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1.
BMC Infect Dis ; 21(1): 357, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863281

RESUMO

BACKGROUND: In 2020, a new coronavirus, SARS-CoV-2, quickly spread worldwide within a few months. Although coronaviruses typically infect the upper or lower respiratory tract, the virus RNA can be detected in plasma. The risk of transmitting coronavirus via transfusion of blood products remains. As more asymptomatic infections are identified in COVID-19 cases, blood safety has become particularly important. Methylene blue (MB) photochemical technology has been proven to inactivate lipid-enveloped viruses with high efficiency and safety. The present study aimed to investigate the SARS-CoV-2 inactivation effects of MB in plasma. METHODS: The SARS-CoV-2 virus strain was isolated from Zhejiang University. The live virus was harvested from cultured VERO-E6 cells, and mixed with MB in plasma. The MB final concentrations were 0, 1, 2, and 4 µM. The "BX-1 AIDS treatment instrument" was used at room temperature, the illumination adjusted to 55,000 ± 0.5 million Lux, and the plasma was irradiated for 0, 2, 5, 10, 20, and 40 mins using light at a single wavelength of 630 nm. Virus load changes were measured using quantitative reverse transcription- PCR. RESULTS: BX-1 could effectively eliminate SARS-CoV-2 within 2 mins in plasma, and the virus titer declined to 4.5 log10 TCID50 (median tissue culture infectious dose)/mL. CONCLUSION: BX-1 is based on MB photochemical technology, which was designed to inactivate HIV-1 virus in plasma. It was proven to be safe and reliable in clinical trials of HIV treatment. In this study, we showed that BX-1 could also be applied to inactivate SARS-CoV-2. During the current outbreak, this technique it has great potential for ensuring the safety of blood transfusions, for plasma transfusion therapy in recovering patients, and for preparing inactivated vaccines.


Assuntos
Segurança do Sangue , /terapia , Azul de Metileno/farmacologia , Inativação de Vírus , Animais , Transfusão de Sangue , Chlorocebus aethiops , Humanos , Imunização Passiva , Plasma/virologia , RNA Viral , Células Vero
2.
Med Hypotheses ; 146: 110455, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33341032

RESUMO

SARS-CoV-2 infection generally begins in the respiratory tract where it can cause bilateral pneumonia. The disease can evolve into acute respiratory distress syndrome and multi-organ failure, due to viral spread in the blood and an excessive inflammatory reaction including cytokine storm. Antiviral and anti-cytokine drugs have proven to be poorly or in-effective in stopping disease progression, and mortality or serious chronic damage is common in severely ill cases. The low efficacy of antiviral drugs is probably due to late administration, when the virus has triggered the inflammatory reaction and is no longer the main protagonist. The relatively poor efficacy of anti-cytokine drugs is explained by the fact that they act on one or a few of the dozens of cytokines involved, and because other mediators of inflammation - reactive oxygen and nitrogen species - are not targeted. When produced in excess, reactive species cause extensive cell and tissue damage. The only drug known to inhibit the excessive production of reactive species and cytokines is methylene blue, a low-cost dye with antiseptic properties used effectively to treat malaria, urinary tract infections, septic shock, and methaemoglobinaemia. We propose testing methylene blue to contrast Covid-related acute respiratory distress syndrome, but particularly suggest testing it early in Covid infections to prevent the hyper-inflammatory reaction responsible for the serious complications of the disease.


Assuntos
/tratamento farmacológico , Azul de Metileno/farmacologia , Modelos Biológicos , Antivirais/farmacologia , /fisiopatologia , Citocinas/antagonistas & inibidores , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/lesões , Humanos , Insuficiência de Múltiplos Órgãos/etiologia , Insuficiência de Múltiplos Órgãos/prevenção & controle , Pandemias , Espécies Reativas de Oxigênio/antagonistas & inibidores , /prevenção & controle , Falha de Tratamento
3.
Cell Death Dis ; 11(12): 1070, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33318476

RESUMO

Lack of effective treatments for aggressive breast cancer is still a major global health problem. We have previously reported that photodynamic therapy using methylene blue as photosensitizer (MB-PDT) massively kills metastatic human breast cancer, marginally affecting healthy cells. In this study, we aimed to unveil the molecular mechanisms behind MB-PDT effectiveness and specificity towards tumor cells. Through lipidomics and biochemical approaches, we demonstrated that MB-PDT efficiency and specificity rely on polyunsaturated fatty acid-enriched membranes and on the better capacity to deal with photo-oxidative damage displayed by non-tumorigenic cells. We found out that, in tumorigenic cells, lysosome membrane permeabilization is accompanied by ferroptosis and/or necroptosis. Our results also pointed at a cross-talk between lysosome-dependent cell death (LDCD) and necroptosis induction after photo-oxidation, and contributed to broaden the understanding of MB-PDT-induced mechanisms and specificity in breast cancer cells. Therefore, we demonstrated that efficient approaches could be designed on the basis of lipid composition and metabolic features for hard-to-treat cancers. The results further reinforce MB-PDT as a therapeutic strategy for highly aggressive human breast cancer cells.


Assuntos
Neoplasias da Mama/patologia , Luz , Antioxidantes/farmacologia , Neoplasias da Mama/tratamento farmacológico , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Carcinogênese/efeitos da radiação , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Linhagem Celular Tumoral , Feminino , Ferroptose/efeitos dos fármacos , Ferroptose/efeitos da radiação , Humanos , Lipídeos/química , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/efeitos da radiação , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Modelos Biológicos , Necroptose/efeitos dos fármacos , Necroptose/efeitos da radiação , Oxirredução , Fotoquimioterapia , Neoplasias de Mama Triplo Negativas/patologia
4.
Int J Food Microbiol ; 333: 108803, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32798958

RESUMO

Alicyclobacillus acidoterrestris is a cause of major concern for the orange juice industry due to its thermal and chemical resistance, as well as its spoilage potential. A. acidoterrestris spoilage of orange juice is due to off-flavor taints from guaiacol production and some halophenols. The present study aimed to evaluate the effectiveness of antimicrobial Photodynamic Treatment (aPDT) as an emerging technology to inactivate the spores of A. acidoterrestris. The aPDT efficiency towards A. acidoterrestris was evaluated using as photosensitizers the tetracationic porphyrin (Tetra-Py+-Me) and the phenothiazinium dye new methylene blue (NMB) in combination with white light-emitting diode (LED; 400-740 nm; 65-140 mW/cm2). The spores of A. acidoterrestris were cultured on YSG agar plates (pH 3.7 ± 0.1) at 45 °C for 28 days and submitted to the aPDT with Tetra-Py+-Me and NMB at 10 µM in phosphate-buffered saline (PBS) in combination with white light (140 mW/cm2). The use of Tetra-Py+-Me at 10 µM resulted in a 7.3 ± 0.04 log reduction of the viability of A. acidoterrestris spores. No reductions in the viability of this bacterium were observed with NMB at 10 µM. Then, the aPDT with Tetra-Py+-Me and NMB at 10 µM in orange juice (UHT; pH 3.9; 11°Brix) alone and combined with potassium iodide (KI) was evaluated. The presence of KI was able to potentiate the aPDT process in orange juice, promoting the inactivation of 5 log CFU/mL of A. acidoterrestris spores after 10 h of white light exposition (140 mW/cm2). However, in the absence of KI, both photosensitizers did not promote a significant reduction in the spore viability. The inactivation of A. acidoterrestris spores artificially inoculated in orange peels (105 spores/mL) was also assessed using Tetra-Py+-Me at 10 and 50 µM in the presence and absence of KI in combination with white light (65 mW/cm2). No significant reductions were observed (p < .05) when Tetra-Py+-Me was used at 10 µM, however at the highest concentration (50 µM) a significant spore reduction (≈ 2.8 log CFU/mL reductions) in orange peels was observed after 6 h of sunlight exposition (65 mW/cm2). Although the color, total phenolic content (TPC), and antioxidant capacity of orange juice and peel (only color evaluation) seem to have been affected by light exposition, the impact on the visual and nutritional characteristics of the products remains inconclusive so far. Besides that, the results found suggest that aPDT can be a potential method for the reduction of A. acidoterrestris spores on orange groves.


Assuntos
Alicyclobacillus/efeitos da radiação , Citrus sinensis/microbiologia , Sucos de Frutas e Vegetais/microbiologia , Luz , Fármacos Fotossensibilizantes/farmacologia , Antibacterianos/farmacologia , Guaiacol , Azul de Metileno/análogos & derivados , Azul de Metileno/farmacologia , Porfirinas/farmacologia , Esporos Bacterianos/efeitos da radiação
5.
Int J Nanomedicine ; 15: 5803-5811, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32821102

RESUMO

Introduction: Photodynamic therapy (PDT), which induces tissue damage by exposing tissue to a specific wavelength of light in the presence of a photosensitizer and oxygen, is a promising alternative treatment that could be used as an adjunct to chemotherapy and surgery in oncology. Cell-penetrating peptides (CPPs) with high arginine content, such as protamine, have membrane translocation and lysosome localization activities. They have been used in an extensive range of drug delivery applications. Methods: We conjugated cell-penetrating peptides (CPPs) with methylene blue (MB) and then purification by FPLC. Synthesis structure was characterized by the absorbance spectrum, FPLC, Maldi-TOF, and then evaluated cell viability by cytotoxicity assay after photodynamic therapy (PDT) assay. An uptake imaging assay was used to determine the sites of MB and MB-Pro in subcellular compartments. Results: In vitro assays showed that MB-Pro has more efficient photodynamic activities than MB alone for the colon cancer cells, owing to lysosome rupture causing the rapid necrotic cell death. In this study, we coupled protamine with MB for high efficacy PDT. The conjugates localized in the lysosomes and enhanced the efficiency of PDT by inducing necrotic cell death, whereas PDT with non-coupled MB resulted in only apoptotic processes. Discussion: Our research aimed to enhance PDT by engineering the photosensitizers using CPPs coupled with methylene blue (MB). MB alone permeates through the cell membrane and distributes into the cytoplasm, whereas coupling of MB dye with CPPs localizes the MB through an endocytic mechanism to a specific organelle where the localized conjugates enhance the generation of reactive oxygen species (ROS) and induce cell damage.


Assuntos
Peptídeos Penetradores de Células/farmacologia , Azul de Metileno/farmacologia , Fotoquimioterapia , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Células HT29 , Humanos , Imageamento Tridimensional , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Azul de Metileno/química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo
6.
Chem Biol Interact ; 329: 109222, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32771325

RESUMO

Extensive application of methylene blue (MB) for therapeutic and diagnostic purposes, and reports for unwanted side effects, demand better understanding of the mechanisms of biological action of this thiazine dye. Because MB is redox-active, its biological activities have been attributed to transfer of electrons, generation of reactive oxygen species, and antioxidant action. Results of this study show that MB is more toxic to a superoxide dismutase-deficient Escherichia coli mutant than to its SOD-proficient parent, which indicates that superoxide anion radical is involved. Incubation of E. coli with MB induced the enzymes fumarase C, SOD, nitroreductase A, and glucose-6-phosphate dehydrogenase, all controlled by the soxRS regulon. Induction of these enzymes was prevented by blocking protein synthesis with chloramphenicol and was not observed when soxRS-negative mutants were incubated with MB. These results show that MB is capable of inducing the soxRS regulon of E. coli, which plays a key role in protecting bacteria against oxidative stress and redox-cycling compounds. Irrespective of the abundance of heme-containing proteins in living cells, which are preferred acceptors of electrons from the reduced form of MB, reduction of oxygen to superoxide radical still takes place. Induction of the soxRS regulon suggests that in humans, beneficial effects of MB could be attributed to activation of redox-sensitive transcription factors like Nrf2 and FoxO. If defense systems are compromised or genes coding for protective proteins are not induced, MB would have deleterious effects.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Azul de Metileno/farmacologia , Regulon/efeitos dos fármacos , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Cloranfenicol/farmacologia , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fumarato Hidratase/genética , Fumarato Hidratase/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo , Transativadores/genética , Fatores de Transcrição/genética
7.
Jt Dis Relat Surg ; 31(2): 246-254, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584721

RESUMO

OBJECTIVES: This study aims to biomechanically and histopathologically investigate the effects of methylene blue (MB) on preventing postoperative adhesion in chickens undergoing full- thickness flexor tendon incision. MATERIALS AND METHODS: This study was performed between June 2017 and June 2018 on Hubbard JA 57 type chickens (age, 6 months; weight, 2.2±0.3 kg). Sixty-four tendons were studied in 32 chickens, including 16 in the control group and 16 in the experimental group. The second and third finger flexor digitorum profundus tendons of the left foot of each chicken were repaired primarily after a full-thickness incision approximately 1 cm proximal to the distal adhesion area. In the control (n=32) and experimental groups (n=32), 0.25 mL of normal saline and 0.25 mL of 1% MB solutions were applied locally to the surgical site, respectively. The operated limb was immobilized using a circular cast. 16 chickens were randomly selected in each group and examined at the fourth week, and the remaining 16 chickens were examined at the sixth week. Thirty-two of these tendons were evaluated using the Tang histopathological adhesion classification system, and the other 32 were evaluated with a biomechanical pull system. RESULTS: Adhesion was found to be less in the experimental group compared to the control group at the end of the fourth and sixth weeks both histopathologically and biomechanically. Furthermore, adhesion was significantly less in the experimental group at the end of the sixth week compared to the fourth week both histopathologically and biomechanically. CONCLUSION: Histopathological and biomechanical results show that MB, which has anti-inflammatory, antiseptic, antimicrobial and antioxidant effects, reduces adhesion during the healing process after tendon repair. We think that local MB application, particularly in surgeries performed after this type of injury, will be beneficial on early rehabilitation and functional results.


Assuntos
Azul de Metileno/farmacologia , Procedimentos Ortopédicos/efeitos adversos , Traumatismos dos Tendões/cirurgia , Tendões , Aderências Teciduais , Cicatrização/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Galinhas , Inibidores Enzimáticos/farmacologia , Modelos Anatômicos , Tendões/patologia , Tendões/fisiopatologia , Tendões/cirurgia , Aderências Teciduais/etiologia , Aderências Teciduais/prevenção & controle
8.
Sci Rep ; 10(1): 7483, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366934

RESUMO

Neospora caninum is an Apicomplexan parasite related to important losses in livestock, causing abortions and decreased fertility in affected cows. Several chemotherapeutic strategies have been developed for disease control; however, no commercial treatment is available. Among the candidate drugs against neosporosis, phenothiazinium dyes, offer a low cost-efficient approach to parasite control. We report the anti-parasitic effects of the phenothiaziums Methylene Blue (MB), New Methylene Blue (NMB), 1,9-Dimethyl Methylene Blue (DMMB) and Toluidine Blue O (TBO) on N. caninum, using in vitro and in vivo models. The dyes inhibited parasite proliferation at nanomolar concentrations (0.019-1.83 µM) and a synergistic effect was achieved when Methylene Blue was combined with New Methylene Blue (Combination Index = 0.84). Moreover, the phenothiazinium dyes improved parasite clearance when combined with Pyrimethamine (Pyr). Combination of Methylene Blue + 1,9-Dimethyl Methylene Blue demonstrated superior efficacy compared to Pyrimethamine based counterparts in an in vivo model of infection. We also observed that Methylene Blue, New Methylene Blue and 1,9-Dimethyl Methylene Blue increased by 5000% the reactive oxygen species (ROS) levels in N. caninum tachyzoites. Phenothiazinium dyes represent an accessible group of candidates with the potential to compound future formulations for neosporosis control.


Assuntos
Coccidiose , Azul de Metileno/análogos & derivados , Neospora/crescimento & desenvolvimento , Animais , Chlorocebus aethiops , Coccidiose/tratamento farmacológico , Coccidiose/metabolismo , Masculino , Azul de Metileno/farmacologia , Camundongos , Células Vero
9.
PLoS One ; 15(4): e0231770, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32298377

RESUMO

The Warburg effect, a hallmark of cancer, has recently been identified as a metabolic limitation of Chinese Hamster Ovary (CHO) cells, the primary platform for the production of monoclonal antibodies (mAb). Metabolic engineering approaches, including genetic modifications and feeding strategies, have been attempted to impose the metabolic prevalence of respiration over aerobic glycolysis. Their main objective lies in decreasing lactate production while improving energy efficiency. Although yielding promising increases in productivity, such strategies require long development phases and alter entangled metabolic pathways which singular roles remain unclear. We propose to apply drugs used for the metabolic therapy of cancer to target the Warburg effect at different levels, on CHO cells. The use of α-lipoic acid, a pyruvate dehydrogenase activator, replenished the Krebs cycle through increased anaplerosis but resulted in mitochondrial saturation. The electron shuttle function of a second drug, methylene blue, enhanced the mitochondrial capacity. It pulled on anaplerotic pathways while reducing stress signals and resulted in a 24% increase of the maximum mAb production. Finally, the combination of both drugs proved to be promising for stimulating Krebs cycle activity and mitochondrial respiration. Therefore, drugs used in metabolic therapy are valuable candidates to understand and improve the metabolic limitations of CHO-based bioproduction.


Assuntos
Anticorpos Monoclonais/biossíntese , Ciclo do Ácido Cítrico/fisiologia , Glicólise/efeitos dos fármacos , Engenharia Metabólica/métodos , Azul de Metileno/farmacologia , Ácido Tióctico/farmacologia , Animais , Células CHO , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Glucose/metabolismo , Glutamina/metabolismo , Glicólise/fisiologia , Ácido Láctico/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Azul de Metileno/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Respiração , Ácido Tióctico/metabolismo
10.
BMC Vet Res ; 16(1): 54, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050965

RESUMO

BACKGROUND: Intestinal ischemia-reperfusion (IR) is an important clinical occurrence seen in common diseases, such as gastric dilatation-volvulus in dogs or colic in horses. Limited data is available on the use of methylene blue in veterinary medicine for intestinal ischemia-reperfusion. The present study aimed to compare the hemodynamic, histopathological, and immunohistochemical effects of two doses of methylene blue in two rabbit model groups In one group, 5 mg/kg IV was administered, and in another, 20 mg/kg IV was administered following a constant rate infusion (CRI) of 2 mg/kg/h that lasted 6 h. All the groups, including a control group had intestinal ischemia-reperfusion. Immunohistochemical analysis was performed using caspase-3. RESULTS: During ischemia, hemodynamic depression with reduced perfusion and elevated lactate were observed. During reperfusion, methylene blue (MB) infusion generated an increase in cardiac output due to a positive chronotropic effect, an elevation of preload, and an intense positive inotropic effect. The changes in heart rate and blood pressure were significantly greater in the group in which methylene blue 5 mg/kg IV was administered (MB5) than in the group in which methylene blue 20 mg/kg IV dose was administered (MB20). In addition, lactate and stroke volume variations were significantly reduced, and vascular resistance was significantly elevated in the MB5 group compared with the control group and MB20 group. The MB5 group showed a significant decrease in the intensity of histopathological lesion scores in the intestines and a decrease in caspase-3 areas, in comparison with other groups. CONCLUSIONS: MB infusion produced improvements in hemodynamic parameters in rabbits subjected to intestinal IR, with increased cardiac output and blood pressure. An MB dosage of 5 mg/kg IV administered at a CRI of 2 mg/kg/h exhibited the most protective effect against histopathological damage caused by intestinal ischemia-reperfusion. Further studies with MB in clinical veterinary pathologies are recommended to fully evaluate these findings.


Assuntos
Inibidores Enzimáticos/farmacologia , Enteropatias/veterinária , Azul de Metileno/farmacologia , Traumatismo por Reperfusão , Animais , Hemodinâmica/efeitos dos fármacos , Coelhos
11.
Toxicology ; 431: 152379, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31962143

RESUMO

Organophosphates (OPs) are valuable as pesticides in agriculture and for controlling deadly vector-borne illnesses; however, they are highly toxic and associated with many deleterious health effects in humans including long-term neurological impairments. Antidotal treatment regimens are available to combat the symptoms of acute OP toxicity, which result from the irreversible inhibition of acetylcholinesterase (AChE). However, there are no established treatments for the long-term neurological consequences of OP exposure. In addition to AChE, OPs can negatively affect multiple protein targets as well as biological processes such as axonal transport. Given the fundamental nature of axonal transport to neuronal health, we rationalized that this process might serve as a general focus area for novel therapeutic strategies against OP toxicity. In the studies described here, we employed a multi-target, phenotypic screening, and drug repurposing strategy for the evaluations of potential novel OP-treatments using a primary neuronal culture model and time-lapse live imaging microscopy. Two multi-target compounds, lithium chloride (LiCl) and methylene blue (MB), which are FDA-approved for other indications, were evaluated for their ability to prevent the negative effects of the OP, diisopropylfluorophosphate (DFP) on axonal transport. The results indicated that both LiCl and MB prevented DFP-induced impairments in anterograde and retrograde axonal transport velocities in a concentration dependent manner. While in vivo studies will be required to confirm our in vitro findings, these experiments support the potential of LiCl and MB as repurposed drugs for the treatment of the long-term neurological deficits associated with OP exposure (currently an unmet medical need).


Assuntos
Transporte Axonal/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Inibidores da Colinesterase/toxicidade , Isoflurofato/antagonistas & inibidores , Isoflurofato/toxicidade , Cloreto de Lítio/farmacologia , Azul de Metileno/farmacologia , Neurônios/efeitos dos fármacos , Animais , Córtex Cerebral/citologia , Relação Dose-Resposta a Droga , Reposicionamento de Medicamentos , Masculino , Fosforilação , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley
12.
Vox Sang ; 115(3): 146-151, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31930543

RESUMO

BACKGROUND: Emerging viruses like severe acute respiratory syndrome coronavirus (SARS-CoV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Nipah virus (NiV) have been identified to pose a potential threat to transfusion safety. In this study, the ability of the THERAFLEX UV-Platelets and THERAFLEX MB-Plasma pathogen inactivation systems to inactivate these viruses in platelet concentrates and plasma, respectively, was investigated. MATERIALS AND METHODS: Blood products were spiked with SARS-CoV, CCHFV or NiV, and then treated with increasing doses of UVC light (THERAFLEX UV-Platelets) or with methylene blue (MB) plus increasing doses of visible light (MB/light; THERAFLEX MB-Plasma). Samples were taken before and after treatment with each illumination dose and tested for residual infectivity. RESULTS: Treatment with half to three-fourths of the full UVC dose (0·2 J/cm2 ) reduced the infectivity of SARS-CoV (≥3·4 log), CCHFV (≥2·2 log) and NiV (≥4·3 log) to the limit of detection (LOD) in platelet concentrates, and treatment with MB and a fourth of the full light dose (120 J/cm2 ) decreased that of SARS-CoV (≥3·1 log), CCHFV (≥3·2 log) and NiV (≥2·7 log) to the LOD in plasma. CONCLUSION: Our study demonstrates that both THERAFLEX UV-Platelets (UVC) and THERAFLEX MB-Plasma (MB/light) effectively reduce the infectivity of SARS-CoV, CCHFV and NiV in platelet concentrates and plasma, respectively.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo/efeitos da radiação , Luz , Azul de Metileno/farmacologia , Vírus Nipah/efeitos da radiação , Vírus da SARS/efeitos da radiação , Raios Ultravioleta , Inativação de Vírus , Plaquetas/virologia , Transfusão de Sangue , Vírus da Febre Hemorrágica da Crimeia-Congo/efeitos dos fármacos , Humanos , Vírus Nipah/efeitos dos fármacos , Plasma/virologia , Vírus da SARS/efeitos dos fármacos
13.
J Photochem Photobiol B ; 203: 111776, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31931388

RESUMO

Due to the emergence of antibiotic resistance, antimicrobial photodynamic therapy (aPDT) has recently been demonstrated as a promising alternative to antibiotics to treat wound infections caused by multidrug-resistant (MDR) pathogens. This study aimed to evaluate the bacterial killing efficiency of aPDT mediated by methylene blue (MB) loaded thermosensitive hydrogels against methicillin-resistant Staphylococcus aureus (MRSA). Box-Behnken Design method was employed to investigate the impacts of the polymer compositions, Poloxamer 407, Poloxamer 188 and Carbopol 934P, on the gelation temperature (Tsol-gel) and release rate of MB. The viscosity and in vitro bacterial killing efficiency of three selected formulations with Tsol-gel ranged 25-34 °C and MB release in 2 h (the incubation time used for aPDT experiment) ≥ 70%, were assessed. The viscosity was found to increase with increasing P407 content and increasing total gel concentration. In the in vitro aPDT experiment, all tested MB-hydrogels demonstrated >2.5 log10 colony forming unit (CFU) reduction against three clinical relevant MRSA strains. Interestingly, the bacterial reduction increased with decreasing amount of gel added (reduced MB concentration). This was possibly attributed to the increased viscosity at higher gel concentration reducing the diffusion rate of released MB towards bacterial cells leading to reduced aPDT efficiency. In summary, aPDT with the thermosensitive MB hydrogel formulations is a promising treatment strategy for wound infections.


Assuntos
Anti-Infecciosos/química , Hidrogéis/química , Azul de Metileno/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Luz , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Azul de Metileno/metabolismo , Azul de Metileno/farmacologia , Reologia , Temperatura , Viscosidade
14.
J Photochem Photobiol B ; 203: 111730, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31855718

RESUMO

OBJECTIVE: To explore the effectiveness, biosafety, photobleaching and mechanism of antimicrobial photodynamic therapy (aPDT) using methylene blue (MB) plus potassium iodide (KI), for root canal infections. METHODS: Different combinations and concentrations of MB, KI and 660 nm LED light were used against E. faecalis in planktonic and in biofilm states by colony-forming unit (CFU), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM). Human gingival fibroblasts (HGF) were used for safety testing by Cell Counting Kit-8 (CCK8) and fluorescence microscopy (FLM). The photobleaching effect and mechanisms were analyzed. RESULTS: KI could not only enhance MB aPDT on E. faecalis in both planktonic and biofilm states even in a hypoxic environment, but also produced a long-lasting bactericidal effect after end of the illumination. KI could accelerate photobleaching to reduce tooth staining by MB, and the mixture was harmless for HGFs. Mechanistic studies showed the generation of hydrogen peroxide and free iodine, and iodine radicals may be formed in hypoxia. CONCLUSION: aPDT with MB plus KI could be used for root canal disinfection and clinical studies are worth pursuing.


Assuntos
Biofilmes/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/fisiologia , Azul de Metileno/farmacologia , Plâncton/efeitos dos fármacos , Iodeto de Potássio/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/metabolismo , Iodo/metabolismo , Luz , Microscopia Confocal , Microscopia Eletrônica de Varredura , Fotodegradação/efeitos dos fármacos
15.
Lasers Med Sci ; 35(3): 573-584, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31372913

RESUMO

The effectiveness of transcranial photobiomodulation (tPBM) and methylene Blue (MB) in treating learning and memory impairments is previously reported. In this study, we investigated the effect of tPBM and MB in combination or alone on unpredictable chronic mild stress (UCMS)-induced learning and memory impairments in mice. Fifty-five male BALB/c mice were randomly allocated to five groups: control, laser sham + normal saline (NS), tPBM + NS, laser sham + MB, and tPBM + MB. All groups except the control underwent UCMS and were treated simultaneously for 4 weeks. Elevated plus maze (EPM) was used to evaluate anxiety-like behaviors. Novel object recognition (NOR) test and Barnes maze tests were used to evaluate learning and memory function. The serum cortisol and brain nitric oxide (NO), reactive oxygen species (ROS), total antioxidant capacity (TAC), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels were measured by spectrophotometric methods. Behavioral tests revealed that UCMS impaired learning and memory, and treatment with PBM, MB, and their combination reversed these impairments. Levels of NO, ROS, SOD activity in brain, and serum cortisol levels significantly increased while brain GPx activity and total antioxidant capacity significantly decreased in the sham + NS animals when compared with the controls. A significant improvement was observed in treatment groups due to reversion of the aforementioned molecular analysis caused by UCMS when it was compared with control levels. Both tPBM and MB in combination or alone have significant therapeutic effects on learning and memory impairments in UCMS-received animals.


Assuntos
Comportamento Animal/efeitos dos fármacos , Comportamento Animal/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Azul de Metileno/farmacologia , Crânio , Animais , Antioxidantes/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiologia , Encéfalo/efeitos da radiação , Modelos Animais de Doenças , Glutationa Peroxidase/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos da radiação , Memória/efeitos dos fármacos , Memória/efeitos da radiação , Camundongos , Camundongos Endogâmicos BALB C , Espécies Reativas de Oxigênio/metabolismo , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/efeitos da radiação , Superóxido Dismutase/metabolismo
16.
Lasers Med Sci ; 35(1): 79-85, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31081523

RESUMO

Chagas disease is endemic in Latin America and increasingly found in non-endemic countries. Its treatment is limited due to the variable efficacy and several side effects of benznidazole. Photodynamic antimicrobial chemotherapy (PACT) may be an attractive approach for treating Chagas disease. Here, the trypanocidal activity of PACT was investigated in vitro using phenothiazine derivatives. The cytotoxicity of both, methylene blue (MB) and toluidine blue (TBO), was determined on macrophages cultures using AlamarBlue method. The trypanocidal activity of the two photosensitizers was initially evaluated by determining their IC50 values against trypomastigote forms. After this, the trypanocidal effect was evaluated in cultures of infected macrophages using an automatized image analysis protocol. All experiments were performed in the dark and in the clear phase (after a photodynamic exposure). The compounds showed no cytotoxicity in both phases at the tested concentrations. The IC50 values for the sole use of MB and TBO were 2.6 and 1.2 µM, respectively. The photoactivation of the compounds using a fixed energy density (J/cm2) caused a reduction of the IC50 values to 1.0 and 0.9 µM, respectively. It was found that, on infected macrophage, the use of TBO significantly reduced the number of infected cells and parasitic load, and this effect was increased in the presence of light. The results of the present study are indicative that PACT may be considered as both selective and effective therapeutic intervention for treating Chagas disease.


Assuntos
Antiparasitários/farmacologia , Fenotiazinas/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Anti-Infecciosos/farmacologia , Antiparasitários/uso terapêutico , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Doença de Chagas/tratamento farmacológico , Humanos , Luz , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos Endogâmicos BALB C , Carga Parasitária , Fenotiazinas/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Cloreto de Tolônio/química , Cloreto de Tolônio/farmacologia , Cloreto de Tolônio/uso terapêutico , Trypanosoma cruzi/efeitos da radiação
17.
Acta Neuropathol Commun ; 7(1): 210, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31843022

RESUMO

Activated Caspase-6 (Casp6) is associated with age-dependent cognitive impairment and Alzheimer disease (AD). Mice expressing human Caspase-6 in hippocampal CA1 neurons develop age-dependent cognitive deficits, neurodegeneration and neuroinflammation. This study assessed if methylene blue (MB), a phenothiazine that inhibits caspases, alters Caspase-6-induced neurodegeneration and cognitive impairment in mice. Aged cognitively impaired Casp6-overexpressing mice were treated with methylene blue in drinking water for 1 month. Methylene blue treatment did not alter Caspase-6 levels, assessed by RT-PCR, western blot and immunohistochemistry, but inhibited fluorescently-labelled Caspase-6 activity in acute brain slice intact neurons. Methylene blue treatment rescued Caspase-6-induced episodic and spatial memory deficits measured by novel object recognition and Barnes maze, respectively. Methylene blue improved synaptic function of hippocampal CA1 neurons since theta-burst long-term potentiation (LTP), measured by field excitatory postsynaptic potentials (fEPSPs) in acute brain slices, was successfully induced in the Schaffer collateral-CA1 pathway in methylene blue-treated, but not in vehicle-treated, Caspase-6 mice. Increased neuroinflammation, measured by ionized calcium binding adaptor molecule 1 (Iba1)-positive microglia numbers and subtypes, and glial fibrillary acidic protein (GFAP)-positive astrocytes, were decreased by methylene blue treatment. Therefore, methylene blue reverses Caspase-6-induced cognitive deficits by inhibiting Caspase-6, and Caspase-6-mediated neurodegeneration and neuroinflammation. Our results indicate that Caspase-6-mediated damage is reversible months after the onset of cognitive deficits and suggest that methylene blue could benefit Alzheimer disease patients by reversing Caspase-6-mediated cognitive decline.


Assuntos
Envelhecimento/metabolismo , Caspase 6/metabolismo , Inibidores de Caspase/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/enzimologia , Azul de Metileno/uso terapêutico , Envelhecimento/efeitos dos fármacos , Envelhecimento/patologia , Animais , Inibidores de Caspase/farmacologia , Disfunção Cognitiva/patologia , Feminino , Humanos , Inflamação/tratamento farmacológico , Inflamação/enzimologia , Inflamação/patologia , Masculino , Azul de Metileno/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos
18.
Sci Rep ; 9(1): 15937, 2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685841

RESUMO

Localized delivery of drugs into an osteoarthritic cartilaginous lesion does not yet exist, which limits pharmaceutical management of osteoarthritis (OA). High-intensity focused ultrasound (HIFU) provides a means to actuate matter from a distance in a non-destructive way. In this study, we aimed to deliver methylene blue locally into bovine articular cartilage in vitro. HIFU-treated samples (n = 10) were immersed in a methylene blue (MB) solution during sonication (f = 2.16 MHz, peak-positive-pressure = 3.5 MPa, mechanical index = 1.8, pulse repetition frequency = 3.0 kHz, cycles per burst: 50, duty cycle: 7%). Adjacent control 1 tissue (n = 10) was first pre-treated with HIFU followed by immersion into MB; adjacent control 2 tissue (n = 10) was immersed in MB without ultrasound exposure. The MB content was higher (p < 0.05) in HIFU-treated samples all the way to a depth of 600 µm from AC surface when compared to controls. Chondrocyte viability and RNA expression levels associated with cartilage degeneration were not different in HIFU-treated samples when compared to controls (p > 0.05). To conclude, HIFU delivers molecules into articular cartilage without major short-term concerns about safety. The method is a candidate for a future approach for managing OA.


Assuntos
Cartilagem Articular/metabolismo , Ablação por Ultrassom Focalizado de Alta Intensidade , Animais , Cartilagem Articular/química , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/metabolismo , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Azul de Metileno/química , Azul de Metileno/metabolismo , Azul de Metileno/farmacologia , Osteoartrite/metabolismo , Osteoartrite/patologia , Osteoartrite/veterinária , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
19.
J Photochem Photobiol B ; 200: 111654, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31671373

RESUMO

The Enterococcus faecalis is a microorganism that causes multiple forms of resistance to a wide range of drugs used clinically. aPDT is a technique in which a visible light activates photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. aPDT is an alternative to antibiotics with the advantage of not causing resistance. The search for an alternative treatment of infections caused by E. faecalis, without using antibiotics, is off great clinical importance. The aim of present investigation was to assess the efficacy of using 3.32 ηg/mL of 1,9-dimethylmethylene blue (DMMB) as photosensitizer associated with the use of either Laser (λ660 nm) or LED (λ632 ±â€¯2 nm) using different energy densities (6, 12 and 18 J/cm2) to kill E. faecalis in vitro. Under different experimental conditions, 14 study groups, in triplicate, were used to compare the efficacy of the aPDT carried out with either the laser or LED lights using different energy densities associated to DMMB. The most probable number method (MPN) was used for quantitative analysis. Photodynamic antimicrobial effectiveness was directly proportional to the energy density used, reaching at 18 J/cm2, 99.999998% reduction of the counts of E. faecalis using both light sources. The results of this study showed that the use of 3.32 ηg/mL of DMMB associated with the use 18 J/cm2 of LED light (λ632 ±â€¯2 nm) reduced >7-log counts of planktonic culture of E. faecalis.


Assuntos
Enterococcus faecalis/efeitos dos fármacos , Luz , Azul de Metileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Animais , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/veterinária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico
20.
Molecules ; 24(21)2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671750

RESUMO

Three-component nanocomposites (Fe3O4/Pd/mpg-C3N4) have been systematically synthesized using a three-step solution method for the photocatalytic bacterial decontamination. The mesoporous g-C3N4 nanosheets (mpg-C3N4), which were prepared by the acid treatment, showed a great improvement in photocatalytic performance. The photoluminescence intensity of the mpg-C3N4 nanosheets was disclosed to drop about 60% from the value of normal g-C3N4 nanosheets. Decoration of mpg-C3N4 with palladium (Pd) nanoparticles led to the effective suppression of carrier recombination and the carrier migration to Fe3O4 nanoparticles. It was revealed that the three-component nanocomposites degraded 99.9% of E. coli and 99.8% of S. aureus bacterial strains within 2 h of solar light irradiation at a 100 µg/mL concentration, demonstrating their superb photocatalytic antibacterial activity. In addition, the nanocomposites could be easily separated from the bacterial cells and repeatedly used for photocatalytic bacterial degradation with good recyclability. The strong photon-induced antibacterial activity and good recyclability of the three-component nanocomposites may represent their potential as a promising antibacterial photocatalyst.


Assuntos
Antibacterianos/farmacologia , Compostos Férricos/química , Magnetismo , Nanocompostos/química , Nitrilos/química , Paládio/farmacologia , Fótons , Catálise , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Azul de Metileno/farmacologia , Nanocompostos/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
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