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1.
Artigo em Inglês | MEDLINE | ID: mdl-38744621

RESUMO

INTRODUCTION: Lung cancer is one of the most prevalent malignancies worldwide. Substantial research has illuminated the intricate interplay between microorganisms and human health, revealing their role in disease regulation. Trichomonads is a flagellated protozoan in the human cavity and have been previously identified as a pathogen associated with pneumonia, contributing to tissue chronic inflammation and carcinogenesis. METHODS: Nested polymerase chain reaction methods were employed to scrutinize the prevalence of trichomonads in the bronchovesicular fluid of patients diagnosed with lung cancer. Subsequently, the influence of Trichomonas tenax invasion on lung cancer cells was elucidated through proliferation assays, migration assays, and transcription analysis. RESULTS: Bronchoalveolar fluid samples from lung cancer patients yielded positive nested PCR results for eight out of twenty-seven samples. Seven of these samples were identified as Trichomonas tenax, while one was identified as Tetratrichomonas spp. Our findings revealed a significant upregulation of pathways associated with carcinogenesis, including cellular proliferation, migration, and drug resistance, in response to T. tenax invasion. CONCLUSIONS: This study underscores the importance of recognizing the presence of trichomonads and the influence of T. tenax invasion on host responses to respiratory diseases. The identified pathways implicated in cancer development may pave the way for developing targeted treatment strategies for pulmonary diseases. These findings hold promise for informing and improving the precision of therapeutic interventions in the context of pulmonary ailments.

2.
Sci Rep ; 13(1): 7894, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37193781

RESUMO

Alveolar macrophages (AMs) are the drivers of pulmonary cytokine storm in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to investigate clinical-regulatory factors for the entrance protein of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2) in AMs. Human AMs were collected from 56 patients using bronchoalveolar lavage. ACE2 expression in AMs was positively correlated with smoking pack-year (Spearman's r = 0.347, P = 0.038). In multivariate analysis, current smoking was associated with increased ACE2 in AMs (ß-coefficient: 0.791, 95% CI 0.019-1.562, P = 0.045). In vitro study, ex-vivo human AMs with higher ACE2 were more susceptible to SARS-CoV-2 pseudovirus (CoV-2 PsV). Treating human AMs using cigarette smoking extract (CSE) increases the ACE2 and susceptibility to CoV-2 PsV. CSE did not significantly increase the ACE2 in AMs of reactive oxygen species (ROS) deficient Cybb-/- mice; however, exogenous ROS increased the ACE2 in Cybb-/- AMs. N-acetylcysteine (NAC) decreases ACE2 by suppressing intracellular ROS in human AMs. In conclusion, cigarette smoking increases the susceptibility to SARS-CoV-2 by increasing ROS-induced ACE2 expression of AMs. Further investigation into the preventive effect of NAC on the pulmonary complications of COVID-19 is required.


Assuntos
COVID-19 , Fumar Cigarros , Humanos , Camundongos , Animais , Espécies Reativas de Oxigênio , Macrófagos Alveolares/metabolismo , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Peptidil Dipeptidase A/metabolismo
3.
Front Immunol ; 12: 743030, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557202

RESUMO

Immune-mediated arthritis is an important chronic inflammatory disease of joints causing debilitating morbidity in affected patients. The mechanisms underlying immune-mediated arthritis have been intensively investigated, however the cellular and molecular factors contributing to the joint inflammation in different redox conditions have not been clearly elucidated. Previous research showed that phagocyte-produced reactive oxygen species (ROS) plays an anti-inflammatory role in K/BxN serum-transfer arthritis and NOX2-deficient mice tend to have more severe arthritis. Although many leukocytes play critical roles in the development of immune-mediated arthritis, the role of neutrophils, which are the main producers of ROS in inflammation, is still controversial. We hence assessed the immunomodulatory function of neutrophils from arthritic joints of NOX2-deficient and wild type mice in this study. We found more neutrophils accumulation in NOX2-deficient inflamed joints. RNA-sequencing and quantitative PCR revealed significantly increased expression of acute inflammation genes including IL1b, Cxcl2, Cxcl3, Cxcl10 and Mmp3 in activated neutrophils from the inflamed joints of NOX2-deficient mice. Moreover, gene set enrichment analysis (GSEA) showed enriched gene signatures in type I and II IFN responses, IL-6-JAK-STAT3 signaling pathway and TNF-α signaling pathway via NF-κB in NOX2-deficient neutrophils. In addition, we found that NOX2-deficient neutrophils expressed lower levels of PD-L1 and were less suppressive than WT neutrophils. Moreover, treatment of PD-L1-Fc decreased cytokine expression and ameliorated the severity of inflammatory arthritis. Our results suggest that NOX2-derived ROS is critical for regulating the function and gene expression in arthritic neutrophils. Both the strong pro-inflammatory and weakened anti-inflammatory functions of neutrophils due to abnormal redox regulation may be targets of treatment for immune-mediated arthritis.


Assuntos
Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Antígeno B7-H1/imunologia , NADPH Oxidase 2/deficiência , Neutrófilos/imunologia , Animais , Artrite Experimental/metabolismo , Artrite Reumatoide/metabolismo , Antígeno B7-H1/metabolismo , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADPH Oxidase 2/imunologia , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo
4.
Eur J Immunol ; 49(11): 2063-2073, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31350760

RESUMO

The role of redox regulation in immune-mediated arthritis has been previously described. However, the relationship between innate immune cells, including innate lymphoid cells (ILCs) and phagocyte-derived ROS, in this process remains unclear. Here, we characterize ILCs and measure the IL-1 family cytokines along with other cytokines relevant to ILC functions and development in serum-induced arthritic joints in wild type and phagocytic NADPH oxidase (NOX2)-deficient Ncf1-/- mice. We found more severe serum-induced joint inflammation and increased NCR+ ILC3s in inflamed joints of Ncf1-/- mice. Furthermore, in vitro stimulation with IL-1ß on Tbet+ ILC1s from joints facilitated their differentiation into ROR-γt+ ILC3s. Moreover, treatment with IL-1 antagonists effectively lowered the proportions of NCR+ ILC3s and IL-17A producing ILC3s in Ncf1-/- arthritic mice and ameliorated the joint inflammation. These results suggest that NOX2 is an essential regulator of ILC transdifferentiation and may mediate this process in a redox-dependent manner through IL-1ß production in the inflammatory joint. Our findings shed important light on the role of ILCs in the initiation and progression in tissue inflammation and delineate a novel innate immune cell-mediated pathogenic mechanism through which redox regulation may determine the direction of immune responses in joints.


Assuntos
Interleucina-1beta/imunologia , Linfócitos/imunologia , NADPH Oxidase 2/deficiência , Espécies Reativas de Oxigênio/imunologia , Tarso Animal/imunologia , Animais , Antirreumáticos/farmacologia , Artrite Experimental/induzido quimicamente , Artrite Experimental/tratamento farmacológico , Artrite Experimental/imunologia , Artrite Experimental/patologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/efeitos dos fármacos , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-1beta/genética , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NADPH Oxidase 2/genética , NADPH Oxidase 2/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Oxirredução/efeitos dos fármacos , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , Fagócitos/patologia , Espécies Reativas de Oxigênio/antagonistas & inibidores , Soro/imunologia , Transdução de Sinais , Proteínas com Domínio T/genética , Proteínas com Domínio T/imunologia , Tarso Animal/efeitos dos fármacos , Tarso Animal/patologia
5.
Nutr Neurosci ; 22(12): 867-876, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29642764

RESUMO

Objectives: The antiepileptic activity of resveratrol has been revealed in various experimental models of epilepsy. The present study evaluated the effects of resveratrol on the seizures and hyperexcitable neuronal activity associated with activation of N-methyl-d-aspartic acid (NMDA) receptor and inhibition of voltage-gated potassium channels.Methods: The effects of resveratrol on seizure thresholds, excitatory field potentials (EFPs) and action potentials induced by NMDA and 4-aminopyridine (4-AP) were monitored in mice, the mouse cortical slices and rat cortical neurons, respectively.Results: Resveratrol increased the NMDA-induced seizure thresholds and suppressed the frequency of NMDA/glycine-evoked EFPs and action potentials. However, resveratrol lowered the 4-AP-induced thresholds for myoclonic twitch and face and forelimb clonus, yet enhanced the thresholds for running and bouncing clonus and tonic hindlimb extension at the higher dose (50 mg/kg). A similar biphasic response of resveratrol was observed in the frequency of EFPs and action potential firings evoked by 4-AP, with enhancement at lower concentrations, but suppression at higher concentrations.Discussion: These findings suggest that resveratrol might be capable of protecting against the seizure types related to neuronal excitability and progression mediated by NMDA receptor activation, but not suitable for the seizures caused by disturbance of the voltage-dependent potassium channels.


Assuntos
4-Aminopiridina/farmacologia , Excitabilidade Cortical/efeitos dos fármacos , N-Metilaspartato/farmacologia , Resveratrol/administração & dosagem , Convulsões/tratamento farmacológico , Animais , Células Cultivadas , Córtex Cerebral/embriologia , Córtex Cerebral/fisiologia , Potenciais Evocados/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Bloqueadores dos Canais de Potássio , Gravidez , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia , Convulsões/induzido quimicamente
6.
Nanoscale Res Lett ; 12(1): 355, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28525950

RESUMO

Less targeted and limited solubility of hydrophobic-based drug are one of the serious obstacles in drug delivery system. Thus, new strategies to enhance the solubility of hydrophobic drug and controlled release behaviors would be developed. Herein, curcumin, a model of hydrophobic drug, has been loaded into PEGylated magnetic liposomes as a drug carrier platform for drug controlled release system. Inductive magnetic heating (hyperthermia)-stimulated drug release, in vitro cellular cytotoxicity assay of curcumin-loaded PEGylated magnetic liposomes and cellular internalization-induced by magnetic guidance would be investigated. The resultant of drug carriers could disperse homogeneously in aqueous solution, showing a superparamagnetic characteristic and could inductive magnetic heating with external high-frequency magnetic field (HFMF). In vitro curcumin release studies confirmed that the drug carriers exhibited no significant release at 37 °C, whereas exhibited rapid releasing at 45 °C. However, it would display enormous (three times higher) curcumin releasing under the HFMF exposure, compared with that without HFMF exposure at 45 °C. In vitro cytotoxicity test shows that curcumin-loaded PEGylated magnetic liposomes could efficiently kill MCF-7 cells in parallel with increasing curcumin concentration. Fluorescence microscopy observed that these drug carriers could internalize efficiently into the cellular compartment of MCF-7 cells. Thus, it would be anticipated that the novel hydrophobic drug-loaded PEGylated magnetic liposomes in combination with inductive magnetic heating are promising to apply in the combination of chemotherapy and thermotherapy for cancer therapy.

7.
Nanoscale Res Lett ; 12(1): 344, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28494572

RESUMO

This paper describes the preparation of nanoarrays composed of silver nanoparticles (AgNPs: 20-50 nm) for use as surface-enhanced Raman scattering (SERS) substrates. The AgNPs were grown on porous anodic aluminum oxide (AAO) templates by electrochemical plating, and the inter-channel gap of AAO channels is between 10 and 20 nm. The size and interparticle gap of silver particles were adjusted in order to achieve optimal SERS signals and characterized by scanning electron microscopy, atomic force microscopy, and Raman spectroscopy. The fluctuation of SERS intensity is about 10-20% when measuring adenine solutions, showing a great reproducible SERS sensing. The nanoparticle arrays offer a large potential for practical applications as shown by the SERS-based quantitative detection and differentiation of adenine (A), thymine (T), cytosine (C), guanine (G), ß-carotene, and malachite green. The respective detection limits are <1 ppb for adenine and <0.63 ppm for ß-carotene and malachite green, respectively. Uniform and reproducible Raman enhancement enabled by Ag nanoparticle array embedded in anodic aluminum oxide differentiates and helps quantify DNA canonical nucleobases (adenine, thymine, cytosine, and guanine).

8.
Food Chem ; 224: 353-358, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28159279

RESUMO

A novel method for the detection of dimethoate based on the peroxidase-like activity of silver-nanoparticles-modified oxidized multiwalled carbon nanotubes (AgNPs/oxMWCNTs) has been developed. The synthesized AgNPs/oxMWCNTs showed excellent peroxidease-like catalytic activity in hydrogen peroxide-Amplex red (AR) system (AR is oxidized to resorufinat, with the resorufin fluorescence at 584nm being used to monitor the catalytic activity). After dimethoate was added to AgNPs/oxMWCNTs, the interaction between dimethoate and the AgNPs inhibited the catalytic activity of AgNPs/oxMWCNTs. The decrease in fluorescence was used for the detection of dimethoate in the range of 0.01-0.35µgmL-1 (R2=0.998) with a detection limit of 0.003µgmL-1 (signal/noise=3). This method exhibited good selectivity for the detection of dimethoate even in the presence of high concentration of other pesticides. Consequently, the method was applied to measure the concentration of dimethoate residue in lake water and fruit, thus obtaining satisfactory results.


Assuntos
Dimetoato/análise , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Prata/química , Fluorometria , Análise de Alimentos , Frutas/química , Peróxido de Hidrogênio/metabolismo , Lagos/química , Limite de Detecção , Praguicidas/análise
9.
Neurobiol Learn Mem ; 128: 56-64, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26743042

RESUMO

Prenatal morphine (PM) affects the development of brain reward system and cognitive function. The present study aimed to determine whether PM exposure increases the vulnerability to MA addiction. Pregnant Sprague-Dawley rats were administered saline or morphine during embryonic days 3-20. The acquisition, extinction and reinstatement of methamphetamine (MA) conditioned place preference (CPP) and intravenous self-administration (SA) paradigms were assessed in the male adult offspring. There was no difference in the acquisition and expression of MA CPP between saline- and PM-exposed rats, whereas PM-exposed rats exhibited slower extinction and greater MA priming-induced reinstatement of drug-seeking behavior than controls. Similarly, MA SA under progressive ratio and fixed ratio schedules was not affected by PM exposure, but PM-exposed rats required more extinction sessions to reach the extinction criteria and displayed more severe MA priming-, but not cue-induced, reinstatement. Such alterations in extinction and reinstatement were not present when PM-exposed rats were tested in an equivalent paradigm assessing operant responding for food pellets. Our results demonstrate that PM exposure did not affect the association memory formation during acquisition of MA CPP or SA, but impaired extinction learning and increased MA-primed reinstatement in both tasks. These findings suggest that the offspring of women using morphine or heroin during pregnancy might predict persistent MA seeking during extinction and enhanced propensity to MA relapse although they might not be more susceptible to the reinforcing effect of MA during initiation of drug use.


Assuntos
Comportamento de Procura de Droga/efeitos dos fármacos , Extinção Psicológica/efeitos dos fármacos , Metanfetamina/administração & dosagem , Morfina/administração & dosagem , Efeitos Tardios da Exposição Pré-Natal/psicologia , Animais , Condicionamento Clássico/efeitos dos fármacos , Feminino , Masculino , Gravidez , Ratos , Ratos Sprague-Dawley
10.
Colloids Surf B Biointerfaces ; 140: 567-573, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26705859

RESUMO

Magnetic silica core/shell nanovehicles presenting atherosclerotic plaque-specific peptide-1 (AP-1) as a targeting ligand (MPVA-AP1 nanovehicles) have been prepared through a double-emulsion method and surface modification. Amphiphilic poly(vinyl alcohol) was introduced as a polymer binder to encapsulate various drug molecules (hydrophobic, hydrophilic, polymeric) and magnetic iron oxide (Fe3O4) nanoparticles. Under a high-frequency magnetic field, magnetic carriers (diameter: ca. 50 nm) incorporating the anti-cancer drug doxorubicin collapsed, releasing approximately 80% of the drug payload, due to the heat generated by the rapidly rotating Fe3O4 nanoparticles, thereby realizing rapid and accurate controlled drug release. Simultaneously, the magnetic Fe3O4 themselves could also kill the tumor cells through a hyperthermia effect (inductive heating). Unlike their ungrafted congeners (MPVA nanovehicles), the AP1-grafted nanovehicles bound efficiently to colorectal cancer cells (CT26-IL4Rα), thereby displaying tumor-cell selectivity. The combination of remote control, targeted dosing, drug-loading flexibility, and thermotherapy and chemotherapy suggests that magnetic nanovehicles such as MPVA-AP1 have great potential for application in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Preparações de Ação Retardada/farmacologia , Doxorrubicina/farmacologia , Animais , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Doxorrubicina/química , Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Compostos Férricos/química , Campos Magnéticos , Camundongos , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Nanopartículas/química , Nanopartículas/ultraestrutura , Propriedades de Superfície , Carga Tumoral/efeitos dos fármacos
11.
ACS Appl Mater Interfaces ; 8(1): 411-8, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26686424

RESUMO

A new class of nanohybrids composed of structurally exfoliated silicate platelets and magnetic iron oxide nanoparticles was synthesized and shown to be capable of capturing microbes in liquid microbiological media. Nanoscale silicate platelets with an approximate thickness of 1.0 nm were prepared from the naturally occurring mineral clays montmorillonite and mica; these clays yielded platelets with lateral dimensions on the order of 80-100 nm and 300-1000 nm, respectively. The magnetic Fe3O4 nanoparticles, approximately 8.3 nm in diameter, were coated in situ onto the silicates during the synthesis process, which involved the coprecipitation of aqueous Fe(2+)/Fe(3+) salts. Owing to the high surface area-to-volume ratios and the presence of ionically charged groups (i.e., ≡SiO(-)Na(+)), the silicate nanoplatelets exhibited intense noncovalent bonding forces between Fe3O4 nanoparticles and the surrounding microorganisms. The Fe3O4-on-nanoplatelet nanohybrids enabled the entrapment of bacterial cells in liquid microbiological media. These captured bacteria formed bacterial aggregates on the order of micrometers that became physically maneuverable under a magnetic field. This phenomenon was demonstrated with Staphylococcus aureus in liquid microbiological media by physically removing them using a magnetic bar; in two experimental examples, bacterial concentrations were reduced from 10(6) to 10(2) and from 10(4) to 10(0) CFU/mL (colony formation unit/mL con). Under a scanning electron microscope, these bacteria appeared to have rough and wrinkled surfaces due to the accumulated silicate platelets. Furthermore, the external application of a high-frequency magnetic field completely destroyed these aggregated microbes by the magnetically induced heat. Hence, the newly developed nanohybrids were shown to be viable for physically capturing microbes and also for potential hyperthermia treatment applications.


Assuntos
Silicatos de Alumínio/farmacologia , Bactérias/efeitos dos fármacos , Magnetismo/métodos , Silicatos de Alumínio/química , Precipitação Química , Argila , Contagem de Colônia Microbiana , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Compostos Férricos/química , Temperatura Alta , Campos Magnéticos , Viabilidade Microbiana/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Silicatos/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura , Difração de Raios X
12.
Nanoscale Res Lett ; 10(1): 397, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26459427

RESUMO

In this research, graphene nanosheets were functionalized with cationic poly (diallyldimethylammonium chloride) (PDDA) and citrate-capped gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) bio-detection application. AuNPs were synthesized by the traditional citrate thermal reduction method and then adsorbed onto graphene-PDDA nanohybrid sheets with electrostatic interaction. The nanohybrids were subject to characterization including X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential, and X-ray photoelectron spectroscopy (XPS). The results showed that the diameter of AuNPs is about 15-20 nm immobilized on the graphene-PDDA sheets, and the zeta potential of various AuNPs/graphene-PDDA ratio is 7.7-38.4 mV. Furthermore, the resulting nanohybrids of AuNPs/graphene-PDDA were used for SERS detection of small molecules (adenine) and microorganisms (Staphylococcus aureus), by varying the ratios between AuNPs and graphene-PDDA. AuNPs/graphene-PDDA in the ratio of AuNPs/graphene-PDDA = 4:1 exhibited the strongest SERS signal in SERS detection of adenine and S. aureus. Thus, it is promising in the application of rapid and label-free bio-detection of bacteria or tumor cells.

13.
Nanoscale Res Lett ; 10(1): 412, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26489855

RESUMO

In this study, multifunctional hybrid nanoparticles composed of iron platinum (FePt), silica (SiO2), and gold nanoparticles (AuNPs) had been developed for surface-enhanced Raman scattering (SERS) application. Core-shell structure of SiO2 and FePt nanoparticles (FePt@SiO2) was fabricated through sol-gel process and then immobilized gold nanoparticles onto the surface of FePt@SiO2, which displays huge Raman enhancement effect and magnetic separation capability. The resulting core-shell nanoparticles were subject to evaluation by transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX), zeta potential measurement, and X-ray photoelectron spectroscopy (XPS). TEM observation revealed that the particle size of resultant nanoparticles displayed spherical structure with the size ~30 nm and further proved the successful immobilization of Au onto the surface of FePt@SiO2. Zeta potential measurement exhibited the successful reaction between FePt@SiO2 and AuNPs. The rapid SERS detection and identification of small biomolecules (adenine) and microorganisms (gram-positive bacteria, Staphylococcus aureus) was conducted through Raman spectroscopy. In summary, the novel core-shell magnetic nanoparticles could be anticipated to apply in the rapid magnetic separation under the external magnetic field due to the core of the FePt superparamagnetic nanoparticles and label-free SERS bio-sensing of biomolecules and bacteria.

14.
Nanoscale Res Lett ; 9(1): 444, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25246863

RESUMO

We are presenting our recent research results about the Ni-NiO nanoparticles on poly-(diallyldimethylammonium chloride)-modified graphene sheet (Ni-NiO/PDDA-G) nanocomposites prepared by the hydrothermal method at 90°C for 24 h. The Ni-NiO nanoparticles on PDDA-modified graphene sheets are measured by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED) pattern for exploring the structural evidence to apply in the electrochemical catalysts. The size of Ni-NiO nanoparticles is around 5 nm based on TEM observations. The X-ray diffraction (XRD) results show the Ni in the (012), (110), (110), (200), and (220) crystalline orientations, respectively. Moreover, the crystalline peaks of NiO are found in (111) and (220). The thermal gravimetric analysis (TGA) result represents the loading content of the Ni metal which is about 34.82 wt%. The electron spectroscopy for chemical analysis/X-ray photoelectron spectroscopy (ESCA/XPS) reveals the Ni(0) to Ni(II) ratio in metal phase. The electrochemical studies with Ni-NiO/PDDA-G in 0.5 M aqueous H2SO4 were studied for oxygen reduction reaction (ORR).

15.
Nanoscale Res Lett ; 9(1): 497, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25246875

RESUMO

In this study, we developed the cancer treatment through the combination of chemotherapy and thermotherapy using doxorubicin-loaded magnetic liposomes. The citric acid-coated magnetic nanoparticles (CAMNP, ca. 10 nm) and doxorubicin were encapsulated into the liposome (HSPC/DSPE/cholesterol = 12.5:1:8.25) by rotary evaporation and ultrasonication process. The resultant magnetic liposomes (ca. 90 to 130 nm) were subject to characterization including transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), zeta potential, Fourier transform infrared (FTIR) spectrophotometer, and fluorescence microscope. In vitro cytotoxicity of the drug carrier platform was investigated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using L-929 cells, as the mammalian cell model. In vitro cytotoxicity and hyperthermia (inductive heating) studies were evaluated against colorectal cancer (CT-26 cells) with high-frequency magnetic field (HFMF) exposure. MTT assay revealed that these drug carriers exhibited no cytotoxicity against L-929 cells, suggesting excellent biocompatibility. When the magnetic liposomes with 1 µM doxorubicin was used to treat CT-26 cells in combination with HFMF exposure, approximately 56% cells were killed and found to be more effective than either hyperthermia or chemotherapy treatment individually. Therefore, these results show that the synergistic effects between chemotherapy (drug-controlled release) and hyperthermia increase the capability to kill cancer cells.

16.
J Opt Soc Am A Opt Image Sci Vis ; 26(12): 2600-6, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19956330

RESUMO

A normalized admittance diagram assists in describing and designing multilayered structures to excite long-range surface-plasmon-polariton (LRSPP) waves of either the p- or the s-polarization state. These structures comprise symmetric periodic multilayers on one or both sides of a metal thin film in either the Kretschmann or the Sarid configuration. The normalized admittance diagram even assists in designing structures that can be used to excite LRSPP waves of both polarization states simultaneously.

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