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1.
PLoS One ; 15(3): e0230022, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32143211

RESUMO

The objective of this study was to regulate the cytotoxicity of cisplatin (cisPt) minimizing its adverse effects. For this purpose, the lowest cisPt concentration needed to obtain a significant positive response in cutaneous squamous cell carcinoma (cSCC) was explored. Two adjuvant agents as gold nanoparticles (AuNP) and chelating tricine were tested as enhancers in cisPt treatment. Effectiveness of all treatments was assessed by means of biochemical techniques, which offer quantitative data, as well as two microscopy-based techniques that provided qualitative cell imaging. The present work confirms the effectiveness of free cisplatin at very low concentrations. In order to enhance its effectiveness while the side effects were probably diminished, cisPt 3.5 µM was administered with AuNP 2.5 mM, showing an effectiveness practically equal to that observed with free cisPt. However, the second treatment investigated, based on cisPt 3.5 µM combined with tricine 50 mM, enhanced drug effectiveness, increasing the percentage of cells dying by apoptosis. This treatment was even better in terms of cell damage than free cisPt at 15 µM. Images obtained by TEM and cryo-SXT confirmed these results, since a notable number of apoptotic bodies were detected when cisPt was combined with tricine. Thus, tricine was clearly a better adjuvant for cisPt treatments.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/química , Portadores de Fármacos/química , Antineoplásicos/química , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Tamanho Celular/efeitos dos fármacos , Quelantes/química , Cisplatino/farmacologia , Glicina/análogos & derivados , Glicina/química , Glicina/toxicidade , Ouro/química , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Microscopia Eletrônica de Transmissão , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia
2.
Front Immunol ; 9: 1652, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30072996

RESUMO

In the search for an eminently practical strategy to develop immunostimulants and vaccines for farmed fish, we have devised recombinant viral antigens presented as "nanopellets" (NPs). These are inclusion bodies of fish viral antigenic proteins produced in Escherichia coli. Soluble recombinant proteins are too labile to endure the in vivo environment and maintain full functionality, and therefore require encapsulation strategies. Yet when they are produced as nanostructures, they can withstand the wide range of gastrointestinal pH found in fish, high temperatures, and lyophilization. Moreover, these nanomaterials are biologically active, non-toxic to fish, cost-effective regarding production and suitable for oral administration. Here, we present three versions of NPs formed by antigenic proteins from relevant viruses affecting farmed fish: the viral nervous necrosis virus coat protein, infectious pancreatic necrosis virus viral protein 2, and a viral haemorrhagic septicemia virus G glycoprotein fragment. We demonstrate that the nanoparticles are taken up in vitro by zebrafish ZFL cells and in vivo by intubating zebrafish as a proof of concept for oral delivery. Encouragingly, analysis of gene expression suggests these NPs evoke an antiviral innate immune response in ZFL cells and in rainbow trout head kidney macrophages. They are therefore a promising platform for immunostimulants and may be candidates for vaccines should protection be demonstrated.

3.
Zygote ; 24(5): 707-13, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26964875

RESUMO

The resazurin reduction test (RRT) is a useful technique to assess the metabolic rate of sperm cells. RRT depends on the ability of metabolically active cells to reduce the non-fluorescent dye resazurin to the fluorescent resorufin. The aim of this study was to develop a vital fluorometric method to evaluate metabolic activity of rabbit sperm cells. Twenty-five rabbit males were included in the study. Viability and morphology, motility and metabolic activity were evaluated using an eosin-nigrosin staining, a computer-assisted semen analysis (CASA) and the RRT, respectively. Spearman rank correlation analysis was used to determine the correlation between RRT and semen parameters. After evaluation, a concentration of 10 × 106 sperm cells/ml was selected for further experiments with RRT. No significant correlation was found between the RRT results and the motility parameters. However, after RRT a significant positive correlation between relative fluorescence units and the percentage of alive spermatozoa (r = 0.62; P = 0.001) and a negative one with the percentage of sperm cells with acrosomic abnormalities (r = -0.45; P < 0.05) were detected. The vital assessment of metabolic rate of sperm cells by RRT could provide more information about semen quality than other routine semen analysis, correlating with sperm viability and acrosome status information.


Assuntos
Fluorometria/métodos , Análise do Sêmen/métodos , Motilidade dos Espermatozoides , Espermatozoides/citologia , Espermatozoides/metabolismo , Reação Acrossômica , Animais , Sobrevivência Celular , Masculino , Oxazinas/metabolismo , Coelhos , Contagem de Espermatozoides , Xantenos/metabolismo
4.
Biol Trace Elem Res ; 163(1-2): 177-83, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25216793

RESUMO

So far, reports in the literature indicate a superior effectiveness of anticancer treatments using drug liposome-encapsulated. In this work, the influence of cisplatin associated with lipid vesicles (liposomes) is studied. Possible induced changes in the elemental composition, distribution, and concentration inside F98 glioma cells are investigated by synchrotron X-ray fluorescence (SXRF) and particle-induced X-ray emission (PIXE), combined with backscattering spectrometry (BS). SXRF at nanometer spatial resolution provides information on the two-dimension variation of elements inside the cells, while PIXE and BS allow the determination of the elemental concentration at µg g(-1) level. In comparison with dead cells, the elemental analysis shows that both platinum and zinc contents decrease in surviving samples. Moreover, higher levels of calcium and lower levels of potassium are revealed in dead cells, especially in those treated with liposomal cisplatin. These findings would mean that liposome-treated cells died mainly by apoptosis. Although further analyses are still necessary, the results presented in this work suggest that the lipid vesicles could provide, thus, a methodology for an effective platinum administration.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Glioma/tratamento farmacológico , Glioma/metabolismo , Platina/metabolismo , Oligoelementos/metabolismo , Animais , Linhagem Celular Tumoral , Glioma/patologia , Ratos , Espectrometria por Raios X
5.
Radiat Oncol ; 6: 37, 2011 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-21489271

RESUMO

BACKGROUND: In the quest of a curative radiotherapy treatment for gliomas new delivery modes are being explored. At the Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF), a new spatially-fractionated technique, called Minibeam Radiation Therapy (MBRT) is under development. The aim of this work is to compare the effectiveness of MBRT and broad-beam (BB) synchrotron radiation to treat F98 glioma rat cells. A dose escalation study was performed in order to delimit the range of doses where a therapeutic effect could be expected. These results will help in the design and optimization of the forthcoming in vivo studies at the ESRF. METHODS: Two hundred thousand F98 cells were seeded per well in 24-well plates, and incubated for 48 hours before being irradiated with spatially fractionated and seamless synchrotron x-rays at several doses. The percentage of each cell population (alive, early apoptotic and dead cells, where either late apoptotic as necrotic cells are included) was assessed by flow cytometry 48 hours after irradiation, whereas the metabolic activity of surviving cells was analyzed on days 3, 4, and 9 post-irradiation by using QBlue test. RESULTS: The endpoint (or threshold dose from which an important enhancement in the effectiveness of both radiation treatments is achieved) obtained by flow cytometry could be established just before 12 Gy in the two irradiation schemes, whilst the endpoints assessed by the QBlue reagent, taking into account the cell recovery, were set around 18 Gy in both cases. In addition, flow cytometric analysis pointed at a larger effectiveness for minibeams, due to the higher proportion of early apoptotic cells. CONCLUSIONS: When the valley doses in MBRT equal the dose deposited in the BB scheme, similar cell survival ratio and cell recovery were observed. However, a significant increase in the number of early apoptotic cells were found 48 hours after the minibeam radiation in comparison with the seamless mode.


Assuntos
Glioma/patologia , Radioterapia/métodos , Animais , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Separação Celular , Sobrevivência Celular/efeitos da radiação , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Citometria de Fluxo , Ratos , Síncrotrons
6.
Cancer Res ; 62(20): 5672-7, 2002 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-12384523

RESUMO

The (1)H spectrum of certain tumor cells, in vivo tumors, and their biopsies in vitro shows a narrow and intense resonance at 1.26 ppm, which has been assigned to the fatty acyl chain of triglycerides [nuclear magnetic resonance (NMR) visible mobile lipids, MLs]. We have used diffusion-weighted NMR spectroscopy to directly address the subcellular origin of MLs in the case of C6 cells in which lactate accumulation had been inhibited by prior iodoacetamide incubation. Borage oil and artificial lipid droplets were used as model systems of free and restricted diffusion, respectively. The characteristic diameter for the ML resonance compartment measured by NMR for the C6 cells was not significantly different from the one obtained with phase contrast microscopy (1.88 +/- 0.04 micro m from NMR versus 1.37 +/- 0.33 micro m from microscopy). We herewith provide direct and noninvasive evidence that the lipid signal at 1.26 ppm in C6 cells, which remains visible in long echo time (T(E) = 136 ms) experiments, mostly originates from subcellular structures with diameters of 1-2 micro m, which correspond to the cytosolic lipid droplets that can be detected in optical microscopy preparations of the same cells.


Assuntos
Glioma/metabolismo , Metabolismo dos Lipídeos , Animais , Imagem de Difusão por Ressonância Magnética , Ácidos Graxos/metabolismo , Microscopia de Fluorescência , Ressonância Magnética Nuclear Biomolecular/métodos , Óleos de Plantas/química , Ratos , Frações Subcelulares/metabolismo , Células Tumorais Cultivadas , Ácido gama-Linolênico
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