Roman Wrzalik

Dr. Roman Wrzalik

orcid

Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 November 2017 in Journal of Materials Science
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KJKarolina Jurkiewicz
Karolina Jurkiewicz
MPMiroslawa Pawlyta
Miroslawa Pawlyta
DZD. Zygadło
D. Zygadło
DCDariusz Chrobak
Dariusz Chrobak
SDS. Duber
S. Duber
ABAndrzej Burian
Andrzej Burian
In order to accommodate an increasing demand for glassy carbon products with tailored characteristics, one has to understand the origin of their structure-related properties. In this work, through the use of high-resolution transmission electron microscopy, Raman spectroscopy, and electron energy loss spectroscopy it has been demonstrated that the structure of glassy carbon at different stages of the carbonization process resembles the curvature observed in fragments of nanotubes, fullerenes, or nanoonions. The measured nanoindentation hardness and reduced Young’s modulus change as a function of the pyrolysis temperature from the range of 600–2500 °C and reach maximum values for carbon pyrolyzed at around 1000 °C. Essentially, the highest values of the mechanical parameters for glassy carbon manufactured at that temperature can be related to the greatest amount of non-planar sp2-hybridized carbon atoms involved in the formation of curved graphene-like layers. Such complex labyrinth-like structure with sp2-type bonding would be rigid and hard to break that explains the glassy carbon high strength and hardness.

31 January 2021 in Molecules
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ECElwira Chrobak
Elwira Chrobak
MJMaria Jastrzębska
Maria Jastrzębska
EBEwa Bębenek
Ewa Bębenek
MKMonika Kadela-Tomanek
Monika Kadela-Tomanek
Krzysztof MarciniecKrzysztof Marciniec
Krzysztof Marciniec
SBStanisław Boryczka
Stanisław Boryczka
A series of 30-diethylphosphate derivatives of betulin were synthesized and evaluated for their in vitro cytotoxic activity against human cancer cell lines, such as amelanotic melanoma (C-32), glioblastoma (SNB-19), and two lines of breast cancer (T47D, MDA-MB-231). The molecular structure and activities of the new compounds were also compared with their 29-phosphonate analogs. Compounds 7a and 7b showed the highest activity against C-32 and SNB-19 cell lines. The IC50 values for 7a were 2.15 and 0.91 μM, and, for 7b, they were 0.76 and 0.8 μM for the C-32 and SNB-19 lines, respectively. The most potent compounds, 7a and 7b, were tested for their effects on markers of apoptosis, such as H3, TP53, BAX, and BCL-2. For the whole series of phosphate derivatives, a lipophilicity study was performed, and the ADME parameters were calculated. The most active products were docked to the active site of the EGFR protein. The relative binding affinity of selected phosphate betulin derivatives toward EGFR was compared with standard erlotinib on the basis of ChemScore and KDEEP score. Positively, all derivatives docked inside the cavity and showed significant interactions. Moreover, a molecular dynamics study also reveals that ligands 7a,b form stable complexes and the plateau phase started after 7 ns.


11 May 2010 in Journal of Materials Science
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MJMaria Jastrzębska
Maria Jastrzębska
IMIwona Mróz
Iwona Mróz
BBBogdan Barwiński
Bogdan Barwiński
RWRoman Wrzalik
Roman Wrzalik
SBStanisław Boryczka
Stanisław Boryczka

17 September 2020 in Materials
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DTDorota Tarnawska
Dorota Tarnawska
KBKatarzyna Balin
Katarzyna Balin
MJMaria Jastrzębska
Maria Jastrzębska
ATAgnieszka Talik
Agnieszka Talik
RWRoman Wrzalik
Roman Wrzalik
An intraocular lens (IOL) is a synthetic, artificial lens placed inside the eye that replaces a natural lens that is surgically removed, usually as part of cataract surgery. The opacification of the artificial lens can be related to the formation of the sediments on its surface and could seriously impair vision. The physicochemical analysis was performed on an explanted hydrophilic IOL and compared to the unused one, considered as a reference IOL. The studies were carried out using surface sensitive techniques, which can contribute to a better understanding of the sedimentation process on hydrophilic IOLs’ surfaces. The microscopic studies allowed us to determine the morphology of sediments observed on explanted IOL. The photoelectron spectroscopy measurements revealed the presence of organic and inorganic compounds at the lens surface. Mass spectroscopy measurements confirmed the chemical composition of deposits and allowed for chemical imaging of the IOL surface. Applied techniques allowed to obtain a new set of information approximating the origin of the sediments’ formation on the surface of the hydrophilic IOLs after Descemet’s stripping endothelial keratoplasty.

Verified
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ASArkadiusz Sokal
Arkadiusz Sokal
RWRoman Wrzalik
Roman Wrzalik
MLMałgorzata Latocha
Małgorzata Latocha
MKMonika Kadela-Tomanek
Monika Kadela-Tomanek
Anticancer drug design has been reformed by the creation of heterocyclic hybrids. The introduction of a quinoline scaffold affects the activity, toxicity, and bioavailability of new compounds. The aim of this study was to synthesize and evaluate the biological activity of hybrids of 1,4-naphthoquinone with the 8-hydroxyquinoline moiety. The structure of the new compounds was characterized using spectroscopic methods, such as HR-MS, NMR, and IR. The analysis was supplemented by calculated NMR and IR spectra. The physicochemical properties and bioavailability of the compounds were examined using in silico methods. An analysis of reactivity descriptors showed that the compounds are good electron acceptors and exhibit high reactivity. Bioavailability properties confirm that hybrids could be good oral administration drugs. The biological potential of hybrids was examined by designation of the enzymatic conversion rate of the NQO1 protein and in vitro against cancer cell lines with overexpression of the gene encoding the NQO1 protein. The possibility of interaction between the tested ligand and the NQO1 protein was examined by molecular docking methods.