Published papers:

1)  Shlapa, Yu.; Timashkov, I.; Veltruska, K.; Siposova, K.; Garcarova, I.; Musatov, A.; Solopan, S.; Kubovcikova, M.; Belous, A. Structural and Physical-Chemical Characterization of Redox Active CeO₂ Nanoparticles Synthesized by the Precipitation in the Water-Alcohol Solutions. Nanotechnology. 2021, 32, 315706 (9pp). (Q1)

Abstract

A set of cerium dioxide nanoparticles (CeO2 NPs) was synthesized by precipitation in water/alcohol solutions under conditions when the physical-chemical parameters of synthesized NPs were controlled by changing the ratio of the reaction components. The size of CeO2 NPs is controlled largely by the dielectric constant of the reaction solution. An increase of the percentage of Ce3+ ions at the surface was observed with a concomitant reduction of the NP sizes. All synthesized CeO2 NPs possess relatively high positive values of zeta-potential (ζ>40 mV) suggesting good stability in aqueous suspensions. Analysis of the valence- and size dependent rate of hydrogen peroxide decomposition revealed that catalase/peroxidase-like activity of CeO2 NPs is higher at a low percentage of Ce3+ at the NP surface. In contrast, smaller CeO2 NPs with a higher percentage of Ce3+ at the NP surface display a higher oxidase-like activity.

Keywords: cerium dioxide nanoparticles, synthesis, chemical state, morphology, catalase/peroxidase activity, zeta-potential

https://doi.org/10.1088/1361-6528/abf7e9

https://iopscience.iop.org/article/10.1088/1361-6528/abf7e9/meta

2)  

Siposova, K., Kozar, T., Stupakova, M., Musatov, A. (2021) “Complementary experimental and computational analysis of the effects of non-ionic detergents and phospholipids on insulin amyloid aggregation” Colloids and Surface B: Biointerfaces, 197, 111428. (Q1)

Abstract

Amphiphilic compounds, both detergents and lipids, are important tools for in vitro analysis of water-soluble and integral membrane proteins. A key question is whether these two groups of amphiphilic molecules use the same pathway to affect structural and functional integrity of proteins. In the present study, we tested the effect of non-ionic detergent dodecyl maltoside (DDM), two phospholipids, 1,2-dimyristoyl-sn-glycero-3- phosphocholine (DMPC), 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), and the detergent-phospholipid mixtures on insulin amyloidogenesis in vitro. Amyloidogenesis of insulin is significantly affected by DDM in a time-and dose-dependent manner, but only slightly affected by either of phospholipids. Addition of DHPC or DMPC to detergent does not alter the inhibiting pattern, suggesting that DDM preferably binds to insulin. The molecular modeling revealed that DDM and the phospholipids occupy equivalent binding sites. DDM, due to the presence of maltose with several oxygen atoms (hydroxylic, glycosidic and ring) is involved in more hydrogen bonds than DHPC or DMPC. Hydrophobic interactions are important factors to stabilize both, DDM and phospholipids in their binding sites. Our results indicate that certain detergents (applying DDM as an example) and selected phospholipids are not always interchangeable in their use to investigate the effect of amphiphilic compounds on the behavior of amyloid-prone proteins.

Keywords: insulin; amyloid aggregation; detergents; phospholipids; hydrogen bonds; hydrophobic interactions;

https://doi.org/10.1016/j.colsurfb.2020.111428

https://www.sciencedirect.com/science/article/abs/pii/S0927776520307840

3)  

Siposova, K., Sedlakova, D., Musatov, A. (2021) “Monitoring the surface tension by the pendant drop technique for detection of insulin fibrillogenesis” Anal. Methods, 13, 4174. (Q1)

Abstract

Monitoring the aggregation of amyloid-prone proteins is critical for understanding the mechanism of amyloid fibril formation. Insulin, when dissolved in low pH buffer, has a surface tension of 61–64 mN m⁻¹, as measured by the pendant drop technique. Formation of insulin amyloid fibrils resulted in the increase of the surface tension values up to 71.2–73.5 mN m⁻¹. The kinetics of fibril formation and fibril morphology were validated by ThT fluorescence and AFM, respectively. The results demonstrate that monitoring the surface tension by the pendant drop technique is a valuable tool for the detection of insulin amyloid aggregation.

https://doi.org/10.1039/D1AY01126J

https://pubs.rsc.org/en/content/articlelanding/2021/ay/d1ay01126j/unauth

4)  

Hovhannisyan, V., Siposova, K., Musatov, A., Chen, Sh.-J. (2021) “Development of multifunctional nanocomposites for controlled drug delivery and hyperthermia” Sci. Rep. 11, Art. No: 5528. (Q1)

Abstract

Magnetic nano/micro-particles based on clinoptilolite-type of natural zeolite (CZ) were fabricated and were expected to act as carriers for controlled drug delivery/release, imaging and local heating in biological systems. Adsorption of rhodamine B, sulfonated aluminum phthalocyanine and hypericin by magnetic CZ nano/micro-particles was investigated, as was the release of hypericin. Using an alternating magnetic field, local temperature increase by 10 °C in animal tissue with injected magnetic CZ particles was demonstrated. In addition, the CZ-based particles have been found to exhibit an anti-amyloidogenic effect on the amyloid aggregation of insulin and lysozyme in a dose- and temperature-dependent manner. Therefore, the mesoporous structure of CZ particles provided a unique platform for preparation of multifunctional magnetic and optical probes suitable for optical imaging, MRI, thermo- and phototherapy and as effective containers for controlled drug delivery. We concluded that magnetic CZ nano/micro-particles could be evaluated for further application in cancer hyperthermia therapy and as anti-amyloidogenic agents.

https://doi.org/10.1038/s41598-021-84927-x

https://www.nature.com/articles/s41598-021-84927-x

5)  Skumiel, A., Kopcansky, P., Timko, M., Molcan, M., Paulovicova, K., Wojciechowski, R. (2022) The influence of a rotating magnetic field on the thermal effect in magnetic fluid” International Journal of Thermal Sciences 171, 107258. (Q1)

Abstract

The physical principles of magnetic hyperthermia are based on the heat generation of magnetic nanoparticles under the influence of applied magnetic fields of different configurations. The choice of a suitable methodology for generating a magnetic field can significantly affect the resulting thermal effect and thus the efficiency itself. The technical details of the apparatus generating a rotating magnetic field and a comparison of the efficiency when the alternating magnetic field is applied are analyzed. While the mechanism of the temperature rise is the same, as shown by the fitting of the dT/dt curves, the intrinsic loss power differs significantly. It was found that the rotating magnetic field produces a thermal effect that is more than twice that of the alternating magnetic field under similar experimental conditions.

Keywords: rotating magnetic field; alternating magnetic field; magnetic fluid; thermal effect; specific loss power

https://doi.org/10.1016/j.ijthermalsci.2021.107258

https://www.sciencedirect.com/science/article/pii/S129007292100418X

6)  Rajnak, M., Dolnik, B., Hodermarsky, P., Paulovicova, K., Cimbala, R., Timko, M., Kopcansky, P. (2021) “Dynamic magnetic response of ferrofluids under a static electric field” Phys. Fluids 33, 082006. (Q1)

Abstract

Magnetic nanoparticles in a non-polar ferrofluid can reassemble in external electric fields. The resulting electric field-driven structural changes in ferrofluids are expected to influence the magnetic response of ferrofluids to an alternating magnetic field. Hence, it should be possible to control the magnetic susceptibility of ferrofluids by electric forces. To address the problem of a possible electro-magnetic coupling, a low-frequency alternating current magnetic susceptibility of a ferrofluid based on insulating oil and iron oxide nanoparticles is measured under a static electric field. The electric field is generated by applying a voltage on a pair of electrodes embracing the ferrofluid and acts parallel and perpendicular to the probing alternating magnetic field. The susceptibility is measured simultaneously with the ferrofluid's temperature and a leakage current. A noticeable susceptibility decrease with increasing voltage is found. The susceptibility decrease is partially caused by the temperature increase. Based on theoretical calculations, it is found that the detected temperature increase cannot be the only reason for the measured susceptibility decrease. Other mechanisms resulting from magnetic nanoparticle interactions with the electric field (nanoparticle trapping due to dielectrophoresis, electric field-induced nanoparticle aggregation) must contribute to the susceptibility drop in a static electric field.

 https://doi.org/10.1063/5.0059285

 https://aip.scitation.org/doi/full/10.1063/5.0059285

Papers submitted to the journals

1)  Veronika Sarnatskaya, Yuliia Shlapa, Alexandra Lykhova, Olga Brieieva, Igor Prokopenko, Alexey Sidorenko, Serhii Solopan, Denis Kolesnik, Anatolii Belous, Vladimir Nikolaev (2021) “Structure and biological activity of micro- nanoparticles produced from highly activated carbonic adsorbent” // Heliyon (Q1) (in press).

2)  

Siposova, K.; Huntosova, V.; Garcarova, I.; Shlapa, Yu.; Timashkov, I; Belous, A.; Musatov, A. Multifunctional, Anti-oxidant and Anti-amyloidogenic Cerium Oxide Nanoparticles Prepared by Controllable Precipitation in Water-Alcohol Solutions. (to be submitted).