Publications by authors named "Roman Timoshenko"

Article Synopsis
  • * Researchers used advanced microscopy techniques to analyze how different Aβ isoforms affect the mechanical properties (Young's modulus) and reactive oxygen species (ROS) levels in SH-SY5Y cells.
  • * Findings indicate that unmodified Aβ increases cell stiffness the most after 4 hours, whereas pS8-Aβ has the strongest effect on stiffness and ROS levels after 24 hours, suggesting that Aβ modifications influence cellular signaling pathways
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This study aims to investigate the potential role of antioxidants in oxidative stress and its consequent impact on the mechanical properties of neuronal cells, particularly the stress induced by amyloid-beta (1-42) (Aβ) aggregates. A key aspect of our research involved using scanning ion-conductance microscopy (SICM) to assess the mechanical properties (Young's modulus) of neuronal cells under oxidative stress. Reactive oxygen species (ROS) level was measured in single-cell using the electrochemical method by low-invasive Pt nanoelectrode.

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Five bifunctional copper chelating agents, , designed to prevent beta-amyloid (Aβ) aggregation, were synthesized, and the leader compound () was chosen. acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity. Reactive oxygen species measurements provided by the Pt-nanoelectrode technique in single Aβ-affected human neuroblastoma SH-SY5Y cells revealed significant antioxidant activity of .

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Background/objectives: One of the hallmarks of Alzheimer's disease (AD) is the accumulation of aggregated beta-amyloid (Aβ) protein in the form of senile plaques within brain tissue. Senile plaques contain various post-translational modifications of Aβ, including prevalent isomerization of Asp7 residue. The Asp7 isomer has been shown to exhibit increased neurotoxicity and induce amyloidogenesis in brain tissue of transgenic mice.

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Ethnopharmacological Relevance: Benja-ummarit (BU), a traditional Thai herbal formula, has been prescribed by traditional Thai practitioners for the treatment of liver cancer. Clinical trials of BU have shown an increase in overall survival in hepatocellular carcinoma (HCC) patients, including stage 1-3 (with or without prior standard chemotherapy) and terminal stage. The clinical outcomes differ from those of other apoptosis-based conventional chemotherapies.

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Zn-containing TiO-based coatings with Na, Ca, Si, and K additives were obtained by plasma electrolytic oxidation (PEO) of Ti in order to achieve an effective and broad bactericidal protection without compromising biocompatibility. A protocol has been developed for cleaning the coating surface from electrolyte residues, ensuring the preservation of the microstructure and composition of the surface layer. Using high-resolution transmission electron microscopy, three characteristic microstructural zones in the PEO-Zn coating are well documented: zone 1 with a TiO-based nanocrystalline structure, zone 2 with an amorphous structure, and zone 3 around pores with an amorphous-nanocrystalline structure.

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Article Synopsis
  • The paper discusses a new nanopipette sensor designed to detect copper ions, which is important for diagnosing and treating diseases like cancer and Alzheimer's.
  • This sensor can measure copper levels in various biological contexts, including individual cancer cells, tumor spheroids, and the brains of transgenic mouse models.
  • The research highlights the sensor's enhanced stability, selectivity, and effectiveness, making it a valuable tool for studying copper metabolism and the effectiveness of copper-based drugs.
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Bone implants with biocompatibility and the ability to biomineralize and suppress infection are in high demand. The occurrence of early infections after implant placement often leads to repeated surgical treatment due to the ineffectiveness of antibiotic therapy. Therefore, an extremely attractive solution to this problem would be the ability to initiate bacterial protection of the implant by an external influence.

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Article Synopsis
  • β-Amyloid aggregation on the surfaces of living cells is linked to neurotoxicity in neurodegenerative diseases, causing cellular function disruptions through processes like calcium ion internalization and apoptosis.
  • This aggregation affects the cytoskeleton, particularly actin filaments and microtubules, leading to changes in cell mechanical properties, including the Young's modulus.
  • The study utilized correlative scanning ion-conductance microscopy (SICM) to explore the relationships between Aβ aggregate formation, reactive oxygen species (ROS) levels, and the mechanical properties of cells, demonstrating how oxidative stress can influence cell stiffness.
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We report a one-pot plasma electrolytic oxidation (PEO) strategy for forming a multi-element oxide layer on the titanium surface using complex electrolytes containing NaHPO, Ca(OH), (NH)CO, NaSiO, CuSO, and KOH compounds. For even better bone implant ingrowth, PEO coatings were additionally loaded with bone morphogenetic protein-2 (BMP-2). The samples were tested in a mouse craniotomy model.

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In connection with the emergence of new pathogenic strains of , the search for more effective antifungal drugs becomes a challenge. Part of the preclinical trials of such drugs can be carried out using the innovative ion-conductance microscopy (ICM) method, whose unique characteristics make it possible to study the biophysical characteristics of biological objects with high accuracy and low invasiveness. We conducted a study of a novel synthesized thiazolidinedione's antimicrobial (for spp.

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Recently, nanopore technology has emerged as a promising technique for the rapid, sensitive, and selective detection of various analytes. In particular, the use of nanopores for the detection of copper ions has attracted considerable attention due to their high sensitivity and selectivity. This review discusses the principles of nanopore technology and its advantages over conventional techniques for copper detection.

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Prostate cancer is the second most common type of cancer among men. The main method of its treatment is androgen deprivation therapy, which has a wide range of side effects. One of the solutions to this challenge is the targeted delivery of drugs to prostate cancer cells.

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Peptide-based hydrogels were shown to serve as good matrices for 3D cell culture and to be applied in the field of regenerative medicine. The study of the cell-matrix interaction is important for the understanding of cell attachment, proliferation, and migration, as well as for the improvement of the matrix. Here, we used scanning ion conductance microscopy (SICM) to study the growth of cells on self-assembled peptide-based hydrogels.

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Electrochemical nano- and microsensors have been a useful tool for measuring different analytes because of their small size, sensitivity, and favorable electrochemical properties. Using such sensors, it is possible to study physiological mechanisms at the cellular, tissue, and organ levels and determine the state of health and diseases. In this review, we highlight recent advances in the application of electrochemical sensors for measuring neurotransmitters, oxygen, ascorbate, drugs, pH values, and other analytes in vivo.

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The biodistribution of chemotherapy compounds within tumor tissue is one of the main challenges in the development of antineoplastic drugs, and techniques for simple, inexpensive, sensitive, and selective detection of various analytes in tumors are of great importance. In this paper we propose the use of platinized carbon nanoelectrodes (PtNEs) for the electrochemical detection of platinum-based drugs in various biological models, including single cells and tumor spheroids and inside solid tumors . We have demonstrated the quantitative direct detection of Pt(II) in breast adenocarcinoma MCF-7 cells treated with cisplatin and a cisplatin-based DNP prodrug.

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A regio- and diastereoselective synthesis of two types of dispiro derivatives of 2-selenoxoimidazolidin-4-ones, differing in the position of the nitrogen atom in the central pyrrolidine ring of the spiro-fused system-namely, 2-selenoxodispiro[imidazolidine-4,3'-pyrrolidine-2',3″-indoline]-2″,5-diones () and 2-senenoxodispiro[imidazolidine-4,3'-pyrrolidine-4',3″-indoline]-2″,5-diones ()-were developed based on a 1,3-dipolar cycloaddition of azomethine ylides generated from isatin and sarcosine or formaldehyde and sarcosine to 5-arylidene or 5-indolidene-2-selenoxo-tetrahydro-4H-imidazole-4-ones. Selenium-containing dispiro indolinones generally exhibit cytotoxic activity near to the activity of the corresponding oxygen and sulfur-containing derivatives. Compounds , , and demonstrated considerable in vitro cytotoxicity in the 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) test (concentration of compounds that caused 50% death of cells (CC) 7.

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In this work, we have developed covalent and low molecular weight docetaxel delivery systems based on conjugation with -acetyl-d-galactosamine and studied their properties related to hepatocellular carcinoma cells. The resulting glycoconjugates have an excellent affinity to the asialoglycoprotein receptor (ASGPR) in the nanomolar range of concentrations and a high cytotoxicity level comparable to docetaxel. Likewise, we observed the 21-75-fold increase in water solubility in comparison with parent docetaxel and prodrug lability to intracellular conditions with half-life values from 25.

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