Wyniki wyszukiwania - Biblioteka Nauki

1

Enhanced cytotoxicity of photosensitizers on cells in vitro by electroporation

100%

Labanauskiene J. , Knudsen M. , Gehl J. , Didziapetriene J. , Satkauskas S. , Venslauskas S.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2004

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tom Vol. 10, nr 1-2

39-39

2

Electroporation of transplantable tumors for the enhanced accumulation of photosensitizers

100%

Tamosiunas M. , Labanauskiene J. , Bagdonas S. , Didziapetriene J. , Rotomskis R.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2004

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tom Vol. 10, nr 1-2

42-42

3

The favourable effect of catechin in electrochemotherapy in human pancreatic cancer cells

100%

Michel O. , Przystupski D. , Saczko J. , Szewczyk A. , Niedzielska N. , Rossowska J. , Kulbacka J.

Acta Biochimica Polonica

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2018

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tom 65

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nr 2

173-184

EN

Until recently, green tea polyphenols were considered strong antioxidants. However, the latest reports have revealed that bioflavonoids can play a multiple role in anticancer therapy, including the inhibition of cell proliferation and generation of the oxidative stress in a dose-dependent manner. The presented research was designed to examine the potential of the green tea (±)-catechin as a reinforcement of the electrochemotherapy (ECT) with cisplatin in pancreatic cancer in vitro. The study was performed on two cell lines of the pancreatic ductal adenocarcinoma (PDA) - parental EPP85-181P and multidrug-resistant EPP85-181RNOV. Prior to the ECT protocol the cells were preincubated with high or low concentration of catechin for 2 or 24 hours, respectively. We assessed the influence of preincubation on the cisplatin toxicity with and without electroporation (EP), the electrosensitivity of PDA cell lines and the uptake of the daunorubicin and propidium iodide. Additionally, we evaluated the antioxidative properties of catechin by the measurement of the ROS-related fluorescence and the immunoreactivity of the oxidative stress-related enzymes superoxide dismutase (SOD2) and glutathione S-transferase (GST). We found that co-treatment with catechin can firmly enhance the efficacy of electroporation with cisplatin in vitro. More favorable effect was obtained for 2-hour incubation, which indicates the involvement of the transcriptional-independent mechanisms of catechin action. The effect may be partially explained by the increased oxidative stress level, which was higher in multidrug-resistant cells. However, further studies on cisplatin-catechin interplay and the thorough examination of the catechin-cell membrane interaction need to be performed.

4

A numerical study on the effect of conductivity change in cell kill distribution in irreversible electroporation

100%

Khorasani A.

Polish Journal of Medical Physics and Engineering

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2020

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tom Vol. 26, Iss. 2

69--76

EN

Introduction: irreversible electroporation (IRE) is a tissue ablation technique and physical process used to kill the undesirable cells. In the IRE process by mathematical modelling we can calculate the cell kill probability and distribution inside the tissue. The purpose of the study is to determine the influence of electric conductivity change in the IRE process into the cell kill probability and distribution. Methods: cell death probability and electric conductivity were calculated with COMSOL Multiphysics software package. 8 pulses with a frequency of 1 Hz, pulse width of 100 μs and electric field intensity from 1000 to 3000 V/Cm with steps of 500 V/Cm used as electric pulses. Results: significantly, the electrical conductivity of tissue will increase during the time of pulse delivery. According to our results, electrical conductivity increased with an electric field intensity of pulses. By considering the effect of conductivity change on cell kill probability, the cell kill probability and distribution will change. Conclusion: we believe that considering the impact of electric conductivity change on the cell kill probability will improve the accuracy of treatment outcome in the clinic for treatment with IRE.

5

Electroporation of transplantable tumors for the enhanced accumulation of photosensitizers

86%

Tamosiunas M. , Bagdonas S. , Didziapetriene J. , Rotomskis R.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2006

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tom Vol. 12, nr 1

57-59

EN

The aim of this study was to verify whether electroporation could affect the accumulation of the hydrophilic photosensitizers: aluminum phthalocyanine tetrasulphonate (AIPcS4) and chlorin e6 (Ce6) in tumor tissue. The experiment was performed in vitro using hybrid mice (C57B1/CBA) bearing the tumors transplanted in the right haunch. The fluorescence intensity of photosensitizers was measured from the surface of the skin covering tumors at different time intervals after the ordinary (passive) and electrically enhanced delivery. The fluorescence spectroscopy results imply that electrical field affected the tumors in a way, which led to the higher accumulation of both photosensitizers (AIPcS4 and e6) in the periphery and the superficial layers of tumors.

PL

Celem badań była ocena wpływu elektroporacji na gromadzenie się w tkankach nowotworowych fotouczulaczy hudrofilowych, tj.:tetrasulfonian glinku ftalecyjaniny (AIPcS4), chlorin e6 (Ce6). W doświadczeniu in vitro użyto hybryd mysz (C57B1/CBA) po wcześniejszym przeszczepieniu komórek nowotworowych. Zmierzono natężenie fluorescencji fotouczulacza z powierzchni skóry pokrywającej zmiany nowotworowe. Badania przeprowadzono w różnych odstępach czasu, po pasywnych i elektrycznie wspomaganych procesach. Wyniki spektroskopii fluorescencyjnej sugerują, iż pole elektryczne wpływa na nowotwory, prowadząc do intensywniejszej akumulacji obu fotouczulaczy (AIPcS4 i e6) w obwodowej oraz powierzchniowej warstwie zmian patologicznych.

6

Nonviral transfection of human umbilical cord blood dendritic cells is feasible, but the yield of dendritic cells with transgene expression limits the application of this method in cancer immunotherapy

86%

Markowicz S. , Niedzielska J. , Kruszewski M. , Ołdak T. , Gajkowska A. , Machaj E. K. , Skurzak H. , Pojda Z.

Acta Biochimica Polonica

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2006

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tom 53

|

nr 1

203-212

EN

Dendritic cells (DC) generated from human umbilical cord blood might replace patients' DC in attempts to elicit tumor-specific immune response in cancer patients. We studied the efficiency of transfection of human cord blood DC with plasmid DNA carrying the enhanced version of green fluorescent protein (EGFP) as a reporter gene, to test if nonviral gene transfer would be a method to load DC with protein antigens for immunotherapy purposes. Cord blood mononuclear cells were cultured in serum-free medium in the presence of granulocyte-monocyte colony stimulating factor (GM-CSF), stem cell factor (SCF) and Flt-3 ligand (FL), to generate DC from their precursors, and thereafter transfected by electroporation. Maturation of DC was induced by stimulation with GM-CSF, SCF, FL and phorbol myristate acetate (PMA). Transfected DC strongly expressed EGFP, but transfection efficiency of DC, defined as HLA-DR+ cells lacking lineage-specific markers, did not exceed 2.5%. Expression of the reporter gene was also demonstrated in the DC generated from transfected, purified CD34+ cord blood cells, by stimulation with GM-CSF, SCF, FL, and tumor necrosis factor α (TNF-α). Transfection of CD34+ cells was very efficient, but proliferation of the transfected cells was much reduced as compared to the untransfected cells. Therefore, the yield of transgene-expressing DC was relatively low. In conclusion, nonviral transfection of cord blood DC proved feasible, but considering the requirements for immunotherapy in cancer patients, transfection of differentiated DC or generation of DC from transfected hematopoietic stem cells provide only a limited number of DC expressing the transgene.

7

Wpływ produktów utlenienia lipidów na właściwości oraz proces elektroporacji dwuwarstwowych płaskich błon lipidowych

86%

Misiak H. , Kubica K.

Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna

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2017

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tom Vol. 23, nr 4

229--245

PL

Alternatywnym sposobem zwiększenia biernej przepuszczalności błon biologicznych dla cząsteczek biologicznie aktywnych, w tym leków, jest elektroporacja. Pod wpływem pola elektrycznego o odpowiednich parametrach w fazie lipidowej błon biologicznych pojawiają się pory. Podatność błony na elektroporację zależy od wielu czynników, w tym otoczenia komórki oraz od stanu lipidów tworzących błony. Wyniki badań doświadczalnych oraz teoretycznych dotyczące wpływu wybranych produktów utlenienia lipidów na podatność błony na elektroporację nie prowadzą do jednoznacznych konkluzji. Celem niniejszej pracy jest zbadanie wpływu wszystkich produktów utlenienia lecytyny jajecznej obecnych w utlenionej lecytynie na przebieg elektroporacji. Produkty utlenienia lecytyny zbadano techniką spektroskopii podczerwieni. Pomiary wartości parametrów elektrycznych i elektroporacyjnych utworzonych błon przeprowadzono za pomocą potencjostatu-galwanostatu w układzie 4-elektrodowym. Porównanie wyników badań z użyciem błon utworzonych z lecytyny utlenionej oraz nieutlenionej wykazało spadek wartości pojemności właściwej, wzrost rezystancji oraz stabilności błony zawierającej produkty utlenionej lecytyny. Uzyskane wyniki badań mogą być przydatne w optymalizacji protokołów elektroporacyjnych u pacjentów szczególnie narażonych na czynniki utleniające np. większą ekspozycję na UV.

EN

An alternative way of increasing the passive permeability of biological membranes to biologically active molecules, including drugs, is electroporation. Electric field of the relevant parameters applied to biological membranes creates pores in lipid part of membranes. Membrane susceptibility to electroporation depends on many factors: external environment of the cell, as well as a condition of membrane lipids. The results of experimental and theoretical research on influence of selected products of lipid oxidation on membrane susceptibility to electroporation do not lead to clear conclusions. The aim of this study is to examine the impact of all the products of oxidation of egg lecithin on the electroporation process. The oxidation of lecithin was examined by infrared spectroscopy. Measurements of the electrical membrane characteristics and parameters of electroporation were performed using a potentiostat-galvanostat in a four-electrode system. Comparison of the results obtained in experiments performed on oxidized and unoxidized lecithin have revealed a decline in the value of the specific capacity, an increase in the resistance, and stability of the membrane containing the oxidized lipids. These results may be useful in optimizing protocols of electroporation for patients, particularly those exposed to oxidizing agents, e.g. exposure to UV.

8

Opposite effects of electroporation of red blood cell membranes under the influence of zinc ions

86%

Kozlova. E. , Chernysh A. , Moroz V. , Sergunova V. , Gudkova O. , Fedorova M. , Kuzovlev A.

Acta of Bioengineering and Biomechanics

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2012

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tom Vol. 14, nr 1

3-13

EN

The goal of the study was to investigate the effects of zinc ions of various concentrations on the nanostructure of membrane of red blood cells in in vitro experiment. The suspension of red blood cells extracted from whole human blood was used. The calibrated electroporation and the atomic force microscopy (AFM) were used to analyse damage to membrane nanostructure. We studied the haemolysis after the electroporation at different zinc concentrations. A low concentration of zinc (0.15-0.5 mM) increased significantly the rate of haemolysis and reduced the residual level of non-haemolyzed cells. At high concentrations of zinc ions (0.5-10 mM), the rate constant was sharply reduced, at the same time the residual level increased. The relationship between haemoglobin coagulants and the zinc concentration was examined. High concentration of zinc caused haemoglobin aggregation. It was shown by AFM that the membrane nanostructure was essentially changed. It was experimentally established that there existed a special point of zinc concentration C = 0.5 +- 0.1 mM at which the course of the conjugate processes on the membranes of red blood cells was changed.

9

Efficiency of chicken blastoderm cell transfection combining two nonviral methods: electroporation and synthetic carriers

86%

Kinal A. , Kozlowska I. , Lakota P. , Wawrzynska M. , Kijewska E.

Folia Biologica

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2017

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tom 65

|

nr 1

10

On stability of circular hole in membrane bilayer

86%

Fosnaric M. , Kralj-Iglic V. , Hagerstrand H. , Iglic A.

Cellular and Molecular Biology Letters

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2001

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tom 06

|

nr 2

11

Messenger RNA electroporation: an efficient tool in immunotherapy and stem cell research

86%

Van Driessche A. , Ponsaerts P. , Van Bockstaele D. R. , Van Tendeloo V. F. I. , Berneman Z. N.

Folia Histochemica et Cytobiologica

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2005

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tom 43

|

nr 4

12

Transient expression assay for optimization of direct gene transfer into cucumber meristem protoplasts by electroporation

86%

Burza W. , Wochniak P. , Wroblewski T. , Malepszy S.

Journal of Applied Genetics

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1995

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tom 36

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nr 1

EN

The paper presents a new way of obtaining viable and very homogeneous cucumber protoplasts. Protoplasts from cells formed in the shoot tip meristem culture were isolated from suspension. Plasmid pBI121 was introduced using impulse electric field. Effectiveness of transformation process was determined by the transient expression of ß-glucuronidase (GUS) gene, controlled by promotor 35S. The activity of ß-glucuronidase enzyme as a product of GUS reporter gene was estimated by fluorimetric method (JEFFERSON 1987). Parameters of electroporation process were optimized. The transient expression of GUS gene was measured 24 h after electroporation. The highest effectiveness of transformation process was achieved using three electric impulses at the initial voltage of 250-350 V at 10-sec. intervals as a result of discharging a 140 µF capacitor and 50-70 µg × cm⁻³ plasmid DNA in the presence of 50 µg × cm⁻³ carrier DNA. The system presented is an effective method of exogenic DNA transfer, which is indicated by a high transient expression of the reporter gene. In comparison to Agrobacterium tumefaciens and A. rhizogenes, this alternative method of gene transfer can be used for obtaining transgenic cucumber plants.

13

Electroporation of Thiobacillus versutus with plasmid DNA

86%

Wlodarczyk M. , Jagusztyn-Krynicka E. K. , Bartosik D. , Kalinowska I.

Acta Microbiologica Polonica

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1994

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tom 43

|

nr 2

14

Cholesterol-induced variations in fluctuations of the pores in bilayer lipid membrane

86%

Koronkiewicz S. , Bryl K.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 4

EN

The constant-current chronopotentiometric measurements of egg yolk phosphatidylcholine bilayer membrane without and with cholesterol are presented. It was demonstrated that the constant-intensity current flow through the bilayer membranes without and with cholesterol generated the oscillating pores in their structures. The presence of cholesterol in the bilayer membrane increased the value of critical potential at which pores could be formed. The shift in the distribution of calculated pore radii towards smaller values was observed in the bilayer containing cholesterol. It was postulated that greater stability of bilayer with cholesterol resulted from increased critical pore radius (at which the bilayer would rupture). The implications of the membrane cholesterol for the application of constant-current method as a biotechnological tool for incorporating molecules of different size are discussed.

15

Membrane electroporation: EPR estimation of pore resealing time

86%

Salwinski L. , Froncisz W.

Current Topics in Biophysics

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1994

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tom 18

|

nr 1

16

Nowe technologie utrwalania żywności – badania modelowe

72%

Skowron M. , Wantuch A.

Przegląd Elektrotechniczny

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2020

|

tom R. 96, nr 2

125--128

PL

Pulsacyjne pole elektromagnetyczne (PEF) o wysokim natężeniu jest stosunkowo nową, nietermiczną technologią konserwacji żywności. Opiera się ona na wykorzystaniu pól elektrycznych do eliminowania patogenów i kontrolowania mikroorganizmów powodujących psucie się żywności. Podstawową zaletą tej technologii jest zdolność do przedłużania okresu trwałości produktów spożywczych bez wykorzystania ciepła. Dzięki temu możliwe jest zachowanie odpowiedniej jakości oraz wartości odżywczych i smakowych. W artykule przedstawiono technologię PEF, możliwości jej zastosowania oraz badania modelowe.

EN

High intensity pulsed electromagnetic field (PEF) is a relatively new, non-thermal food preservation technology. It is based on the use of electric fields to eliminate pathogens and control food spoilage microorganisms. The main advantage of this technology is the ability to extend the shelf life of food products without using heat. Thanks to this, it is possible to preserve the right quality as well as nutritional and taste values. The article presents PEF technology, the possibilities of its application and model research.

17

Influence of electroporation on chicken blastoderm cell viability in vitro

72%

Wawrzynska M. , Bednarczyk M. , Lakota P. , Lubiszewska M.

Folia Biologica

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2008

|

tom 56

|

nr 3-4

197-201

18

Electroporation and morphogenic potential of Gentiana kurroo (Royle) embryogenic cell suspension protoplasts

72%

Wojcik A. , Rybczynski J. J.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

|

2015

|

tom 96

|

nr 1

19

Reversible and irreversible electroporation of cell suspensions flowing through a localized dc electric field

72%

Korohoda W. , Grys M. , Madeja Z.

Cellular and Molecular Biology Letters

|

2013

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tom 18

|

nr 1

EN

Experiments on reversible and irreversible cell electroporation were carried out with an experimental setup based on a standard apparatus for horizontal electrophoresis, a syringe pump with regulated cell suspension flow velocity and a dcEF power supply. Cells in suspension flowing through an orifice in a barrier inserted into the electrophoresis apparatus were exposed to defined localized dcEFs in the range of 0–1000 V/cm for a selected duration in the range 10–1000 ms. This method permitted the determination of the viability of irreversibly electroperforated cells. It also showed that the uptake by reversibly electroperforated cells of fluorescent dyes (calcein, carboxyfluorescein, Alexa Fluor 488 Phalloidin), which otherwise do not penetrate cell membranes, was dependent upon the dcEF strength and duration in any given single electrical field exposure. The method yields reproducible results, makes it easy to load large volumes of cell suspensions with membrane non-penetrating substances, and permits the elimination of irreversibly electroporated cells of diameter greater than desired. The results concur with and elaborate on those in earlier reports on cell electroporation in commercially available electroporators. They proved once more that the observed cell perforation does not depend upon the thermal effects of the electric current upon cells. In addition, the method eliminates many of the limitations of commercial electroporators and disposable electroporation chambers. It permits the optimization of conditions in which reversible and irreversible electroporation are separated. Over 90% of reversibly electroporated cells remain viable after one short (less than 400 ms) exposure to the localized dcEF. Experiments were conducted with the AT-2 cancer prostate cell line, human skin fibroblasts and human red blood cells, but they could be run with suspensions of any cell type. It is postulated that the described method could be useful for many purposes in biotechnology and biomedicine and could help optimize conditions for in vivo use of both reversible and irreversible electroporation.

20

In vitro evaluation of electroporated gold nanoparticles and extremely-low frequency electromagnetic field anticancer activity against Hep-2 laryngeal cancer cells

72%

Alshehri M. A. , Wierzbicki P. M. , Kaboo H. F. , Nasr M. S. M. , Amer M. E. , Abuamara T. M. M. , Badr D. A. , Saleh K. A. , Fazary A. E. , Mohamed A. F.

Folia Histochemica et Cytobiologica

|

2019

|

tom 57

|

nr 4