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1.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200719

RESUMO

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.


Assuntos
Aminoácidos/química , Anti-Inflamatórios não Esteroides/farmacologia , Celulose/química , Ésteres/química , Ibuprofeno/farmacologia , Absorção Cutânea/efeitos dos fármacos , Pele/efeitos dos fármacos , Administração Cutânea , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Bactérias/metabolismo , Sistemas de Liberação de Medicamentos , Ibuprofeno/administração & dosagem , Ibuprofeno/química , Suínos
2.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200927

RESUMO

Bacterial cellulose membranes (BCs) are becoming useful as a drug delivery system to the skin. However, there are very few reports on their application of plant substances to the skin. Komagataeibacter xylinus was used for the production of bacterial cellulose (BC). The BC containing 5% and 10% ethanolic extract of Epilobium angustifolium (FEE) (BC-5%FEE and BC-10%FEE, respectively) were prepared. Their mechanical, structural, and antioxidant properties, as well as phenolic acid content, were evaluated. The bioavailability of BC-FESs using mouse L929 fibroblasts as model cells was tested. Moreover, In Vitro penetration through the pigskin of the selected phenolic acids contained in FEE and their accumulation in the skin after topical application of BC-FEEs was examined. The BC-FEEs were characterized by antioxidant activity. The BC-5% FEE showed relatively low toxicity to healthy mouse fibroblasts. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), 3-hydroxybenzoic acid (3-HB), and caffeic acid (CA) found in FEE were also identified in the membranes. After topical application of the membranes to the pigskin penetration of some phenolic acid and other antioxidants through the skin as well as their accumulation in the skin was observed. The bacterial cellulose membrane loaded by plant extract may be an interesting solution for topical antioxidant delivery to the skin.


Assuntos
Antioxidantes/administração & dosagem , Celulose/química , Epilobium/química , Fibroblastos/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Pele/efeitos dos fármacos , Administração Tópica , Animais , Bactérias/química , Fibroblastos/metabolismo , Camundongos , Pele/metabolismo , Suínos
3.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299003

RESUMO

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.


Assuntos
Biopolímeros/química , Biopolímeros/farmacologia , Celulose/química , Quitosana/química , Nanocompostos/química , Embalagem de Produtos/métodos , Óxido de Zinco/química , Anti-Infecciosos , Celulose/ultraestrutura , Escherichia coli , Testes Mecânicos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/ultraestrutura , Nanofibras/química , Nanofibras/ultraestrutura , Propriedades de Superfície , Resistência à Tração , Difração de Raios X
4.
Int J Mol Sci ; 22(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071384

RESUMO

Since the effect of MFs (magnetic fields) on various biological systems has been studied, different results have been obtained from an insignificant effect of weak MFs on the disruption of the circadian clock system. On the other hand, magnetic fields, electromagnetic fields, or electric fields are used in medicine. The presented study was conducted to determine whether a low-frequency RMF (rotating magnetic field) with different field parameters could evoke the cellular response in vitro and is possible to modulate the cellular response. The cellular metabolic activity, ROS and Ca2+ concentration levels, wound healing assay, and gene expression analyses were conducted to evaluate the effect of RMF. It was shown that different values of magnetic induction (B) and frequency (f) of RMF evoke a different response of cells, e.g., increase in the general metabolic activity may be associated with the increasing of ROS levels. The lower intracellular Ca2+ concentration (for 50 Hz) evoked the inability of cells to wound closure. It can be stated that the subtle balance in the ROS level is crucial in the wound for the effective healing process, and it is possible to modulate the cellular response to the RMF in the context of an in vitro wound healing.


Assuntos
Cálcio/metabolismo , Campos Eletromagnéticos , Fibroblastos/metabolismo , Queratinócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Cicatrização/fisiologia , Animais , Linhagem Celular , Sobrevivência Celular/genética , Fibroblastos/citologia , Expressão Gênica , Humanos , Queratinócitos/citologia , Camundongos , Rotação , Cicatrização/genética , Proteína cdc42 de Ligação ao GTP/genética
5.
Microb Drug Resist ; 27(1): 25-35, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32543337

RESUMO

The emergence of multidrug-resistant (MDR) bacterial infections poses a catastrophic threat to medicine. The development of phage-based therapy combined with antibiotics might be an advantageous weapon in the arms race between human and MDR bacteria. A cocktail composed of the MDR Acinetobacter baumannii infecting bacteriophages with high lytic activity was used in combination with antibiotics to destroy a bacterial biofilm in human urine. A. baumannii exhibited varying susceptibility to the host range of bacteriophages used in this study, ranging from 56% to 84%. This study demonstrated that bacteriophages could reduce biofilm biomass in a human urine model, and some of the antibiotics commonly used in the treatment of urinary tract infection (UTI) act synergistically with phage cocktails. Additionally, the combined treatment showed a significantly greater reduction of biofilm biomass and clearance of persister cells.

6.
Microorganisms ; 8(11)2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33142809

RESUMO

The cultivation of bacteria sets a ground for studying biological processes in many scientific disciplines. The development of the bacterial population is commonly described with three factors that can be used to evaluate culture conditions. However, selecting only one of them for the optimization protocol is rather problematic and may lead to unintended errors. Therefore, we proposed a novel mathematical approach to obtain a single factor that could be used as the objective function to evaluate the whole growth dynamic and support the optimization of the biomass production process. The sigmoidal-shape curve, which is the commonly used function to plot the amount of biomass versus time, was the base for the mathematical analysis. The key process parameters, such as maximal specific growth rate and lag-phase duration were established with the use of mathematical coefficients of the model curve and combined to create the single growth parameter. Moreover, this parameter was used for the exemplary optimization of the cultivation conditions of Klebsiella pneumoniae that was cultured to be further used in the production of lytic bacteriophages. The proposed growth parameter was successfully validated and used to calculate the optimal process temperature of the selected bacterial strain. The obtained results indicated that the proposed mathematical approach could be effortlessly adapted for a precise evaluation of growth curves.

7.
Int J Mol Sci ; 21(12)2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575645

RESUMO

Increasing multidrug resistance has led to renewed interest in phage-based therapy. A combination of the bacteriophages and antibiotics presents a promising approach enhancing the phage therapy effectiveness. First, phage candidates for therapy should be deeply characterized. Here we characterize the bacteriophage vB_AbaP_AGC01 that poses antibacterial activity against clinical Acinetobacter baumannii strains. Moreover, besides genomic and phenotypic analysis our study aims to analyze phage-antibiotic combination effectiveness with the use of ex vivo and in vivo models. The phage AGC01 efficiently adsorbs to A. baumannii cells and possesses a bacteriolytic lifecycle resulting in high production of progeny phages (317 ± 20 PFU × cell-1). The broad host range (50.27%, 93 out of 185 strains) against A. baumannii isolates and the inability of AGC01 to infect other bacterial species show its high specificity. Genomic analysis revealed a high similarity of the AGC01 genome sequence with that of the Friunavirus genus from a subfamily of Autographivirinae. The AGC01 is able to significantly reduce the A. baumannii cell count in a human heat-inactivated plasma blood model (HIP-B), both alone and in combination with antibiotics (gentamicin (GEN), ciprofloxacin (CIP), and meropenem (MER)). The synergistic action was observed when a combination of phage treatment with CIP or MER was used. The antimicrobial activity of AGC01 and phage-antibiotic combinations was confirmed using an in vivo larva model. This study shows the greatest increase in survival of G. mellonella larvae when the combination of phage (MOI = 1) and MER was used, which increased larval survival from 35% to 77%. Hence, AGC01 represents a novel candidate for phage therapy. Additionally, our study suggests that phages and antibiotics can act synergistically for greater antimicrobial effect when used as combination therapy.


Assuntos
Infecções por Acinetobacter/terapia , Acinetobacter baumannii/virologia , Antibacterianos/uso terapêutico , Bacteriófagos/fisiologia , Lepidópteros/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/crescimento & desenvolvimento , Animais , Antibacterianos/farmacologia , Bacteriólise , Bacteriófagos/classificação , Bacteriófagos/genética , Ciprofloxacina/farmacologia , Ciprofloxacina/uso terapêutico , Terapia Combinada , Modelos Animais de Doenças , Genoma Viral , Temperatura Alta , Humanos , Meropeném/farmacologia , Meropeném/uso terapêutico , Terapia por Fagos , Fenótipo , Especificidade da Espécie , Sequenciamento Completo do Genoma
8.
Appl Biochem Biotechnol ; 187(1): 176-193, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29911267

RESUMO

Bacterial cellulose spheres subjected to amination and inlaid modification with superparamagnetic molecules were analyzed with regard to possibility of their application as an immobilization carrier of Lecitase® Ultra (LU) enzyme. The starting point to obtain the carrier was synthesis of bacterial cellulose spheres performed in shaking cultures of Komagataeibacter xylinus. These spheres were subsequently subjected to a multi-stage modification to increase the efficiency of the immobilization process and to separate product from the reaction medium. Maximal yield of Lecitase® Ultra immobilization equaled 70%. It was also found that immobilization process did not affect the pH and LU temperature optimum. Moreover, immobilized enzyme exhibited similar temperature stability profile as its native form. The immobilization process did not significantly affect the enzyme KM value. The immobilized enzyme retained over 70% of its initial activity after 8 cycles of use. The immobilized enzyme displayed good storage stability and retained 80% of its initial activity after 4 weeks at 4 °C. The potential application of such modified cellulose-based carrier may be correlated with lower costs of process thanks to higher enzyme's reusability in comparison to unbound enzyme. Moreover, data presented in the current study may serve as proof of a concept of cellulose-based carrier utilization for immobilization of enzymes other than LU and of high industrial importance.


Assuntos
Acetobacteraceae/química , Celulose/química , Enzimas Imobilizadas/química , Lipase/química , Campos Magnéticos
9.
Int J Biol Macromol ; 108: 462-470, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29223754

RESUMO

The usefulness of bacterial cellulose (BC), obtained from the cultures of Komagataeibacter xylinus exposed to rotating magnetic field (RMF), as a carrier for laccase immobilization was investigated in this study. It was found that the highest yield of laccase immobilization (>70%) was achieved in pH of 4.0 and this value was optimal in the case of both types of cellulose carriers applied. The pH equals 4.0 was also the optimal one with regard to immobilized enzymes' activity, while in case of free laccase, optimal pH value was 3.0. Process of immobilization had an impact on enzyme's optimal temperatures: while free laccase and laccase bound to RMF-unexposed cellulose was the most effective at 60°C, optimal activity of enzyme immobilized on RMF-exposed carrier was reached at 70°C. Laccase immobilized on both type of carriers had also better thermal stability at 70°C compared to free laccase. After 8 cycles of use, laccase immobilized on RMF-exposed BC remained more active than laccase immobilized on RMF-unexposed BC (65% vs. 50% of initial activity, respectively). Our results indicate that RMF-modified BC may be successfully used as a carrier for the laccase immobilization.


Assuntos
Bactérias/química , Celulose , Enzimas Imobilizadas , Lacase , Campos Magnéticos , Celulose/química , Ativação Enzimática , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Lacase/química , Lacase/metabolismo , Modelos Moleculares , Conformação Proteica , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
10.
Carbohydr Polym ; 161: 208-218, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28189230

RESUMO

The main aim of the current study was to evaluate the usefulness of the two-dimensional correlation analysis (2DCorr) technique in assessing the physicochemical properties of bacterial cellulose (BC) depending on the synthesis time and Komagataeibacter xylinus strain used for its production. It was demonstrated that 2DCorr analysis allows to characterize substantial changes in the structure of BC at the molecular level occurring during its synthesis, which are difficult to determine using ATR-FTIR spectral analysis. Furthermore, it was found that 2DCorr analysis allows to identify the differences in the structure and the properties of BC according to the bacterial strain used for its synthesis. It was concluded that 2DCorr analysis of the ATR-FTIR spectra may be a useful tool for controlling BC production in order to obtain material with the desired properties.


Assuntos
Celulose/química , Técnicas de Química Analítica/métodos , Gluconacetobacter xylinus/química , Técnicas de Química Analítica/normas
11.
Electromagn Biol Med ; 36(2): 192-201, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27786558

RESUMO

The current study describes properties of bacterial cellulose (BC) obtained from Komagataeibacter xylinus cultures exposed to the rotating magnetic field (RMF) of 50 Hz frequency and magnetic induction of 34 mT for controlled time during 6 days of cultivation. The experiments were carried out in the customized RMF exposure system adapted for biological studies. The obtained BC displayed an altered micro-structure, degree of porosity, and water-related parameters in comparison to the non-treated, control BC samples. The observed effects were correlated to the duration and the time of magnetic exposure during K. xylinus cultivation. The most preferred properties in terms of water-related properties were found for BC obtained in the setting, where RMF generator was switched off for the first 72 h of cultivation and switched on for the next 72 h. The described method of BC synthesis may be of special interest for the production of absorbent, antimicrobial-soaked dressings and carrier supports for the immobilization of microorganisms and proteins.


Assuntos
Acetobacteraceae/metabolismo , Celulose/biossíntese , Celulose/química , Campos Magnéticos , Rotação , Água/análise , Porosidade , Fatores de Tempo
12.
Appl Biochem Biotechnol ; 180(4): 805-816, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27188971

RESUMO

The present study aimed to explore and describe the properties of bacterial cellulose (BC) membranes obtained from three different strains of Gluconacetobacter xylinus for 72, 120, and 168 h, used as a carrier support for the immobilization of Saccharomyces cerevisiae. The experiments also included the analysis of glucose consumption and alcohol production during the fermentation process displayed by yeasts immobilized on the BC surface. The results of the present study demonstrate that the number of immobilized yeast cells is dependent on the type of cellulose-synthesizing strain, cellulose form, and duration of its synthesis. The BC in the form of wet membranes obtained after 3 days of synthesis displayed the most favorable properties as a carrier for yeast immobilization. The immobilization of yeast cells on BC, regardless of its form, increased the amount of the produced alcohol as compared to free cells. The yeast cells immobilized in BC were able to multiply on its surface during the fermentation process.


Assuntos
Celulose/biossíntese , Dessecação , Gluconacetobacter xylinus/metabolismo , Saccharomyces cerevisiae/citologia , Água/química , Contagem de Células , Células Imobilizadas/citologia , Fermentação , Glucose/metabolismo , Membranas Artificiais , Peso Molecular
13.
J Biomater Appl ; 30(9): 1392-406, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26809700

RESUMO

The effect of hybrid material-graphene flakes with Fe3O4 nanospheres (GO-Fe3O4), graphene oxide (GO) and magnetite nanospheres (Fe3O4) in rotating magnetic field on mammalian cells metabolism has been studied. Several reports shown that exposure to magnetic field may have influence on cellular membrane permeability. Thus, the aim of presented study was to determine the cellular response of L929 fibroblast cells to nanomaterials and rotating magnetic field for 8-h exposure experiment. The GO had tendency to adsorb proteins, thus cell metabolism was decreased and the effect of that mechanism was enhanced by impact of nanospheres and rotating magnetic field. The highest reduction of cellular metabolism was recorded for WST-1 and NR assays at concentration 100 µg/mL of all tested nanomaterials and magnetic induction value 10.06 mT. The lactate dehydrogenase leakage assay has shown significant changes in membrane permeability. Further studies need to be carried out to precisely determine the mechanism of that process.


Assuntos
Fibroblastos/metabolismo , Grafite/química , Nanopartículas de Magnetita/química , Óxidos/química , Animais , Linhagem Celular , Permeabilidade da Membrana Celular , Fibroblastos/citologia , Grafite/metabolismo , L-Lactato Desidrogenase/metabolismo , Campos Magnéticos , Nanopartículas de Magnetita/ultraestrutura , Camundongos , Mitocôndrias/metabolismo , Óxidos/metabolismo
14.
Carbohydr Polym ; 133: 52-60, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26344254

RESUMO

The aim of the study was to assess the influence of rotating magnetic field (RMF) on production rate and quality parameters of bacterial cellulose synthetized by Glucanacetobacter xylinus. Bacterial cultures were exposed to RMF (frequency f=50Hz, magnetic induction B=34mT) for 72h at 28°C. The study revealed that cellulose obtained under RMF influence displayed higher water absorption, lower density and less interassociated microfibrils comparing to unexposed control. The application of RMF significantly increased the amount of obtained wet cellulose pellicles but decreased the weight and thickness of dry cellulose. Summarizing, the exposure of cellulose-synthesizing G. xylinus to RMF alters cellulose biogenesis and may offer a new biotechnological tool to control this process. As RMF-modified cellulose displays better absorbing properties comparing to non-modified cellulose, our finding, if developed, may find application in the production of dressings for highly exudative wounds.


Assuntos
Celulose/biossíntese , Gluconacetobacter xylinus/metabolismo , Campos Magnéticos , Rotação , Glucose/metabolismo
15.
Electromagn Biol Med ; 34(1): 48-55, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24460420

RESUMO

The aim of the present study was to determine the effect of the rotating magnetic field (RMF) on the growth, cell metabolic activity and biofilm formation by S. aureus, E. coli, A. baumannii, P. aeruginosa, S. marcescens, S. mutans, C. sakazakii, K. oxytoca and S. xylosus. Bacteria were exposed to the RMF (RMF magnetic induction B = 25-34 mT, RMF frequency f = 5-50 Hz, time of exposure t = 60 min, temperature of incubation 37 °C). The persistence of the effect of exposure (B = 34 mT, f = 50 Hz, t = 60 min) on bacteria after further incubation (t = 300 min) was also studied. The work showed that exposure to RMF stimulated the investigated parameters of S. aureus, E. coli, S. marcescens, S. mutans, C. sakazakii, K. oxytoca and S. xylosus, however inhibited cell metabolic activity and biofilm formation by A. baumannii and P. aeruginosa. The results obtained in this study proved, that the RMF, depending on its magnetic induction and frequency can modulate functional parameters of different species of bacteria.


Assuntos
Fenômenos Fisiológicos Bacterianos , Campos Magnéticos , Rotação , Bactérias/citologia , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Fenômenos Ópticos
16.
Electromagn Biol Med ; 33(1): 29-34, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23713419

RESUMO

This study presents results of research on the influence of rotating magnetic field (RMF) of the induction of 30 mT and the frequency of 50 Hz on the growth dynamics and cell metabolic activity of E. coli and S. aureus, depending on the exposure time. The studies showed that the RMF caused an increase in the growth and cell metabolic activity of all the analyzed bacterial strains, especially in the time interval t = 30 to 150 min. However, it was also found that the optical density and cell metabolic activity after exposition to RMF were significantly higher in S. aureus cultures. In turn, the study of growth dynamics, revealed a rapid and a significant decrease in these values from t = 90 min) in the case of E. coli samples. The obtained results prove that RMF (B = 30 mT, f = 50 Hz) has a stimulatory effect on the growth and metabolic activity of E. coli and S. aureus. Furthermore, taking into account the time of exposure, stronger influence of RMF on the viability was observed in S. aureus cultures, which may indicate that this effect depends on the shape of the exposed cells.


Assuntos
Escherichia coli/fisiologia , Campos Magnéticos/efeitos adversos , Viabilidade Microbiana , Rotação , Staphylococcus aureus/fisiologia , Escherichia coli/citologia , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Staphylococcus aureus/citologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Fatores de Tempo
17.
Nanoscale Res Lett ; 9(1): 656, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25593549

RESUMO

The novel approach for deposition of iron oxide nanoparticles with narrow size distribution supported on different sized graphene oxide was reported. Two different samples with different size distributions of graphene oxide (0.5 to 7 µm and 1 to 3 µm) were selectively prepared, and the influence of the flake size distribution on the mitochondrial activity of L929 with WST1 assay in vitro study was also evaluated. Little reduction of mitochondrial activity of the GO-Fe3O4 samples with broader size distribution (0.5 to 7 µm) was observed. The pristine GO samples (0.5 to 7 µm) in the highest concentrations reduced the mitochondrial activity significantly. For GO-Fe3O4 samples with narrower size distribution, the best biocompatibility was noticed at concentration 12.5 µg/mL. The highest reduction of cell viability was noted at a dose 100 µg/mL for GO (1 to 3 µm). It is worth noting that the chemical functionalization of GO and Fe3O4 is a way to enhance the biocompatibility and makes the system independent of the size distribution of graphene oxide.

18.
Int J Radiat Biol ; 84(9): 752-60, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18821389

RESUMO

PURPOSE: The aim of the study was to analyze the influence of rotating magnetic fields (RMF) on the expression and intranuclear distribution of nucleolin, protein involved in ribosome biosynthesis, in HL-60 (acute promyelocytic leukemia) and K-562 (chronic myelogenous leukemia) established human cell lines. MATERIALS AND METHODS: Cells were exposed to RMF for two chosen states of the magnetic field induction: B=10 mT and B=20 mT in experimental set-up for 30 min with 24-h intervals for four days. Cytospin slides were prepared and expression of nucleolin was detected using monoclonal antibodies. Parameters of fluorescence related to nucleolin were measured in at least 2000 tumor cells in each slide by a laser scanning cytometer with an argon laser. Percentages of cells in different phases of cell cycle were also analyzed. RESULTS: The repeated exposition of cells to RMF caused significant increase in nucleolin expression in the whole nucleus and in the nucleolin aggregates (NUA). The redistribution of nucleolin measured by changes in number of NUA was also observed. The exposition of both cell lines studied to RMF did not alter the cell cycle. CONCLUSION: The nucleolin is responsive to RMF in HL-60 and K-562. The increase of its expression may indicate a reaction of cells to RMF and it may influence their other biological properties.


Assuntos
Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Exposição Ambiental , Regulação da Expressão Gênica/efeitos da radiação , Magnetismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Rotação , Ciclo Celular/efeitos da radiação , Células HL-60 , Humanos , Células K562 , Padrões de Referência , Fatores de Tempo
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