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Iliev I, Mavrova A, Yancheva D, Dimov S, Staneva G, Nesheva A, Tsoneva I, Nikolova B. 2-Alkyl-Substituted-4-Amino-Thieno[2,3- d]Pyrimidines: Anti-Proliferative Properties to In Vitro Breast Cancer Models. Molecules 2023; 28:6347. [PMID: 37687177 PMCID: PMC10489817 DOI: 10.3390/molecules28176347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
Thienopyrimidines are structural analogs of quinazolines, and the creation of new 2-alkyl derivatives of ethyl 4-aminothienopyrimidine-6-carboxylates for the study of their anti-proliferative properties is of great pharmacological interest. Some 2-alkyl-4-amino-thieno[2,3-d]pyrimidines 2-5 were synthesized, and their cyto- and phototoxicity against BALB 3T3 cells were established by an in vitro 3T3 NRU test. The obtained results indicate that the tested compounds are not cytotoxic or phototoxic, and that they are appropriate to be studied for their anti-proliferative and anti-tumor properties. The anti-proliferative potential of the compounds was investigated on MCF-7 and MDA-MB-231 cancer cells, as well as a MCF-10A cell line (normal human mammary epithelial cells). The most toxic to MCF-7 was thienopyrimidine 3 with IC50 13.42 μg/mL (IC50 0.045 μM), followed by compound 4 (IC50 28.89 μg/mL or IC50 0.11 μM). The thienopyrimidine 4 revealed higher selectivity to MCF-7 and lower activity (IC50 367 μg/mL i.e., 1.4 μM) than compound 3 with MCF-10A cells. With respect to MDA-MB-231 cells, ester 2 manifested the highest effect with IC50 52.56 μg/mL (IC50 0.16 μM), and 2-ethyl derivative 4 revealed IC50 62.86 μg/mL (IC50 0.24 μM). It was estimated that the effect of the substances on the cell cycle progression was due to cell cycle arrest in the G2 stage for MDA-MB-231, while arrest in G1 was detected for the estrogen (ER)-positive MCF-7 cell line. The tested compound's effects on the change of the zeta potential in the tumorigenic cells utilized in this study were determined. The calculation which we performed of the physicochemical properties and pharmacokinetic parameters influencing the biological activity suggested high intestinal absorption, as well as drug-likeness.
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Affiliation(s)
- Ivan Iliev
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 25, 1113 Sofia, Bulgaria;
| | - Anelia Mavrova
- Department of Organic Chemistry, Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, S8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria; (A.M.); (S.D.)
| | - Denitsa Yancheva
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 9, 1113 Sofia, Bulgaria;
| | - Stefan Dimov
- Department of Organic Chemistry, Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, S8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria; (A.M.); (S.D.)
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria; (A.N.); (I.T.)
| | - Alexandrina Nesheva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria; (A.N.); (I.T.)
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria; (A.N.); (I.T.)
| | - Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 21, 1113 Sofia, Bulgaria; (A.N.); (I.T.)
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Robev B, Iliev I, Tsoneva I, Momchilova A, Nesheva A, Kostadinova A, Staneva G, Nikolova B. Antitumor Effect of Iscador on Breast Cancer Cell Lines with Different Metastatic Potential. Int J Mol Sci 2023; 24:ijms24065247. [PMID: 36982323 PMCID: PMC10049140 DOI: 10.3390/ijms24065247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Studies were performed for the first time on the effect of Iscador Qu and Iscador M on phototoxicity, cytotoxicity, antiproliferative activity, changes in ξ-potential of cells, membrane lipid order, actin cytoskeleton organization and migration on three breast cancer lines with different metastatic potential: MCF10A (control), MCF-7 (low metastatic) and MDA-MB231 (high metastatic) cells. The tested Iscador Qu and M did not show any phototoxicity. The antiproliferative effect of Iscador species appeared to be dose-dependent and was related to the metastatic potential of the tested cell lines. A higher selectivity index was obtained for Iscador Qu and M towards the low metastatic MCF-7 cell line compared to the high metastatic MDA-MB-231. Iscador Qu demonstrated higher selectivity for both cancer cell lines compared to Iscador M. The malignant cell lines exhibited a decrease in fibril number and thickness regardless of the type of Iscador used. The strongest effect on migration potential was observed for the low metastatic cancer cell line MCF-7 after Iscador treatment. Both Iscador species induced a slight increase in the percentage of cells in early apoptosis for the low and high metastatic cell lines, MCF-7 and MDA-MB-231, unlike control cells. Changes in the zeta potential and membrane lipid order were observed for the low metastatic MCF-7 cell line in contrast to the high metastatic MDA-MB-231 cells. The presented results reveal a higher potential of Iscador as an antitumor agent for the low metastatic cancer cell line MCF-7 compared to the high metastatic one. Iscador Qu appears to be more potent compared to Iscador M, but at this point, the exact mechanism of action is still unclear and needs further investigations.
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Affiliation(s)
- Bozhil Robev
- Department of Medical Oncology, University Hospital “Sv. Ivan Rilski”, 15 Acad. Ivan Geshov Blvd., 1431 Sofia, Bulgaria
| | - Ivan Iliev
- Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 25, 1113 Sofia, Bulgaria
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - Albena Momchilova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
- Correspondence:
| | - Alexandrina Nesheva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - Aneliya Kostadinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
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Semkova S, Nikolova B, Tsoneva I, Antov G, Ivanova D, Angelov A, Zhelev Z, Bakalova R. Redox-mediated Anticancer Activity of Anti-parasitic Drug Fenbendazole in Triple-negative Breast Cancer Cells. Anticancer Res 2023; 43:1207-1212. [PMID: 36854536 DOI: 10.21873/anticanres.16267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 03/02/2023]
Abstract
BACKGROUND/AIM An increasing number of studies are reporting anticancer activity of widely used antiparasitic drugs and particularly benzimidazoles. Fenbendazole is considered safe and tolerable in most animal species at the effective doses as an anthelmintic. Little is known about the redox-modulating properties of fenbendazole and the molecular mechanisms of its antiproliferative effects. Our study aimed to investigate the possibility of selective redox-mediated treatment of triple-negative breast cancer cells by fenbendazole without affecting the viability and redox status of normal breast epithelial cells. MATERIALS AND METHODS The experiments were performed on three cell lines: normal breast epithelial cells (MCF-10A) and cancer breast epithelial cells (MCF7 - luminal adenocarcinoma, low metastatic; MDA-MB-231 - triple-negative adenocarcinoma, highly metastatic). Cells were treated with fenbendazole for 48-h and three parameters were analyzed using conventional assays: cell viability and proliferation, level of intracellular superoxide, and level of hydroperoxides. RESULTS The data demonstrated that MDA-MB-231 cells were more vulnerable to fenbendazole-induced oxidative stress than MCF-7 cells. In normal breast epithelial cells MCF-10A, fenbendazole significantly suppressed oxidative stress compared to untreated controls. These data correlate with the effect of fenbendazole on cell viability and the IC50 values, which is indirect evidence of the potential targeting anticancer effect of the drug, especially in MDA-MB-231 cells. CONCLUSION The difference in the levels of oxidative stress induced by fenbendazole in MDA-MB-231 and MCF-7 indicates that the two types of breast cancer respond to the drug through different redox-related mechanisms.
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Affiliation(s)
- Severina Semkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria;
| | - Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Georgi Antov
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Donika Ivanova
- Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria
| | - Anton Angelov
- Thoracic Surgery, Acıbadem City Clinic Tokuda Hospital, Sofia, Bulgaria
| | - Zhivko Zhelev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Faculty of Medicine, Trakia University, Stara Zagora, Bulgaria
| | - Rumiana Bakalova
- Department of Molecular Imaging and Theranostics, National Institutes for Quantum Science and Technology (QST), Chiba, Japan; .,Faculty of Medicine, Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
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Dimov S, Mavrova AT, Yancheva D, Nikolova B, Tsoneva I. Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti- Breast Cancer (MDA-MB-231, MCF-7) Agents. Anticancer Agents Med Chem 2021; 21:1441-1450. [PMID: 32698751 DOI: 10.2174/1871520620666200721131431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/08/2020] [Accepted: 06/17/2020] [Indexed: 11/22/2022]
Abstract
AIMS The purpose of this study was the synthesis of some new thienopyrimidine derivatives of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity against MDA-MB-231, MCF-7, and 3T3 cells lines. BACKGROUND An overexpression or mutational activation of TK receptors EGFR and HER2/neu is characteristic of tumors. It has been found that some thieno[2,3-d]pyrimidines exhibited better inhibitory activity against Epidermal Growth Factor Receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDA-MB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragments in order to evaluate their cytotoxicity to the above-mentioned cell lines. OBJECTIVE The objectives of the study were to design and synthesize a novel series of thieno[2,3-d]pyrimidines bearing biologically active moieties, such as 1,3-disubstituted-benzimidazole heterocycle, structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, and MCF-7 breast cancer cell lines. METHODS N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium The interaction of chloroethyl-2-thienopyrimidines, 2-amino-benzimidazole and benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions led to new thienopyrimidines. MTT assay for cell survival was performed in order to evaluate the cytotoxicity of the tested compounds. A fluorescence study was conducted to elucidate some aspects of the mechanism of action. RESULTS The effects of nine synthesized compounds were investigated towards MDA-MB-231, MCF-7 and 3T3 cell lines. Thieno[2,3-d]pyirimidine-4-one 16 (IC50 - 0.058μM) and 21 (IC50 - 0.029μM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most cytotoxic compounds against breast cancer MCF-7 cells was compound 21 (IC50 - 0.074μM), revealing lower cytotoxicity against mouse fibroblast 3T3 cells with IC50 - 0.20μM. SAR analysis was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of the mechanism of action. CONCLUSION The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.
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Affiliation(s)
- Stefan Dimov
- Department of Organic Synthesis, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria
| | - Anelia Ts Mavrova
- Department of Organic Synthesis, University of Chemical Technology and Metallurgy, 8 Kliment Ohridski Blvd., 1756 Sofia, Bulgaria
| | - Denitsa Yancheva
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Build. 9, 1113 Sofia, Bulgaria
| | - Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Build. 21, 1113 Sofia, Bulgaria
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Build. 21, 1113 Sofia, Bulgaria
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Dimitrova D, Nikolova B, Bogoeva V, Robev B, Tsoneva I, Dimitrov S, Kadinov B. Do Mistletoe (Viscum album L.) Lectins Influence Isometric Contraction of Non-diseased Human Mesenteric Arteries ex vivo? Int J Bioautomation 2021. [DOI: 10.7546/ijba.2021.25.1.000788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Mistletoe (Viscum album L., VA) lectins (MLs) are plant lectins with potent anticancer activity. Although wide use of VA extracts in curing cancer, the effects of purified MLs on human vasculature in term of possible side effect of the lectin has not yet been reported. The present study was aimed to investigate isometric contractions of isolated human mesenteric arteries during MLs application. The contractile response of arteries was studied using Mulvany-Halpern myograph and the isometric contractions under MLs’ treatment were examined in artery segments with either intact endothelium or after endothelium removal. Furthermore, the effect of the lectin was assessed in arterial preparations in basal tension, in arteries precontracted with 42 mM KCl as a depolarizing stimulus or endothelin-1 (ET-1) as a potent receptor-operated agonist of vascular smooth muscle contraction. The results showed that MLs (1 to 100 nM) failed to affect the high K+-induced contractions of both endothelium-intact and endothelium-denuded arteries. The contractions of tissue preparations without endothelium in basal tone or after ET-1 (1 nM) treatment were also not affected by the application of MLs. The observed mild effect of MLs on the contractility of human vasculature may potentially be beneficial with MLs-based anticancer therapy without vascular side effects.
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Nikolova B, Semkova S, Tsoneva I, Stoyanova E, Lefterov P, Lazarova D, Zhelev Z, Aoki I, Higashi T, Bakalova R. Redox-related Molecular Mechanism of Sensitizing Colon Cancer Cells to Camptothecin Analog SN38. Anticancer Res 2020; 40:5159-5170. [PMID: 32878804 DOI: 10.21873/anticanres.14519] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/26/2020] [Accepted: 07/27/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The aim of this study was to elucidate the possibility of sensitizing colon cancer cells to the chemotherapeutic drug SN38 and investigate its mechanism of action after combined treatment with electroporation (EP). MATERIALS AND METHODS Cells were treated with SN38, EP and their combination for 24/48 h. The cell viability, actin cytoskeleton integrity, mitochondrial superoxide, hydroperoxides, total glutathione, phosphatidyl serine expression, DNA damages and expression of membrane ABC transporters were analyzed using conventional analytical tests. RESULTS The combination of EP and SN38 affected cell viability and cytoskeleton integrity. This effect was accompanied by: (i) high production of intracellular superoxide and hydroperoxides and depletion of glutathione; (ii) increased DNA damage and apoptotic/ferroptotic cell death; (iii) changes in the expression of membrane ABC transporters - up-regulation of SLCO1B1 and retention of SN38 in the cells. CONCLUSION The anticancer effect of the combined treatment of SN38 and EP is related to changes in the redox-homeostasis of cancer cells, leading to cell death via apoptosis and/or ferroptosis. Thus, electroporation has a potential to increase the sensitivity of cancer cells to conventional anticancer therapy with SN38.
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Affiliation(s)
- Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences (NIRS), and
| | - Severina Semkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences (NIRS), and.,Group of Quantum-State Controlled MRI, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Elena Stoyanova
- Institute of Biology and Immunology of Reproduction "Acad. Kiril Bratanov", Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Pavel Lefterov
- Faculty of Educational Studies and the Arts, Sofia University, Sofia, Bulgaria
| | | | - Zhivko Zhelev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Medical Faculty, Trakia University, Stara Zagora, Bulgaria
| | - Ichio Aoki
- Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences (NIRS), and.,Group of Quantum-State Controlled MRI, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Tatsuya Higashi
- Group of Quantum-State Controlled MRI, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Rumiana Bakalova
- Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences (NIRS), and .,Group of Quantum-State Controlled MRI, Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,Medical Faculty, Sofia University, Sofia, Bulgaria
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Kadinov B, Nikolova B, Tsoneva I, Semkova S, Kabaivanova L, Dimitrova D. Trehalose Lipid Biosurfactant Reduced Cancer Cell Viability but Did not Affect the Isometric Contraction of Rat Mesenteric Arteries in vitro. Int J Bioautomation 2020. [DOI: 10.7546/ijba.2020.24.1.000708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Nikolova B, Antov G, Semkova S, Tsoneva I, Christova N, Nacheva L, Kardaleva P, Angelova S, Stoineva I, Ivanova J, Vasileva I, Kabaivanova L. Bacterial Natural Disaccharide (Trehalose Tetraester): Molecular Modeling and in Vitro Study of Anticancer Activity on Breast Cancer Cells. Polymers (Basel) 2020; 12:E499. [PMID: 32102469 PMCID: PMC7077702 DOI: 10.3390/polym12020499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 12/24/2022] Open
Abstract
Isolation and characterization of new biologically active substances affecting cancer cells is an important issue of fundamental research in biomedicine. Trehalose lipid was isolated from Rhodococcus wratislaviensis strain and purified by liquid chromatography. The effect of trehalose lipid on cell viability and migration, together with colony forming assays, were performed on two breast cancer (MCF7-low metastatic; MDA-MB231-high metastatic) and one "normal" (MCF10A) cell lines. Molecular modeling that details the structure of the neutral and anionic form (more stable at physiological pH) of the tetraester was carried out. The tentative sizes of the hydrophilic (7.5 Å) and hydrophobic (12.5 Å) portions of the molecule were also determined. Thus, the used trehalose lipid is supposed to interact as a single molecule. The changes in morphology, adhesion, viability, migration, and the possibility of forming colonies in cancer cell lines induced after treatment with trehalose lipid were found to be dose and time dependent. Based on the theoretical calculations, a possible mechanism of action and membrane asymmetry between outer and inner monolayers of the bilayer resulting in endosome formation were suggested. Initial data suggest a mechanism of antitumor activity of the purified trehalose lipid and its potential for biomedical application.
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Affiliation(s)
- Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (G.A.); (S.S.); (I.T.)
| | - Georgi Antov
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (G.A.); (S.S.); (I.T.)
- Institute of Plant Physiology and Genetics Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (J.I.); (I.V.)
| | - Severina Semkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (G.A.); (S.S.); (I.T.)
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (G.A.); (S.S.); (I.T.)
| | - Nelly Christova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 26, 1113 Sofia, Bulgaria; (N.C.); (L.N.)
| | - Lilyana Nacheva
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 26, 1113 Sofia, Bulgaria; (N.C.); (L.N.)
| | - Proletina Kardaleva
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 9, 1113 Sofia, Bulgaria; (P.K.); (I.S.)
| | - Silvia Angelova
- Institute of Optical Materials and Technologies “Acad. Jordan Malinowski”, Bulgarian Academy of Sciences, Sofia, “Acad. G. Bonchev” Str., Bl. 109, 1113 Sofia, Bulgaria;
| | - Ivanka Stoineva
- Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 9, 1113 Sofia, Bulgaria; (P.K.); (I.S.)
| | - Juliana Ivanova
- Institute of Plant Physiology and Genetics Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (J.I.); (I.V.)
| | - Ivanina Vasileva
- Institute of Plant Physiology and Genetics Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 21, 1113 Sofia, Bulgaria; (J.I.); (I.V.)
| | - Lyudmila Kabaivanova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, “Acad. G. Bonchev” Str., Bl. 26, 1113 Sofia, Bulgaria; (N.C.); (L.N.)
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Nikolova B, Semkova S, Tsoneva I, Antov G, Ivanova J, Vasileva I, Kardaleva P, Stoineva I, Christova N, Nacheva L, Kabaivanova L. Characterization and potential antitumor effect of a heteropolysaccharide produced by the red alga Porphyridium sordidum. Eng Life Sci 2019; 19:978-985. [PMID: 32624987 PMCID: PMC6999067 DOI: 10.1002/elsc.201900019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/25/2019] [Accepted: 07/01/2019] [Indexed: 01/18/2023] Open
Abstract
Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all chemotherapy drugs currently on the market cause serious side effects. Fortunately, several studies have shown that some non-toxic biological macromolecules, including algal polysaccharides, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Polysaccharides are characteristic secondary metabolites of many algae. The efficacy of polysaccharides on the normal and cancer cells is not well investigated, but our investigations proved a cell specific effect of a newly isolated extracellular polysaccharide from the red microalga Porphyridium sordidum. The investigated substance was composed of xylose:glucose and galactose:manose:rhamnose in a molar ratio of 1:0.52:0.44:0.31. Reversible electroporation has been exploited to increase the transport through the plasma membrane into the tested breast cancer tumor cells MCF-7 and MDA-MB231. Application of 75 µg/mL polysaccharide in combination with 200 V/cm electroporation induced 40% decrease in viability of MDA-MB231 cells and changes in cell morphology while control cells (MCF10A) remained with normal morphology and kept vitality.
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Affiliation(s)
- Biliana Nikolova
- Institute of Biophysics and Biomedical EngineeringBulgarian Academy of SciencesSofiaBulgaria
| | - Severina Semkova
- Institute of Biophysics and Biomedical EngineeringBulgarian Academy of SciencesSofiaBulgaria
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical EngineeringBulgarian Academy of SciencesSofiaBulgaria
| | - Georgi Antov
- Institute of Biophysics and Biomedical EngineeringBulgarian Academy of SciencesSofiaBulgaria
| | - Juliana Ivanova
- Institute of Plant Physiology and GeneticsBulgarian Academy of SciencesSofiaBulgaria
| | - Ivanina Vasileva
- Institute of Plant Physiology and GeneticsBulgarian Academy of SciencesSofiaBulgaria
| | - Proletina Kardaleva
- Institute of Organic Chemistry with Centre of PhytochemistryBulgarian Academy of SciencesSofiaBulgaria
| | - Ivanka Stoineva
- Institute of Organic Chemistry with Centre of PhytochemistryBulgarian Academy of SciencesSofiaBulgaria
| | - Nelly Christova
- The Stephan Angeloff Institute of MicrobiologyBulgarian Academy of SciencesSofiaBulgaria
| | - Lilyana Nacheva
- The Stephan Angeloff Institute of MicrobiologyBulgarian Academy of SciencesSofiaBulgaria
| | - Lyudmila Kabaivanova
- The Stephan Angeloff Institute of MicrobiologyBulgarian Academy of SciencesSofiaBulgaria
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Semkova S, Nikolova B, Zhelev Z, Tsoneva I, Zlateva G, Aoki I, Bakalova R. Loading Efficiency of Polymersomes with Contrast Agents and their Intracellular Delivery: Quantum Dots Versus Organic Dyes. Anticancer Res 2018; 38:825-831. [PMID: 29374708 DOI: 10.21873/anticanres.12290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM Contrast nanocarriers as drug-delivery systems, capable of selective delivery to cancer cells and solid tumors, are essential for the development of new diagnostic and therapeutic (theranostic) strategies. The present study aimed to investigate the loading efficiency of chitosan-based polymersomes with fluorescent contrast substances [quantum dots (QDs) and conventional organic dyes] and the possibility to control their release from the polymer matrix into cells by chemical modifications and electroporation. MATERIALS AND METHODS All investigated fluorophores were retained within the polymer globule via electrostatic and hydrophilic-hydrophobic interactions, without conjugation with the polymer. The fluorophore-loaded polymersomes were characterized by dynamic light scattering, zeta-potential titration, and fluorescence spectroscopy. The release of fluorophore from the polymersomes, passively or after electroporation, was detected by 5-step spin-ultrafiltration, combined with fluorescence spectroscopy of the upper phase (supernatant) of the filter unit. Passive intracellular delivery of the nanoparticles to HeLa cells was detected by fluorescence confocal microscopy. RESULTS The QDs were retained tightly and continuously in the polymer matrix, while the organic fluorophores [fluorescein isothiocyanate (FITC), FITC-dextran10,000 and FITC-dextran70,000] were released rapidly from the polymersomes. The detergent Brij significantly increased the retention of FITC-dextran10,000 in the polymer globule. Electroporation up to 1000 V/cm did not induce release of QDs from the polymersomes, but accelerated the release of Brij-treated FITC-dextran10,000 B from the polymer matrix. High-voltage pulses (over 750 V/cm) induced also fragmentation or aggregation of the nanoparticles. QD_labeled polymersomes penetrated passively in cancer cells after 24-hour incubation. CONCLUSION The results suggest that QD-labeled polymersomes are appropriate fluorescent probes and a nano-drug delivery system with high tracing opportunities for in vitro and in vivo applications. Furthermore, loading polymersomes with organic dyes with different molecular weights (such as FITC-dextrans) is a simple model for visualizing and predicting the rate of release of small organic molecules (e.g. conventional drugs, other contrasts, stabilizers, and supplements) from the polymer matrix.
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Affiliation(s)
- Severina Semkova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Zhivko Zhelev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.,Medical Faculty, Trakia University, Stara Zagora, Bulgaria
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | | | - Ichio Aoki
- Department of Molecular Imaging and Theranostics, National Institutes for Quantum and Radiological Sciences (QST/NIRS), Inage, Japan.,Group of Quantum-state Controlled MRI, National Institutes for Quantum and Radiological Sciences (QST/NIRS), Inage, Japan
| | - Rumiana Bakalova
- Medical Faculty, Sofia University, Sofia, Bulgaria .,Department of Molecular Imaging and Theranostics, National Institutes for Quantum and Radiological Sciences (QST/NIRS), Inage, Japan.,Group of Quantum-state Controlled MRI, National Institutes for Quantum and Radiological Sciences (QST/NIRS), Inage, Japan
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Bakalova R, Zhelev Z, Nikolova B, Murayama S, Lazarova D, Tsoneva I, Aoki I. Lymph node mapping using quantum dot-labeled polymersomes. Gen Physiol Biophys 2016. [PMID: 26221745 DOI: 10.4149/gpb_2015007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study was designed to investigate whether poly-ion complex hollow vesicles (polymersomes), based on chemically-modified chitosan, are appropriate for lymph node mapping in the context of their application in the development of theranostic nanosized drug delivery systems (nano-DDS). The experiments were performed on Balb/c nude mice (colon cancer-grafted). The mice were subjected to anesthesia and quantum dot (QD(705))-labeled polymersomes (d-120 nm) were injected intravenously via the tail vein. The optical imaging was carried out on Maestro EX Imaging System (excitation filter: 435-480 nm; emission filter: 700 nm). A strong fluorescent signal, corresponding to QD(705) fluorescence, was detected in the lymph nodes, as well as in the tumor. A very weak fluorescent signal was found in the liver area. The half-life of QD(705)-labelled polymersomes was 6 ± 2 hours in the bloodstream and 11 ± 3 hours in the lymph nodes. The data suggest that polymersomes are very promising carriers for lymph node mapping using QD as a contrast agent. They are useful matrix for development of nano-formulations with theranostic capabilities.
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Dodoff NI, Iordanov I, Tsoneva I, Grancharov K, Detcheva R, Pajpanova T, Berger MR. Cytotoxic Activity of Platinum(II) and Palladium(II) Complexes of N-3-Pyridinylmethanesulfonamide: the Influence of Electroporation. ACTA ACUST UNITED AC 2014; 64:179-85. [DOI: 10.1515/znc-2009-3-405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The series of complexes: cis-[Pd(PMSA)2X2], cis-[Pt(PMSA)2X2], trans-[Pt(PMSA)2I2] and [Pt(PMSA)4]Cl2 (PMSA = N-3-pyridinylmethanesulfonamide; X = Cl, Br, I), previously synthesized and characterized by us, as well as the free ligand PMSA, were tested for their cytotoxic activity without electroporation - against murine leukemia F4N and human SKW-3 and MDA-MB-231 tumour cell lines - and with electroporation - against the latter two cell lines. The majority of the complexes exhibited cytotoxic effects (IC50 < 100 μmol/l) under the conditions of electroporation. Both cis- and trans-[Pt(PMSA)2I2] had pronounced cytotoxic effects (29 - 61 μmol/l against MDA-MB-231 cells).
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Affiliation(s)
| | - Iordan Iordanov
- Institute of Biophysics, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 21, 1113 Sofia, Bulgaria
| | - Iana Tsoneva
- Institute of Biophysics, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 21, 1113 Sofia, Bulgaria
| | - Konstantin Grancharov
- Institute of Molecular Biology “Acad. R. Tsanev”, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 21, 1113 Sofia, Bulgaria
| | - Roumyana Detcheva
- Institute of Molecular Biology “Acad. R. Tsanev”, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 21, 1113 Sofia, Bulgaria
| | - Tamara Pajpanova
- Institute of Molecular Biology “Acad. R. Tsanev”, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, Block 21, 1113 Sofia, Bulgaria
| | - Martin R. Berger
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
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Pehlivanova V, Uzunova V, Tsoneva I, Berger MR, Ugrinova I, Tzoneva R. Effect of Erufosine on the Reorganization of Cytoskeleton and Cell Death in Adherent Tumor and Non-Tumorigenic Cells. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.5504/bbeq.2012.0120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Nikolova B, Kostadinova A, Dimitrov B, Zhelev Z, Bakalova R, Aoki I, Saga T, Tsoneva I. Fluorescent imaging for assessment of the effect of combined application of electroporation and rifampicin on HaCaT cells as a new therapeutic approach for psoriasis. Sensors (Basel) 2013; 13:3625-34. [PMID: 23493125 PMCID: PMC3658765 DOI: 10.3390/s130303625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 02/13/2013] [Accepted: 03/06/2013] [Indexed: 11/26/2022]
Abstract
The study aimed to clarify the role of electric pulses in combination with chemotherapy on the viability of keratinocyte cell line HaCaT, in the context of its application as a new therapeutic approach for psoriasis. The data show that electroporation of HaCaT cells in combination with rifampicin induces cytoskeleton disruption and increases permeability of cell monolayer due to cell-cell junctions' interruption, visualized by fluorescent imaging of E-cadherin and actin integrity. This was accompanied with synergistic reduction of cell viability. The study proposes a new opportunity for more effective skin treatment than chemotherapy. The future application of this electrochemotherapeutic approach for combined local treatment of psoriasis may have serous benefits because of a high possibility to avoid side-effects of conventional chemotherapy.
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Affiliation(s)
- Biliana Nikolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad.G. Bonchev Str., bl. 21, Sofia 1113, Bulgaria; E-Mails: (B.N.); (A.K.); (B.D.); (Z.Z.); (I.T.)
| | - Anelia Kostadinova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad.G. Bonchev Str., bl. 21, Sofia 1113, Bulgaria; E-Mails: (B.N.); (A.K.); (B.D.); (Z.Z.); (I.T.)
| | - Borislav Dimitrov
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad.G. Bonchev Str., bl. 21, Sofia 1113, Bulgaria; E-Mails: (B.N.); (A.K.); (B.D.); (Z.Z.); (I.T.)
| | - Zhivko Zhelev
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad.G. Bonchev Str., bl. 21, Sofia 1113, Bulgaria; E-Mails: (B.N.); (A.K.); (B.D.); (Z.Z.); (I.T.)
- Medical Faculty, Trakia University, 11 Armeiska Str., Stara Zagora 6000, Bulgaria
| | - Rumiana Bakalova
- Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; E-Mails: (I.A.); (T.S.)
- Medical Faculty, Sofia University, 1 Koziak Str., Sofia 1407, Bulgaria
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-42-206-3274; Fax: +81-42-206-9470
| | - Ichio Aoki
- Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; E-Mails: (I.A.); (T.S.)
| | - Tsuneo Saga
- Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; E-Mails: (I.A.); (T.S.)
| | - Iana Tsoneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad.G. Bonchev Str., bl. 21, Sofia 1113, Bulgaria; E-Mails: (B.N.); (A.K.); (B.D.); (Z.Z.); (I.T.)
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Escoffre JM, Nikolova B, Mallet L, Henri J, Favard C, Golzio M, Teissie J, Tsoneva I, Rols MP. New Insights in the Gene Electrotransfer Process: Evidence for the Involvement of the Plasmid DNA Topology. Curr Gene Ther 2012; 12:417-22. [DOI: 10.2174/156652312802762554] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 06/01/2012] [Accepted: 06/01/2012] [Indexed: 11/22/2022]
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Tzoneva R, Weckwerth C, Seifert B, Behl M, Heuchel M, Tsoneva I, Lendlein A. In vitro evaluation of elastic multiblock co-polymers as a scaffold material for reconstruction of blood vessels. J Biomater Sci Polym Ed 2010; 22:2205-26. [PMID: 21073803 DOI: 10.1163/092050610x537147] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There is a need to create cell- and histocompatible implant materials, which might temporarily replace the mechanical function of a native tissue for regenerative therapies. To match the elastic behavior of the native tissue two different multiblock co-polymers were investigated: PDC, consisting of poly(p-dioxanone) (PPDO)/poly(ε-caprolactone) (PCL), and PDD, based on PPDO/poly((adipinate-alt-1,4-butanediol)-co-(adipinate-alt-ethylene glycol)-co-adipinate-alt-diethylene glycol) (Diorez). PDC is capable of a shapememory effect. Both multiblock co-polymers show an improved elasticity compared to materials applied in established vascular prosthesis. PDD is softer than PDC at 20°C, while PDC maintains its elasticity at 37°C. Thermodynamic characteristics indicate a more polar surface of PDD. Low cell adhesion was found on surfaces with low molar free energy of hysteresis (ΔG) derived from contact angle measurements in wetting and dewetting mode and high cell adhesion on high-ΔG surfaces. An increasing content of PCL in PDC improved cell adhesion and spreading of human umbilical vein endothelial cells. The prothrombotic potential of PDD is higher than PDC. Finally, it is concluded that PDC is a promising material for vascular tissue engineering because of its improved elastic properties, as well as balanced prothrombotic and anti-thrombotic properties with endothelial cells.
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Affiliation(s)
- Rumiana Tzoneva
- Institute of Biophysics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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Tsoneva I, Iordanov I, Berger AJ, Tomov T, Nikolova B, Mudrov N, Berger MR. Electrodelivery of drugs into cancer cells in the presence of poloxamer 188. J Biomed Biotechnol 2010; 2010:314213. [PMID: 20706647 PMCID: PMC2913842 DOI: 10.1155/2010/314213] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 04/07/2010] [Accepted: 06/10/2010] [Indexed: 12/21/2022] Open
Abstract
In the present study it is shown that poloxamer 188, added before or immediately after an electrical pulse used for electroporation, decreases the number of dead cells and at the same time does not reduce the number of reversible electropores through which small molecules (cisplatin, bleomycin, or propidium iodide) can pass/diffuse. It was suggested that hydrophobic sections of poloxamer 188 molecules are incorporated into the edges of pores and that their hydrophilic parts act as brushy pore structures. The formation of brushy pores may reduce the expansion of pores and delay the irreversible electropermeability. Tumors were implanted subcutaneously in both flanks of nude mice using HeLa cells, transfected with genes for red fluorescent protein and luciferase. The volume of tumors stopped to grow after electrochemotherapy and the use of poloxamer 188 reduced the edema near the electrode and around the subcutaneously growing tumors.
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Affiliation(s)
- Iana Tsoneva
- Institute of Biophysics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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20
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Peycheva E, Daskalov I, Tsoneva I. Electrochemotherapy of Mycosis fungoides by interferon-alpha. Bioelectrochemistry 2006; 70:283-6. [PMID: 17150416 DOI: 10.1016/j.bioelechem.2006.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 09/15/2006] [Accepted: 10/13/2006] [Indexed: 12/21/2022]
Abstract
Eight patients with 29 lesions of histologically verified 1st stage of Mycosis fungoides were successfully treated by electrochemotherapy with interferon-alpha. For this purpose 8 biphasic pulses were used, each of 50+50 micros duration with 900 micros interpulse intervals, resulting in a burst of 7.1 ms total duration. Compared to the traditional monoimmunotherapy with interferon-alpha applied three times weekly for a total of 4 weeks, the electrochemotherapy was very efficient. Complete response (CR) was observed in 25 (86%) of the 29 treated lesions by single-act electrochemotherapy with interferon-alpha. At the end of the 12-month period, all 29 lesions showed 100% complete response (CR). New lesions for a period of 12 months were not observed. The expected mechanism involved in multiple cytotoxic action of interferon-alpha could be the local increased concentration in the tumour and prolongation of the time of its action after the application of pulses.
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Affiliation(s)
- E Peycheva
- National Centre of Oncology, Clinic of Oncodermatology, 6 Plovdivsko pole Blv., 1756 Sofia, Bulgaria
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Tsoneva I, Nikolova B, Georgieva M, Guenova M, Tomov T, Rols MP, Berger MR. Induction of apoptosis by electrotransfer of positively charged proteins as Cytochrome C and Histone H1 into cells. Biochim Biophys Acta Gen Subj 2005; 1721:55-64. [PMID: 15652179 DOI: 10.1016/j.bbagen.2004.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 07/21/2004] [Accepted: 10/07/2004] [Indexed: 11/28/2022]
Abstract
Cytochrome C (Cyt. C) is a mitochondrial protein inducing apoptosis when it is accumulated in the cytosol by a currently unknown mechanism, but regulated by the bcl-2 family of proteins. The linker Histone H1 is another basic protein with highly conservative structure, composition, and equal molecular weight, not changed during the evolution. An attempt was made to understand better the apoptotic processes by electroloading of leukemic cells, such as K562, HL-60, and SKW3, and human lymphocytes with positively charged proteins, such as Cyt. C, Histone H1, and methylated BSA albumin (mBSA). The triggering apoptotic processes followed by MTT test, FACS analysis, and DNA fragmentation after the electrotransfer of these proteins into the cells were observed. Histone H1 and mBSA induce the release of Cyt. C from rat liver mitochondria. Cytochrome C release was higher when mitochondria were in "high-energy" state. It is supposed that release of Cyt. C from mitochondria is due to the mechanical rupture of the outer mitochondrial membrane, rich in negatively charged groups, predominately due to cardiolipin. The reason for the morphological rupture of the outer mitochondial membrane could be the rigidification and segregation of the membrane and the destroyed membrane asymmetries of both monolayers in the presence of positively charged proteins at higher linear charges such as Histone H1. We suggested that Histone H1, at a given moment of activated signaling for apoptosis, could be not transported to the nucleus and could lead to the release of Cyt. C from the mitochondria in the cytoplasm. It is temping to speculate that Histone H1 has other physiological extranuclear functions involved in apoptosis.
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Affiliation(s)
- I Tsoneva
- Institute of Biophysics, Bulg. Acad. Sci., Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
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Berger MR, Tsoneva I, Konstantinov SM, Eibl H. Induction of apoptosis by erucylphospho-N,N,N-trimethylammonium is associated with changes in signal molecule expressionand location. Ann N Y Acad Sci 2004; 1010:307-10. [PMID: 15033740 DOI: 10.1196/annals.1299.054] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
At concentrations effecting apoptosis, the alkylphosphocholine ErPC3 induced increased expression of the Rb protein in breast cancer (MCF-7) and leukemia (SKW-3, AR-230) cell lines as well as hypophosphorylation (K-562, CMLT-1, DOHH-2) and fragmentation of Rb (BV-173, SKW-3) in leukemia cell lines. ErPC3 exerts at least part of its antineoplastic activity by apoptosis, and this chain of events comprises early changes in the lipid raft fraction of the cellular membrane as well as modulation of different signal molecules, such as Abl, Bcr-Abl (fusion protein), and Rb.
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Affiliation(s)
- Martin R Berger
- Unit of Toxicology and Chemotherapy, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Hristova NI, Angelova MI, Tsoneva I. An experimental approach for direct observation of the interaction of polyanions with sphingosine-containing giant vesicles. Bioelectrochemistry 2002; 58:65-73. [PMID: 12401572 DOI: 10.1016/s1567-5394(02)00124-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new approach for direct optical microscopy observation of polyanion interactions with bilayers of giant cationic liposomes (GUVs) was suggested. Polyanions as DNA, dextran sulfate (DS), heparin (H) and polyacrylic acids (PA) were locally delivered by a micropipette to a part of a giant unilamellar vesicle membrane. The phenomena were directly observed under optical microscope. GUVs, about 100 micro m in diameter, formed of phosphatidylcholines and up to 33 mol% of the natural bioactive cationic amphiphile sphingosine (Sph), were prepared by electroformation. The effects of water-soluble molecules with high negative linear charge density as dextran sulfate (DS), heparin (H) polyacrylic acids (PA) and adenosine-5'-triphosphoric acid (ATP) were compared with those of DNAs. The resulting membrane topology transformations were monitored in phase contrast, while the DNA distribution was followed in fluorescence. DNA-induced endocytosis-like membrane morphology transformation due to the DNA/lipid membrane local interactions was observed. The DS, H and PA induced membrane topology transformations similar to those of the DNAs, while ATP did not cause any detectable ones. The endocytosis mechanism involves the formation of ordered domains in the GUV membrane where some surface and charge asymmetries between the two membrane monolayers were created. The sizes of created polyanionic/cationic membrane domains depend on the form, length and elasticity of the adsorbed highly charged molecules. Endosome-including capacities of polyanionic molecules depend heavily on the high linear negative charge at a certain length. An original method for direct studying of the DNA/membrane interactions in autoadaptable giant liposome system imitating biological membrane interactions was forwarded. The model observations could also help for understanding events associated with cationic liposome/DNA complex formation in gene transfer processes.
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Affiliation(s)
- N I Hristova
- Institute of Biophysics, Bulgarian Academy of Sciences, Acad. G. Bonchev Str, Bl.21, 1113, Sofia, Bulgaria
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Dimitrov V, Stoimenova M, Tsoneva I. Electrically induced concentration fluctuations in Escherichia coli suspensions. Colloids Surf A Physicochem Eng Asp 2002. [DOI: 10.1016/s0927-7757(02)00181-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
The electrodes used for electroporation, electrofusion, and electrotransfection, as well as in electrochemotherapy should not interact with the object and release electrolysis products. We studied how far the stainless steel electrodes fulfil these requirements. The results showed that in the case of the exponential electric pulses with amplitude of 3 kV cm(-1) and time constant of 0.5 ms, the stainless steel electrodes released ferrous ions to a concentration of several micromoles per liter. We determined experimentally the dependence of the amount of the released ferrous ions on the pulse parameters and on the ionic strength of the medium. It was shown that the released ferrous ions should not be ignored. They could be of importance for the bleomycin electrochemotherapy.
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Affiliation(s)
- T Tomov
- Institute of Biophysics, Bulgarian Academy of Sciences, Sofia
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Abstract
DNA interactions with the bilayers of cationic liposomes were studied using a novel model experiment: DNAs were locally injected by a micropipette to a part of a giant unilamellar vesicle. The resulting phenomena were directly observed in optical microscope. Giant unilamellar vesicles (GUVs), about 100 microm in diameter, made of phosphatidylcholines and up to 33 mol% of the natural bioactive cationic amphiphile sphingosine, were obtained by electroformation. The effects of DNAs of different length were tested: (i) 'short' DNAs-oligonucleotide 21b, and calf thymus 250 bp; (ii) 'long' DNAs-plasmid DNAs in super coil or liner form (between 2.7 and 8.0 kbp). DNAs were injected native, as well as marked with the fluorescent dye Hoechst. The resulting membrane topology transformations were monitored in phase contrast, while the DNA distribution was followed in fluorescence. DNA-induced endocytosis was observed due to the DNA/lipid membrane local interactions for all DNAs tested. Some of the DNA in the formed complex was associated with the induced endosomes, and some of it remained spread over the 'mother' GUV membrane for all DNAs tested, except for the longest one--the linear plasmid of 8 kbp. The last remained at the 'mother' GUV membrane and was not transported with the induced endosomes to the internal GUV space. Possible mechanisms for DNA/lipid membrane interaction were suggested. One of them involves DNA encapsulation within an inverted micelle included in the lipid membrane. The model observations could help in understanding events associated with interaction of DNA with biological membranes, as well as cationic liposomes/DNA complexes formation in gene transfer processes.
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Affiliation(s)
- M I Angelova
- Institute of Biophysics, Bulgarian Academy of Sciences, Sofia.
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Abstract
We suggest a novel approach for direct optical microscopy observation of DNA interaction with the bilayers of giant cationic liposomes. Giant unilamellar vesicles, about 100 microns in diameter, made of phosphatidyl-cholines and up to 33 mol% of the natural bioactive cationic amphiphile sphingosine, were obtained by electroformation. "Short" DNAs (oligonucleotide 21 b and calf thymus 250 bp) were locally injected by micropipette to a part of the giant unilamellar vesicle (GUV) membrane. DNAs were injected native, as well as marked with a fluorescent dye. The resulting membrane topology transformations were monitored in phase contrast, while DNA distribution was followed in fluorescence. We observed DNA-induced endocytosis due to the DNA/lipid membrane local interactions and complex formation. A characteristic minimum concentration (Cendo) of D-erythrosphingosine (Sph+) in the GUV membrane was necessary for the endocytic phenomenon to occur. Below Cendo, only lateral adhesions between neighboring vesicles were observed upon DNA local addition. Cendo depends on the type of zwitterionic (phosphocholine) lipid used, being about 10 mol% for DPhPC/Sph+ GUVs and about 20 mol% for SOPC/Sph+ or eggPC/Sph+ GUVs. The characteristic sizes and shapes of the resulting endosomes depend on the kind of DNA, and initial GUV membrane tension. When the fluorescent DNA marker dye was injected after the DNA/lipid local interaction and complex formation, no fluorescence was detected. This observation could be explained if one assumes that the DNA is protected by lipids in the DNA/lipid complex, thereby inaccessible for the dye molecules. We suggest a possible mechanism for DNA/lipid membrane interaction involving DNA encapsulation within an inverted micelle included in the lipid membrane. Our model observations could help in understanding events associated with the interaction of DNA with biological membranes, as well as cationic liposomes/DNA complex formation in gene transfer processes.
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Affiliation(s)
- M I Angelova
- Institute of Biophysics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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Abstract
When the cationic sphingosine is present in planar lipid bilayers, the adsorption of pDNA is enhanced and the electroporatability of the bilayer is facilitated. Furthermore, pDNA, adsorbed to lipid bilayers composed of diphytanoyl lecithin and D-sphingosine causes electroporative channel-like events of conductance 1 to 7 pS, provided the voltage polarity is correct and the voltage is high enough, Vm > or = +30 mV. The data suggest electrotransport of pDNA through the bilayer, mediated by transient complexes between DNA and the lipids in the pore edges of elongated, electropercolated hydrophilic pore zones. The results are the basis for the optimisation of electroporative transfer of DNA or oligonucleotides to cells and tissue.
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Affiliation(s)
- N I Hristova
- Institute of Biophysics, Bulg. Acad. Sci., Sofia, Bulgaria
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Neumann E, Kakorin S, Tsoneva I, Nikolova B, Tomov T. Calcium-mediated DNA adsorption to yeast cells and kinetics of cell transformation by electroporation. Biophys J 1996; 71:868-77. [PMID: 8842225 PMCID: PMC1233543 DOI: 10.1016/s0006-3495(96)79288-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Detailed kinetic data suggest that the direct transfer of plasmid DNA (YEp 351, 5.6 kbp, supercoiled, Mr approximately 3.5 x 10(6)) by membrane electroporation of yeast cells (Saccharomyces cerevisiae, strain AH 215) is mainly due to electrodiffusive processes. The rate-limiting step for the cell transformation, however, is a bimolecular DNA-binding interaction in the cell interior. Both the adsorption of DNA, directly measured with [32P]dCTP DNA, and the number of transformants are collinearly enhanced with increasing total concentrations [Dt] and [Cat] of DNA and of calcium, respectively. At [Cat] = 1 mM, the half-saturation or equilibrium constant is KD = 15 +/- 1 nM at 293 K (20 degrees C). The optimal transformation frequency is TFopt = 4.1 +/- 0.4 X 10(-5) if a single exponential pulse of initial field strength E0 = 4 kV cm-1 and decay time constant tauE = 45 ms is applied at [Dt] = 2.7 nM and 10(8) cells in 0.1 ml. The dependence of TF on [Cat] yields the equilibrium constants KCazero = 1.8 +/- 0.2 mM (in the absence of DNA) and K'Ca (at 2.7 nM DNA), comparable with and derived from electrophoresis data. In yeast cells, too, the appearance of a DNA molecule in its whole length in the cell interior is clearly an after-field event. At Eo = 4.0 kV cm-1 and T = 293 K, the flow coefficient of DNA through the porous membrane patches is Kto = 7.0 +/- 0.7 x 10(3)S-1 and the electrodiffusion of DNA is approximately 10 times more effective than simple diffusion: D/D0 approximately 10.3. The mean radius of these pores is rp = 0.39 +/- 0.05 nm, and the mean number of pores per cell (of size ø approximately 5.5 microns) is Np = 2.2 +/- 0.2 x 10(4). The maximal membrane area that is involved in the electrodiffusive penetration of adsorbed DNA into the outer surface of the electroporated cell membrane patches is only 0.023% of the total cell surface. The surface penetration is followed either by additional electrodiffusive or by passive (after-field) diffusive translocation of the inserted DNA into the cell interior. For practical purposes of optimal transformation efficiency, 1 mM calcium is necessary for sufficient DNA binding and the relatively long pulse duration of 20-40 ms is required to achieve efficient electrodiffusive transport across the cell wall and into the outer surface of electroporated cell membrane patches.
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Affiliation(s)
- E Neumann
- Department of Physical and Biophysical Chemistry, Faculty of Chemistry, University of Bielefeld, Germany.
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Spassova M, Tsoneva I, Petrov AG, Petkova JI, Neumann E. Dip patch clamp currents suggest electrodiffusive transport of the polyelectrolyte DNA through lipid bilayers. Biophys Chem 1994; 52:267-74. [PMID: 7999976 DOI: 10.1016/0301-4622(94)00097-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Planar lipid bilayers formed from monolayers of diphytanoyl lecithin (DPhL) were found to interact with plasmid DNA (5.6 kbp; M(r) = 3.7 x 10(6)) leading to an increase in the conductance of the membrane. The association of DNA with a lipid bilayer greatly facilitates the transport of the small ions of the main salt KCl. The appearance of long-lived current levels, for instance, of 27.6 pA at Vm = +60 mV membrane voltage, where the actual contact (adsorption) is electrophoretically enhanced, suggests a locally conductive DNA/lipid interaction zone where parts of the DNA strand may be transiently inserted in the bilayer, leaving other parts of the DNA probably protruding out from the outer surface of the bilayer. At Vm = -60 mV, where DNA can be electrophoretically moved away from the membrane, the membrane current is practically zero. This current asymmetry is initially also observed at higher voltages, for instance at 200 mV. However, if the voltage sign (Vm = +200 mV) is changed after a transient positive current (approximately 15 pA) was observed, there is also now (at Vm = -200 mV) a finite negative current at the negative membrane voltage. Thus, it appears that at Vm = +200 mV the adsorbed parts of the polyelectrolyte DNA are not only transiently inserted in, but actually also electrophoretically pulled through, the porous zones onto the other membrane side leaving the bilayer structure basically intact. These data provide direct electric evidence for the electrophoretic transport of a highly charged and hydrated macromolecule, probably together with the associated gegen-ions, through the thin hydrophobic film of the lipid bilayer.
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Affiliation(s)
- M Spassova
- Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia
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Tomov T, Tsoneva I. Influence of electrical pulses on the transmembrane potential in yeast. J Electroanal Chem (Lausanne) 1992. [DOI: 10.1016/0022-0728(92)85031-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tsoneva I, Tomov T, Panova I, Doncheva J. Electrofusion in the presence of divalent cations. J Electroanal Chem (Lausanne) 1992. [DOI: 10.1016/0022-0728(92)85032-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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33
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Doncheva J, Georgiev O, Milchev G, Tsoneva I. Stable transfer of plasmid pSV3 neo in CV-1 cells by electroporation. J Electroanal Chem (Lausanne) 1991. [DOI: 10.1016/0022-0728(91)85607-q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Tsoneva I, Tomov T, Panova I, Strahilov D. Effective production by electrofusion of hybridomas secreting monoclonal antibodies against Hc-antigen of Salmonella. J Electroanal Chem (Lausanne) 1990. [DOI: 10.1016/0022-0728(90)87489-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Tsoneva I, Tomov T, Panova I, Strahilov D. Effective production by electrofusion of hybridomas secreting monoclonal antibodies against Hc-antigen of Salmonella. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0302-4598(80)85005-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
This communication presents experimental evidence that intact fragile (osmotic sensitive) yeasts can be electrofused and give viable hybrids. The yield increases with one order of magnitude for electrofusion of intact fragile yeasts with protoplasts of non-fragile ones. The yield of viable hybrids, obtained by electrofusion of protoplasts of fragile and non-fragile yeasts, is one order of magnitude higher than the yield from protoplasts of non-fragile yeasts. The destabilized cell wall and plasma membrane of the mutant yeasts could be a possible explanation for this phenomenon.
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Affiliation(s)
- I Tsoneva
- Central Laboratory of Biophysics, Bulgarian Academy of Sciences, Sofia
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Zhelev D, Dimitrov D, Tsoneva I. Electrical breakdown of protoplast membranes under different osmotic pressures. J Electroanal Chem (Lausanne) 1988. [DOI: 10.1016/0022-0728(88)87059-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
Abstract
Pea protoplasts dielectrophoretic coefficients were measured in alternating electric fields of frequency 1 M Hz and voltage 5 V applied between two concentric cylindrical metal electrodes of outer and inner radii 0.24 mm and 1 mm, respectively. They do not vary significantly with solution osmolarity, but show a clear expressed maximum in isotonic conditions; the values in 0.4 ᴍ, 0.5 ᴍ, 0.6 ᴍ and 0.7 ᴍ manitol solutions are (6.5, 10.2, 8.8 and 5.6) × 10−24 A2s4/Kg, pectively. The average cell radii in those conditions are 14.2 µm, 14.6 µm, 13.8 µm and 13.6 µm. The radii of cell-to-electrode contacts follow the same dependence on the osmolarity as the dielectrophoretic coefficients; they do not depend on the applied voltages up to 18V. The times of cell approach near to the electrode were too short to be explained by the action only of the dielectrophoretic force; consequently an attractive force appeared at very close approach. These results may be of use in future studies of membrane adhesion and fusion.
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Stoicheva N, Tsoneva I, Dimitrov DS, Panaiotov I. Kinetics of calcium-induced fusion of cell-size liposomes with monolayers in solutions of different osmolarity. Z Naturforsch C Biosci 1985; 40:92-6. [PMID: 3922148 DOI: 10.1515/znc-1985-1-218] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effects of osmolarity, calcium concentration and cell-size liposomes in the subphase on the surface tension of phospholipid monolayers were investigated. The monolayers were spread from chloroform solutions of phosphatidic acid at air/water solution interface. The liposomes (of average diameter 3 micron) were formed from phosphatidic acid/egg lecithin (1:2) mixtures in water or 0.1 M water solutions of sucrose. For this system there were critical concentrations of calcium ions to produce a large reduction of the monolayer surface tension. The threshold calcium concentrations depended upon the sucrose concentration in the subphase. Without sucrose the threshold calcium concentration was 8 mM, while for isoosmotic sucrose solutions (0.1/0.1 M in/out of liposome) it was 14 mM. It sharply increased to 28 mM CaCl2 at sucrose concentration difference across the liposome membrane 0.02 M and decreased to 26 mM, 19 mM, and 18 mM with further increase of that difference to 0.04 M, 0.06 M, and 0.08 M, respectively. The rate of monolayer surface tension decrease was measured as a function of time at 30 mM CaCl2 and different sucrose concentrations in the subphase solution. The initial rates at first decreased with increasing the osmotic pressure and after that they increased. The minimum occurred at sucrose concentration gradient across the liposome membrane 0.02 M, i.e., at the point of maximum threshold calcium concentration required for large decrease of the monolayer surface tension. These facts may be explained by recent theories of dynamics of adhesion, instability and fusion of membranes modeled as thin films.
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