
Nanoscale Research Letters | Year: 2016

Our research was aimed at the study of aluminum films and porous anodic alumina (PAA) films in thin-film РАА/Al structures for optical sensors, based on metal-clad waveguides (MCWG). The results of the scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the structure of Al films, deposited by DC magnetron sputtering, and of PAA films, formed on them, are presented in this work. The study showed that the structure of the Al films is defined by the deposition rate of aluminum and the thickness of the film. We saw that under anodization in 0.3 M aqueous oxalic acid solution at a voltage of 40 V, the PAA film with a disordered array of pores was formed on aluminum films 200–600 nm thick, which were deposited on glass substrates with an ultra-thin adhesive Nb layer. The research revealed the formation of two differently sized types of pores. The first type of pores is formed on the grain boundaries of aluminum film, and the pores are directed perpendicularly to the surface of aluminum. The second type of pores is formed directly on the grains of aluminum. They are directed perpendicularly to the grain plains. There is a clear tendency to self-ordering in this type of pores. © 2016, Lebyedyeva et al.


PubMed | Institute of Semiconductor Physics of Ukraine and Nanomedtech LLC
Type: | Journal: Nanoscale research letters | Year: 2015

Using a scanning electron microscopy, elemental analysis, electron paramagnetic resonance, and Raman scattering methods, two types of the shungite materials (Sh-II from Zazhogino deposit and shungite from a commercial filter (ShF)), with different carbon content and porosity, are studied in this work. It was established by scanning electron microscopy data that the structure of the shungite samples is formed by a micron-size agglomeration of carbon and silicon dioxide clusters. It is found from the Raman data that carbon fraction is formed from sp(2)-hybridized clusters, size of which increases from 9 up to 12nm after annealing of the samples. High conductivity of shungite is found to belong to the carbon nanoclusters of different sizes. Big clusters give the conduction electron spin resonance signal with a Dysonian line shape with variable g-factor and line width. The careful search of the nature of two other narrow electron paramagnetic resonance signals in shungite, which used to be prescribed to fullerene-like molecules, is fulfilled. Here, it is shown that the oxygen-deficient E centers are responsible for these signals. A strong correlation is revealed between the concentration of centers and the line width of conduction electron spin resonance signal, which occurs under annealing process of the samples at T=570K. The correlation reasons are a spin-spin coupling between two spin subsystems and time dependent of the concentration during annealing process.


PubMed | Ukrainian Academy of Sciences and NanoMedTech LLC
Type: Journal Article | Journal: Nanoscale research letters | Year: 2016

Our research was aimed at the study of aluminum films and porous anodic alumina (PAA) films in thin-film /Al structures for optical sensors, based on metal-clad waveguides (MCWG). The results of the scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies of the structure of Al films, deposited by DC magnetron sputtering, and of PAA films, formed on them, are presented in this work.The study showed that the structure of the Al films is defined by the deposition rate of aluminum and the thickness of the film. We saw that under anodization in 0.3M aqueous oxalic acid solution at a voltage of 40V, the PAA film with a disordered array of pores was formed on aluminum films 200-600 nm thick, which were deposited on glass substrates with an ultra-thin adhesive Nb layer. The research revealed the formation of two differently sized types of pores. The first type of pores is formed on the grain boundaries of aluminum film, and the pores are directed perpendicularly to the surface of aluminum. The second type of pores is formed directly on the grains of aluminum. They are directed perpendicularly to the grain plains. There is a clear tendency to self-ordering in this type of pores.

Loading NanoMedTech LLC collaborators
Loading NanoMedTech LLC collaborators