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1.
Mar Drugs ; 20(9)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36135775

RESUMO

SARS-CoV-2 is the causative agent of the COVID-19 pandemic. This in silico study aimed to elucidate therapeutic efficacies against SARS-CoV-2 of phyco-compounds from the seaweed, Ulva fasciata. Twelve phyco-compounds were isolated and toxicity was analyzed by VEGA QSAR. Five compounds were found to be nonmutagenic, noncarcinogenic and nontoxic. Moreover, antiviral activity was evaluated by PASS. Binding affinities of five of these therapeutic compounds were predicted to possess probable biological activity. Fifteen SARS-CoV-2 target proteins were analyzed by the AutoDock Vina program for molecular docking binding energy analysis and the 6Y84 protein was determined to possess optimal binding affinities. The Desmond program from Schrödinger's suite was used to study high performance molecular dynamic simulation properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol-6Y84 for better drug evaluation. The ligand with 6Y84 had stronger binding affinities (-5.9 kcal/mol) over two standard drugs, Chloroquine (-5.6 kcal/mol) and Interferon α-2b (-3.8 kcal/mol). Swiss ADME calculated physicochemical/lipophilicity/water solubility/pharmacokinetic properties for 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, showing that this therapeutic agent may be effective against SARS-CoV-2.


Assuntos
Antivirais , SARS-CoV-2 , Ulva , Antivirais/química , Antivirais/farmacologia , Cloroquina , Álcoois Graxos/química , Álcoois Graxos/farmacologia , Humanos , Interferon-alfa , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Inibidores de Proteases/química , SARS-CoV-2/efeitos dos fármacos , Terpenos/química , Terpenos/farmacologia , Ulva/química , Tratamento Farmacológico da COVID-19
2.
Artigo em Inglês | MEDLINE | ID: mdl-35707479

RESUMO

Breast cancer is the most common cause of cancer mortality in Western nations, with a terrible prognosis. Many studies show that siRNA plays a role in the development of tumors by acting as a tumor suppressor and apoptosis inhibitor or both. siRNAs may be used as diagnostic and prognostic biomarkers in breast cancer. Antisurvivin siRNA was chosen as a therapeutic target in breast cancer treatment because it directly targets survivin, an inhibitor of apoptosis protein, that causes cell death. However, siRNA-based treatment has significant limitations, including a lack of tissue selectivity, a lack of effective delivery mechanisms, low cellular absorption, and the possibility of systemic toxicity. To address some of these issues, we provide a siRNA delivery method based on cationic lipids. In the recent past, cationic liposomes have displayed that they offer a remarkable perspective in proficient siRNA delivery. The presence of a positive charge plays a vital role in firm extracellular siRNA binding along with active intracellular siRNA separation and low biological adversities. Consequently, the methods for developing innovative cationic lipids through rendering and utilization of appropriate positive charges would certainly be helpful for benign and effective siRNA delivery. In the current study, an effort was made to synthesize a 3,4-dimethoxyaniline lipid (DMA) to improve the effectiveness and protection of successful siRNA delivery. DMA cationic lipid successfully delivered survivin siRNA that reduced the survivin mRNA expression, indicating the possibility of utilizing siRNA therapeutics for breast cancer. It is expected that this innovative quaternary amine-based liposome can open up new avenues in the process of developing an easy and extensively used platform for siRNA delivery. Cationic lipoplexes, a potential carrier system for siRNA-based therapies in the treatment of breast cancer, were proven by our data.

3.
NPJ Vaccines ; 5(1): 111, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33335100

RESUMO

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly emergent tick-borne bunyavirus first discovered in 2009 in China. SFTSV is a growing public health problem that may become more prominent owing to multiple competent tick-vectors and the expansion of human populations in areas where the vectors are found. Although tick-vectors of SFTSV are found in a wide geographic area, SFTS cases have only been reported from China, South Korea, Vietnam, and Japan. Patients with SFTS often present with high fever, leukopenia, and thrombocytopenia, and in some cases, symptoms can progress to severe outcomes, including hemorrhagic disease. Reported SFTSV case fatality rates range from ~5 to >30% depending on the region surveyed, with more severe disease reported in older individuals. Currently, treatment options for this viral infection remain mostly supportive as there are no licensed vaccines available and research is in the discovery stage. Animal models for SFTSV appear to recapitulate many facets of human disease, although none of the models mirror all clinical manifestations. There are insufficient data available on basic immunologic responses, the immune correlate(s) of protection, and the determinants of severe disease by SFTSV and related viruses. Many aspects of SFTSV virology and epidemiology are not fully understood, including a detailed understanding of the annual numbers of cases and the vertebrate host of the virus, so additional research on this disease is essential towards the development of vaccines and therapeutics.

4.
Ecotoxicol Environ Saf ; 182: 109362, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31254856

RESUMO

In low concentration, fluoride is considered a necessary compound for human health. Exposure to high concentrations of fluoride is the reason for a serious disease called fluorosis. Fluorosis is categorized as Skeletal and Dental fluorosis. Several Asian countries, such as India, face contamination of water resources with fluoride. In this study, a comprehensive overview on fluoride contamination in Asian water resources has been presented. Since water contamination with fluoride in India is higher than other Asian countries, a separate section was dedicated to review published articles on fluoride contamination in this country. The status of health effects in Asian countries was another topic that was reviewed in this study. The effects of fluoride on human organs/systems such as urinary, renal, endocrine, gastrointestinal, cardiovascular, brain, and reproductive systems were another topic that was reviewed in this study. Different methods to remove fluoride from water such as reverse osmosis, electrocoagulation, nanofiltration, adsorption, ion-exchange and precipitation/coagulation were introduced in this study. Although several studies have been carried out on contamination of water resources with fluoride, the situation of water contamination with fluoride and newly developed technology to remove fluoride from water in Asian countries has not been reviewed. Therefore, this review is focused on these issues: 1) The status of fluoride contamination in Asian countries, 2) health effects of fluoride contamination in drinking water in Asia, and 3) the existing current technologies for defluoridation in Asia.


Assuntos
Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Adsorção , Ásia/epidemiologia , Água Potável , Recuperação e Remediação Ambiental , Filtração , Fluorose Dentária/epidemiologia , Trato Gastrointestinal/química , Humanos , Índia , Desenvolvimento Industrial , Rim/química , Poluição da Água , Recursos Hídricos
5.
Macromol Biosci ; 19(2): e1800225, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30451373

RESUMO

Surgical clipping and endovascular coiling are well recognized as conventional treatments of Penetrating Brain Injury aneurysms. These clinical approaches show partial success, but often result in thrombus formation and the rupture of aneurysm near arterial walls. The authors address these challenging brain traumas with a unique combination of a highly biocompatible biopolymer hydrogel rendered magnetic in a flexible and resilient membrane coating integrated to a scaffold stent platform at the aneurysm neck orifice, which enhances the revascularization modality. This work focuses on the in situ diagnosis of nano-mechanical behavior of bacterial nanocellulose (BNC) membranes in an aqueous environment used as tissue reconstruction substrates for cerebral aneurysmal neck defects. Nano-mechanical evaluation, performed using instrumented nano-indentation, shows with very low normal loads between 0.01 to 0.5 mN, in the presence of deionized water. Mechanical testing and characterization reveals that the nano-scale response of BNC behaves similar to blood vessel walls with a very low Young´s modulus, E (0.0025 to 0.04 GPa), and an evident creep effect (26.01 ± 3.85 nm s-1 ). These results confirm a novel multi-functional membrane using BNC and rendered magnetic with local adhesion of iron-oxide magnetic nanoparticles.


Assuntos
Revascularização Cerebral/métodos , Procedimentos Endovasculares/métodos , Hidrogéis/uso terapêutico , Aneurisma Intracraniano/cirurgia , Nanopartículas de Magnetita/uso terapêutico , Celulose/uso terapêutico , Procedimentos Endovasculares/efeitos adversos , Gluconacetobacter xylinus/metabolismo , Humanos , Aneurisma Intracraniano/fisiopatologia , Fenômenos Mecânicos , Instrumentos Cirúrgicos
6.
ACS Biomater Sci Eng ; 5(7): 3325-3339, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-33405575

RESUMO

A new generation of biomaterials are evolving from being biologically inert toward bioactive surfaces, which can further interact with biological components at the nanoscale. Here, we present directed irradiation synthesis (DIS) as a novel technology to selectively apply plasma ions to bombard any type of biomaterial and tailor the nanofeatures needed for in vitro growth stimulation. In this work, we demonstrate for the first time, the influence of physiochemical cues (e.g., self-organized topography at nanoscale) of medical grade Ti6Al4V results in control of cell shape, adhesion, and proliferation of human aortic smooth muscle stem cells. The control of surface nanostructures was found to be correlated to ion-beam incidence angle linked to a surface diffusive regime during irradiation synthesis with argon ions at energies below 1 keV and a fluence of 2.5 × 1017 cm-2. Cell viability and cytoskeleton morphology were evaluated at 24 h, observing an advance cell attachment state on post-DIS surfaces. These modified surfaces showed 84% of cell biocompatibility and an increase in cytoplasmatic protusions ensuring a higher cell adhesion state. Filopodia density was promoted by a 3-fold change for oblique incidence angle DIS treatment compared to controls (e.g., no patterning) and lamellipodia structures were increased more than a factor of 2, which are indicators of cell attachment stimulation due to DIS modification. In addition, the morphology of the nanofeatures were tailored, with high fidelity control of the main DIS parameters that control diffusive and erosive regimes of self-organization. We have correlated the morphology and the influence in cell behavior, where nanoripple formation is the most active morphology for cell stimulation.

7.
Curr Opin Virol ; 29: 72-78, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29642053

RESUMO

Severe Fever with Thrombocytopenia Syndrome (SFTS) is a new emerging tick-borne disease caused by the phlebovirus, SFTS virus (SFTSV). The virus was discovered in central China in 2009 and has since been identified in both Japan and South Korea. Significant progress has been made on the molecular biology of the virus, and this has been used to develop diagnostic assays and reagents. Less progress has been made on the epidemiology, maintenance and transmission, clinical manifestations, immunological responses, and treatment regimens. A number of animal models have been investigated but, to date, none recapitulate all the clinical manifestations seen in humans. Vaccine development is at an early discovery phase.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Febre por Flebótomos/prevenção & controle , Phlebovirus/imunologia , Vacinas Virais/imunologia , Animais , Modelos Animais de Doenças , Humanos , Imunidade , Modelos Moleculares , Febre por Flebótomos/diagnóstico , Febre por Flebótomos/epidemiologia , Febre por Flebótomos/virologia , Phlebovirus/classificação , Phlebovirus/genética , Filogenia , Conformação Proteica , RNA Viral , Proteínas Virais/química , Proteínas Virais/genética
8.
NPJ Vaccines ; 3: 11, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29581897

RESUMO

Lassa fever (LF) is a zoonotic disease associated with acute and potentially fatal hemorrhagic illness caused by the Lassa virus (LASV), a member of the family Arenaviridae. It is generally assumed that a single infection with LASV will produce life-long protective immunity. This suggests that protective immunity induced by vaccination is an achievable goal and that cell-mediated immunity may play a more important role in protection, at least following natural infection. Seropositive individuals in endemic regions have been shown to have LASV-specific T cells recognizing epitopes for nucleocapsid protein (NP) and glycoprotein precursor (GPC), suggesting that these will be important vaccine immunogens. The role of neutralizing antibodies in protective immunity is still equivocal as recent studies suggest a role for neutralizing antibodies. There is extensive genetic heterogeneity among LASV strains that is of concern in the development of assays to detect and identify all four LASV lineages. Furthermore, the gene disparity may complicate the synthesis of effective vaccines that will provide protection across multiple lineages. Non-human primate models of LASV infection are considered the gold standard for recapitulation of human LF. The most promising vaccine candidates to date are the ML29 (a live attenuated reassortant of Mopeia and LASV), vesicular stomatitis virus (VSV) and vaccinia-vectored platforms based on their ability to induce protection following single doses, high rates of survival following challenge, and the use of live virus platforms. To date no LASV vaccine candidates have undergone clinical evaluation.

9.
Drug Res (Stuttg) ; 68(8): 436-443, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29388174

RESUMO

GSK-3 inhibitors are an emerging tool for clinical interventions in human diseases and represent a niche area in combinational therapy. They possess diverse facets in applications of nervous system disorders, Type 2 diabetes, regenerative medicine and cancer. However, conflicting reports suggest the controversial role of GSK-3 inhibitors in cancers. This review aims to highlight the rise of GSK-3 inhibitors as tools for molecular-targeted research and its shift to a promising drug candidate. The review also focuses on key GSK-3 inhibitors and their roles in cancer and regenerative medicine with special emphasis to tideglusib. In addition, the decisive roles of GSK-3 in various molecular pathways will be concisely reviewed. Finally, this review concludes the emergence of GSK-3 inhibitors as a 'double-edged sword' in the treatment against human diseases cautioning researchers about the potential ramifications of off-target pharmacological effects.


Assuntos
Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Tiadiazóis/farmacologia , Tiadiazóis/uso terapêutico , Animais , Humanos , Neoplasias/metabolismo , Medicina Regenerativa/métodos
10.
Macromol Biosci ; 17(6)2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28116837

RESUMO

Current treatments for brain aneurysms are invasive, traumatic, and not suitable in most patients with increased risks. A new alternative method is using scaffold stents to create a local and focal attraction force of cells for an in situ reconstruction of the tunica media. For this purpose, a nanostructured bioactive coating is designed to render an asymmetric region of the stent scaffold magnetic and biomimetic, which utilizes bacterial nanocellulose (BNC) as a platform for both magnetic and cell attraction as well as proliferation. The magnetization of the BNC is realized through the reaction of Fe III and II, precipitating superparamagnetic iron oxide nanoparticles (SPION). Subsequently, magnetic bacterial nanocellulose (MBNC) is coated with polyethylene glycol to improve its biocompatibility. Cytotoxicity and biocompatibility are evaluated using porcine aortic smooth muscle cells. Preliminary cellular migration assays demonstrate the behavior between MBNC and cells labeled with SPION. In this work, (1) synthesis of BNC impregnated with magnetic nanoparticles is successfully demonstrated; (2) a viable, resilient, and biocompatible hydrogel membrane is tested for neuroendovascular application using a stent scaffold; (3) cell viability and minimal cytotoxicity is achieved; (4) cell migration tests and examination of cellular magnetic attraction confirm the viability of MBNC as a multifunctional coating.


Assuntos
Celulose/química , Compostos Férricos/química , Aneurisma Intracraniano/terapia , Nanopartículas de Magnetita/química , Stents , Animais , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Celulose/farmacologia , Compostos Férricos/farmacologia , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Hidrogel de Polietilenoglicol-Dimetacrilato/uso terapêutico , Aneurisma Intracraniano/fisiopatologia , Nanopartículas de Magnetita/uso terapêutico , Teste de Materiais , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Polietilenoglicóis/química , Suínos
11.
J Environ Pathol Toxicol Oncol ; 36(4): 321-344, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29431064

RESUMO

This study aims to unravel the use of GSK-3 inhibitors as viable apoptotic inducers for teratocarcinoma-derived ovarian PA-1 cells. MTT assay was carried out to assess inhibitory concentrations of LiCl and TDG. AO/EB staining and Hoechst 33258 staining were employed to assess the damage. Mitochondrial membrane potential (ΔΨm) and ROS generation were assessed with IC50 concentrations of LiCl and TDG. Tumor-related genes (p53, p21, IL-8, TNF-α, MMP-2, Fas-L, Cox-2, and caspase-3) were assessed with 1/4 IC50, 1/2 IC50, IC50 concentrations by semi-quantitative RT- PCR. Cell cycle analysis was performed with IC50 concentration of LiCl and TDG. Western blot analysis was performed for caspase-3, caspase-7, caspase-9, PARP to estimate the possible damage induced by GSK-3 inhibitors and regulation of GSK-3ß, pGSK-3ß, Cox-2. GSK-3 inhibitors demonstrated a concentration and time-dependent reduction in cell viability, exhibiting significant ROS generation and reduced ΔΨm at their IC50 values. Substantial concentration-dependent gene expression changes with significant upregulation of P21, Cox-2, TNF-α, caspase-3, Fas-L were observed. Protein expression of caspase-3 caspase-7, caspase-9, PARP exhibited significant cleavage in LiCl and TDG-treated cells. Protein expression of Cox-2 was significantly increased in IC50 concentration of TDG. Cell cycle analysis showed significant accumulation of cells at sub-G0-G1.


Assuntos
Apoptose/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Neoplasias Ovarianas/tratamento farmacológico , Teratocarcinoma/tratamento farmacológico , Tiadiazóis/farmacologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Relação Dose-Resposta a Droga , Feminino , Humanos , Cloreto de Lítio/farmacologia , Metaloproteinase 2 da Matriz/genética , Potencial da Membrana Mitocondrial , Neoplasias Ovarianas/patologia , Espécies Reativas de Oxigênio/metabolismo , Teratocarcinoma/patologia
12.
Environ Toxicol Pharmacol ; 46: 194-205, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27490211

RESUMO

Neuroblastoma is the most common tumor amongst children amounting to nearly 15% of cancer deaths. This cancer is peculiar in its characteristics, exhibiting differentiation, maturation and metastatic transformation leading to poor prognosis and low survival rates among children. Chemotherapy, though toxic to normal cells, has shown to improve the survival of the patient with emphasis given more towards targeting angiogenesis. Recently, Tideglusib was designed as an 'Orphan Drug' to target the neurodegenerative Alzheimer's disease and gained significant momentum in its function during clinical trials. Duffy et al. recently reported a reduction in cell viability of human IMR32 neuroblastoma cells when treated with Tideglusib at varying concentrations. We investigated the effects of Tideglusib, at various concentrations, compared to Lithium chloride at various concentrations, on IMR32 cells. Lithium, a known GSK-3 inhibitor, was used as a standard to compare the efficiency of Tideglusib in a dose-dependent manner. Cell viability was assessed by MTT assay. The stages of apoptosis were evaluated by AO/EB staining and nuclear damage was determined by Hoechst 33258 staining. Reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were assessed by DCFDA dye and Rhodamine-123 dye, respectively. Tideglusib reported a significant dose-dependent increase in pro-apoptotic proteins (PARP, Caspase-9, Caspase-7, Caspase-3) and tumor-related genes (FasL, TNF-α, Cox-2, IL-8, Caspase-3). Anti-GSK3 ß, pGSK3 ß, Bcl-2, Akt-1, p-Akt1 protein levels were observed with cells exposed to Tideglusib and Lithium chloride. No significant dose-dependent changes were observed for the mRNA expression of collagenase MMP-2, the tumor suppressor p53, or the cell cycle protein p21. Our study also reports Tideglusib reducing colony formation and increasing the level of sub-G0/G1 population in IMR32 cells. Our investigations report the significance of Tideglusib as a promising apoptotic inducer in human neuroblastoma IMR32 cells. Our study also reports that LiCl reduced cell viability in IMR32 cells inducing apoptosis mediated by ROS generation.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Fase G1/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fase de Repouso do Ciclo Celular/efeitos dos fármacos , Tiadiazóis/farmacologia , Antineoplásicos/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Cloreto de Lítio/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Tiadiazóis/metabolismo
13.
J Biomed Mater Res A ; 104(11): 2801-9, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27376695

RESUMO

Bacterial cellulose (BC) has been used as a scaffold for tissue regeneration (TR). Improving functional TR requires highly selective strategies for specific cell attraction. Embedding iron oxide nanoparticles into a BC matrix can drive magnetically labeled cells to specific tissues where they may begin to heal injured tissue. This article focuses on characterization and in vitro toxicity assessment of magnetic BC (MBC). We proposed to detect the production of radical oxygen species (ROS), esterase activity, and apoptosis to study cytotoxic interactions of MBC within its bioenvironment. Morphological characterization was performed using scanning electron microscopy where evidence shows that the diameter of MBC fibers compared to BC fibers was 33% smaller, and the pore areas were 25% bigger. Cytotoxicity assays in porcine aortic smooth muscle cells exposed for 24 hours to BC, MBC, and poly(ethylene glycol)-coated MBC (MBC-PEG) reveals 96% viability and 9% ROS production for MBC-PEG. In contrast, 25% of cells exposed to MBC were apoptotic, suggesting that even when the cells were metabolically active, MBC can induce damage. These outcomes support the need for more integral assessment in the hopes of assessing the potential biosafety and uses of nanocomposites for TR. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2801-2809, 2016.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Gluconacetobacter xylinus/química , Nanopartículas de Magnetita/química , Miócitos de Músculo Liso/citologia , Animais , Apoptose/efeitos dos fármacos , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Celulose/síntese química , Celulose/toxicidade , Compostos Férricos/química , Compostos Férricos/toxicidade , Nanopartículas de Magnetita/toxicidade , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Suínos
14.
J Vis Exp ; (111)2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27285589

RESUMO

In this study, bacterial nanocellulose (BNC) produced by the bacteria Gluconacetobacter xylinus is synthesized and impregnated in situ with iron oxide nanoparticles (IONP) (Fe3O4) to yield a magnetic bacterial nanocellulose (MBNC). The synthesis of MBNC is a precise and specifically designed multi-step process. Briefly, bacterial nanocellulose (BNC) pellicles are formed from preserved G. xylinus strain according to our experimental requirements of size and morphology. A solution of iron(III) chloride hexahydrate (FeCl3·6H2O) and iron(II) chloride tetrahydrate (FeCl2·4H2O) with a 2:1 molar ratio is prepared and diluted in deoxygenated high purity water. A BNC pellicle is then introduced in the vessel with the reactants. This mixture is stirred and heated at 80 °C in a silicon oil bath and ammonium hydroxide (14%) is then added by dropping to precipitate the ferrous ions into the BNC mesh. This last step allows forming in situ magnetite nanoparticles (Fe3O4) inside the bacterial nanocellulose mesh to confer magnetic properties to BNC pellicle. A toxicological assay was used to evaluate the biocompatibility of the BNC-IONP pellicle. Polyethylene glycol (PEG) was used to cover the IONPs in order to improve their biocompatibility. Scanning electron microscopy (SEM) images showed that the IONP were located preferentially in the fibril interlacing spaces of the BNC matrix, but some of them were also found along the BNC ribbons. Magnetic force microscope measurements performed on the MBNC detected the presence magnetic domains with high and weak intensity magnetic field, confirming the magnetic nature of the MBNC pellicle. Young's modulus values obtained in this work are also in a reasonable agreement with those reported for several blood vessels in previous studies.


Assuntos
Prótese Vascular , Celulose/química , Compostos Férricos/química , Nanopartículas de Magnetita/química , Aorta/citologia , Materiais Biocompatíveis/química , Celulose/biossíntese , Quebras de DNA de Cadeia Simples , Compostos Ferrosos/química , Gluconacetobacter xylinus/metabolismo , Humanos , Magnetismo/métodos , Microscopia Eletrônica de Varredura , Músculo Liso Vascular/citologia , Músculo Liso Vascular/fisiologia
15.
NPJ Vaccines ; 1: 16007, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29263851

RESUMO

Zika virus (ZIKV) is a member of the family Flaviviridae, genus Flavivirus, and is transmitted by Aedes sp. mosquitoes. There are three genetic lineages of ZIKV: the East African, West African and Asian lineages. Until recently, Zika fever (ZF) has normally been considered a rare, mild febrile disease, but reports since 2012 have shown potentially severe complications associated with ZIKV infection, including microcephaly and Guillain-Barré syndrome. There are no licensed vaccines for ZIKV; however, many vaccine platforms/approaches that have been utilised for other flavivirus vaccines are being applied to ZIKV. Given the current outbreak of ZIKV in the Americas with its associated risks to pregnancy, we summarise what is known about the virus, how knowledge of currently licensed flavivirus vaccines can be applied to ZIKV vaccine development and the assessments of potential challenges for ZIKV vaccine testing and evaluation.

16.
Cytometry A ; 75(2): 155-62, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19061247

RESUMO

Current methods to screen for bacterial contamination involve using costly reagents such as antibodies or PCR reagents or time-costly growth in cultures. There is need for portable, real-time, multiplex pathogen detection technology that can predict the safety of food. Surface plasmon resonance (SPR) imaging is a sensitive, label-free method that can detect the binding of an analyte to a surface by the changes in refractive index that occur upon binding. We have designed a hybrid microfluidic biochip to perform multiplexed detection of single-celled pathogens using a combination of SPR and fluorescence imaging. The device consists of an array of gold spots, each functionalized with a capture biomolecule targeting a specific pathogen. This biosensor array is enclosed by a polydimethylsiloxane microfluidic flow chamber that delivers a magnetically concentrated sample to be tested. The sample is imaged by SPR on the bottom of the biochip and epi-fluorescence on the top. The prototype instrument was successfully able to image antibody-captured E. coli O157:H7 bacteria by SPR and fluorescence imaging. The efficiency of capture of these bacteria by the magnetic particles was determined using spectrophotometric ferric oxide absorbance measurements. The binding of the E. coli to each spot was quantified by measuring the percent of the gold spot area upon which the bacteria was bound and analyzed using NIH ImageJ software. This hybrid imaging approach of pathogenic E. coli detection coupled with an estimate of relative infectivity is shown to be a working example of a testing device for potential foodborne pathogens.


Assuntos
Escherichia coli O157/isolamento & purificação , Microbiologia de Alimentos , Citometria por Imagem/métodos , Magnetismo/métodos , Técnicas Analíticas Microfluídicas/métodos , Ressonância de Plasmônio de Superfície/métodos , Fluorescência , Citometria por Imagem/instrumentação , Magnetismo/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação
17.
Cytometry A ; 69(7): 641-51, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16807893

RESUMO

BACKGROUND: Scanning cytometry now has many of the features (and power) of multiparameter flow cytometry while keeping its own advantages as an imaging technology. Modern instruments combine capabilities of scanning cytometry with the ability to manipulate cells. A new technology, called LEAP (laser-enabled analysis and processing), offers a unique combination of capabilities in cell purification and selective macromolecule delivery (optoinjection). METHODS: LEAP-mediated cell purification and optoinjection effects were assessed in model experiments using adherent and suspension cell types and cell mixtures plated and processed at different densities. Optoinjection effects were visualized by delivering fluorescent dextrans into cells. Results were analyzed using the LEAP instrument's own imaging system as well as by fluorescence and confocal microscopy. RESULTS: Live cell samples (adherent and suspension) could be purified to 90-100% purity with 50-90% yield, causing minimal cell damage depending on the cell type and plating density. Nearly one hundred percent of the targeted cells of all cell types examined could be successfully optoinjected with dextrans of 3-70 kDa, causing no visual damage to the cells. Indirect optoinjection effects were observed on untargeted cells within 5-60 microm to targeted areas under conditions used here. CONCLUSIONS: LEAP provides solutions in cell purification and targeted macromolecule delivery for traditional and challenging applications where other methods fall short.


Assuntos
Hepatócitos/citologia , Citometria de Varredura a Laser/métodos , Animais , Adesão Celular/fisiologia , Separação Celular/instrumentação , Separação Celular/métodos , Células Cultivadas , Células HeLa , Humanos , Citometria de Varredura a Laser/instrumentação , Camundongos , Camundongos Endogâmicos C57BL , Coloração e Rotulagem
18.
Cytometry A ; 59(2): 191-202, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15170598

RESUMO

BACKGROUND: Most biological samples are cell mixtures. Some basic questions are still unanswered about analyzing these heterogeneous samples using gene expression microarray technology (MAT). How meaningful is a cell mixture's overall gene expression profile (GEP)? Is it necessary to purify the cells of interest before microarray analysis, and how much purity is needed? How much does the purification itself distort the GEP, and how well can the GEP of a small cell subset be recovered? METHODS: Model cell mixtures with different cell ratios were analyzed by both spotted and Affymetrix MAT. GEP distortion during cell purification and GEPs of purified cells were studied. CD34+ cord blood cells were purified and analyzed by MAT. RESULTS: GEPs for mixed cell populations were found to mirror the cell ratios in the mixture. Over 75% pure samples were indistinguishable from pure cells by their overall GEP. Cell purification preserved the GEP. The GEPs of small cell subsets could be accurately recovered by cell sorting both from model cell mixtures and from cord blood. CONCLUSIONS: Purification of small cell subsets from a mixture prior to MAT is necessary for meaningful results. Even completely hidden GEPs of small cell subpopulations can be recovered by cell sorting.


Assuntos
Separação Celular/métodos , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Células Sanguíneas , Linhagem Celular , Células , Citometria de Fluxo/métodos , Humanos , Processamento de Imagem Assistida por Computador
19.
Nucleic Acids Res ; 31(10): e54, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12736320

RESUMO

An immunofluorescence assay was developed to identify proteins specifically binding to oligonucleoside phosphorodithioate (ODN) aptamers from a bead-bound ODN library. Accordingly, NF-kappaB p50 protein was incubated with either bead-bound NF-kappaB consensus sequence or a bead-bound ODN combinatorial library and adsorption was then assessed using a specific primary antibody and a secondary antibody conjugated with Alexa 488 fluorescent dye. This assay avoids any problems related to fluorescently labeling target proteins. The method is straightforward and readily applicable to other transcription factors and proteins, and the feasibility of its application for high-throughput screening of large aptamer bead-based libraries by flow cytometry is demonstrated.


Assuntos
NF-kappa B/metabolismo , Oligonucleotídeos/metabolismo , Ligação Competitiva , Proteínas de Ligação a DNA/metabolismo , Citometria de Fluxo/métodos , Imunofluorescência , Subunidade p50 de NF-kappa B , Oligonucleotídeos/química , Oligonucleotídeos/isolamento & purificação , Tionucleotídeos/química
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