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1.
Nat Immunol ; 25(6): 1059-1072, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38802511

RESUMO

Asthma, the most prevalent respiratory disease, affects more than 300 million people and causes more than 250,000 deaths annually. Type 2-high asthma is characterized by interleukin (IL)-5-driven eosinophilia, along with airway inflammation and remodeling caused by IL-4 and IL-13. Here we utilize IL-5 as the targeting domain and deplete BCOR and ZC3H12A to engineer long-lived chimeric antigen receptor (CAR) T cells that can eradicate eosinophils. We call these cells immortal-like and functional IL-5 CAR T cells (5TIF) cells. 5TIF cells were further modified to secrete an IL-4 mutein that blocks IL-4 and IL-13 signaling, designated as 5TIF4 cells. In asthma models, a single infusion of 5TIF4 cells in fully immunocompetent mice, without any conditioning regimen, led to sustained repression of lung inflammation and alleviation of asthmatic symptoms. These data show that asthma, a common chronic disease, can be pushed into long-term remission with a single dose of long-lived CAR T cells.


Assuntos
Asma , Receptores de Antígenos Quiméricos , Animais , Asma/imunologia , Asma/terapia , Camundongos , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Imunoterapia Adotiva/métodos , Linfócitos T/imunologia , Interleucina-5/imunologia , Interleucina-5/metabolismo , Modelos Animais de Doenças , Humanos , Interleucina-4/imunologia , Interleucina-4/metabolismo , Camundongos Endogâmicos C57BL , Eosinófilos/imunologia , Feminino , Interleucina-13/metabolismo , Interleucina-13/imunologia
2.
J Exp Med ; 221(5)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38530240

RESUMO

Long-term antitumor efficacy of chimeric antigen receptor (CAR) T cells depends on their functional persistence in vivo. T cells with stem-like properties show better persistence, but factors conferring bona fide stemness to T cells remain to be determined. Here, we demonstrate the induction of CAR T cells into an immortal-like and functional state, termed TIF. The induction of CARTIF cells depends on the repression of two factors, BCOR and ZC3H12A, and requires antigen or CAR tonic signaling. Reprogrammed CARTIF cells possess almost infinite stemness, similar to induced pluripotent stem cells while retaining the functionality of mature T cells, resulting in superior antitumor effects. Following the elimination of target cells, CARTIF cells enter a metabolically dormant state, persisting in vivo with a saturable niche and providing memory protection. TIF represents a novel state of T cells with unprecedented stemness, which confers long-term functional persistence of CAR T cells in vivo and holds broad potential in T cell therapies.


Assuntos
Células-Tronco Pluripotentes Induzidas , Transdução de Sinais
3.
J Exp Med ; 220(6)2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-36971758

RESUMO

Ca2+ in endoplasmic reticulum (ER) dictates T cell activation, proliferation, and function via store-operated Ca2+ entry. How naive T cells maintain an appropriate level of Ca2+ in ER remains poorly understood. Here, we show that the ER transmembrane protein VMP1 is essential for maintaining ER Ca2+ homeostasis in naive T cells. VMP1 promotes Ca2+ release from ER under steady state, and its deficiency leads to ER Ca2+ overload, ER stress, and secondary Ca2+ overload in mitochondria, resulting in massive apoptosis of naive T cells and defective T cell response. Aspartic acid 272 (D272) of VMP1 is critical for its ER Ca2+ releasing activity, and a knockin mouse strain with D272 mutated to asparagine (D272N) demonstrates all functions of VMP1 in T cells in vivo depend on its regulation of ER Ca2+. These data uncover an indispensable role of VMP1 in preventing ER Ca2+ overload and maintaining naive T cell survival.


Assuntos
Cálcio , Linfócitos T , Animais , Camundongos , Cálcio/metabolismo , Sobrevivência Celular , Linfócitos T/metabolismo , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo
4.
Biosens Bioelectron ; 227: 115123, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36812793

RESUMO

We report quantitative determination of extracellular H2O2 released from single COS-7 cells with high spatial resolution, using scanning electrochemical microscopy (SECM). Our strategy of depth scan imaging in vertical x-z plane was conveniently utilized to a single cell for obtaining probe approach curves (PACs) to any positions on the membrane of a live cell by simply drawing a vertical line on one depth SECM image. This SECM mode provides an efficient way to record a batch of PACs, and visualize cell topography simultaneously. The H2O2 concentration at the membrane surface in the center of an intact COS-7 cell was deconvoluted from apparent O2, and determined to be 0.020 mM by overlapping the experimental PAC with the simulated one having a known H2O2 release value. The H2O2 profile determined in this way gives insight into physiological activity of single live cells. In addition, intracellular H2O2 profile was demonstrated using confocal microscopy by labelling the cells with a luminomphore, 2',7'-dichlorodihydrofluorescein diacetate. The two methodologies have illustrated complementary experimental results of H2O2 detection, indicating that H2O2 generation is centered at endoplasmic reticula.


Assuntos
Técnicas Biossensoriais , Peróxido de Hidrogênio , Animais , Chlorocebus aethiops , Microscopia Eletroquímica de Varredura/métodos , Células COS , Microscopia Confocal
5.
J Orthop Surg Res ; 17(1): 75, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123521

RESUMO

BACKGROUND: Minimally invasive surgery for carpal tunnel syndrome has been consistently the mainstay of treatment. In this study, we developed a novel bush hook via a mini-transverse incision at proximal wrist crease to surgically treat carpal tunnel syndrome and our aim was to compare the results with those of mid-palmar small longitudinal incision in carpal tunnel release. METHODS: This is a retrospective study on patients who received a mini-transverse incision and a novel bush hook or a mid-palmar small longitudinal incision for treatment of carpal tunnel syndrome. The decision to receive either technique was made mainly based on patients' choice. The clinical results were evaluated at 1 week, 1 month, 3 and 6 months postoperatively and compared. RESULTS: In total, 58 patients in mini-transverse incision group and 74 in mid-palmar longitudinal incision group were include. The follow-up period was 6.8 ± 1.6 months. The mini-transverse incision group had a significantly smaller incision (4.3 ± 0.4 mm vs. 26.2 ± 1.6 mm), shorter surgical time (7.8 ± 2.6 min vs. 19.7 ± 2.8 min), but not for hospital stay (3.2 ± 1.9 vs. 3.6 ± 2.2 days). Both groups showed significant improvement from baseline level at any time points postoperatively (all P < 0.001). At 1 month and 3 months, the mini-transverse incision group showed a significantly better improvement of VAS, SSS and FSS score (P < 0.05). At 6 months, the differences were no longer significant (P > 0.05). In addition, the mini-transverse incision group showed a significantly reduced time to return to the work and activities, tendency to higher rate of excellence and good outcomes and fewer complications. CONCLUSIONS: This novel technique via a mini-transverse incision and bush hook showed better clinical effectiveness and safety, and can be considered as an alternative for wrist tunnel release after the results are validated by higher-level evidence studies. Evidence level: III.


Assuntos
Síndrome do Túnel Carpal/cirurgia , Descompressão Cirúrgica/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Ferida Cirúrgica , Adulto , Síndrome do Túnel Carpal/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento , Articulação do Punho
6.
Cell Rep ; 37(10): 110083, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34879274

RESUMO

Robust expansion of adoptively transferred T cells is a prerequisite for effective cancer immunotherapy, but how many genes in the genome modulate T cell expansion remains unknown. Here, we perform in vivo and in vitro CRISPR screens to systematically identify genes influencing CD8 T cell expansion. In the mouse genome, ∼2,600 and ∼1,500 genes are required for optimal CD8 T cell expansion in vivo and in vitro, respectively. In vivo-specific CD8 T cell essential genes are enriched in metabolic pathways, including mitochondrial metabolism. The strongest repressor of CD8 T cell expansion is Roquin, the ablation of which drastically boosts T cell proliferation by enhancing cell-cycle progression and upregulation of IRF4. Roquin deficiency or IRF4 overexpression potently enhances anti-tumor immunity. These data provide a functional catalog of CD8 T cell fitness genes and suggest that targeting the Roquin-IRF4 axis is an effective strategy to enhance efficacy of adoptive transfer therapy for cancer.


Assuntos
Linfócitos T CD8-Positivos/transplante , Proliferação de Células , Citotoxicidade Imunológica , Imunoterapia Adotiva , Ativação Linfocitária , Neoplasias/terapia , Ubiquitina-Proteína Ligases/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/metabolismo , Fenótipo , Transdução de Sinais , Evasão Tumoral , Ubiquitina-Proteína Ligases/metabolismo
8.
J Orthop Surg Res ; 16(1): 462, 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34281573

RESUMO

PURPOSE: This study aimed to investigate the outcomes of a mini-transverse incision with a bush-hook versus a conventional open incision for carpal tunnel release (CTR). METHODS: This was a prospective study. The decision to receive either technique (mini-transverse incision with a bush-hook or conventional open incision) was primarily based on patients' choice. Patients' symptom severity, functional status, and symptomatic pain were measured at pre-operation, 1 month, and 3 and 6 months postoperatively, and any relevant complications were recorded. Kelly's scale was used to evaluate the overall clinical efficacy. RESULTS: Eighty-nine patients were included in the open CTR group and 85 patients in the mini-transverse incision group. The mini-transverse incision group had a significantly smaller incision (4.4±0.6 vs 44.8±3.7 mm), shorter surgical time (7.8±1.9 vs 21.2±3.4 min), and shorter hospital stay (3.7±1.6 vs 5.9±2.0 days) than did the open CTR group. Both groups showed significant improvements from baseline levels (all P<0.001). At postoperative 1 month and 3 months, the transverse incision group showed a significantly better VAS, SSS, and FSS (all P<0.05), but the difference was non-significant at 6 months except for FSS (P=0.022). Also, mini-transverse incision showed a significantly reduced time to return to work and activities, trend to a higher rate of excellence, and good and fewer complications than did the open CTR. CONCLUSIONS: The mini-transverse incision exhibited better performance in surgery-related measures, symptomatic remission, functional recovery, and postoperative morbidity, thus could be considered a promising technique alternative.


Assuntos
Síndrome do Túnel Carpal/cirurgia , Procedimentos Ortopédicos/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Prospectivos
9.
Protein Expr Purif ; 178: 105783, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33122138

RESUMO

Natural killer (NK) cells are potent cytotoxic effector cells of the innate immune system and play an important role in tumor immunosurveillance and control. NKG2D is an activating receptor of NK cells. The NKG2D receptor-ligand system has contributed to immune cells recognizing tumor cells and the tumor microenvironment. In order to stretch the application of NK cells on adoptive immunotherapy for B-cell malignancies, we designed and produced a novel bispecific ULBP1×CD19-scFv fusion protein, in which the extracellular domain of NKG2D ligand ULBP1 was fused to a single chain variable fragment (scFv) of anti-CD19. The vector expressing ULBP1×CD19-scFv protein was constructed and expressed in Pichia pastoris. Effects of medium composition, concentration of methanol as the inducer, induction time and broth content in shake flask on the expression of the recombinant protein were investigated. The results showed that the optimized conditions for ULBP1×CD19-scFv expression were 1% methanol induction for 96 h with 15% broth content. The secreted recombinant protein was purified using ammonium sulfate fractionation and Ni-NTA affinity chromatography and the purity is about 93%. The cytotoxicity of NK92-MI cells against CD19+ Raji cells was enhanced in the presence of purified ULBP1×CD19-scFv protein. These results indicated that ULBP1 could be used as an activating element of bispecific killer engagers (BiKEs) and Pichia pastoris yeast might be an alternative expression host for BiKEs production.


Assuntos
Anticorpos Biespecíficos , Antígenos CD19/imunologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Anticorpos de Cadeia Única , Anticorpos Biespecíficos/química , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/isolamento & purificação , Células Hep G2 , Humanos , Subfamília K de Receptores Semelhantes a Lectina de Células NK/antagonistas & inibidores , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Proteínas Recombinantes de Fusão , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/isolamento & purificação
10.
Cell Death Differ ; 28(1): 303-319, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32770108

RESUMO

Pyrroline-5-carboxylate synthase (P5CS) catalyzes the synthesis of pyrroline-5-carboxylate (P5C), a key precursor for the synthesis of proline and ornithine. P5CS malfunction leads to multiple human diseases; however, the molecular mechanism underlying these diseases is unknown. We found that P5CS localizes in mitochondria in rod- and ring-like patterns but diffuses inside the mitochondria upon cellular starvation or exposure to oxidizing agents. Some of the human disease-related mutant forms of P5CS also exhibit diffused distribution. Multimerization (but not the catalytic activity) of P5CS regulates its localization. P5CS mutant cells have a reduced proliferation rate and are sensitive to cellular stresses. Flies lacking P5CS have reduced eclosion rates. Lipid droplets accumulate in the eyes of the newly eclosed P5CS mutant flies, which degenerate with aging. The loss of P5CS in cells leads to abnormal purine metabolism and lipid-droplet accumulation. The reduced lipid-droplet consumption is likely due to decreased expression of the fatty acid transporter, CPT1, and few ß-oxidation-related genes following P5CS knockdown. Surprisingly, we found that P5CS is required for mitochondrial respiratory complex organization and that the respiration defects in P5CS knockout cells likely contribute to the metabolic defects in purine synthesis and lipid consumption. This study links amino acid synthesis with mitochondrial respiration and other key metabolic processes, whose imbalance might contribute to P5CS-related disease conditions.


Assuntos
Mitocôndrias/metabolismo , Ornitina-Oxo-Ácido Transaminase/metabolismo , Animais , Drosophila , Células HeLa , Humanos , Dinâmica Mitocondrial , Ornitina/biossíntese , Ornitina-Oxo-Ácido Transaminase/genética , Prolina/biossíntese
11.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-876120

RESUMO

@#[Abstract] Objective: To construct and purify the recombinant bispecific antibody (BsAb) targeting PD-1 and CD19 and evaluate its activity. Methods: With pCAR1 plasmid as the vector, the eukaryotic expression vector of anti-PD-1/CD19 BsAb was constructed by molecular cloning technology, and then transfected into mammalian cell line CHO-S by PEI reagent for transiently expressing antibody. The BsAb was purified by Affinity chromatography and then identified by SDS-PAGE and WB. The blocking activity of BsAb on PD-1/PD-L1 in vitro was detected by Luciferase reporter gene assay. The activity of antibody (BsAb)-dependent cell (PBMC)-mediated cytotoxicity (ADCC) in vitro was evaluated by lactate dehydrogenase (LDH) cytotoxicity assay. Results: The double plasmid eukaryotic expression vector pCAR1-19X3 was successfully constructed, and anti-PD-1/CD19 BsAb was successfully expressed in CHO-S cells, named pCAR1-19X3-TY. pCAR1-19X3-TY could effectively block the binding of PD-1 to its ligand PD-L1 in vitro, and the EC50 based on the dose-response curve was 0.306 μg/ml. ADCC results showed that pCAR1-19X3-TY could mediate the cytotoxicity of PBMC against Raji cells, and the curve showed a linear upward trend; when the effect/target ratio was 50∶1, the target cell lysis rate of pCAR1-19X3-TY was (38.9±0.3)%, which was not significantly different from that of the positive treatment group (46.7±4.9)% (P>0.05), but significantly higher than that of the negative control group (1.2±0.1)% (P<0.05). Conclusion: The recombinant anti-PD-1/CD19 BsAb can effectively block the binding of PD-1 and PD-L1 and activate PBMC mediated cytotoxicity against Raji cells. pCAR1-19X3-TY has the potential application value in the treatment of B-cell malignant tumor.

12.
Sci Adv ; 5(9): eaax0365, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31555733

RESUMO

Mitochondria are highly dynamic organelles. Through a large-scale in vivo RNA interference (RNAi) screen that covered around a quarter of the Drosophila melanogaster genes (4000 genes), we identified 578 genes whose knockdown led to aberrant shapes or distributions of mitochondria. The complex analysis revealed that knockdown of the subunits of proteasomes, spliceosomes, and the electron transport chain complexes could severely affect mitochondrial morphology. The loss of Dhpr, a gene encoding an enzyme catalyzing tetrahydrobiopterin regeneration, leads to a reduction in the numbers of tyrosine hydroxylase neurons, shorter lifespan, and gradual loss of muscle integrity and climbing ability. The affected mitochondria in Dhpr mutants are swollen and have fewer cristae, probably due to lower levels of Drp1 S-nitrosylation. Overexpression of Drp1, but not of S-nitrosylation-defective Drp1, rescued Dhpr RNAi-induced mitochondrial defects. We propose that Dhpr regulates mitochondrial morphology and tissue homeostasis by modulating S-nitrosylation of Drp1.


Assuntos
Di-Hidropteridina Redutase , Proteínas de Drosophila , Mitocôndrias , Proteínas Mitocondriais , Animais , Di-Hidropteridina Redutase/genética , Di-Hidropteridina Redutase/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Interferência de RNA
13.
J Cell Sci ; 131(1)2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29158224

RESUMO

Mitochondria-ER contact sites (MERCs) enable communication between the ER and mitochondria and serve as platforms for many cellular events, including autophagy. Nonetheless, the molecular organization of MERCs is not known, and there is no bona fide marker of these contact sites in mammalian cells. In this study, we designed a genetically encoded reporter using split GFP protein for labeling MERCs. We subsequently analyzed its distribution and dynamics during the cell cycle and under stressful cellular conditions such as starvation, apoptosis and ER stress. We found that MERCs are dynamic structures that undergo remodeling within minutes. Mitochondrial morphology, but not ER morphology, affected the distribution of MERCs. We also found that carbonyl cyanidem-chlorophenyl hydrazone (CCCP) and oligomycin A treatment enhanced MERC formation. The stimulations that led to apoptosis or autophagy increased the MERC signal. By contrast, increasing cellular lipid droplet load did not change the pattern of MERCs.


Assuntos
Autofagia , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Linhagem Celular Tumoral , Imunofluorescência , Humanos , Ligação Proteica
14.
Mol Cell ; 61(1): 111-24, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26711011

RESUMO

Mitochondria undergo frequent morphological changes through fission and fusion. Mutations in core members of the mitochondrial fission/fusion machinery are responsible for severe neurodegenerative diseases. However, the mitochondrial fission/fusion mechanisms are poorly understood. We found that the loss of a mitochondrial protein encoding gene, mitoguardin (miga), leads to mitochondrial defects and neurodegeneration in fly eyes. Mammals express two orthologs of miga: Miga1 and Miga2. Both MIGA1 and MIGA2 form homotypic and heterotypic complexes on the outer membrane of the mitochondria. Loss of MIGA results in fragmented mitochondria, whereas overexpression of MIGA leads to clustering and fusion of mitochondria in both fly and mammalian cells. MIGA proteins function downstream of mitofusin and interact with MitoPLD to stabilize MitoPLD and facilitate MitoPLD dimer formation. Therefore, we propose that MIGA proteins promote mitochondrial fusion by regulating mitochondrial phospholipid metabolism via MitoPLD.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/enzimologia , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Neurônios/enzimologia , Fosfolipase D/metabolismo , Animais , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Endorribonucleases , Feminino , Genótipo , Células HEK293 , Células HeLa , Homeostase , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Mitocôndrias/patologia , Membranas Mitocondriais/enzimologia , Proteínas Mitocondriais/genética , Mutação , Células NIH 3T3 , Neurônios/patologia , Fenótipo , Fosfolipase D/genética , Células Fotorreceptoras de Invertebrados/enzimologia , Multimerização Proteica , Interferência de RNA , Transfecção
15.
J Biol Chem ; 290(12): 7943-51, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25670863

RESUMO

The endoplasmic reticulum (ER) is a highly dynamic organelle that plays a critical role in many cellular processes. Abnormal ER morphology is associated with some human diseases, although little is known regarding how ER morphology is regulated. Using a forward genetic screen to identify genes that regulated ER morphology in Drosophila, we identified a mutant of Sec22, the orthologs of which in yeast, plants, and humans are required for ER to Golgi trafficking. However, the physiological function of Sec22 has not been previously investigated in animal development. A loss of Sec22 resulted in ER proliferation and expansion, enlargement of late endosomes, and abnormal Golgi morphology in mutant larvae fat body cells. However, starvation-induced autophagy was not affected by a loss of Sec22. Mosaic analysis of the eye revealed that Sec22 was required for photoreceptor morphogenesis. In Sec22 mutant photoreceptor cells, the ER was highly expanded and gradually lost normal morphology with aging. The rhabdomeres in mutants were small and sometimes fused with each other. The morphology of Sec22 mutant eyes resembled the eye morphology of flies with overexpressed eyc (eyes closed). eyc encodes for a Drosophila p47 protein that is required for membrane fusion. A loss of Syntaxin5 (Syx5), encoding for a t-SNARE on Golgi, also phenocopied the Sec22 mutant. Sec22 formed complexes with Syx5 and Eyc. Thus, we propose that appropriate trafficking between the ER and Golgi is required for maintaining ER morphology and for Drosophila eye morphogenesis.


Assuntos
Autofagia/fisiologia , Proteínas de Drosophila/fisiologia , Retículo Endoplasmático/metabolismo , Olho/embriologia , Sequência de Bases , Primers do DNA
16.
Electrochim Acta ; 56(14-7): 5016-5021, 2011 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-21785491

RESUMO

Patterned copper sulfide (Cu(x)S) microstructures on Si (1 1 1) wafers were successfully fabricated by a relatively simple solution growth method using copper sulfate, ethylenediaminetetraacetate and sodium thiosulfate aqueous solutions as precursors. The Cu(x)S particles were selectively deposited on a patterned self-assembled monolayer of 3-aminopropyltriethoxysilane regions created by photolithography. To obtain high quality Cu(x)S films, preparative conditions such as concentration, proportion, pH and temperature of the precursor solutions were optimized. Various techniques such as optical microscopy, atomic force microscopy (AFM), X-ray diffraction, optical absorption and scanning electrochemical microscopy (SECM) were employed to examine the topography and properties of the micro-patterned Cu(x)S films. Optical microscopy and AFM results indicated that the Cu(x)S micro-pattern possessed high selectivity and clear edge resolution. From combined X-ray diffraction analysis and optical band gap calculations we conclude that Cu(9)S(5) (digenite) was the main phase within the resultant Cu(x)S film. Both SECM image and cyclic voltammograms confirmed that the Cu(x)S film had good electrical conductivity. Moreover, from SECM approach curve analysis, the apparent electron-transfer rate constant (k) in the micro-pattern of Cu(x)S dominated surface was estimated as 0.04 cm/s. The SECM current map showed high edge acuity of the micro-patterned Cu(x)S.

17.
Anal Chem ; 82(20): 8371-3, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20873801

RESUMO

Detection of reactive oxygen species (ROS) released from live macrophage cells (RAW264.7) without any addition of external redox mediators using constant-height and constant-distance mode scanning electrochemical microscopy (SECM) was presented in this Letter. The successful separation of the ROS profile from the topography of cells in the physiological condition was demonstrated by recording the amperometric current and probing position in the z-direction along with lateral coordinates at each pixel where an alternating current (AC) was kept constant. It was discovered that the nucleus region of the cell releases more ROS than other organelle regions and the height of the cell is approximately 4.8 µm. To our best knowledge, this work reports the first spatially monitored ROS release without the influence of cell morphology using SECM.


Assuntos
Macrófagos/química , Microscopia Eletrônica de Varredura/métodos , Animais , Linhagem Celular , Sobrevivência Celular , Macrófagos/citologia , Camundongos , Espécies Reativas de Oxigênio/análise
18.
Electrophoresis ; 26(3): 687-93, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15690421

RESUMO

A simultaneous electrochemical (EC) and electrochemiluminescence (ECL) detection scheme was introduced to both microchip and conventional capillary electrophoresis (CE). In this dual detection scheme, tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)3(2+)) was used as an ECL reagent as well as a catalyst (in the formation of Ru(bpy)3(3+)) for the EC detection. In the Ru(bpy)3(2+)-ECL process, Ru(bpy)3(3+) was generated and then reacted with analytes resulting in an ECL emission and a great current enhancement in EC detection due to the catalysis of Ru(bpy)3(3+). The current response and ECL signals were monitored simultaneously. In the experiments, dopamine and three kinds of pharmaceuticals, anisodamine, ofloxacin, and lidocaine, were selected to validate this dual detection strategy. Typically, for the EC detection of dopamine with the presence of Ru(bpy)3(2+), a approximately 5 times higher signal-to-noise ratio (S/N) can be achieved than that without Ru(bpy)3(2+), during the simultaneous EC and ECL detection of a mixture of dopamine and lidocaine using CE separation. The results indicated that this dual EC and ECL detection strategy could provide a simple and convenient detection method for analysis of more kinds of analytes in CE separation than the single EC or ECL detection alone, and more information of analytes could be achieved in analytical applications simultaneously.


Assuntos
Eletroquímica , Eletroforese Capilar/métodos , Luminescência , Eletroforese em Microchip , Compostos Organometálicos , Alcaloides de Solanáceas/isolamento & purificação
19.
Electrophoresis ; 25(20): 3422-6, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15490448

RESUMO

A new technique for investigating drug-protein binding was developed employing capillary electrophoresis (CE) coupled with tris(2,2'-bipyridyl) ruthenium(II) [Ru(bpy)(3) (2+)] electrochemiluminescence (ECL) (CE-ECL) detection after equilibrium dialysis. Three basic drugs, namely pridinol, procyclidine and its analogue trihexyphenidyl, were successfully separated by capillary zone electrophoresis with end-column Ru(bpy)(3) (2+) ECL detection. The relative drug binding to human serum albumin (HSA) for each single drug as well as for the three drugs binding simultaneously was calculated. It was found that the three antiparkinsonian drugs compete for the same binding site on HSA. This work demonstrated that Ru(bpy)(3) (2+) CE-ECL can be a suitable technique for studying drug-protein binding.


Assuntos
Antiparkinsonianos/análise , Eletroforese Capilar/métodos , Medições Luminescentes/métodos , Albumina Sérica/metabolismo , Antiparkinsonianos/metabolismo , Ligação Competitiva , Humanos , Compostos Organometálicos/análise , Compostos Organometálicos/química , Piperidinas/análise , Piperidinas/metabolismo , Prociclidina/análise , Prociclidina/metabolismo , Ligação Proteica , Albumina Sérica/química , Triexifenidil/análise , Triexifenidil/metabolismo
20.
Artigo em Inglês | MEDLINE | ID: mdl-15358317

RESUMO

In this article, an antibiotic, lincomycin was determined in the urine sample by microchip capillary electrophoresis (CE) with integrated indium tin oxide (ITO) working electrode based on electrochemiluminescence (ECL) detection. This microchip CE-ECL system can be used for the rapid analysis of lincomycin within 40s. Under the optimized conditions, the linear range was obtained from 5 to 100 microM with correlation coefficient of 0.998. The limit of detection (LOD) of 3.1 microM was obtained for lincomycin in the standard solution. We also applied this method to analyzing lincomycin in the urine matrix. The limit of detection of 9.0 microM was obtained. This method can determine lincomycin in the urine sample without pretreatment, which demonstrated that it is a promising method of detection of lincomycin in clinical and pharmaceutical area.


Assuntos
Antibacterianos/urina , Lincomicina/urina , Microcomputadores , Soluções Tampão , Dimetilpolisiloxanos , Eletroquímica , Eletrodos , Eletroforese , Humanos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Índio , Medições Luminescentes , Reprodutibilidade dos Testes , Silicones , Compostos de Estanho
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