Gintautas Saulis - Academia.edu (original) (raw)

Papers by Gintautas Saulis

TechConnect Briefs, May 22, 2016

The aim of this study was to investigate the relationships between the energy of the PEF treatmen... more The aim of this study was to investigate the relationships between the energy of the PEF treatment required to electroporate the cell and pulse duration and to determine whether there exists the electric pulse with the minimum energy required to electroporate the cell. Experiments were performed in vitro with human erythrocytes and mouse hepatoma cell line MH-22A. Cell electroporation was determined from the extent of the release of intra-cellular K + and from the extent of erythrocyte lysis after long incubation at low temperature. Energy of an electric pulse required to electroporate the cell was a function of the pulse duration and there existed a minimum of the pulse energy required to porate the cell for both theoretical and experimental dependencies. It was situated in the range of 0.1-10 µs. It depended on the cell size and was about 0.13 and 0.07 J/g for human erythrocytes (radius 3.0 µm) and mouse hepatoma MH-22A cells (radius 7.7 µm), respectively.

Melanoma – is one of the most prevalent skin cancer form, which is formed often by the sun's ... more Melanoma – is one of the most prevalent skin cancer form, which is formed often by the sun's ultraviolet (UV) light and it damages DNA or do injuries for the skin cells. This cancer is one of the most diagnosed tumor in the USA. According to the Lithuanian Cancer Registry data, in 2012 the male and female skin cancer was one of the most abundant of the malignant oncological diseases locations (National Cancer Society, 2015). Concerning mortality, liver carcinoma is in the third place in the world. We need to find effective, non-invasive treatment that may cause cancer cells death except healthy tissue. Research shows that vitamin C (VC), vitamin (VK3) has anti-cancer features and using this compound, ratio 100:1 (VC:VK3), shows an increase of synergistic cytotoxicity. Cell’s damage are available of oxidative stress (caused by vitamins) during the reaction between free radicals compose reactive oxygen species (ROS) or their precursors, such as hydrogen peroxide. In this work, stu...

Vytauto Didžiojo universiteta

Article no. OR-191Biologijos katedraVytauto Didžiojo universiteta

Electroporation is an effective method for the modification of the cell membrane permeability wit... more Electroporation is an effective method for the modification of the cell membrane permeability with an increasing number of applications in biology, oncology, genetics, immunology, and biotechnology. When using high-voltage electrical pulses for treatment of cells and tissues, scientists must keep in mind that the products generated due to electrochemical reactions can influence various processes taking part in their experimental systems. Due to this, the efficiency of electroporation technique depends not only on the parameters of electric treatment but on the electrochemical processes as well. The primary anodic and cathodic electrochemical reactions and secondary processes that can take place during the treatment by high-voltage electrical pulses used in electroporation experiments are reviewed. These include pH changes (acidification around the anode and alkalinisation at the cathode), the production of H2, O2, and Cl2 gases, and the release of the metal ions from the electrodes....

Biologijos katedraVytauto Didžiojo universiteta

Bibliogr.: p. 248-357Lietuvoje ląstelių elektroporacijos reiškinys buvo pradėtas tyrinėti prieš b... more Bibliogr.: p. 248-357Lietuvoje ląstelių elektroporacijos reiškinys buvo pradėtas tyrinėti prieš beveik 25 metus. Deja, iki šiol apie šį reiškinį lietuvių kalba beveik nėra jokios spausdintos informacijos. Šiuo leidiniu autorius nori skaitytojus supažindinti su stiprių elektrinių laukų sukeliamo ląstelių elektroporacijos reiškinio atradimo, tyrimų ir pritaikymo raidos istorija bei suteikti pagrindinę informaciją apie ląstelių elektroporacijos reiškinio mechanizmą. Antroje monografijos dalyje trumpai aptariami įvairūs galimi elektroporacijos reiškinio mechanizmai. Monografija yra skirta doktorantams ir mokslininkams, tiriantiems stiprių elektrinių laukų poveikį bio¬loginėms membranoms bei taikantiems ląstelių elektroporaciją biologijoje, biotechnologijoje, medicinoje ar pramonėje, taip pat biofizikos, bioelektrochemijos ar biologijos specialistamsVytauto Didžiojo universiteta

Santrauka. Jau trejetą dešimtmečių žinoma, kad, biologines ląsteles paveikus trumpalaikiais, tači... more Santrauka. Jau trejetą dešimtmečių žinoma, kad, biologines ląsteles paveikus trumpalaikiais, tačiau stipriais elektriniais laukais, vyksta ląstelės plazminės membranos elektropermeabilizacija (elektroporacija), dėl to laikinai pakinta jos pralaidumas įvairiems cheminiams junginiams. Reiškinys vadinamas elektroporacija, arba elektropermeabilizacija. Dėl fizikinės prigimties ir paprastumo elektroporacija pradėta plačiai taikyti ląstelės biologijoje, biotechnologijoje ir medicinoje. Darbe pateikiama pagrindinių elektroporacijos in vitro pritaikymų-elektrosterilizacijos (electrosterilization), ląstelių apkrovimas bioaktyviosiomis medžiagomis (electroloading), elektrosuliejimo (electrofusion), elektroįvedimo (electroinsertion)-apžvalga. Neseniai elektroporacija buvo pritaikyta priešvėžinių vaistų (pvz., bleomicino) in vivo leidimui į navikines ląsteles. Naujas vėžio gydymo būdas-elektrochemoterapija-leidžia pasiekti stiprų gydymo atsaką net ir naudojant daug mažesnes bleomicino dozes. Vi...

Membranes, 2022

High-voltage pulses applied to a cell suspension cause not only cell membrane permeabilization, b... more High-voltage pulses applied to a cell suspension cause not only cell membrane permeabilization, but a variety of electrolysis reactions to also occur at the electrode–solution interfaces. Here, the cytotoxicity of a culture medium treated by a single electric pulse and the role of the iron ions in this cytotoxicity were studied in vitro. The experiments were carried out on mouse hepatoma MH-22A, rat glioma C6, and Chinese hamster ovary cells. The cell culture medium treated with a high-voltage pulse was highly cytotoxic. All cells died in the medium treated by a single electric pulse with a duration of 2 ms and an amplitude of just 0.2 kV/cm. The medium treated with a shorter pulse was less cytotoxic. The cell viability was inversely proportional to the amount of electric charge that flowed through the solution. The amount of iron ions released from the stainless steel anode (> 0.5 mM) was enough to reduce cell viability. However, iron ions were not the sole reason of cell death....

AbstractThe changes of the stainless-steel electrode surface morphology occurring due to dissolut... more AbstractThe changes of the stainless-steel electrode surface morphology occurring due to dissolution of the anode under the action of electric pulseswhich are commonly utilized in cell electromanipulation procedures, have been studied by using atomic force microscopy. The surface of thepolished electrode was rather smooth — the average roughness was 13–17 nm and the total roughness 140–180 nm. After the treatment of thechamber filled with 154 mM NaCl solution to a series of short (about 20 μs), high-voltage (4 kV) pulses, the roughness of the surface of the anodehas increased, depending on the total amount of the electric charge that has passed through the unit area of the electrode, and exceeded 400 nm forthe dissolution charge of 0.24 A s/cm 2 . No changes of the cathode surface were detected. Well-defined peaks with the width of 1–2 μm and theheight of over 400 nm have appeared. These peaks create local enhancements of the electric field at the interface between the solution and ...

The aim of this study was to estimate the energy barrier to pore formation at zero transmembrane ... more The aim of this study was to estimate the energy barrier to pore formation at zero transmembrane potential ∆Wf(0) and the pore radius r* corresponding to the top of this barrier for four different cell lines. Experiments were performed in vitro with two non-tumor cell lines (human erythrocytes and Chinese hamster ovary (CHO) cells) and two tumor cell lines (mouse hepatoma MH-22A and rat glioma C6 cells). Cell electroporation was determined from the extent of the release of intra-cellular K + . By comparing the theoretical dependences of the electric field strength required to create a single pore in the cell with the experimental dependences of the electric field strength required to electroporate 50% of cells on the pulse duration, the values of ∆Wf(0) and r* were estimated for each cell line. Obtained values were close to each other for erythrocytes, CHO, mouse hepatoma MH-22A, and rat glioma C6 cells and were in the range ∆Wf(0) = 41–43 kT, and r* = 0.3–0.35 nm.

International Journal of Biological Macromolecules, 2019

Kraft lignin is a polyphenolic compound generated as a by-product from the kraft pulping process ... more Kraft lignin is a polyphenolic compound generated as a by-product from the kraft pulping process in large quantities annually worldwide. In addition to its commercial availability, its structural features make it worth to be considered in the pharmaceutical area. The present study was carried out to evaluate in vitro antioxidant and cytotoxic properties of kraft lignin on mouse hepatoma MH-22A, melanoma B16 (tumor cells) and Chinese hamster ovary (CHO, noncancerous) cells. Moreover, several analytical techniques were used in order to elucidate the chemical structure of isolated industrial lignins (FT-IR, GPC, Py-GC-MS, 2D HSQC NMR). Results revealed high phenolic content in their composition, high-condensed structure and high phenolic hydroxyls group content. DPPH and ABTS *+ radical scavenging assays demonstrated their strong antioxidant activity, which was higher than found for commercial antioxidant (BHT). Kraft lignins act cytotoxically inducing apoptosis-and necrosis-like processes on both on tumor and normal cells. However, the results evidenced that MH-22A cells showed greater sensitive behavior than B16 and non-cancerous CHO cells, which were more tolerant of kraft lignin.

Carbohydrate Polymers, 2019

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Physicochemical and in vitro cytotoxic properties of chitosan from mushroom species (Boletus bovinus and Laccaria laccata

Acta Physica Polonica A, 2009

In this study the influence of high-voltage pulses on bleomycin cytotoxicity towards mouse hepato... more In this study the influence of high-voltage pulses on bleomycin cytotoxicity towards mouse hepatoma MH-22A and rat glioma C6 cells in vitro was determined. It was obtained that combining bleomycin with pulses of strong electric field significantly enhances the number of cells killed by bleomycin. Bleomycin alone was cytotoxic to both cell lines at concentrations above 1 µM. Treatment of cells by electric pulses in the presence of bleomycin greatly potentiated its cytotoxicity towards both cell lines tested-the bleomycin concentration required to reduce cell survival by 50% was 3.5-3.8 nM only. Exposure of cells to electric pulses only did not reduce cell viability.

Cellular and molecular life sciences : CMLS, Jan 16, 2016

Tumor ablation by nanosecond pulsed electric fields (nsPEF) is an emerging therapeutic modality. ... more Tumor ablation by nanosecond pulsed electric fields (nsPEF) is an emerging therapeutic modality. We compared nsPEF cytotoxicity for human cell lines of cancerous (IMR-32, Hep G2, HT-1080, and HPAF-II) and non-cancerous origin (BJ and MRC-5) under strictly controlled and identical conditions. Adherent cells were uniformly treated by 300-ns PEF (0-2000 pulses, 1.8 kV/cm, 50 Hz) on indium tin oxide-covered glass coverslips, using the same media and serum. Cell survival plotted against the number of pulses displayed three distinct regions (initial resistivity, logarithmic survival decline, and residual resistivity) for all tested cell types, but with differences in LD50 spanning as much as nearly 80-fold. The non-cancerous cells were less sensitive than IMR-32 neuroblastoma cells but more vulnerable than the other cancers tested. The cytotoxic efficiency showed no apparent correlation with cell or nuclear size, cell morphology, metabolism level, or the extent of membrane disruption by n...

The Journal of membrane biology, 2016

In this study, the role of the cell plasma membrane as a barrier in the mechanism of the cytotoxi... more In this study, the role of the cell plasma membrane as a barrier in the mechanism of the cytotoxicity of nitrogen-containing bisphosphonates and menadione was studied, and the possibility of increasing the efficiency of bisphosphonates and menadione (vitamin K3) as chemotherapeutic agents by permeabilizing the cell plasma membrane has been investigated in vitro. The plasma membrane barrier was reduced by electropermeabilization with the pulse of strong electric field. Two membrane-impermeant bisphosphonates with different hydrophilicities were chosen as study objects: ibandronate and pamidronate. For the comparison, an amphiphilic vitamin K3, which is able to cross the cell membrane, was studied as well. The impact of nitrogen-containing bisphosphonates and vitamin K3 on MH-22A cells viability was evaluated for the case of long (9 days) and short (20 min) exposure. When cells were cultured in the medium with vitamin K3 for 9-10 days, it exhibited toxicity of 50 % over the control at...

Acta Physica Polonica Series a, Jun 1, 2009

Biotechnology for Biofuels, 2016

Fossil resources-free sustainable development can be achieved through a transition to bioeconomy,... more Fossil resources-free sustainable development can be achieved through a transition to bioeconomy, an economy based on sustainable biomass-derived food, feed, chemicals, materials, and fuels. However, the transition to bioeconomy requires development of new energy-efficient technologies and processes to manipulate biomass feed stocks and their conversion into useful products, a collective term for which is biorefinery. One of the technological platforms that will enable various pathways of biomass conversion is based on pulsed electric fields applications (PEF). Energy efficiency of PEF treatment is achieved by specific increase of cell membrane permeability, a phenomenon known as membrane electroporation. Here, we review the opportunities that PEF and electroporation provide for the development of sustainable biorefineries. We describe the use of PEF treatment in biomass engineering, drying, deconstruction, extraction of phytochemicals, improvement of fermentations, and biogas production. These applications show the potential of PEF and consequent membrane electroporation to enable the bioeconomy and sustainable development.