Strongly Coupled Molybdenum Carbide on Carbon Sheets as a Bifunctional Electrocatalyst for Overall Water Splitting.

PubMed

Wang, Hao; Cao, Yingjie; Sun, Cheng; Zou, Guifu; Huang, Jianwen; Kuai, Xiaoxiao; Zhao, Jianqing; Gao, Lijun

2017-09-22

High-performance and affordable electrocatalysts from earth-abundant elements are desirably pursued for water splitting involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Here, a bifunctional electrocatalyst of highly crystalline Mo 2 C nanoparticles supported on carbon sheets (Mo 2 C/CS) was designed toward overall water splitting. Owing to the highly active catalytic nature of Mo 2 C nanoparticles, the high surface area of carbon sheets and efficient charge transfer in the strongly coupled composite, the designed catalysts show excellent bifunctional behavior with an onset potential of -60 mV for HER and an overpotential of 320 mV to achieve a current density of 10 mA cm -2 for OER in 1 m KOH while maintaining robust stability. Moreover, the electrolysis cell using the catalyst only requires a low cell voltage of 1.73 V to achieve a current density of 10 mA cm -2 and maintains the activity for more than 100 h when employing the Mo 2 C/CS catalyst as both anode and cathode electrodes. Such high performance makes Mo 2 C/CS a promising electrocatalyst for practical hydrogen production from water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

RuO2 nanoparticles decorated MnOOH/C as effective bifunctional electrocatalysts for lithium-air battery cathodes with long-cycling stability

NASA Astrophysics Data System (ADS)

Kim, Gil-Pyo; Lim, Dongwook; Park, Inyeong; Park, Hyelee; Shim, Sang Eun; Baeck, Sung-Hyeon

2016-08-01

Manganite (MnOOH) is one of the most effective electrocatalysts for oxygen reduction reaction (ORR), and RuO2 nanoparticles exhibit high activity for oxygen evolution reaction (OER). We herein report a facile means of producing well dispersed RuO2/MnOOH on Ketjen black (RuO2/MnOOH/C) as a bifunctional catalyst for lithium-air (Li-air) batteries. RuO2/MnOOH/C was simply synthesized using a hydrothermal/precipitation based method, and was used as a cathode for a Li-air battery using a Swagelok-type cell. The importance of dispersing active catalysts on a carbon support was clearly demonstrated by textural, charge-discharge voltammetric, and electrochemical impedance spectroscopic (EIS) analyses, comparing results with a catalyst produced by physically mixing RuO2/MnOOH with carbon (RuO2/MnOOH + C). RuO2/MnOOH/C showed low overpotential and stable cycleability up to 170th cycles with 1000 mAh g-1 of charge-discharge capacity, which was attributed to its enhanced active surface area and low charge-transfer resistance. The results obtained suggest that this strategy can be widely applied to bifunctional electrocatalysis, such as secondary batteries and regenerative fuel cell (RFC).

Polymer-Based Surfaces Designed to Reduce Biofilm Formation: From Antimicrobial Polymers to Strategies for Long-Term Applications.

PubMed

Riga, Esther K; Vöhringer, Maria; Widyaya, Vania Tanda; Lienkamp, Karen

2017-10-01

Contact-active antimicrobial polymer surfaces bear cationic charges and kill or deactivate bacteria by interaction with the negatively charged parts of their cell envelope (lipopolysaccharides, peptidoglycan, and membrane lipids). The exact mechanism of this interaction is still under debate. While cationic antimicrobial polymer surfaces can be very useful for short-term applications, they lose their activity once they are contaminated by a sufficiently thick layer of adhering biomolecules or bacterial cell debris. This layer shields incoming bacteria from the antimicrobially active cationic surface moieties. Besides discussing antimicrobial surfaces, this feature article focuses on recent strategies that were developed to overcome the contamination problem. This includes bifunctional materials with simultaneously presented antimicrobial and protein-repellent moieties; polymer surfaces that can be switched from an antimicrobial, cell-attractive to a cell-repellent state; polymer surfaces that can be regenerated by enzyme action; degradable antimicrobial polymers; and antimicrobial polymer surfaces with removable top layers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large-scale Generation of Patterned Bubble Arrays on Printed Bi-functional Boiling Surfaces

NASA Astrophysics Data System (ADS)

Choi, Chang-Ho; David, Michele; Gao, Zhongwei; Chang, Alvin; Allen, Marshall; Wang, Hailei; Chang, Chih-Hung

2016-04-01

Bubble nucleation control, growth and departure dynamics is important in understanding boiling phenomena and enhancing nucleate boiling heat transfer performance. We report a novel bi-functional heterogeneous surface structure that is capable of tuning bubble nucleation, growth and departure dynamics. For the fabrication of the surface, hydrophobic polymer dot arrays are first printed on a substrate, followed by hydrophilic ZnO nanostructure deposition via microreactor-assisted nanomaterial deposition (MAND) processing. Wettability contrast between the hydrophobic polymer dot arrays and aqueous ZnO solution allows for the fabrication of heterogeneous surfaces with distinct wettability regions. Heterogeneous surfaces with various configurations were fabricated and their bubble dynamics were examined at elevated heat flux, revealing various nucleate boiling phenomena. In particular, aligned and patterned bubbles with a tunable departure frequency and diameter were demonstrated in a boiling experiment for the first time. Taking advantage of our fabrication method, a 6 inch wafer size heterogeneous surface was prepared. Pool boiling experiments were also performed to demonstrate a heat flux enhancement up to 3X at the same surface superheat using bi-functional surfaces, compared to a bare stainless steel surface.

Therapeutic Potential of a Non-Steroidal Bifunctional Anti-Inflammatory and Anti-Cholinergic Agent against Skin Injury Induced by Sulfur Mustard

PubMed Central

Chang, Yoke-Chen; Wang, James D.; Hahn, Rita A.; Gordon, Marion K.; Joseph, Laurie B.; Heck, Diane E.; Heindel, Ned D.; Young, Sherri C.; Sinko, Patrick J.; Casillas, Robert P.; Laskin, Jeffrey D.; Laskin, Debra L.; Gerecke, Donald R.

2014-01-01

Sulfur mustard (bis(2-chloroethyl) sulfide, SM) is a highly reactive bifunctional alkylating agent inducing edema, inflammation, and the formation of fluid-filled blisters in the skin. Medical countermeasures against SM-induced cutaneous injury have yet to be established. In the present studies, we tested a novel, bifunctional anti-inflammatory prodrug (NDH 4338) designed to target cyclooxygenase 2 (COX2), an enzyme that generates inflammatory eicosanoids, and acetylcholinesterase, an enzyme mediating activation of cholinergic inflammatory pathways in a model of SM-induced skin injury. Adult SKH-1 hairless male mice were exposed to SM using a dorsal skin vapor cup model. NDH 4338 was applied topically to the skin 24, 48, and 72 hr post-SM exposure. After 96 hr, SM was found to induce skin injury characterized by edema, epidermal hyperplasia, loss of the differentiation marker, keratin 10 (K10), upregulation of the skin wound marker keratin 6 (K6), disruption of the basement membrane anchoring protein laminin 322, and increased expression of epidermal COX2. NDH 4338 post-treatment reduced SM-induced dermal edema and enhanced skin re-epithelialization. This was associated with a reduction in COX2 expression, increased K10 expression in the suprabasal epidermis, and reduced expression of K6. NDH 4338 also restored basement membrane integrity, as evidenced by continuous expression of laminin 332 at the dermalepidermal junction. Taken together, these data indicate that a bifunctional anti-inflammatory prodrug stimulates repair of SM induced skin injury and may be useful as a medical countermeasure. PMID:25127551

Therapeutic potential of a non-steroidal bifunctional anti-inflammatory and anti-cholinergic agent against skin injury induced by sulfur mustard.

PubMed

Chang, Yoke-Chen; Wang, James D; Hahn, Rita A; Gordon, Marion K; Joseph, Laurie B; Heck, Diane E; Heindel, Ned D; Young, Sherri C; Sinko, Patrick J; Casillas, Robert P; Laskin, Jeffrey D; Laskin, Debra L; Gerecke, Donald R

2014-10-15

Sulfur mustard (bis(2-chloroethyl) sulfide, SM) is a highly reactive bifunctional alkylating agent inducing edema, inflammation, and the formation of fluid-filled blisters in the skin. Medical countermeasures against SM-induced cutaneous injury have yet to be established. In the present studies, we tested a novel, bifunctional anti-inflammatory prodrug (NDH 4338) designed to target cyclooxygenase 2 (COX2), an enzyme that generates inflammatory eicosanoids, and acetylcholinesterase, an enzyme mediating activation of cholinergic inflammatory pathways in a model of SM-induced skin injury. Adult SKH-1 hairless male mice were exposed to SM using a dorsal skin vapor cup model. NDH 4338 was applied topically to the skin 24, 48, and 72 h post-SM exposure. After 96 h, SM was found to induce skin injury characterized by edema, epidermal hyperplasia, loss of the differentiation marker, keratin 10 (K10), upregulation of the skin wound marker keratin 6 (K6), disruption of the basement membrane anchoring protein laminin 322, and increased expression of epidermal COX2. NDH 4338 post-treatment reduced SM-induced dermal edema and enhanced skin re-epithelialization. This was associated with a reduction in COX2 expression, increased K10 expression in the suprabasal epidermis, and reduced expression of K6. NDH 4338 also restored basement membrane integrity, as evidenced by continuous expression of laminin 332 at the dermal-epidermal junction. Taken together, these data indicate that a bifunctional anti-inflammatory prodrug stimulates repair of SM induced skin injury and may be useful as a medical countermeasure. Copyright © 2014 Elsevier Inc. All rights reserved.

Self-assembly of cobalt-centered metal organic framework and multiwalled carbon nanotubes hybrids as a highly active and corrosion-resistant bifunctional oxygen catalyst

NASA Astrophysics Data System (ADS)

Fang, Yiyun; Li, Xinzhe; Li, Feng; Lin, Xiaoqing; Tian, Min; Long, Xuefeng; An, Xingcai; Fu, Yan; Jin, Jun; Ma, Jiantai

2016-09-01

Metal organic frameworks (MOF) derived carbonaceous materials have emerged as promising bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts for electrochemical energy conversion and storage. But previous attempts to overcome the poor electrical conductivity of MOFs hybrids involve a harsh high-template pyrolytic process to in situ form carbon, which suffer from extremely complex operation and inevitable carbon corrosion at high positive potentials when OER is operated. Herein, a self-assembly approach is presented to synthesize a non-precious metal-based, high active and strong durable Co-MOF@CNTs bifunctional catalyst for OER and ORR. CNTs not only improve the transportation of the electrons but also can sustain the harsh oxidative environment of OER without carbon corrosion. Meanwhile, the unique 3D hierarchical structure offers a large surface area and stable anchoring sites for active centers and CNTs, which enables the superior durability of hybrid. Moreover, a synergistic catalysis of Co(II), organic ligands and CNTs will enhance the bifunctional electrocatalytic performance. Impressively, the hybrid exhibits comparable OER and ORR catalytic activity to RuO2 and 20 wt% Pt/C catalysts and superior stability. This facile and versatile strategy to fabricating MOF-based hybrids may be extended to other electrode materials for fuel cell and water splitting applications.

Engineered bifunctional proteins and stem cells: next generation of targeted cancer therapeutics.

PubMed

Choi, Sung Hugh; Shah, Khalid

2016-09-01

Redundant survival signaling pathways and their crosstalk within tumor and/or between tumor and their microenvironment are key impediments to developing effective targeted therapies for cancer. Therefore developing therapeutics that target multiple receptor signaling pathways in tumors and utilizing efficient platforms to deliver such therapeutics are critical to the success of future targeted therapies. During the past two decades, a number of bifunctional multi-targeting antibodies, fusion proteins, and oncolytic viruses have been developed and various stem cell types have been engineered to efficiently deliver them to tumors. In this review, we discuss the design and efficacy of therapeutics targeting multiple pathways in tumors and the therapeutic potential of therapeutic stem cells engineered with bifunctional agents.

Preparation of a Versatile Bifunctional Zeolite for Targeted Imaging Applications

PubMed Central

Ndiege, Nicholas; Raidoo, Renugan; Schultz, Michael K.; Larsen, Sarah

2011-01-01

Bifunctional zeolite Y was prepared for use in targeted in vivo molecular imaging applications. The strategy involved functionalization of the external surface of zeolite Y with chloropropyltriethoxysilane followed by reaction with sodium azide to form azide-functionalized NaY, which is amenable to copper(1) catalyzed click chemistry. In this study, a model alkyne (4-pentyn-1-ol) was attached to the azide-terminated surface via click chemistry to demonstrate feasibility for attachment of molecular targeting vectors (e.g., peptides, aptamers) to the zeolite surface. The modified particle efficiently incorporates the imaging radioisotope gallium-68 (68Ga) into the pores of the azide-functionalized NaY zeolite to form a stable bifunctional molecular targeting vector. The result is a versatile “clickable” zeolite platform that can be tailored for future in vivo molecular targeting and imaging modalities. PMID:21306141

Oxygen electrode bifunctional electrocatalyst NiCo2O4 spinel

NASA Technical Reports Server (NTRS)

Fielder, William L.; Singer, Joseph

1988-01-01

A significant increase in energy density may be possible if a two-unit alkaline regenerative H2-O2 fuel cell is replaced with a single-unit system that uses passive means for H2O transfer and thermal control. For this single-unit system, new electrocatalysts for the O2 electrode will be required which are not only bifunctionally active but also chemically and electrochemically stable between the voltage range of about 0.7 and 1.5 V. NiCo2O4 spinel is reported to have certain characteristics that make it useful for a study of electrode fabrication techniques. High surface area NiCo2O4 powder was fabricated into unsupported, bifunctional, PTFE-bonded, porous gas fuel cell electrodes by commercial sources using varying PTFE contents and sintering temperatures. The object of this study is to measure the bifunctional activities of these electrodes and to observe what performance differences might result from different commercial electrode fabricators. O2 evolution and O2 reduction data were obtained at 80 C (31 percent KOH). An irreversible reaction (i.e., aging) occurred during O2 evolution at potentials greater than about 1.5 V. Anodic Tafel slopes of 0.06 and 0.12 V/decade were obtained for the aged electrodes. Within the range of 15 to 25 percent, the PTFE content was not a critical parameter for optimizing the electrode for O2 evolution activity. Sintering temperatures between 300 and 340 C may be adequate but heating at 275 C may not be sufficient to properly sinter the PTFE-NiCo2O4 mixture. Electrode disintegration was observed during O2 reduction. Transport of O2 to the NiCo2O4 surface became prohibitive at greater than about -0.02 A/sq cm. Cathodic Tafel slopes of -0.6 and -0.12 V/decade were assumed for the O2 reduction process. A PTFE content of 25 percent (or greater) appears to be preferable for sintering the PTFE-NiCo2O4 mixture.

Large-scale Generation of Patterned Bubble Arrays on Printed Bi-functional Boiling Surfaces

PubMed Central

Choi, Chang-Ho; David, Michele; Gao, Zhongwei; Chang, Alvin; Allen, Marshall; Wang, Hailei; Chang, Chih-hung

2016-01-01

Bubble nucleation control, growth and departure dynamics is important in understanding boiling phenomena and enhancing nucleate boiling heat transfer performance. We report a novel bi-functional heterogeneous surface structure that is capable of tuning bubble nucleation, growth and departure dynamics. For the fabrication of the surface, hydrophobic polymer dot arrays are first printed on a substrate, followed by hydrophilic ZnO nanostructure deposition via microreactor-assisted nanomaterial deposition (MAND) processing. Wettability contrast between the hydrophobic polymer dot arrays and aqueous ZnO solution allows for the fabrication of heterogeneous surfaces with distinct wettability regions. Heterogeneous surfaces with various configurations were fabricated and their bubble dynamics were examined at elevated heat flux, revealing various nucleate boiling phenomena. In particular, aligned and patterned bubbles with a tunable departure frequency and diameter were demonstrated in a boiling experiment for the first time. Taking advantage of our fabrication method, a 6 inch wafer size heterogeneous surface was prepared. Pool boiling experiments were also performed to demonstrate a heat flux enhancement up to 3X at the same surface superheat using bi-functional surfaces, compared to a bare stainless steel surface. PMID:27034255

ZIF-67 incorporated with carbon derived from pomelo peels: A highly efficient bifunctional catalyst for oxygen reduction/evolution reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hao; Yin, Feng-Xiang; Chen, Biao-Hua

Developing carbon catalyst materials using natural, abundant and renewable resources as precursors plays an increasingly important role in clean energy generation and environmental protection. In this work, N-doped pomelo-peel-derived carbon (NPC) materials were prepared using a widely available food waste-pomelo peels and melamine. The synthetic NPC exhibits well-defined porosities and a highly doped-N content (e.g. 6.38 at% for NPC-2), therefore affords excellent oxygen reduction reaction (ORR) catalytic activities in alkaline electrolytes. NPC was further integrated with ZIF-67 to form ZIF-67@NPC hybrids through solvothermal reactions. The hybrid catalysts show substantially enhanced ORR catalytic activities comparable to that of commercial 20 wamore » Pt/C. Furthermore, the catalysts also exhibit excellent oxygen evolution reaction (OER) catalytic activities. Among all prepared ZIF-67@NPC hybrids, the optimal composition with ZIF-67 to NPC ratio of 2:1 exhibits the best ORR and OER bifunctional catalytic performance and the smallest Delta E (E-OER@10 mA cm(-2)-E-ORR@-1 mA cm(-2)) value of 0.79 V. The catalyst also demonstrated desirable 4-electron transfer pathways and superior catalytic stabilities. The Co-N-4 in ZIF-67, electrochemical active surface area, and the strong interactions between ZIF-67 and NPC are attributed as the main contributors to the bifunctional catalytic activities. These factors act synergistically, resulting in substantially enhanced bifunctional catalytic activities and stabilities; consequently, this hybrid catalyst is among the best of the reported bifunctional electrocatalysts and is promising for use in metal-air batteries and fuel cells. (C) 2016 Elsevier B.V. All rights reserved.« less

Electronic and Morphological Dual Modulation of Cobalt Carbonate Hydroxides by Mn Doping toward Highly Efficient and Stable Bifunctional Electrocatalysts for Overall Water Splitting.

PubMed

Tang, Tang; Jiang, Wen-Jie; Niu, Shuai; Liu, Ning; Luo, Hao; Chen, Yu-Yun; Jin, Shi-Feng; Gao, Feng; Wan, Li-Jun; Hu, Jin-Song

2017-06-21

Developing bifunctional efficient and durable non-noble electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable and challenging for overall water splitting. Herein, Co-Mn carbonate hydroxide (CoMnCH) nanosheet arrays with controllable morphology and composition were developed on nickel foam (NF) as such a bifunctional electrocatalyst. It is discovered that Mn doping in CoCH can simultaneously modulate the nanosheet morphology to significantly increase the electrochemical active surface area for exposing more accessible active sites and tune the electronic structure of Co center to effectively boost its intrinsic activity. As a result, the optimized Co 1 Mn 1 CH/NF electrode exhibits unprecedented OER activity with an ultralow overpotential of 294 mV at 30 mA cm -2 , compared with all reported metal carbonate hydroxides. Benefited from 3D open nanosheet array topographic structure with tight contact between nanosheets and NF, it is able to deliver a high and stable current density of 1000 mA cm -2 at only an overpotential of 462 mV with no interference from high-flux oxygen evolution. Despite no reports about effective HER on metal carbonate hydroxides yet, the small overpotential of 180 mV at 10 mA cm -2 for HER can be also achieved on Co 1 Mn 1 CH/NF by the dual modulation of Mn doping. This offers a two-electrode electrolyzer using bifunctional Co 1 Mn 1 CH/NF as both anode and cathode to perform stable overall water splitting with a cell voltage of only 1.68 V at 10 mA cm -2 . These findings may open up opportunities to explore other multimetal carbonate hydroxides as practical bifunctional electrocatalysts for scale-up water electrolysis.

3D printing of biomaterials with mussel-inspired nanostructures for tumor therapy and tissue regeneration.

PubMed

Ma, Hongshi; Luo, Jian; Sun, Zhe; Xia, Lunguo; Shi, Mengchao; Liu, Mingyao; Chang, Jiang; Wu, Chengtie

2016-12-01

Primary bone cancer brings patients great sufferings. To deal with the bone defects resulted from cancer surgery, biomaterials with good bone-forming ability are necessary to repair bone defects. Meanwhile, in order to prevent possible tumor recurrence, it is essential that the remaining tumor cells around bone defects are completely killed. However, there are few biomaterials with the ability of both cancer therapy and bone regeneration until now. Here, we fabricated a 3D-printed bioceramic scaffold with a uniformly self-assembled Ca-P/polydopamine nanolayer surface. Taking advantage of biocompatibility, biodegradability and the excellent photothermal effect of polydopamine, the bifunctional scaffolds with mussel-inspired nanostructures could be used as a satisfactory and controllable photothermal agent, which effectively induced tumor cell death in vitro, and significantly inhibited tumor growth in mice. In addition, owing to the nanostructured surface, the prepared polydopamine-modified bioceramic scaffolds could support the attachment and proliferation of rabbit bone mesenchymal stem cells (rBMSCs), and significantly promoted the formation of new bone tissues in rabbit bone defects even under photothermal treatment. Therefore, the mussel-inspired nanostructures in 3D-printed bioceramic exhibited a remarkable capability for both cancer therapy and bone regeneration, offering a promising strategy to construct bifunctional biomaterials which could be widely used for therapy of tumor-induced tissue defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microscopic visualization of metabotropic glutamate receptors on the surface of living cells using bifunctional magnetic resonance imaging probes.

PubMed

Mishra, Anurag; Mishra, Ritu; Gottschalk, Sven; Pal, Robert; Sim, Neil; Engelmann, Joern; Goldberg, Martin; Parker, David

2014-02-19

A series of bimodal metabotropic glutamate-receptor targeted MRI contrast agents has been developed and evaluated, based on established competitive metabotropic Glu receptor subtype 5 (mGluR5) antagonists. In order to directly visualize mGluR5 binding of these agents on the surface of live astrocytes, variations in the core structure were made. A set of gadolinium conjugates containing either a cyanine dye or a fluorescein moiety was accordingly prepared, to allow visualization by optical microscopy in cellulo. In each case, surface receptor binding was compromised and cell internalization observed. Another approach, examining the location of a terbium analogue via sensitized emission, also exhibited nonspecific cell uptake in neuronal cell line models. Finally, biotin derivatives of two lead compounds were prepared, and the specificity of binding to the mGluR5 cell surface receptors was demonstrated with the aid of their fluorescently labeled avidin conjugates, using both total internal reflection fluorescence (TIRF) and confocal microscopy.

Nanocarbon/oxide composite catalysts for bifunctional oxygen reduction and evolution in reversible alkaline fuel cells: A mini review

NASA Astrophysics Data System (ADS)

Chen, Mengjie; Wang, Lei; Yang, Haipeng; Zhao, Shuai; Xu, Hui; Wu, Gang

2018-01-01

A reversible fuel cell (RFC), which integrates a fuel cell with an electrolyzer, is similar to a rechargeable battery. This technology lies on high-performance bifunctional catalysts for the oxygen reduction reaction (ORR) in the fuel cell mode and the oxygen evolution reaction (OER) in the electrolyzer mode. Current catalysts are platinum group metals (PGM) such as Pt and Ir, which are expensive and scarce. Therefore, it is highly desirable to develop PGM-free catalysts for large-scale application of RFCs. In this mini review, we discussed the most promising nanocarbon/oxide composite catalysts for ORR/OER bifunctional catalysis in alkaline media, which is mainly based on our recent progress. Starting with the effectiveness of selected oxides and nanocarbons in terms of their activity and stability, we outlined synthetic methods and the resulting structures and morphologies of catalysts to provide a correlation between synthesis, structure, and property. A special emphasis is put on understanding of the possible synergistic effect between oxide and nanocarbon for enhanced performance. Finally, a few nanocomposite catalysts are discussed as typical examples to elucidate the rules of designing highly active and durable bifunctional catalysts for RFC applications.

In situ surface-enhanced Raman scattering monitoring of reduction of 4-nitrothiophenol on bifunctional metallic nanostructure

NASA Astrophysics Data System (ADS)

Du, Pan; Zhang, Xin; Yin, Hongjun; Zhao, Yongmei; Liu, Luo; Wu, Zhenglong; Xu, Haijun

2018-03-01

Bifunctional Au/Ag nanoparticle-decorated silicon nanowire arrays (Au/Ag@SiNWAs) were prepared using a facile wet chemical method. This surface-enhanced Raman scattering (SERS) substrate not only showed excellent reutilization capabilities by the simple NaBH4 washing, but also could reach a detection limit for drop-dried rhodamine 6G molecules as low as 10-16 M. More importantly, this substrate could be used to monitor the in situ reduction of 4-nitrothiophenol by NaBH4 using SERS spectroscopy. Our findings demonstrate that the bifunctional substrate can serve as a powerful system for the real-time in situ SERS monitoring of catalytic reactions, which should be beneficial for new catalyst exploration.

Bifunctional alkaline oxygen electrodes

NASA Technical Reports Server (NTRS)

Swette, L.; Kackley, N.; Mccatty, S. A.

1991-01-01

The authors describe the identification and testing of electrocatalysts and supports for the positive electrode of moderate-temperature, single-unit, rechargeable alkaline fuel cells. Recent work on Na(x)Pt3O4, a potential bifunctional catalyst, is described, as well as the application of novel approaches to the development of more efficient bifunctional electrode structures. The three dual-character electrodes considered here showed similar superior performance; the Pt/RhO2 and Rh/RhO2 electrodes showed slightly better performance than the Pt/IrO2 electrode. It is concluded that Na(x)Pt3O4 continues to be a promising bifunctional oxygen electrode catalyst but requires further investigation and development.

Dendritic Cell-Based Genetic Immunotherapy for Ovarian Cancer

DTIC Science & Technology

2007-12-01

CAR. CD40 is a surface marker expressed by DCs that plays a crucial role in their maturation and subsequent stimulation of T cells. DC infection with... surface . CD40 is a cell surface marker expressed by DCs, is crucial for their maturation and the subsequent activation of the immune system by the DCs...cell surface . CD40 is a cell surface marker expressed by DCs, is crucial for their maturation and the subsequent activation of the immune system by the

A bifunctional aminoglycoside acetyltransferase/phosphotransferase conferring tobramycin resistance provides an efficient selectable marker for plastid transformation.

PubMed

Tabatabaei, Iman; Ruf, Stephanie; Bock, Ralph

2017-02-01

A new selectable marker gene for stable transformation of the plastid genome was developed that is similarly efficient as the aadA, and produces no background of spontaneous resistance mutants. More than 25 years after its development for Chlamydomonas and tobacco, the transformation of the chloroplast genome still represents a challenging technology that is available only in a handful of species. The vast majority of chloroplast transformation experiments conducted thus far have relied on a single selectable marker gene, the spectinomycin resistance gene aadA. Although a few alternative markers have been reported, the aadA has remained unrivalled in efficiency and is, therefore, nearly exclusively used. The development of new marker genes for plastid transformation is of crucial importance to all efforts towards extending the species range of the technology as well as to those applications in basic research, biotechnology and synthetic biology that involve the multistep engineering of plastid genomes. Here, we have tested a bifunctional resistance gene for its suitability as a selectable marker for chloroplast transformation. The bacterial enzyme aminoglycoside acetyltransferase(6')-Ie/aminoglycoside phosphotransferase(2″)-Ia possesses an N-terminal acetyltransferase domain and a C-terminal phosphotransferase domain that can act synergistically and detoxify aminoglycoside antibiotics highly efficiently. We report that, in combination with selection for resistance to the aminoglycoside tobramycin, the aac(6')-Ie/aph(2″)-Ia gene represents an efficient marker for plastid transformation in that it produces similar numbers of transplastomic lines as the spectinomycin resistance gene aadA. Importantly, no spontaneous antibiotic resistance mutants appear under tobramycin selection.

A protein crosslinking assay for measuring cell surface expression of glutamate receptor subunits in the rodent brain after in vivo treatments

PubMed Central

Boudreau, Amy C.; Milovanovic, Mike; Conrad, Kelly L.; Nelson, Christopher; Ferrario, Carrie R.; Wolf, Marina E.

2012-01-01

Trafficking of neurotransmitter receptors between intracellular and cell surface compartments is important for regulating neurotransmission. We developed a method for determining if an in vivo treatment has altered receptor distribution in a particular region of rodent brain. After the treatment, brain slices are rapidly prepared from the region of interest. Then cell surface-expressed receptors are covalently crosslinked to nearby proteins using the membrane-impermeable, bifunctional crosslinker bis(sulfosuccinimidyl)suberate (BS3). This increases the apparent molecular weight of surface receptors, while intracellular receptors are not modified. Thus, surface and intracellular receptor pools can be separated and quantified using SDS-PAGE and immunoblotting. This method is particularly useful for analyzing AMPA receptor subunits, offering advantages in accuracy, efficiency and cost compared to biotinylation. A disadvantage is that some antibodies no longer recognize their target protein after crosslinking. We have used this method to quantify changes in receptor distribution after acute and chronic exposure to psychomotor stimulants. PMID:22470150

Multifunctional nanostructured electrocatalysts for energy conversion and storage: current status and perspectives.

PubMed

Ghosh, Srabanti; Basu, Rajendra N

2018-06-21

Electrocatalytic oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) have attracted widespread attention because of their important role in the application of various energy storage and conversion devices, such as fuel cells, metal-air batteries and water splitting devices. However, the sluggish kinetics of the HER/OER/ORR and their dependency on expensive noble metal catalysts (e.g., Pt) obstruct their large-scale application. Hence, the development of efficient and robust bifunctional or trifunctional electrocatalysts in nanodimension for both oxygen reduction/evolution and hydrogen evolution reactions is highly desired and challenging for their commercialization in renewable energy technologies. This review describes some recent developments in the discovery of bifunctional or trifunctional nanostructured catalysts with improved performances for application in rechargeable metal-air batteries and fuel cells. The role of the electronic structure and surface redox chemistry of nanocatalysts in the improvement of their performance for the ORR/OER/HER under an alkaline medium is highlighted and the associated reaction mechanisms developed in the recent literature are also summarized.

Bifunctional Bisphosphonates for Delivering Biomolecules to Bone

DTIC Science & Technology

2012-01-13

targeted PTH stimulated greater synthesis of cAMP in preosteoblasts compared to surfaces with simply adsorbed PTH. HBPs were also found to have similar pro...targeted PTH stimulated greater synthesis of cAMP in pre- osteoblasts compared to surfaces with simply adsorbed PTH. HBPs were also found to have similar...30 Chapter Two: Synthesis and Characterization of Bifunctional Bisphosphonates….31 Experimental Section……………………………………………………….……38 Reagents

Label-free detection of surface markers on stem cells by oblique-incidence reflectivity difference microscopy

PubMed Central

Lo, Kai-Yin; Sun, Yung-Shin; Landry, James P.; Zhu, Xiangdong; Deng, Wenbin

2012-01-01

Conventional fluorescent microscopy is routinely used to detect cell surface markers through fluorophore-conjugated antibodies. However, fluorophore-conjugation of antibodies alters binding properties such as strength and specificity of the antibody in ways often uncharacterized. The binding between antibody and antigen might not be in the native situation after such conjugation. Here, we present an oblique-incidence reflectivity difference (OI-RD) microscope as an effective method for label-free, real-time detection of cell surface markers and apply such a technique to analysis of Stage-Specific Embryonic Antigen 1 (SSEA1) on stem cells. Mouse stem cells express SSEA1 on their surfaces and the level of SSEA1 decreases when the cells start to differentiate. In this study, we immobilized mouse stem cells and non-stem cells (control) on a glass surface as a microarray and reacted the cell microarray with unlabeled SSEA1 antibodies. By monitoring the reaction with an OI-RD microscope in real time, we confirmed that the SSEA1 antibodies only bind to the surface of the stem cells while not to the surface of non-stem cells. From the binding curves, we determined the equilibrium dissociation constant (Kd) of the antibody with the SSEA1 markers on the stem cell surface. The results concluded that OI-RD microscope can be used to detect binding affinities between cell surface markers and unlabeled antibodies bound to the cells. The information could be another indicator to determine the cell stages. PMID:21781038

Bifunctional redox tagging of carbon nanoparticles

NASA Astrophysics Data System (ADS)

Poon, Jeffrey; Batchelor-McAuley, Christopher; Tschulik, Kristina; Palgrave, Robert G.; Compton, Richard G.

2015-01-01

Despite extensive work on the controlled surface modification of carbon with redox moieties, to date almost all available methodologies involve complex chemistry and are prone to the formation of polymerized multi-layer surface structures. Herein, the facile bifunctional redox tagging of carbon nanoparticles (diameter 27 nm) and its characterization is undertaken using the industrial dye Reactive Blue 2. The modification route is demonstrated to be via exceptionally strong physisorption. The modified carbon is found to exhibit both well-defined oxidative and reductive voltammetric redox features which are quantitatively interpreted. The method provides a generic approach to monolayer modifications of carbon and carbon nanoparticle surfaces.

Perovskite-nitrogen-doped carbon nanotube composite as bifunctional catalysts for rechargeable lithium-air batteries.

PubMed

Park, Hey Woong; Lee, Dong Un; Park, Moon Gyu; Ahmed, Raihan; Seo, Min Ho; Nazar, Linda F; Chen, Zhongwei

2015-03-01

Developing an effective bifunctional catalyst is a significant issue, as rechargeable metal-air batteries are very attractive for future energy systems. In this study, a facile one-pot process is introduced to prepare an advanced bifunctional catalyst (op-LN) incorporating nitrogen-doped carbon nanotubes (NCNTs) into perovskite La0.5 Sr0.5 Co0.8 Fe0.2 O3 nanoparticles (LSCF-NPs). Confirmed by half-cell testing, op-LN exhibits synergistic effects of LSCF-NP and NCNT with excellent bifunctionality for both the oxygen reduction reaction and the oxygen evolution reaction. Furthermore, op-LN exhibits comparable performances in these reactions to Pt/C and Ir/C, respectively, which highlights its potential for use as a commercially viable bifunctional catalyst. Moreover, the results obtained by testing op-LN in a practical Li-air battery demonstrate improved and complementary charge/discharge performance compared to those of LSCF-NP and NCNT, and this confirms that simply prepared op-LN is a promising candidate as a highly effective bifunctional catalyst for rechargeable metal-air batteries. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vascular Regeneration in a Basal Chordate Is Due to the Presence of Immobile, Bi-Functional Cells

PubMed Central

Braden, Brian P.; Taketa, Daryl A.; Pierce, James D.; Kassmer, Susannah; Lewis, Daniel D.; De Tomaso, Anthony W.

2014-01-01

The source of tissue turnover during homeostasis or following injury is usually due to proliferation of a small number of resident, lineage-restricted stem cells that have the ability to amplify and differentiate into mature cell types. We are studying vascular regeneration in a chordate model organism, Botryllus schlosseri, and have previously found that following surgical ablation of the extracorporeal vasculature, new tissue will regenerate in a VEGF-dependent process within 48 hrs. Here we use a novel vascular cell lineage tracing methodology to assess regeneration in parabiosed individuals and demonstrate that the source of regenerated vasculature is due to the proliferation of pre-existing vascular resident cells and not a mobile progenitor. We also show that these cells are bi-potential, and can reversibly adopt two fates, that of the newly forming vessels or the differentiated vascular tissue at the terminus of the vasculature, known as ampullae. In addition, we show that pre-existing vascular resident cells differentially express progenitor and differentiated cell markers including the Botryllus homologs of CD133, VEGFR-2, and Cadherin during the regenerative process. PMID:24736432

Cell-surface marker discovery for lung cancer

PubMed Central

Cohen, Allison S.; Khalil, Farah K.; Welsh, Eric A.; Schabath, Matthew B.; Enkemann, Steven A.; Davis, Andrea; Zhou, Jun-Min; Boulware, David C.; Kim, Jongphil; Haura, Eric B.; Morse, David L.

2017-01-01

Lung cancer is the leading cause of cancer deaths in the United States. Novel lung cancer targeted therapeutic and molecular imaging agents are needed to improve outcomes and enable personalized care. Since these agents typically cannot cross the plasma membrane while carrying cytotoxic payload or imaging contrast, discovery of cell-surface targets is a necessary initial step. Herein, we report the discovery and characterization of lung cancer cell-surface markers for use in development of targeted agents. To identify putative cell-surface markers, existing microarray gene expression data from patient specimens were analyzed to select markers with differential expression in lung cancer compared to normal lung. Greater than 200 putative cell-surface markers were identified as being overexpressed in lung cancers. Ten cell-surface markers (CA9, CA12, CXorf61, DSG3, FAT2, GPR87, KISS1R, LYPD3, SLC7A11 and TMPRSS4) were selected based on differential mRNA expression in lung tumors vs. non-neoplastic lung samples and other normal tissues, and other considerations involving known biology and targeting moieties. Protein expression was confirmed by immunohistochemistry (IHC) staining and scoring of patient tumor and normal tissue samples. As further validation, marker expression was determined in lung cancer cell lines using microarray data and Kaplan–Meier survival analyses were performed for each of the markers using patient clinical data. High expression for six of the markers (CA9, CA12, CXorf61, GPR87, LYPD3, and SLC7A11) was significantly associated with worse survival. These markers should be useful for the development of novel targeted imaging probes or therapeutics for use in personalized care of lung cancer patients. PMID:29371917

Gold and Iron-Gold Nanoparticles for Intracellular Tracking and in Vivo Medical Applicatons

NASA Astrophysics Data System (ADS)

Fu, Wei

2005-03-01

We have fabricated Au and Fe-Au nanoparticles for potential use in ex vivo experiments such as intracellular tracking, as well as a variety of in vivo medical applications. In order to improve their targeting potential, circulation time and flexibility, gold NPs were surface modified using a hetero-bifunctional poly(ethylene glycol) (PEG, MW 1,500) spacers. A coumarin-PEG-gold NP complex was formed and cell viability studies and optical fluorescence experiments were carried out demonstrating the use of these surface-modified gold NPs for drug delivery, gene therapy and cell trafficking experiments. Fe-Au nanoparticles were also fabricated and show significant contrast enhancement in MRI studies through a substantial reduction of the T2 relaxation time.

Dendritic Cell-Based Genetic Immunotherapy for Ovarian Cancer

DTIC Science & Technology

2008-12-01

transduction of dendritic cells (DCs) is inefficient because of the lack of the primary Ad receptor, CAR. CD40 is a surface marker expressed by DCs that...ligands or antibodies that can bind to the cell surface markers expressed by DCs. The tumor antigen or peptides are linked to the ligands...thus pose the risk of insertional mutagenesis and oncogenesis. The various cell- surface markers that have been exploited for targeting DCs have

Cell-surface markers for colon adenoma and adenocarcinoma

PubMed Central

Sewda, Kamini; Coppola, Domenico; Enkemann, Steven; Yue, Binglin; Kim, Jongphil; Lopez, Alexis S.; Wojtkowiak, Jonathan W.; Stark, Valerie E.; Morse, Brian; Shibata, David; Vignesh, Shivakumar; Morse, David L.

2016-01-01

Early detection of colorectal cancer (CRC) is crucial for effective treatment. Among CRC screening techniques, optical colonoscopy is widely considered the gold standard. However, it is a costly and invasive procedure with a low rate of compliance. Our long-term goal is to develop molecular imaging agents for the non-invasive detection of CRC by molecular imaging-based colonoscopy using CT, MRI or fluorescence. To achieve this, cell surface targets must be identified and validated. Here, we report the discovery of cell-surface markers that distinguish CRC from surrounding tissues that could be used as molecular imaging targets. Profiling of mRNA expression microarray data from patient tissues including adenoma, adenocarcinoma, and normal gastrointestinal tissues was used to identify potential CRC specific cell-surface markers. Of the identified markers, six were selected for further validation (CLDN1, GPR56, GRM8, LY6G6D/F, SLCO1B3 and TLR4). Protein expression was confirmed by immunohistochemistry of patient tissues. Except for SLCO1B3, diffuse and low expression was observed for each marker in normal colon tissues. The three markers with the greatest protein overexpression were CLDN1, LY6G6D/F and TLR4, where at least one of these markers was overexpressed in 97% of the CRC samples. GPR56, LY6G6D/F and SLCO1B3 protein expression was significantly correlated with the proximal tumor location and with expression of mismatch repair genes. Marker expression was further validated in CRC cell lines. Hence, three cell-surface markers were discovered that distinguish CRC from surrounding normal tissues. These markers can be used to develop imaging or therapeutic agents targeted to the luminal surface of CRC. PMID:26894861

Cell-surface markers for colon adenoma and adenocarcinoma.

PubMed

Sewda, Kamini; Coppola, Domenico; Enkemann, Steven; Yue, Binglin; Kim, Jongphil; Lopez, Alexis S; Wojtkowiak, Jonathan W; Stark, Valerie E; Morse, Brian; Shibata, David; Vignesh, Shivakumar; Morse, David L

2016-04-05

Early detection of colorectal cancer (CRC) is crucial for effective treatment. Among CRC screening techniques, optical colonoscopy is widely considered the gold standard. However, it is a costly and invasive procedure with a low rate of compliance. Our long-term goal is to develop molecular imaging agents for the non-invasive detection of CRC by molecular imaging-based colonoscopy using CT, MRI or fluorescence. To achieve this, cell surface targets must be identified and validated. Here, we report the discovery of cell-surface markers that distinguish CRC from surrounding tissues that could be used as molecular imaging targets. Profiling of mRNA expression microarray data from patient tissues including adenoma, adenocarcinoma, and normal gastrointestinal tissues was used to identify potential CRC specific cell-surface markers. Of the identified markers, six were selected for further validation (CLDN1, GPR56, GRM8, LY6G6D/F, SLCO1B3 and TLR4). Protein expression was confirmed by immunohistochemistry of patient tissues. Except for SLCO1B3, diffuse and low expression was observed for each marker in normal colon tissues. The three markers with the greatest protein overexpression were CLDN1, LY6G6D/F and TLR4, where at least one of these markers was overexpressed in 97% of the CRC samples. GPR56, LY6G6D/F and SLCO1B3 protein expression was significantly correlated with the proximal tumor location and with expression of mismatch repair genes. Marker expression was further validated in CRC cell lines. Hence, three cell-surface markers were discovered that distinguish CRC from surrounding normal tissues. These markers can be used to develop imaging or therapeutic agents targeted to the luminal surface of CRC.

Construction of Bifunctional Co/H-ZSM-5 Catalysts for the Hydrodeoxygenation of Stearic Acid to Diesel-range Alkanes.

PubMed

Wu, Guangjun; Zhang, Nan; Dai, Weili; Guan, Naijia; Li, Landong

2018-04-27

Bifunctional Co/H-ZSM-5 zeolites were prepared by surface organometallic chemistry grafting route, namely by the stoichiometric reaction between cobaltocene and the Brønsted acid sites in zeolites, and applied to the model reaction of stearic acid catalytic hydrodeoxygenation. Cobalt species existed in the form of isolated Co2+ ions at exchange positions after grafting, transformed to CoO species on the surface of zeolite and stabilized inside zeolite channels upon calcination in air, and finally reduced to metallic cobalt species of homogeneous clusters of ca. 1.5 nm by hydrogen. During this process, the Brønsted acid sites of H-ZSM-5 zeolites could be preserved with acid strength slightly reduced. The as-prepared bifunctional catalyst exhibited a ~16 times higher activity in stearic acid hydrodeoxygenation (2.11 gSAgcat-1h-1) than the reference catalyst (0.13 gSAgcat-1h-1) prepared by solid-state ion exchange, and a high C18/C17 ratio of ~24 was achieved as well. The remarkable hydrodeoxygenation performance of bifunctional Co/H-ZSM-5 could be explained from the effective synergy between the uniformed metallic cobalt clusters and the Brønsted acid sites in H-ZSM-5 zeolite. The simplified reaction network and kinetics of stearic acid hydrodeoxygenation catalyzed by the as-prepared bifunctional Co/H-ZSM-5 zeolites were also investigated. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Unique Procedure to Identify Cell Surface Markers Through a Spherical Self-Organizing Map Applied to DNA Microarray Analysis.

PubMed

Sugii, Yuh; Kasai, Tomonari; Ikeda, Masashi; Vaidyanath, Arun; Kumon, Kazuki; Mizutani, Akifumi; Seno, Akimasa; Tokutaka, Heizo; Kudoh, Takayuki; Seno, Masaharu

2016-01-01

To identify cell-specific markers, we designed a DNA microarray platform with oligonucleotide probes for human membrane-anchored proteins. Human glioma cell lines were analyzed using microarray and compared with normal and fetal brain tissues. For the microarray analysis, we employed a spherical self-organizing map, which is a clustering method suitable for the conversion of multidimensional data into two-dimensional data and displays the relationship on a spherical surface. Based on the gene expression profile, the cell surface characteristics were successfully mirrored onto the spherical surface, thereby distinguishing normal brain tissue from the disease model based on the strength of gene expression. The clustered glioma-specific genes were further analyzed by polymerase chain reaction procedure and immunocytochemical staining of glioma cells. Our platform and the following procedure were successfully demonstrated to categorize the genes coding for cell surface proteins that are specific to glioma cells. Our assessment demonstrates that a spherical self-organizing map is a valuable tool for distinguishing cell surface markers and can be employed in marker discovery studies for the treatment of cancer.

The fibroblast surface markers FAP, anti-fibroblast, and FSP are expressed by cells of epithelial origin and may be altered during epithelial-to-mesenchymal transition.

PubMed

Kahounová, Zuzana; Kurfürstová, Daniela; Bouchal, Jan; Kharaishvili, Gvantsa; Navrátil, Jiří; Remšík, Ján; Šimečková, Šárka; Študent, Vladimír; Kozubík, Alois; Souček, Karel

2017-04-06

The identification of fibroblasts and cancer-associated fibroblasts from human cancer tissue using surface markers is difficult, especially because the markers used currently are usually not expressed solely by fibroblasts, and the identification of fibroblast-specific surface molecules is still under investigation. It was aimed to compare three commercially available antibodies in the detection of different surface epitopes of fibroblasts (anti-fibroblast, fibroblast activation protein α, and fibroblast surface protein). The specificity of their expression, employing fibroblast cell lines and tumor-derived fibroblasts from breast and prostate tissues was investigated. Both the established fibroblast cell line HFF-1 and ex vivo primary fibroblasts isolated from breast and prostate cancer tissues expressed the tested surface markers to different degrees. Surprisingly, those markers were expressed also by permanent cell lines of epithelial origin, both benign and cancer-derived (breast-cell lines MCF 10A, HMLE and prostate-cell lines BPH-1, DU 145, and PC-3). The expression of fibroblast activation protein α increased on the surface of previously described models of epithelial cells undergoing epithelial-to-mesenchymal transition in response to treatment with TGF-β1. To prove the co-expression of the fibroblast markers on cells of epithelial origin, we used freshly dissociated human prostate and breast cancer tissues. The results confirmed the co-expression of anti-fibroblast and fibroblast surface protein on CD31/CD45-negative/EpCAM-positive epithelial cells. In summary, our data support the findings that the tested fibroblast markers are not fibroblast specific and may be expressed also by cells of epithelial origin (e.g., cells undergoing EMT). Therefore, the expression of these markers should be interpreted with caution, and the combination of several epitopes for both positive (anti-fibroblast or fibroblast activation protein α) and negative (EpCAM) identification of fibroblasts from breast and prostate tumor tissues is advised. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

Programmable and multiparameter DNA-based logic platform for cancer recognition and targeted therapy.

PubMed

You, Mingxu; Zhu, Guizhi; Chen, Tao; Donovan, Michael J; Tan, Weihong

2015-01-21

The specific inventory of molecules on diseased cell surfaces (e.g., cancer cells) provides clinicians an opportunity for accurate diagnosis and intervention. With the discovery of panels of cancer markers, carrying out analyses of multiple cell-surface markers is conceivable. As a trial to accomplish this, we have recently designed a DNA-based device that is capable of performing autonomous logic-based analysis of two or three cancer cell-surface markers. Combining the specific target-recognition properties of DNA aptamers with toehold-mediated strand displacement reactions, multicellular marker-based cancer analysis can be realized based on modular AND, OR, and NOT Boolean logic gates. Specifically, we report here a general approach for assembling these modular logic gates to execute programmable and higher-order profiling of multiple coexisting cell-surface markers, including several found on cancer cells, with the capacity to report a diagnostic signal and/or deliver targeted photodynamic therapy. The success of this strategy demonstrates the potential of DNA nanotechnology in facilitating targeted disease diagnosis and effective therapy.

A monoclonal antibody recognizes undifferentiation-specific carbohydrate moieties expressed on cell surface of the human dental pulp cells.

PubMed

Kang, Kyung-Jung; Ko, Seon-Yle; Ryu, Chun-Jeih; Jang, Young-Joo

2017-05-01

Human dental pulp cells are obtained from dental pulp tissue, and have the ability to form dentin and a pulp-like complex. Although adult stem cells have been identified from the primary culture by using specific cell surface markers, the identity of surface markers for the purification of stem cells within the dental pulp population are still unclear. Previously, we had constructed monoclonal antibodies against the undifferentiated cell-specific surface markers of human dental pulp cells (hDPCs) by performing decoy immunization. Among them, a monoclonal antibody against the cell surface antigen of the undifferentiated hDPCs (named UPSA-1) was purified and its heavy and light chain consensus regions were analyzed. The cell surface binding affinity of UPSA-1 mAb on the undifferentiated hDPCs was stronger than that on the differentiated cells. When tunicamycin was applied to hDPSCs during culture, the cell surface binding affinity of the antibody was dramatically decreased, and dentinogenic differentiation was reduced. The purified UPSA-1 antigen band resulting from immunoprecipitation disappeared or shifted down on the SDS-PAGE by deglycosylation. These data suggested that glycosylation on the cell surface might be a marker of an undifferentiated state, and that UPSA-1 mAb might be useful for identifying the carbohydrate moiety on the cell surface of undifferentiated pulp cells. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of water and alkali modifications on ETS-10 for the cycloaddition of CO2 to propylene oxide.

PubMed

Doskocil, Eric J

2005-02-17

Sodium oxide (NaOx) impregnated Engelhard Titanosilicate-10 (ETS-10) molecular sieve catalysts were prepared to enhance the basicity associated with ETS-10 and subsequently investigated for the cycloaddition of carbon dioxide to propylene oxide to produce propylene carbonate. For dry NaOx-modified ETS-10 catalysts that contained no adsorbed water, a maximum yield of propylene carbonate was achieved at a loading of 2.0 excess NaOx species per unit cell. However, the greatest enhancements in the rate of reaction were observed when small amounts of water were adsorbed onto the unmodified ETS-10 catalyst immediately prior to reaction. Surface-bound water appears to enhance the surface Bronsted acidity of the unmodified ETS-10 catalyst via the formation of surface -OH groups at lower water loadings, producing a surface of better-tuned acid-base bifunctional characteristics for the cycloaddition reaction. At levels of hydration greater than 12.5% by mass, the yield of propylene carbonate was further enhanced, but at a smaller rate than that observed at lower rehydration levels, which is more indicative of an enhanced transport effect. Adsorption microcalorimetry of carbon dioxide indicated that, at loadings less than 2.0 NaOx per unit cell, the total uptake of the CO2 adsorption sites required for the reaction were less than in the parent ETS-10 material. However, at higher levels of NaOx occlusion, where the total uptake and strength of the adsorption sites exceeded those observed for the as-received ETS-10 material, the cycloaddition activity of this catalyst suffered due to the reduced pore volume and surface area. It appears that precise tuning of both the surface acidity and basicity is crucial in creating an effective acid-base bifunctional ETS-10 catalyst for the cycloaddition reaction investigated.

Microarrays for the evaluation of cell-biomaterial surface interactions

NASA Astrophysics Data System (ADS)

Thissen, H.; Johnson, G.; McFarland, G.; Verbiest, B. C. H.; Gengenbach, T.; Voelcker, N. H.

2007-01-01

The evaluation of cell-material surface interactions is important for the design of novel biomaterials which are used in a variety of biomedical applications. While traditional in vitro test methods have routinely used samples of relatively large size, microarrays representing different biomaterials offer many advantages, including high throughput and reduced sample handling. Here, we describe the simultaneous cell-based testing of matrices of polymeric biomaterials, arrayed on glass slides with a low cell-attachment background coating. Arrays were constructed using a microarray robot at 6 fold redundancy with solid pins having a diameter of 375 μm. Printed solutions contained at least one monomer, an initiator and a bifunctional crosslinker. After subsequent UV polymerisation, the arrays were washed and characterised by X-ray photoelectron spectroscopy. Cell culture experiments were carried out over 24 hours using HeLa cells. After labelling with CellTracker ® Green for the final hour of incubation and subsequent fixation, the arrays were scanned. In addition, individual spots were also viewed by fluorescence microscopy. The evaluation of cell-surface interactions in high-throughput assays as demonstrated here is a key enabling technology for the effective development of future biomaterials.

Identification and validation of multiple cell surface markers of clinical-grade adipose-derived mesenchymal stromal cells as novel release criteria for good manufacturing practice-compliant production.

PubMed

Camilleri, Emily T; Gustafson, Michael P; Dudakovic, Amel; Riester, Scott M; Garces, Catalina Galeano; Paradise, Christopher R; Takai, Hideki; Karperien, Marcel; Cool, Simon; Sampen, Hee-Jeong Im; Larson, A Noelle; Qu, Wenchun; Smith, Jay; Dietz, Allan B; van Wijnen, Andre J

2016-08-11

Clinical translation of mesenchymal stromal cells (MSCs) necessitates basic characterization of the cell product since variability in biological source and processing of MSCs may impact therapeutic outcomes. Although expression of classical cell surface markers (e.g., CD90, CD73, CD105, and CD44) is used to define MSCs, identification of functionally relevant cell surface markers would provide more robust release criteria and options for quality control. In addition, cell surface expression may distinguish between MSCs from different sources, including bone marrow-derived MSCs and clinical-grade adipose-derived MSCs (AMSCs) grown in human platelet lysate (hPL). In this work we utilized quantitative PCR, flow cytometry, and RNA-sequencing to characterize AMSCs grown in hPL and validated non-classical markers in 15 clinical-grade donors. We characterized the surface marker transcriptome of AMSCs, validated the expression of classical markers, and identified nine non-classical markers (i.e., CD36, CD163, CD271, CD200, CD273, CD274, CD146, CD248, and CD140B) that may potentially discriminate AMSCs from other cell types. More importantly, these markers exhibit variability in cell surface expression among different cell isolates from a diverse cohort of donors, including freshly prepared, previously frozen, or proliferative state AMSCs and may be informative when manufacturing cells. Our study establishes that clinical-grade AMSCs expanded in hPL represent a homogeneous cell culture population according to classical markers,. Additionally, we validated new biomarkers for further AMSC characterization that may provide novel information guiding the development of new release criteria. Use of Autologous Bone Marrow Aspirate Concentrate in Painful Knee Osteoarthritis (BMAC): Clinicaltrials.gov NCT01931007 . Registered August 26, 2013. MSC for Occlusive Disease of the Kidney: Clinicaltrials.gov NCT01840540 . Registered April 23, 2013. Mesenchymal Stem Cell Therapy in Multiple System Atrophy: Clinicaltrials.gov NCT02315027 . Registered October 31, 2014. Efficacy and Safety of Adult Human Mesenchymal Stem Cells to Treat Steroid Refractory Acute Graft Versus Host Disease. Clinicaltrials.gov NCT00366145 . Registered August 17, 2006. A Dose-escalation Safety Trial for Intrathecal Autologous Mesenchymal Stem Cell Therapy in Amyotrophic Lateral Sclerosis. Clinicaltrials.gov NCT01609283 . Registered May 18, 2012.

Bifunctional catalytic electrode

NASA Technical Reports Server (NTRS)

Cisar, Alan (Inventor); Murphy, Oliver J. (Inventor); Clarke, Eric (Inventor)

2005-01-01

The present invention relates to an oxygen electrode for a unitized regenerative hydrogen-oxygen fuel cell and the unitized regenerative fuel cell having the oxygen electrode. The oxygen electrode contains components electrocatalytically active for the evolution of oxygen from water and the reduction of oxygen to water, and has a structure that supports the flow of both water and gases between the catalytically active surface and a flow field or electrode chamber for bulk flow of the fluids. The electrode has an electrocatalyst layer and a diffusion backing layer interspersed with hydrophilic and hydrophobic regions. The diffusion backing layer consists of a metal core having gas diffusion structures bonded to the metal core.

Dual-Doped Molybdenum Trioxide Nanowires: A Bifunctional Anode for Fiber-Shaped Asymmetric Supercapacitors and Microbial Fuel Cells.

PubMed

Yu, Minghao; Cheng, Xinyu; Zeng, Yinxiang; Wang, Zilong; Tong, Yexiang; Lu, Xihong; Yang, Shihe

2016-06-01

A novel in situ N and low-valence-state Mo dual doping strategy was employed to significantly improve the conductivity, active-site accessibility, and electrochemical stability of MoO3 , drastically boosting its electrochemical properties. Consequently, our optimized N-MoO3-x nanowires exhibited exceptional performances as a bifunctional anode material for both fiber-shaped asymmetric supercapacitors (ASCs) and microbial fuel cells (MFCs). The flexible fiber-shaped ASC and MFC device based on the N-MoO3-x anode could deliver an unprecedentedly high energy density of 2.29 mWh cm(-3) and a remarkable power density of 0.76 μW cm(-1) , respectively. Such a bifunctional fiber-shaped N-MoO3-x electrode opens the way to integrate the electricity generation and storage for self-powered sources. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of space flight on surface marker expression

NASA Astrophysics Data System (ADS)

Sonnenfeld, G.

1999-01-01

Space flight has been shown to affect expression of several cell surface markers. These markers play important roles in regulation of immune responses, including CD4 and CD8. The studies have involved flight of experimental animals and humans followed by analysis of tissue samples (blood in humans, rats and monkeys, spleen, thymus, lymph nodes and bone marrow in rodents). The degree and direction of the changes induced by space flight have been determined by the conditions of the flight. Also, there may be compartmentalization of the response of surface markers to space flight, with differences in the response of cells isolated from blood and local immune tissue. The same type of compartmentalization was also observed with cell adhesion molecules (integrins). In this case, the expression of integrins from lymph node cells differed from that of splenocytes isolated from rats immediately after space flight. Cell culture studies have indicated that there may be an inhibition in conversion of a precursor cell line to cells exhibiting mature macrophage characteristics after space flight, however, these experiments were limited as a result of technical difficulties. In general, it is clear that space flight results in alterations of cell surface markers. The biological significance of these changes remains to be established.

Programmable and Multiparameter DNA-Based Logic Platform For Cancer Recognition and Targeted Therapy

PubMed Central

2014-01-01

The specific inventory of molecules on diseased cell surfaces (e.g., cancer cells) provides clinicians an opportunity for accurate diagnosis and intervention. With the discovery of panels of cancer markers, carrying out analyses of multiple cell-surface markers is conceivable. As a trial to accomplish this, we have recently designed a DNA-based device that is capable of performing autonomous logic-based analysis of two or three cancer cell-surface markers. Combining the specific target-recognition properties of DNA aptamers with toehold-mediated strand displacement reactions, multicellular marker-based cancer analysis can be realized based on modular AND, OR, and NOT Boolean logic gates. Specifically, we report here a general approach for assembling these modular logic gates to execute programmable and higher-order profiling of multiple coexisting cell-surface markers, including several found on cancer cells, with the capacity to report a diagnostic signal and/or deliver targeted photodynamic therapy. The success of this strategy demonstrates the potential of DNA nanotechnology in facilitating targeted disease diagnosis and effective therapy. PMID:25361164

Antibody-immobilized column for quick cell separation based on cell rolling.

PubMed

Mahara, Atsushi; Yamaoka, Tetsuji

2010-01-01

Cell separation using methodological standards that ensure high purity is a very important step in cell transplantation for regenerative medicine and for stem cell research. A separation protocol using magnetic beads has been widely used for cell separation to isolate negative and positive cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a cell depends on its developmental stage and differentiation ability. Rapid and label-free separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody-immobilized cell-rolling column, that can separate cells depending on the CD34 density of the cell surfaces. Various conditions for the cell-rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34-positive and -negative cell lines, the cell separation potential of the column was established. We observed a difference in the rolling velocities between CD34-positive and CD34-negative cells on antibody-immobilized microfluidic device. Cell separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated cells in each fraction were analyzed using a cell-sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that cells with a given surface marker density can be continuously separated using the cell rolling column.

Fullerene-Like Nickel Oxysulfide Hollow Nanospheres as Bifunctional Electrocatalysts for Water Splitting.

PubMed

Liu, Junli; Yang, Yong; Ni, Bing; Li, Haoyi; Wang, Xun

2017-02-01

Fullerene-like nickel oxysulfide hollow nanospheres with ≈50 nm are constructed by in situ growth on the surface of nickel foam by taking advantage of solvothermal reaction. The as-prepared composite exhibits exhilaratingly high HER and OER performance in 1 m KOH, which opens up a very promising aspect for non-noble metal chalcogenides as bifunctional electrocatalysts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cell surface marker profiling of human tracheal basal cells reveals distinct subpopulations, identifies MST1/MSP as a mitogenic signal, and identifies new biomarkers for lung squamous cell carcinomas.

PubMed

Van de Laar, Emily; Clifford, Monica; Hasenoeder, Stefan; Kim, Bo Ram; Wang, Dennis; Lee, Sharon; Paterson, Josh; Vu, Nancy M; Waddell, Thomas K; Keshavjee, Shaf; Tsao, Ming-Sound; Ailles, Laurie; Moghal, Nadeem

2014-12-31

The large airways of the lungs (trachea and bronchi) are lined with a pseudostratified mucociliary epithelium, which is maintained by stem cells/progenitors within the basal cell compartment. Alterations in basal cell behavior can contribute to large airway diseases including squamous cell carcinomas (SQCCs). Basal cells have traditionally been thought of as a uniform population defined by basolateral position, cuboidal cell shape, and expression of pan-basal cell lineage markers like KRT5 and TP63. While some evidence suggests that basal cells are not all functionally equivalent, few heterogeneously expressed markers have been identified to purify and study subpopulations. In addition, few signaling pathways have been identified that regulate their cell behavior. The goals of this work were to investigate tracheal basal cell diversity and to identify new signaling pathways that regulate basal cell behavior. We used flow cytometry (FACS) to profile cell surface marker expression at a single cell level in primary human tracheal basal cell cultures that maintain stem cell/progenitor activity. FACS results were validated with tissue staining, in silico comparisons with normal basal cell and lung cancer datasets, and an in vitro proliferation assay. We identified 105 surface markers, with 47 markers identifying potential subpopulations. These subpopulations generally fell into more (~ > 13%) or less abundant (~ < 6%) groups. Microarray gene expression profiling supported the heterogeneous expression of these markers in the total population, and immunostaining of large airway tissue suggested that some of these markers are relevant in vivo. 24 markers were enriched in lung SQCCs relative to adenocarcinomas, with four markers having prognostic significance in SQCCs. We also identified 33 signaling receptors, including the MST1R/RON growth factor receptor, whose ligand MST1/MSP was mitogenic for basal cells. This work provides the largest description to date of molecular diversity among human large airway basal cells. Furthermore, these markers can be used to further study basal cell function in repair and disease, and may aid in the classification and study of SQCCs.

Rational geometrical engineering of palladium sulfide multi-arm nanostructures as a superior bi-functional electrocatalyst.

PubMed

Nandan, R; Nanda, K K

2017-08-31

Geometrical tunability offers sharp edges and an open-armed structure accompanied with a high electrochemical active surface area to ensure the efficient and effective utilization of materials by exposing the electrochemical active sites for facile accessibility of reactant species. Herein, we report a one-step, single-pot, surfactant-free, electroless, and economic route to synthesize palladium sulfide nanostructures with different geometries at mild temperatures and their catalytic properties towards the oxygen reduction reaction (ORR) and methanol electro-oxidation (MOR). For ORR, the positive on-set, half wave potentials, smaller Tafel slope, high electrochemical active surface area, large roughness factor, and better cyclic stability of the proposed nanostructures as compared to those of the commercial state-of-the-art Pt-C/PdS catalysts suggest their superiority in an alkaline medium. In addition, high mass activity (J f ∼ 715 mA mg -1 ), in comparison with that of the commercial state-of-the-art Pt-C/PdS catalysts (J f ∼ 138/41 mA mg -1 , respectively), and high J f /J b (1.52) along with the superior operational stability of the multi-arm palladium sulfide nanostructures towards MOR advocates the bi-functional behavior of the catalyst and its potential as a promising Pt-free anode/cathode electrocatalyst in fuel cells.

Micro-Topographies Promote Late Chondrogenic Differentiation Markers in the ATDC5 Cell Line.

PubMed

Le, Bach Q; Vasilevich, Aliaksei; Vermeulen, Steven; Hulshof, Frits; Stamatialis, Dimitrios F; van Blitterswijk, Clemens A; de Boer, Jan

2017-05-01

Chemical and mechanical cues are well-established influencers of in vitro chondrogenic differentiation of ATDC5 cells. Here, we investigate the role of topographical cues in this differentiation process, a study not been explored before. Previously, using a library of surface micro-topographies we found some distinct patterns that induced alkaline phosphatase (ALP) production in human mesenchymal stromal cells. ALP is also a marker for hypertrophy, the end stage of chondrogenic differentiation preceding bone formation. Thus, we hypothesized that these patterns could influence end-stage chondrogenic differentiation of ATDC5 cells. In this study, we randomly selected seven topographies among the ALP influencing hits. Cells grown on these surfaces displayed varying nuclear shape and actin filament structure. When stimulated with insulin-transferrin-selenium (ITS) medium, nodule formation occurred and in some cases showed alignment to the topographical patterns. Gene expression analysis of cells growing on topographical surfaces in the presence of ITS medium revealed a downregulation of early markers and upregulation of late markers of chondrogenic differentiation compared to cells grown on a flat surface. In conclusion, we demonstrated that surface topography in addition to other cues can promote hypertrophic differentiation suitable for bone tissue engineering.

Clinical trial tests first-in-class bifunctional immunotherapy drug in HPV-associated cancers | Center for Cancer Research

Cancer.gov

HPV-associated cancers that spread or do not respond to treatment are often incurable. Julius Strauss, M.D., of the Laboratory of Tumor Immunology and Biology is testing a first-in-class bifunctional immunotherapy to see if it can control the growth of HPV-associated tumors by restoring and improving the immune system’s ability to kill cancer cells.

FACS-based isolation, propagation and characterization of mouse embryonic cardiomyocytes based on VCAM-1 surface marker expression.

PubMed

Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K; Jovinge, Stefan

2013-01-01

Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (FACS) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The FACS-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of FACS is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through FACS, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our FACS protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes.

FACS-Based Isolation, Propagation and Characterization of Mouse Embryonic Cardiomyocytes Based on VCAM-1 Surface Marker Expression

PubMed Central

Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K.; Jovinge, Stefan

2013-01-01

Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (FACS) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The FACS-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of FACS is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through FACS, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our FACS protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes. PMID:24386094

Heat shock 70-kDa protein 8 isoform 1 is expressed on the surface of human embryonic stem cells and downregulated upon differentiation.

PubMed

Son, Yeon Sung; Park, Jae Hyun; Kang, Young Kook; Park, Jin-Sung; Choi, Hong Seo; Lim, Ji Young; Lee, Jeoung Eun; Lee, Jung Bok; Ko, Myoung Seok; Kim, Yong-Sam; Ko, Jeong-Heon; Yoon, Hyun Soo; Lee, Kwang-Woong; Seong, Rho Hyun; Moon, Shin Yong; Ryu, Chun Jeih; Hong, Hyo Jeong

2005-01-01

The cell-surface markers used routinely to define the undifferentiated state and pluripotency of human embryonic stem cells (hESCs) are those used in mouse embryonic stem cells (mESCs) because of a lack of markers directly originated from hESC itself. To identify more hESC-specific cell-surface markers, we generated a panel of monoclonal antibodies (MAbs) by immunizing the irradiated cell clumps of hESC line Miz-hES1, and selected 26 MAbs that were able to bind to Miz-hES1 cells but not to mESCs, mouse embryonic fibroblast cells, and STO cells. Most antibodies did not bind to human neural progenitor cells derived from the Miz-hES1 cells, either. Of these, MAb 20-202S (IgG1, kappa) immunoprecipitated a cell-surface protein of 72-kDa from the lysate of biotin-labeled Miz-hES1 cells, which was identified to be heat shock 70-kDa protein 8 isoform 1 (HSPA8) by quadrupole time-of-flight tandem mass spectrometry. Immunocytochemical analyses proved that the HSPA8 protein was also present on the surface of hESC lines Miz-hES4, Miz-hES6, and HSF6. Two-color flow cytometric analysis of Miz-hES1 and HSF6 showed the coexpression of the HSPA8 protein with other hESC markers such as stage-specific embryonic antigen 3 (SSEA3), SSEA4, TRA-1-60, and TRA-1-81. Flow cytometric and Western blot analyses using various cells showed that MAb 20-202S specifically bound to the HSPA8 protein on the surface of Miz-hES1, contrary to other anti-HSP70 antibodies examined. Furthermore, the surface expression of the HSPA8 protein on Miz-hES1 was markedly downregulated upon differentiation. These data indicate that a novel MAb 20-202S recognizes the HSPA8 protein on the surface of hESCs and suggest that the HSPA8 protein is a putative cell-surface marker for undifferentiated hESCs.

Methods of making functionalized nanorods

DOEpatents

Gur, Ilan [San Francisco, CA; Milliron, Delia [Berkeley, CA; Alivisatos, A Paul [Oakland, CA; Liu, Haitao [Berkeley, CA

2012-01-10

A process for forming functionalized nanorods. The process includes providing a substrate, modifying the substrate by depositing a self-assembled monolayer of a bi-functional molecule on the substrate, wherein the monolayer is chosen such that one side of the bi-functional molecule binds to the substrate surface and the other side shows an independent affinity for binding to a nanocrystal surface, so as to form a modified substrate. The process further includes contacting the modified substrate with a solution containing nanocrystal colloids, forming a bound monolayer of nanocrystals on the substrate surface, depositing a polymer layer over the monolayer of nanocrystals to partially cover the monolayer of nanocrystals, so as to leave a layer of exposed nanocrystals, functionalizing the exposed nanocrystals, to form functionalized nanocrystals, and then releasing the functionalized nanocrystals from the substrate.

Cell surface differences of Naegleria fowleri and Naegleria lovaniensis exposed with surface markers.

PubMed

González-Robles, Arturo; Castañón, Guadalupe; Cristóbal-Ramos, Ana Ruth; Hernández-Ramírez, Verónica Ivonne; Omaña-Molina, Maritza; Martínez-Palomo, Adolfo

2007-12-01

Differences in the distribution of diverse cell surface coat markers were found between Naegleria fowleri and Naegleria lovaniensis. The presence of carbohydrate-containing components in the cell coat of the two species was detected by selective staining with ruthenium red and alcian blue. Using both markers, N. fowleri presented a thicker deposit than N. lovaniensis. The existence of exposed mannose or glucose residues was revealed by discriminatory agglutination with the plant lectin Concanavalin A. These sugar residues were also visualized at the cell surface of these parasites either by transmission electron microscopy or by fluorescein-tagged Concanavalin A. Using this lectin cap formation was induced only in N. fowleri. The anionic sites on the cell surface detected by means of cationized ferritin were more apparent in N. fowleri. Biotinylation assays confirmed that even though the two amoebae species have some analogous plasma membrane proteins, there is a clear difference in their composition.

A combination of CoO and Co nanoparticles supported on electrospun carbon nanofibers as highly stable air electrodes

NASA Astrophysics Data System (ADS)

Alegre, Cinthia; Busacca, Concetta; Di Blasi, Orazio; Antonucci, Vincenzo; Aricò, Antonino Salvatore; Di Blasi, Alessandra; Baglio, Vincenzo

2017-10-01

Bifunctional materials able to catalyze both the oxygen reduction (ORR) and the oxygen evolution (OER) reactions in alkaline media are still a challenge for the progress of energy conversion and storage devices such as metal-air batteries or unitized regenerative fuel cells. In this work, carbon nanofibers synthesized by electrospinning are modified with a combination of cobalt oxide and metallic cobalt (CoO-Co/CNF) and studied as a bifunctional air electrode for metal-air batteries. The performance of CoO-Co/CNF for both reactions is compared with state-of-the-art catalysts such as Pt/C and IrO2. The combination of cobalt oxide and metallic cobalt, finely distributed on the surface of graphitic carbon nanofibers, leads to a bifunctional catalyst with a half-wave potential for the ORR slightly better than Pt/C and a reversibility (ΔEOER-ORR) of 809 mV. The stability of CoO-Co/CNF is assessed by means of different stress tests: polarizations at high electrochemical potentials (2 V vs. RHE), rapid charge-discharge cycles at ±80 mA cm-2 and long durability tests by charging for 12 h at 60 mA cm-2 and discharging for 8 h at -80 mA cm-2. CoO-Co/CNF shows a remarkable stability, maintaining, at least, an 82% of its performance for the ORR after the stress tests, even when cycled for more than 100 h.

Isolation and characterization of human CXCR4-positive pancreatic cells.

PubMed

Koblas, T; Zacharovová, K; Berková, Z; Mindlová, M; Girman, P; Dovolilová, E; Karasová, L; Saudek, F

2007-01-01

The existence of an adult PSC that may be used in the treatment of diabetes is still a matter of scientific debate as conclusive evidence of such a stem cell in the adult pancreas has not yet been presented. The main reason why putative PSC has not yet been identified is the lack of specific markers that may be used to isolate and purify them. In order to increase the list of potential PSC markers we have focused on the human pancreatic cells that express cell surface receptor CXCR4, a marker of stem cells derived from different adult tissues. Here we report that CXCR4-positive pancreatic cells express markers of pancreatic endocrine progenitors (neurogenin-3, nestin) and markers of pluripotent stem cells (Oct-4, Nanog, ABCG2, CD133, CD117). Upon in vitro differentiation, these cells form ILCC and produce key islet hormones including insulin. Based on our results, we assume that CXCR4 marks pancreatic endocrine progenitors and in combination with other cell surface markers may be used in the attempt to identify and isolate PSC.

Targeting Therapy Resistant Tumor Vessels

DTIC Science & Technology

2007-05-01

Porkka K, Laakko- nen P, Ruoslahti E. Nucleolin expressed at the cell surface is a marker of endothelial cells in angiogenic blood vessels. J Cell...anti-angiogenic therapy. Markers of such vessels will be useful in developing strategies for complete destruction of breast cancer vasculature, and in...express specific markers , and that these lymphatic markers are tumor type specific and distinct from blood vessel markers in the same tumors. The

A bifunctional electrolyte additive for separator wetting and dendrite suppression in lithium metal batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Hao; Xie, Yong; Xiang, Hongfa

Reformulation of electrolyte systems and improvement of separator wettability are vital to electrochemical performances of rechargeable lithium (Li) metal batteries, especially for suppressing Li dendrites. In this work we report a bifunctional electrolyte additive that improves separator wettability and suppresses Li dendrite growth in LMBs. A triblock polyether (Pluronic P123) was introduced as an additive into a commonly used carbonate-based electrolyte. It was found that addition of 0.2~1% (by weight) P123 into the electrolyte could effectively enhance the wettability of polyethylene separator. More importantly, the adsorption of P123 on Li metal surface can act as an artificial solid electrolyte interphasemore » layer and contribute to suppress the growth of Li dendrites. A smooth and dendritic-free morphology can be achieved in the electrolyte with 0.2% P123. The Li||Li symmetric cells with the 0.2% P123 containing electrolyte exhibit a relatively stable cycling stability at high current densities of 1.0 and 3.0 mA cm-2.« less

In vivo marking of spontaneous or vaccine-induced fibrosarcomas in the domestic house cat, using an adenoviral vector containing a bifunctional fusion protein, GAL-TEK.

PubMed

Marini, F C; Cannon, J P; Belmont, J W; Shillitoe, E J; Lapeyre, J N

1995-09-01

We evaluated the ability of a replication-deficient, recombinant adenoviral vector to transfer the bifunctional gene GAL-TEK, which expresses a marking/therapeutic gene product, to naturally occurring cat fibrosarcomas in situ. GAL-TEK contains an in-frame fusion of the bacterial LacZ gene for histochemical marking of tumors with beta-galactosidase (beta-Gal) and the HSV tk gene for enzyme-prodrug activation of the prodrug ganciclovir (GCV) to induce selective tumor cell killing. GAL-TEK bifunctional marking and cell killing activities were tested in vitro after adenoviral vector infection of HT1080 human fibrosarcoma cells. The tk activity of GAL-TEK is shown to be almost as potent as HSV tk to catalyze conversion of GCV to GCV nucleotides and promote selective cell killing. Using 8 cats with recurring 2.5-cm2 fibrosarcomas that either arose spontaneously or were induced by vaccine, we determined experimentally the administration routes and times required for optimum GAL-TEK gene transfer by beta-Gal histological staining and reverse transcriptase polymerase chain reaction to the multiple compartments of the growing fibrosarcomas consonant with minimizing collateral infection of neighboring tissues and other unwanted side effects.

Surface receptors on human haematopoietic cell lines.

PubMed Central

Huber, C; Sundström, C; Nilsson, K; Wigzell, H

1976-01-01

The expression of complement receptors, of Fc receptors, of SRBC receptors and of S-Ig was investigated on human haematopoietic cell lines of proved malignant derivation. According to their origin and to a panel of phenotypic markers these lines have been classified into lymphoma lines, myeloma lines and leukemia lines. Results were compared with those obtained on non-malignant EBV carrying lymphoblastoid cell lines (LCL). Among the lymphoid cell lines the LCL showed a pattern of B-lymphocyte surface markers, i.e. surface immunoglobulins, C3 receptors but low density of Fc receptors. The non-Burkitt lymphoma lines bore in varying degree these B-lymphocyte markers. The lines U-698 M and DG-75 were exceptional in having only surface immunoglobulin. The Burkitt lymphoma lines had all B-lymphocyte markers. The myeloma lines differed from the lymphoid lines in lacking C3 and Fc receptors and showed only trace amounts of surface immunoglobulins. In contrast to lymphoid and myeloma lines, the leukaemia lines were completely lacking surface immunoglobulins, but showed C3 and Fc receptors in variable densities. On line, the ALL derived line MOLT-3 showed the capacity to spontaneous rosette formation with SRBC. The findings that LCL presented a homogeneous pattern of B-lymphocyte surface markers may be of value in order to discriminate between these lines and lines derived from haematopoietic malignancies other than Burkitt lymphomas. PMID:963908

Structural Changes in the Skin of Hairless Mice Following Exposure to Sulfur Mustard Correlate with Inflammation and DNA Damage

PubMed Central

Joseph, Laurie B.; Gerecke, Donald R.; Heck, Diane E.; Black, Adrienne T.; Sinko, Patrick J.; Cervelli, Jessica A.; Casillas, Robert P.; Babin, Michael C.; Laskin, Debra L.; Laskin, Jeffrey D.

2011-01-01

Sulfur mustard (SM, bis(2-chloroethyl)sulfide) is a bifunctional alkylating agent that causes dermal inflammation, edema and blistering. To investigate the pathogenesis of SM-induced injury, we used a vapor cup model which provides an occlusive environment in which SM is in constant contact with the skin. The dorsal skin of SKH-1 hairless mice was exposed to saturated SM vapor or air control. Histopathological changes, inflammatory markers and DNA damage were analyzed 1–14 days later. After 1 day, SM caused epidermal thinning, stratum corneum shedding, basal cell karyolysis, hemorrhage and macrophage and neutrophil accumulation in the dermis. Cleaved caspase-3 and phosphorylated histone 2A.X (phospho-H2A.X), markers of apoptosis and DNA damage, respectively, were increased whereas proliferating cell nuclear antigen (PCNA) was down-regulated after SM exposure. By 3 days, epithelial cell hypertrophy, edema, parakeratosis and loss of epidermal structures were noted. Enzymes generating pro-inflammatory mediators including myeloperoxidase and cyclooxygenase-2 were upregulated. After 7 days, keratin-10, a differentiation marker, was evident in the stratum corneum. This was associated with an underlying eschar, as neoepidermis began to migrate at the wound edges. Trichrome staining revealed increased collagen deposition in the dermis. PCNA expression in the epidermis was correlated with hyperplasia, hyperkeratosis, and parakeratosis. By 14 days, there was epidermal regeneration with extensive hyperplasia, and reduced expression of cleaved caspase-3, cyclooxygenase-2 and phospho-H2A.X. These findings are consistent with the pathophysiology of SM-induced skin injury in humans suggesting that the hairless mouse can be used to investigate the dermatoxicity of vesicants and the potential efficacy of countermeasures. PMID:21672537

Structural changes in the skin of hairless mice following exposure to sulfur mustard correlate with inflammation and DNA damage.

PubMed

Joseph, Laurie B; Gerecke, Donald R; Heck, Diane E; Black, Adrienne T; Sinko, Patrick J; Cervelli, Jessica A; Casillas, Robert P; Babin, Michael C; Laskin, Debra L; Laskin, Jeffrey D

2011-10-01

Sulfur mustard (SM, bis(2-chloroethyl)sulfide) is a bifunctional alkylating agent that causes dermal inflammation, edema and blistering. To investigate the pathogenesis of SM-induced injury, we used a vapor cup model which provides an occlusive environment in which SM is in constant contact with the skin. The dorsal skin of SKH-1 hairless mice was exposed to saturated SM vapor or air control. Histopathological changes, inflammatory markers and DNA damage were analyzed 1-14 days later. After 1 day, SM caused epidermal thinning, stratum corneum shedding, basal cell karyolysis, hemorrhage and macrophage and neutrophil accumulation in the dermis. Cleaved caspase-3 and phosphorylated histone 2A.X (phospho-H2A.X), markers of apoptosis and DNA damage, respectively, were increased whereas proliferating cell nuclear antigen (PCNA) was down-regulated after SM exposure. By 3 days, epithelial cell hypertrophy, edema, parakeratosis and loss of epidermal structures were noted. Enzymes generating pro-inflammatory mediators including myeloperoxidase and cyclooxygenase-2 were upregulated. After 7 days, keratin-10, a differentiation marker, was evident in the stratum corneum. This was associated with an underlying eschar, as neoepidermis began to migrate at the wound edges. Trichrome staining revealed increased collagen deposition in the dermis. PCNA expression in the epidermis was correlated with hyperplasia, hyperkeratosis, and parakeratosis. By 14 days, there was epidermal regeneration with extensive hyperplasia, and reduced expression of cleaved caspase-3, cyclooxygenase-2 and phospho-H2A.X. These findings are consistent with the pathophysiology of SM-induced skin injury in humans suggesting that the hairless mouse can be used to investigate the dermatoxicity of vesicants and the potential efficacy of countermeasures. Copyright © 2011 Elsevier Inc. All rights reserved.

CD44 Is a Negative Cell Surface Marker for Pluripotent Stem Cell Identification during Human Fibroblast Reprogramming

PubMed Central

Vaz, Candida; Tanavde, Vivek; Lakshmipathy, Uma

2014-01-01

Induced pluripotent stem cells (iPSCs) are promising tools for disease research and cell therapy. One of the critical steps in establishing iPSC lines is the early identification of fully reprogrammed colonies among unreprogrammed fibroblasts and partially reprogrammed intermediates. Currently, colony morphology and pluripotent stem cell surface markers are used to identify iPSC colonies. Through additional clonal characterization, we show that these tools fail to distinguish partially reprogrammed intermediates from fully reprogrammed iPSCs. Thus, they can lead to the selection of suboptimal clones for expansion. A subsequent global transcriptome analysis revealed that the cell adhesion protein CD44 is a marker that differentiates between partially and fully reprogrammed cells. Immunohistochemistry and flow cytometry confirmed that CD44 is highly expressed in the human parental fibroblasts used for the reprogramming experiments. It is gradually lost throughout the reprogramming process and is absent in fully established iPSCs. When used in conjunction with pluripotent cell markers, CD44 staining results in the clear identification of fully reprogrammed cells. This combination of positive and negative surface markers allows for easier and more accurate iPSC detection and selection, thus reducing the effort spent on suboptimal iPSC clones. PMID:24416407

Constructing bio-layer of heparin and type IV collagen on titanium surface for improving its endothelialization and blood compatibility.

PubMed

Zhang, Kun; Chen, Jun-ying; Qin, Wei; Li, Jing-an; Guan, Fang-xia; Huang, Nan

2016-04-01

The modification of cardiovascular stent surface for a better micro-environment has gradually changed to multi-molecule, multi-functional designation. In this study, heparin (Hep) and type IV collagen (IVCol) were used as the functional molecule to construct a bifunctional micro-environment of anticoagulation and promoting endothelialization on titanium (Ti). The surface characterization results (AFM, Alcian Blue 8GX Staining and fluorescence staining of IVCol) indicated that the bio-layer of Hep and IVCol were successfully fabricated on the Ti surface through electrostatic self-assembly. The APTT and platelet adhesion test demonstrated that the bionic layer possessed better blood compatibility compared with Ti surface. The adhesion, proliferation, migration and apoptosis tests of endothelial cells proved that the Hep/IVCol layer was able to enhance the endothelialization of the Ti surface. The in vivo animal implantation results manifested that the bionic surface could encourage new endothelialization. This work provides an important reference for the construction of multifunction micro-environment on the cardiovascular scaffold surface.

Bifunctional air electrodes containing elemental iron powder charging additive

DOEpatents

Liu, Chia-tsun; Demczyk, Brian G.; Gongaware, Paul R.

1982-01-01

A bifunctional air electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer essentially comprises a hydrophilic composite which includes: (i) carbon; (ii) elemental iron particles having a particle size of between about 25 microns and about 700 microns diameter; (iii) an oxygen evolution material; (iv) a nonwetting agent; and (v) a catalyst, where at least one current collector is formed into said composite.

Hydrophilic cobalt sulfide nanosheets as a bifunctional catalyst for oxygen and hydrogen evolution in electrolysis of alkaline aqueous solution.

PubMed

Zhu, Mingchao; Zhang, Zhongyi; Zhang, Hu; Zhang, Hui; Zhang, Xiaodong; Zhang, Lixue; Wang, Shicai

2018-01-01

Hydrophilic medium and precursors were used to synthesize a hydrophilic electro-catalyst for overall water splitting. The cobalt sulfide (Co 3 S 4 ) catalyst exhibits a layered nanosheet structure with a hydrophilic surface, which can facilitate the diffusion of aqueous substrates into the electrode pores and towards the active sites. The Co 3 S 4 catalyst shows excellent bifunctional catalytic activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solution. The assembled water electrolyzer based on Co 3 S 4 exhibits better performance and stability than that of Pt/C-RuO 2 catalyst. Thereforce the hydrophilic Co 3 S 4 is a highly promising bifunctional catalyst for the overall water splitting reaction. Copyright © 2017 Elsevier Inc. All rights reserved.

Expression of Master Regulators of T-cell, Helper T-cell and Follicular Helper T-cell Differentiation in Angioimmunoblastic T-cell Lymphoma.

PubMed

Matsumoto, Yosuke; Nagoshi, Hisao; Yoshida, Mihoko; Kato, Seiichi; Kuroda, Junya; Shimura, Kazuho; Kaneko, Hiroto; Horiike, Shigeo; Nakamura, Shigeo; Taniwaki, Masafumi

2017-11-01

Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.

Design and development of novel linker for PbS quantum dots/TiO₂ mesoscopic solar cell.

PubMed

Etgar, Lioz; Park, Jinhyung; Barolo, Claudia; Nazeeruddin, Md K; Viscardi, Guido; Graetzel, Michael

2011-09-01

A novel bifunctional linker molecule, bis(4-mercaptophenyl)phosphinic acid, is designed to be used in a QDs solar cells. The linker anchors to TiO(2) mesoporous film through the phosphinic acid functional group and to the PbS QDs through the two thiol groups. The way of attachment of this new linker molecule in a photovoltaic PbS QDs/TiO(2) mesoporous device was studied by FTIR measurements. The photovoltaic performance of this new linker in a heterojunction PbS QDs solar cell show high V(oc) relative to QDs based solar cells, which will allow to receive high power conversion efficiency using this novel designed linker. This novel bifunctional linker molecule should pave the way for enhancing binding strength, and efficiency of QDs solar cells compared to the state-of-the-art linkers.

Synthesis of bifunctional molecules containing [12]aneN3 and coumarin moieties as effective DNA condensation agents and new non-viral gene vectors.

PubMed

Yue, Pan; Zhang, Ying; Guo, Zhi-Fo; Cao, Ao-Cheng; Lu, Zhong-Lin; Zhai, Yong-Gong

2015-04-21

A series of bifunctional molecules with different combinations of macrocyclic polyamine [12]aneN3 and coumarin moieties, 4a/b and 5a/b, were synthesized by a two-step copper(I)-mediated alkyne–azide click reactions between 1,3,5-tris(azidomethyl)benzene and Boc-protected N-propynyl-[12]aneN3/7-propynyloxycoumarins. Agarose gel electrophoresis experiments indicated that bifunctional molecules 4b and 5b effectively induced complete plasmid DNA condensation at concentrations up to 40 μM. It was found that the structural variation had a major impact on the condensation behavior of these compounds. The electrostatic interaction involving the [12]aneN3 moiety can be compensated by the binding contribution of the coumarin units during the DNA condensation process. These two types of interaction showed different effects on the reversibility of DNA condensation. Results from studies using dynamic laser scattering, atomic force microscopy, and EB replacement assay further supported the above conclusion. Cytotoxicity assays on bifunctional compounds 4a/b and 5a/b indicated their low cytotoxicity. Results from cellular uptake and cell transfection experiments proved that bifunctional compounds 4b and 5b successfully served as non-viral gene vectors. Furthermore, methyl substituents attached to the coumarin unit (4b and 5b) greatly enhanced their DNA condensation capability and gene transfection. These bifunctional molecules, with the advantages of lower cytotoxicity, good water solubility, and potential structural modification, will have great potential for the development of new non-viral gene delivery agents.

SIRPA is a specific cell-surface marker for isolating cardiomyocytes derived from human pluripotent stem cells.

PubMed

Dubois, Nicole C; Craft, April M; Sharma, Parveen; Elliott, David A; Stanley, Edouard G; Elefanty, Andrew G; Gramolini, Anthony; Keller, Gordon

2011-10-23

To identify cell-surface markers specific to human cardiomyocytes, we screened cardiovascular cell populations derived from human embryonic stem cells (hESCs) against a panel of 370 known CD antibodies. This screen identified the signal-regulatory protein alpha (SIRPA) as a marker expressed specifically on cardiomyocytes derived from hESCs and human induced pluripotent stem cells (hiPSCs), and PECAM, THY1, PDGFRB and ITGA1 as markers of the nonmyocyte population. Cell sorting with an antibody against SIRPA allowed for the enrichment of cardiac precursors and cardiomyocytes from hESC/hiPSC differentiation cultures, yielding populations of up to 98% cardiac troponin T-positive cells. When plated in culture, SIRPA-positive cells were contracting and could be maintained over extended periods of time. These findings provide a simple method for isolating populations of cardiomyocytes from human pluripotent stem cell cultures, and thereby establish a readily adaptable technology for generating large numbers of enriched cardiomyocytes for therapeutic applications.

Structural changes in hair follicles and sebaceous glands of hairless mice following exposure to sulfur mustard.

PubMed

Joseph, Laurie B; Heck, Diane E; Cervelli, Jessica A; Composto, Gabriella M; Babin, Michael C; Casillas, Robert P; Sinko, Patrick J; Gerecke, Donald R; Laskin, Debra L; Laskin, Jeffrey D

2014-06-01

Sulfur mustard (SM) is a bifunctional alkylating agent causing skin inflammation, edema and blistering. A hallmark of SM-induced toxicity is follicular and interfollicular epithelial damage. In the present studies we determined if SM-induced structural alterations in hair follicles and sebaceous glands were correlated with cell damage, inflammation and wound healing. The dorsal skin of hairless mice was treated with saturated SM vapor. One to seven days later, epithelial cell karyolysis within the hair root sheath, infundibulum and isthmus was apparent, along with reduced numbers of sebocytes. Increased numbers of utriculi, some with connections to the skin surface, and engorged dermal cysts were also evident. This was associated with marked changes in expression of markers of DNA damage (phospho-H2A.X), apoptosis (cleaved caspase-3), and wound healing (FGFR2 and galectin-3) throughout pilosebaceous units. Conversely, fatty acid synthase and galectin-3 were down-regulated in sebocytes after SM. Decreased numbers of hair follicles and increased numbers of inflammatory cells surrounding the utriculi and follicular cysts were noted within the wound 3-7 days post-SM exposure. Expression of phospho-H2A.X, cleaved caspase-3, FGFR2 and galectin-3 was decreased in dysplastic follicular epidermis. Fourteen days after SM, engorged follicular cysts which expressed galectin-3 were noted within hyperplastic epidermis. Galectin-3 was also expressed in basal keratinocytes and in the first few layers of suprabasal keratinocytes in neoepidermis formed during wound healing indicating that this lectin is important in the early stages of keratinocyte differentiation. These data indicate that hair follicles and sebaceous glands are targets for SM in the skin. Copyright © 2014 Elsevier Inc. All rights reserved.

Isolation and characterisation of mesenchymal stem/stromal cells in the ovine endometrium.

PubMed

Letouzey, Vincent; Tan, Ker Sin; Deane, James A; Ulrich, Daniela; Gurung, Shanti; Ong, Y Rue; Gargett, Caroline E

2015-01-01

Mesenchymal stem/stromal cells (MSC) were recently discovered in the human endometrium. These cells possess key stem cell properties and show promising results in small animal models when used for preclinical tissue engineering studies. A small number of surface markers have been identified that enrich for MSC from bone marrow and human endometrium, including the Sushi Domain-containing 2 (SUSD2; W5C5) and CD271 markers. In preparation for developing a large animal preclinical model for urological and gynecological tissue engineering applications we aimed to identify and characterise MSC in ovine endometrium and determine surface markers to enable their prospective isolation. Ovine endometrium was obtained from hysterectomised ewes following progesterone synchronisation, dissociated into single cell suspensions and tested for MSC surface markers and key stem cell properties. Purified stromal cells were obtained by flow cytometry sorting with CD49f and CD45 to remove epithelial cells and leukocytes respectively, and MSC properties investigated. There was a small population CD271+ stromal cells (4.5 ± 2.3%) in the ovine endometrium. Double labelling with CD271 and CD49f showed that the sorted CD271+CD49f- stromal cell population possessed significantly higher cloning efficiency, serial cloning capacity and a qualitative increased ability to differentiate into 4 mesodermal lineages (adipocytic, smooth muscle, chondrocytic and osteoblastic) than CD271-CD49f- cells. Immunolabelling studies identified an adventitial perivascular location for ovine endometrial CD271+ cells. This is the first study to characterise MSC in the ovine endometrium and identify a surface marker profile identifying their location and enabling their prospective isolation. This knowledge will allow future preclinical studies with a large animal model that is well established for pelvic organ prolapse research.

Sialyl-lactotetra, a novel cell surface marker of undifferentiated human pluripotent stem cells.

PubMed

Barone, Angela; Säljö, Karin; Benktander, John; Blomqvist, Maria; Månsson, Jan-Eric; Johansson, Bengt R; Mölne, Johan; Aspegren, Anders; Björquist, Petter; Breimer, Michael E; Teneberg, Susann

2014-07-04

Cell surface glycoconjugates are used as markers for undifferentiated pluripotent stem cells. Here, antibody binding and mass spectrometry characterization of acid glycosphingolipids isolated from a large number (1 × 10(9) cells) of human embryonic stem cell (hESC) lines allowed identification of several novel acid glycosphingolipids, like the gangliosides sialyl-lactotetraosylceramide and sialyl-globotetraosylceramide, and the sulfated glycosphingolipids sulfatide, sulf-lactosylceramide, and sulf-globopentaosylceramide. A high cell surface expression of sialyl-lactotetra on hESC and human induced pluripotent stem cells (hiPSC) was demonstrated by flow cytometry, immunohistochemistry, and electron microscopy, whereas sulfated glycosphingolipids were only found in intracellular compartments. Immunohistochemistry showed distinct cell surface anti-sialyl-lactotetra staining on all seven hESC lines and three hiPSC lines analyzed, whereas no staining of hESC-derived hepatocyte-like or cardiomyocyte-like cells was obtained. Upon differentiation of hiPSC into hepatocyte-like cells, the sialyl-lactotetra epitope was rapidly down-regulated and not detectable after 14 days. These findings identify sialyl-lactotetra as a promising marker of undifferentiated human pluripotent stem cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Improved electron transfer and plasmonic effect in dye-sensitized solar cells with bi-functional Nb-doped TiO2/Ag ternary nanostructures.

PubMed

Park, Jung Tae; Chi, Won Seok; Jeon, Harim; Kim, Jong Hak

2014-03-07

TiO2 nanoparticles are surface-modified via atom transfer radical polymerization (ATRP) with a hydrophilic poly(oxyethylene)methacrylate (POEM), which can coordinate to the Ag precursor, i.e. silver trifluoromethanesulfonate (AgCF3SO3). Following the reduction of Ag ions, a Nb2O5 doping process and calcination at 450 °C, bi-functional Nb-doped TiO2/Ag ternary nanostructures are generated. The resulting nanostructures are characterized by energy-filtering transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. The dye-sensitized solar cell (DSSC) based on the Nb-doped TiO2/Ag nanostructure photoanode with a polymerized ionic liquid (PIL) as the solid polymer electrolyte shows an overall energy conversion efficiency (η) of 6.9%, which is much higher than those of neat TiO2 (4.7%) and Nb-doped TiO2 (5.4%). The enhancement of η is mostly due to the increase of current density, attributed to the improved electron transfer properties including electron injection, collection, and plasmonic effects without the negative effects of charge recombination or problems with corrosion. These properties are supported by intensity modulated photocurrent/voltage spectroscopy (IMPS/IMVS) and incident photon-to-electron conversion efficiency (IPCE) measurements.

Stem Cell Therapy for Healing Wounded Skin and Soft Tissues

DTIC Science & Technology

2012-07-01

changes of ASC surface markers due to repetitive in vitro sub-culturing. ASCs were harvested, washed in PBS to remove cell culture medium, and resuspended...Our in vitro and in vivo studies suggest that ASC and BM-MSC are not identical, though they have similar surface markers . We found that topically...ofpolybrene. Transduced cells were selected by treating 10 J.!g/rnl ofblasticidin. GFP expressing cells were further selected by flow cytometry using

Does the liposuction method influence the phenotypic characteristic of human adipose-derived stem cells?

PubMed

Bajek, Anna; Gurtowska, Natalia; Gackowska, Lidia; Kubiszewska, Izabela; Bodnar, Magdalena; Marszałek, Andrzej; Januszewski, Rafał; Michalkiewicz, Jacek; Drewa, Tomasz

2015-05-14

Adipose-derived stem cells (ASCs) possess a high differentiation and proliferation potential. However, the phenotypic characterization of ASCs is still difficult. Until now, there is no extensive analysis of ASCs markers depending on different liposuction methods. Therefore, the aim of the present study was to analyse 242 surface markers and determine the differences in the phenotypic pattern between ASCs obtained during mechanical and ultrasound-assisted liposuction. ASCs were isolated from healthy donors, due to mechanical and ultrasound-assisted liposuction and cultured in standard medium to the second passage. Differentiation potential and markers expression was evaluated to confirm the mesenchymal nature of cells. Then, the BD LyoplateTM Human Cell Surface Marker Screening Panel was used. Results shown that both population of ASCs are characterized by high expression of markers specific for ASCs: cluster of differentiation (CD)9, CD10, CD34, CD44, CD49d, CD54, CD55, CD59, CD71 and low expression of CD11a, CD11c and CD144. Moreover, we have noticed significant differences in antigen expression in 58 markers from the 242 studied. Presented study shows for the first time that different liposuction methods are not a significant factor which can influence the expression of human ASCs surface markers. © 2015 The Authors.

Apigenin inhibited hypoxia induced stem cell marker expression in a head and neck squamous cell carcinoma cell line.

PubMed

Ketkaew, Yuwaporn; Osathanon, Thanaphum; Pavasant, Prasit; Sooampon, Sireerat

2017-02-01

Cancer stem cells contribute to tumor recurrence, and a hypoxic environment is critical for maintaining cancer stem cells. Apigenin is a natural product with anticancer activity. However, the effect of apigenin on cancer stem cells remains unclear. Our aim was to investigate the effect of apigenin on cancer stem cell marker expression in head and neck squamous cell carcinoma cells under hypoxia. We used three head and neck squamous cell carcinoma cell lines; HN-8, HN-30, and HSC-3. The mRNA expression of cancer stem cell markers was determined by semiquantitative RT-PCR and Real-time PCR. The cytotoxic effect of apigenin was determined by MTT colorimetric assay. Flow cytometry was used to reveal the number of cells expressing cancer stem cell surface markers. HN-30 cells, a cancer cell line from the pharynx, showed the greatest response to hypoxia by increasing their expression of CD44, CD105, NANOG, OCT-4, REX-1, and VEGF. Apigenin significantly decreased HN-30 cell viability in dose- and time-dependent manners. In addition, 40μM apigenin significantly down-regulated the mRNA expression of CD44, NANOG, and CD105. Consistent with these results, the hypoxia-induced increase in CD44 + cells, CD105 + cells, and STRO-1 + cells was significantly abolished by apigenin. Apigenin suppresses cancer stem cell marker expression and the number of cells expressing cell surface markers under hypoxia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bifunctional silica nanospheres with 3-aminopropyl and phenyl groups. Synthesis approach and prospects of their applications

NASA Astrophysics Data System (ADS)

Kotsyuda, Sofiya S.; Tomina, Veronika V.; Zub, Yuriy L.; Furtat, Iryna M.; Lebed, Anastasia P.; Vaclavikova, Miroslava; Melnyk, Inna V.

2017-10-01

Spherical silica particles with bifunctional (tbnd Si(CH2)3NH2/tbnd SiC6H5) surface layers were synthesized by the Stöber method using ternary alkoxysilanes systems. The influence of the synthesis conditions, such as temperature and stirring time on the process of nanoparticles formation was studied. The presence of introduced functional groups was confirmed by FTIR. The composition of the surface layers examined by elemental analysis and acid-base titration was shown to be independent from the synthesis temperature. However, the size of the obtained particles depends on the synthesis temperature and, according to photon cross-correlation spectroscopy, can be varied from 50 to 846 nm. The variation of electric charges of N-functional groups was disclosed in obtained nanospheres and attributed to different surface location of these groups and their surrounding with other groups. The sorption of Cu(II) ions by functionalized silicas depends on the concentration of amino groups, which correlates with the isoelectric point values (determined to vary from 8.26 to 9.21). Bifunctional nanoparticles adsorb 99.0 mg/g of methylene blue, compared with 48.0 mg/g by silica sample with only amino groups. The nanospheres, both with and without adsorbed Cu2+, demonstrate reasonable antibacterial activity against S. aureus ATCC 25923, depending on particle concentration in water suspension.

The Biological Properties of OGI Surfaces Positively Act on Osteogenic and Angiogenic Commitment of Mesenchymal Stem Cells

PubMed Central

Bressan, Eriberto; Gardin, Chiara; Ferroni, Letizia; Soldini, Maria Costanza; Mandelli, Federico; Soldini, Claudio

2017-01-01

Osteogenesis process displays a fundamental role during dental implant osteointegration. In the present work, we studied the influence of Osteon Growth Induction (OGI) surface properties on the angiogenic and osteogenic behaviors of Mesenchymal Stem cells (MSC). MSC derived from dental pulp and HUVEC (Human Umbilical Vein Endothelial Cells) were grown in on OGI titanium surfaces, and cell proliferation and DNA synthesis were evaluated by MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide] test and DNA quantification. Gene expression has been performed in order to evaluate the presence of mRNA related to endothelial and osteogenesis markers. Moreover, morphological and biochemical analyses of osteogenesis commitments has been performed. On OGI surfaces, MSC and HUVEC are able to proliferate. Gene expression profiler confirms that MSC on OGI surfaces are able to express endothelial and osteogenic markers, and that these expression are higher compared the expression on control surfaces. In conclusion On OGI surfaces proliferation, expression and morphological analyses of angiogenesis-associated markers in MSC are promoted. This process induces an increasing on their osteogenesis commitment. PMID:29149082

Different culture media affect growth characteristics, surface marker distribution and chondrogenic differentiation of human bone marrow-derived mesenchymal stromal cells.

PubMed

Hagmann, Sebastien; Moradi, Babak; Frank, Sebastian; Dreher, Thomas; Kämmerer, Peer Wolfgang; Richter, Wiltrud; Gotterbarm, Tobias

2013-07-30

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) play an important role in modern tissue engineering, while distinct variations of culture media compositions and supplements have been reported. Because MSCs are heterogeneous regarding their regenerative potential and their surface markers, these parameters were compared in four widely used culture media compositions. MSCs were isolated from bone marrow and expanded in four established cell culture media. MSC yield/1000 MNCs, passage time and growth index were observed. In P4, typical MSC surface markers were analysed by fluorescence cytometry. Additionally, chondrogenic, adipogenic and osteogenic differentiation potential were evaluated. Growth index and P0 cell yield varied importantly between the media. The different expansion media had a significant influence on the expression of CD10, CD90, CD105, CD140b CD146 and STRO-1. While no significant differences were observed regarding osteogenic and adipogenic differentiation, chondrogenic differentiation was superior in medium A as reflected by GAG/DNA content. The choice of expansion medium can have a significant influence on growth, differentiation potential and surface marker expression of mesenchymal stromal cells, which is of fundamental importance for tissue engineering procedures.

Signal peptide cleavage is essential for surface expression of a regulatory T cell surface protein, leucine rich repeat containing 32 (LRRC32)

PubMed Central

2011-01-01

Background Elevated numbers of regulatory T cells (Tregs) have been implicated in certain cancers. Depletion of Tregs has been shown to increase anti-tumor immunity. Tregs also play a critical role in the suppression of autoimmune responses. The study of Tregs has been hampered by a lack of adequate surface markers. Leucine Rich Repeat Containing 32 (LRRC32), also known as Glycoprotein A Repetitions Predominant (GARP), has been postulated as a novel surface marker of activated Tregs. However, there is limited information regarding the processing of LRRC32 or the regulatory phenotype and functional activity of Tregs expressing LRRC32. Results Using naturally-occurring freshly isolated Tregs, we demonstrate that low levels of LRRC32 are present intracellularly prior to activation and that freshly isolated LRRC32+ Tregs are distinct from LRRC32- Tregs with respect to the expression of surface CD62L. Using LRRC32 transfectants of HEK cells, we demonstrate that the N-terminus of LRRC32 is cleaved prior to expression of the protein at the cell surface. Furthermore, we demonstrate using a construct containing a deleted putative signal peptide region that the presence of a signal peptide region is critical to cell surface expression of LRRC32. Finally, mixed lymphocyte assays demonstrate that LRRC32+ Tregs are more potent suppressors than LRRC32- Tregs. Conclusions A cleaved signal peptide site in LRRC32 is necessary for surface localization of native LRRC32 following activation of naturally-occurring freshly-isolated regulatory T cells. LRRC32 expression appears to alter the surface expression of activation markers of T cells such as CD62L. LRRC32 surface expression may be useful as a marker that selects for more potent Treg populations. In summary, understanding the processing and expression of LRRC32 may provide insight into the mechanism of action of Tregs and the refinement of immunotherapeutic strategies aimed at targeting these cells. PMID:21615933

Sequential CD34 cell fractionation by magnetophoresis in a magnetic dipole flow sorter.

PubMed

Schneider, Thomas; Karl, Stephan; Moore, Lee R; Chalmers, Jeffrey J; Williams, P Stephen; Zborowski, Maciej

2010-01-01

Cell separation and fractionation based on fluorescent and magnetic labeling procedures are common tools in contemporary research. These techniques rely on binding of fluorophores or magnetic particles conjugated to antibodies to target cells. Cell surface marker expression levels within cell populations vary with progression through the cell cycle. In an earlier work we showed the reproducible magnetic fractionation (single pass) of the Jurkat cell line based on the population distribution of CD45 surface marker expression. Here we present a study on magnetic fractionation of a stem and progenitor cell (SPC) population using the established acute myelogenous leukemia cell line KG-1a as a cell model. The cells express a CD34 cell surface marker associated with the hematopoietic progenitor cell activity and the progenitor cell lineage commitment. The CD34 expression level is approximately an order of magnitude lower than that of the CD45 marker, which required further improvements of the magnetic fractionation apparatus. The cells were immunomagnetically labeled using a sandwich of anti-CD34 antibody-phycoerythrin (PE) conjugate and anti-PE magnetic nanobead and fractionated into eight components using a continuous flow dipole magnetophoresis apparatus. The CD34 marker expression distribution between sorted fractions was measured by quantitative PE flow cytometry (using QuantiBRITE PE calibration beads), and it was shown to be correlated with the cell magnetophoretic mobility distribution. A flow outlet addressing scheme based on the concept of the transport lamina thickness was used to control cell distribution between the eight outlet ports. The fractional cell distributions showed good agreement with numerical simulations of the fractionation based on the cell magnetophoretic mobility distribution in the unsorted sample.

Is sphere assay useful for the identification of cancer initiating cells of the ovary?

PubMed

Martínez-Serrano, María José; Caballero-Baños, Miguel; Vilella, Ramon; Vidal, Laura; Pahisa, Jaume; Martínez-Roman, Sergio

2015-01-01

Current evidence suggests that the presence of tumor-initiating cells (TICs) in epithelial ovarian cancer (EOC) has a role in chemoresistance and relapse. Surface markers such as CD44(+)/CD24(-), CD117(+), and CD133(+) expression have been reported as potential markers for TICs related to ovarian cancer and tumorigenic cell lines. In this study, we have investigated if spheroid forms are TIC specific or whether they can also be produced by somatic stem cells from healthy tissue in vitro. In addition, we also investigated the specificity of surface markers to identify TICs from papillary serous EOC patients. Cells were obtained from fresh tumors from 10 chemotherapy-naive patients with EOC, and cells from ovarian and tubal epithelium were obtained from 5 healthy menopausal women undergoing surgery for benign pathology and cultured in standard and in selective medium. Cells forming nonadherent spheroids were considered TICs, and the adherent cells were considered as non-TIC-like. Percentages of CD24(+), CD44(+), CD117(+), CD133(+), and vascular endothelial growth factor receptor (VEGF-R)(+) cell surface markers were analyzed by flow cytometry. Four of 10 EOC cell tissues were excluded from the study. Tumor cells cultured in selective medium developed spheroid forms after 1 to 7 weeks in 5 of 6 EOC patients. No spheroid forms were observed in cultures of cells from healthy women. Unlike previously published data, low levels of CD24(+), CD44(+), CD117(+), and VEGF-R(+) expression were observed in spheroid cells, whereas expression of CD133(+) was moderate but higher in adherent cells from papillary serous EOC cells in comparison with adherent cells from controls. Papillary serous EOC contains TICs that form spheroids with low expression of CD44(+), CD24(+), CD117(+) and VEGF-R(+). Further research is required to find specific surface markers to identify papillary serous TICs.

GSK-3β: A Bifunctional Role in Cell Death Pathways.

PubMed

Jacobs, Keith M; Bhave, Sandeep R; Ferraro, Daniel J; Jaboin, Jerry J; Hallahan, Dennis E; Thotala, Dinesh

2012-01-01

Although glycogen synthase kinase-3 beta (GSK-3β) was originally named for its ability to phosphorylate glycogen synthase and regulate glucose metabolism, this multifunctional kinase is presently known to be a key regulator of a wide range of cellular functions. GSK-3β is involved in modulating a variety of functions including cell signaling, growth metabolism, and various transcription factors that determine the survival or death of the organism. Secondary to the role of GSK-3β in various diseases including Alzheimer's disease, inflammation, diabetes, and cancer, small molecule inhibitors of GSK-3β are gaining significant attention. This paper is primarily focused on addressing the bifunctional or conflicting roles of GSK-3β in both the promotion of cell survival and of apoptosis. GSK-3β has emerged as an important molecular target for drug development.

IAP-Based Cell Sorting Results in Homogeneous Transplantable Dopaminergic Precursor Cells Derived from Human Pluripotent Stem Cells.

PubMed

Lehnen, Daniela; Barral, Serena; Cardoso, Tiago; Grealish, Shane; Heuer, Andreas; Smiyakin, Andrej; Kirkeby, Agnete; Kollet, Jutta; Cremer, Harold; Parmar, Malin; Bosio, Andreas; Knöbel, Sebastian

2017-10-10

Human pluripotent stem cell (hPSC)-derived mesencephalic dopaminergic (mesDA) neurons can relieve motor deficits in animal models of Parkinson's disease (PD). Clinical translation of differentiation protocols requires standardization of production procedures, and surface-marker-based cell sorting is considered instrumental for reproducible generation of defined cell products. Here, we demonstrate that integrin-associated protein (IAP) is a cell surface marker suitable for enrichment of hPSC-derived mesDA progenitor cells. Immunomagnetically sorted IAP + mesDA progenitors showed increased expression of ventral midbrain floor plate markers, lacked expression of pluripotency markers, and differentiated into mature dopaminergic (DA) neurons in vitro. Intrastriatal transplantation of IAP + cells sorted at day 16 of differentiation in a rat model of PD resulted in functional recovery. Grafts from sorted IAP + mesDA progenitors were more homogeneous in size and DA neuron density. Thus, we suggest IAP-based sorting for reproducible prospective enrichment of mesDA progenitor cells in clinical cell replacement strategies. Copyright © 2017 Miltenyi Biotec GmbH. Published by Elsevier Inc. All rights reserved.

The Endogenous GRP78 Interactome in Human Head and Neck Cancers: A Deterministic Role of Cell Surface GRP78 in Cancer Stemness.

PubMed

Chen, Hsin-Ying; Chang, Joseph Tung-Chieh; Chien, Kun-Yi; Lee, Yun-Shien; You, Guo-Rung; Cheng, Ann-Joy

2018-01-11

Cell surface glucose regulated protein 78 (GRP78), an endoplasmic reticulum (ER) chaperone, was suggested to be a cancer stem cell marker, but the influence of this molecule on cancer stemness is poorly characterized. In this study, we developed a mass spectrometry platform to detect the endogenous interactome of GRP78 and investigated its role in cancer stemness. The interactome results showed that cell surface GRP78 associates with multiple molecules. The influence of cell population heterogeneity of head and neck cancer cell lines (OECM1, FaDu, and BM2) according to the cell surface expression levels of GRP78 and the GRP78 interactome protein, Progranulin, was investigated. The four sorted cell groups exhibited distinct cell cycle distributions, asymmetric/symmetric cell divisions, and different relative expression levels of stemness markers. Our results demonstrate that cell surface GRP78 promotes cancer stemness, whereas drives cells toward a non-stemlike phenotype when it chaperones Progranulin. We conclude that cell surface GRP78 is a chaperone exerting a deterministic influence on cancer stemness.

Flow cytometry on the stromal-vascular fraction of white adipose tissue.

PubMed

Brake, Danett K; Smith, C Wayne

2008-01-01

Adipose tissue contains cell types other than adipocytes that may contribute to complications linked to obesity. For example, macrophages have been shown to infiltrate adipose tissue in response to a high-fat diet. Isolation of the stromal-vascular fraction of adipose tissue allows one to use flow cytometry to analyze cell surface markers on leukocytes. Here, we present a technical approach to identify subsets of leukocytes that differentially express cell surface markers.

A dual marker label free electrochemical assay for Flavivirus dengue diagnosis.

PubMed

Santos, Adriano; Bueno, Paulo R; Davis, Jason J

2018-02-15

Dengue is a RNA viral illness of the genus Flavivirus which can cause, depending on the pervasiveness of the infection, hemorrhagic dengue fever or dengue shock syndrome. Herein we present an electrochemical label free approach enabling the rapid sensitive quantification of NS1 and IgG (supporting an ability to distinguish primary and secondary infections). Using a bifunctional SAM containing PEG moieties and a tethered redox thiol, both markers are detectable across clinically relevant levels by label free impedance derived redox capacitance. A subsequent frequency specific immittance function approach enables assaying (within seconds) with no impairment of analytical quality (linearity, sensitivity and variance). Copyright © 2017 Elsevier B.V. All rights reserved.

An Efficient Bifunctional Electrocatalyst for a Zinc-Air Battery Derived from Fe/N/C and Bimetallic Metal-Organic Framework Composites.

PubMed

Wang, Mengfan; Qian, Tao; Zhou, Jinqiu; Yan, Chenglin

2017-02-15

Efficient bifunctional electrocatalysts with desirable oxygen activities are closely related to practical applications of renewable energy systems including metal-air batteries, fuel cells, and water splitting. Here a composite material derived from a combination of bimetallic zeolitic imidazolate frameworks (denoted as BMZIFs) and Fe/N/C framework was reported as an efficient bifunctional catalyst. Although BMZIF or Fe/N/C alone exhibits undesirable oxygen reaction activity, a combination of these materials shows unprecedented ORR (half-wave potential of 0.85 V as well as comparatively superior OER activities (potential@10 mA cm -2 of 1.64 V), outperforming not only a commercial Pt/C electrocatalyst but also most reported bifunctional electrocatalysts. We then tested its practical application in Zn-air batteries. The primary batteries exhibit a high peak power density of 235 mW cm -2 , and the batteries are able to be operated smoothly for 100 cycles at a curent density of 10 mA cm -2 . The unprecedented catalytic activity can be attritued to chemical coupling effects between Fe/N/C and BMZIF and will aid the development of highly active electrocatalysts and applications for electrochemical energy devices.

Increasing round trip efficiency of hybrid Li-air battery with bifunctional catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, K; Li, YF; Xing, YC

2013-07-30

Previously it was shown that Pt as cathode catalyst ha's a large overpotential during charge in rechargeable hybrid Li-air battery with sulfuric acid catholyte. This article demonstrates that a bifunctional catalyst composed of Pt and IrO2 supported on carbon nanotubes can address this problem. The specially designed and synthesized bifunctional catalyst showed significant overpotential reduction and achieved a round trip energy efficiency of 81% after 10 cycles, higher than many achieved in aprotic Li-O-2 batteries. The hybrid Li-air battery was discharged and recharged for 20 cycles at 0.2 mA/cm(2), showing a fairly stable cell performance. A specific capacity of 306more » mAh/g and a specific energy of 1110 Wh/kg were obtained for the hybrid Li-air battery in terms of acid weight. (c) 2013 Elsevier Ltd. All rights reserved.« less

Rational design of micro-RNA-like bifunctional siRNAs targeting HIV and the HIV coreceptor CCR5.

PubMed

Ehsani, Ali; Saetrom, Pål; Zhang, Jane; Alluin, Jessica; Li, Haitang; Snøve, Ola; Aagaard, Lars; Rossi, John J

2010-04-01

Small-interfering RNAs (siRNAs) and micro-RNAs (miRNAs) are distinguished by their modes of action. SiRNAs serve as guides for sequence-specific cleavage of complementary mRNAs and the targets can be in coding or noncoding regions of the target transcripts. MiRNAs inhibit translation via partially complementary base-pairing to 3' untranslated regions (UTRs) and are generally ineffective when targeting coding regions of a transcript. In this study, we deliberately designed siRNAs that simultaneously direct cleavage and translational suppression of HIV RNAs, or cleavage of the mRNA encoding the HIV coreceptor CCR5 and suppression of translation of HIV. These bifunctional siRNAs trigger inhibition of HIV infection and replication in cell culture. The design principles have wide applications throughout the genome, as about 90% of genes harbor sites that make the design of bifunctional siRNAs possible.

One-Dimensional RuO2/Mn2O3 Hollow Architectures as Efficient Bifunctional Catalysts for Lithium-Oxygen Batteries.

PubMed

Yoon, Ki Ro; Lee, Gil Yong; Jung, Ji-Won; Kim, Nam-Hoon; Kim, Sang Ouk; Kim, Il-Doo

2016-03-09

Rational design and massive production of bifunctional catalysts with fast oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics are critical to the realization of highly efficient lithium-oxygen (Li-O2) batteries. Here, we first exploit two types of double-walled RuO2 and Mn2O3 composite fibers, i.e., (i) phase separated RuO2/Mn2O3 fiber-in-tube (RM-FIT) and (ii) multicomposite RuO2/Mn2O3 tube-in-tube (RM-TIT), by controlling ramping rate during electrospinning process. Both RM-FIT and RM-TIT exhibited excellent bifunctional electrocatalytic activities in alkaline media. The air electrodes using RM-FIT and RM-TIT showed enhanced overpotential characteristics and stable cyclability over 100 cycles in the Li-O2 cells, demonstrating high potential as efficient OER and ORR catalysts.

Topography and behavior of Sertoli cells in sparse culture during the transitional remodeling phase.

PubMed

Tung, P S; Choi, A H; Fritz, I B

1988-01-01

We report observations on the behavior of Sertoli cells in sparse culture during the period from the time of plating to the time of initial confluence (the transitional remodeling phase). Changes in shape, structure, and polarity of cells, as well as changes in migration patterns and cell-cell association patterns, have been followed during the transitional remodeling phase with the aid of topographical markers. These markers are based upon differences between ultrastructural features of the basolateral and apicolateral surfaces. The basolateral surface is characterized by plasmalemmal blebs, whereas the apicolateral surface is characterized by filopodial extensions. Structural differences observed in situ remain evident in Sertoli cells isolated by sequential enzymatic treatments that are described. Another marker is provided by laminin-binding sites, which are detected exclusively on the blebbed, basolateral surfaces of freshly prepared Sertoli cell aggregates. The orientation described is sustained during the initial radial migration of Sertoli cells explanted on uncoated glass coverslips. Under these conditions, blebs are detected only on the dorsal surfaces, and filopodial extensions are evident only on the ventral surfaces. In contrast, Sertoli cells sparsely plated on a reconstituted basement membrane (air-dried Matrigel) migrate rapidly, display an extraordinary capacity to form elaborate cytoplasmic extensions for cell-cell and cell-substratum contacts, and readily retract blebs and filopodial extensions. These cells do not form mosaic borders, whereas cells plated on uncoated glass do form a monolayer with mosaic-like borders. Cells sparsely seeded on gelated Matrigel migrate preferentially at gaps between adjacent cell explants, and develop a compact cell-cell association pattern. These cells display few, if any, cytoplasmic extensions. We compare the behavior of Sertoli cells sparsely plated on Matrigel with the behavior of Sertoli cells in situ during different stages of development.

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures.

PubMed

Wiklander, Oscar P B; Bostancioglu, R Beklem; Welsh, Joshua A; Zickler, Antje M; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O; Mohammad, Dara K; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z; Jones, Jennifer C; El Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell's activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Effects of a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen and ultraviolet-A radiation on murine dendritic epidermal cells.

PubMed

Aubin, F; Alcalay, J; Dall'Acqua, F; Kripke, M L

1990-06-01

Although some psoralens are therapeutically active in the treatment of cutaneous hyperproliferative diseases when combined with UVA (320-400 nm) radiation, the toxic effects of these compounds have led physicians to seek new photochemotherapeutic agents. One such agent is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional psoralen compound. We investigated the effects of repetitive treatments with TMAP plus UVA radiation on the number of dendritic immune cells in murine epidermis and on the induction of phototoxicity. Mice treated 3 times per week for 4 weeks with 129 microgram TMAP plus 10 kJ/m2 UVA radiation exhibited no gross or microscopic evidence of phototoxicity. During this treatment, the numbers of ATPase+, Ia+, and Thy-l+ dendritic epidermal cells were greatly reduced, and by the end of the treatment period, few dendritic immune cells could be detected. We conclude that morphological alterations of cutaneous immune cells can occur in the absence of overt phototoxicity, and that TMAP plus low-dose UVA radiation decreases the numbers of detectable Langerhans cells and Thy-1+ cells in murine skin.

Hybrid Antibody-Induced Topographical Redistribution of Surface Immunoglobulins, Alloantigens, and Concanavalin A Receptors on Mouse Lymphoid Cells

PubMed Central

Stackpole, Christopher W.; De Milio, Lawrence T.; Hämmerling, Ulrich; Jacobson, Janet B.; Lardis, Michael P.

1974-01-01

Redistribution of surface immunoglobulins, H-2b, Thy-1.2, and TL.1,2,3 alloantigens, and concanavalin A receptors on mouse lymphoid cells induced by hybrid rabbit F(ab′)2 antibody (anti-mouse immunoglobulin/anti-visual marker or anti-concanavalin A/anti-visual marker) was studied by immunofluorescence. When used directly to label surface immunoglobulin, and indirectly to label alloantigens and concanavalin A receptors, hybrid antibodies induced similar displacement of all surface components from a uniform distribution into “patches” and “caps” at 37°. One hybrid antibody preparation, antimouse immunoglobulin/anti-ferritin, contained negligible amounts of bivalent anti-mouse immunoglobulin antibody, and was therefore “monovalent” for the antimouse immunoglobulin specificity. This observation suggests that factors other than multivalent crosslinking are responsible for hybrid antibody-induced redistribution of cell-surface components. Cap formation induced by hybrid antibody was enhanced markedly by attachment of the visual marker, either ferritin or southern bean mosaic virus, at 37°. At -5°, hybrid antibody does not displace uniformly distributed H-2b alloantigen-alloantibody complexes, but patches of label develop when ferritin attaches to the hybrid antibody. These results explain the patchy distribution of cell-surface components, which is a temperature-independent characteristic of labeling with hybrid antibodies and visual markers for electron microscopy. Images PMID:4595577

Wilms tumor gene product: sensitive and contextually specific marker of serous carcinomas of ovarian surface epithelial origin.

PubMed

Hwang, Harry; Quenneville, Louise; Yaziji, Hadi; Gown, Allen M

2004-06-01

Carcinomas of ovarian surface epithelial origin can arise from, and often present at, extraovarian sites. There are few available markers for the positive identification of carcinomas of ovarian surface epithelial origin, which might aid in distinguishing them from metastatic carcinomas, such as of breast, colon, or lung origin. Recently, the Wilms tumor gene product (WT-1) has been shown to be expressed in ovarian surface and mesothelial epithelium. We tested the hypothesis that WT-1 would be a sensitive and specific marker of ovarian surface epithelium carcinomas. An archived series of 116 ovarian carcinomas (57 serous [43 ovarian, 14 extraovarian], 31 mucinous, 15 clear cell, 13 endometrioid), 118 breast carcinomas, 46 colonic carcinomas, and 45 nonsmall cell lung cancers were selected. A polyclonal antibody to the WT-1 gene product was applied to deparaffinized, formalin-fixed tissue sections after epitope retrieval. Fifty-two of 57 (93%) serous carcinomas of ovarian surface epithelial origin were WT-1-positive, in a nuclear pattern, with virtually all the tumor cell population positive in the majority of cases. None of the mucinous, clear cell, or endometrioid ovarian cancers were positive, and only 8 of 118 breast, 0 of 46 colonic, and 0 of 45 lung nonsmall cell carcinomas were WT-1-positive. These findings demonstrate that WT-1 is a highly sensitive and specific marker of serous carcinomas of ovarian surface epithelial origin (both ovarian and extraovarian). These results also contradict recent reports demonstrating WT-1 expression in both breast and lung carcinomas.

The cellular prion protein identifies bipotential cardiomyogenic progenitors.

PubMed

Hidaka, Kyoko; Shirai, Manabu; Lee, Jong-Kook; Wakayama, Takanari; Kodama, Itsuo; Schneider, Michael D; Morisaki, Takayuki

2010-01-08

The paucity of specific surface markers for cardiomyocytes and their progenitors has impeded the development of embryonic or pluripotent stem cell-based transplantation therapy. Identification of relevant surface markers may also enhance our understanding of the mechanisms underlying differentiation. Here, we show that cellular prion protein (PrP) serves as an effective surface marker for isolating nascent cardiomyocytes as well as cardiomyogenic progenitors. Embryonic stem (or embryo-derived) cells were analyzed using flow cytometry to detect surface expression of PrP and intracellular myosin heavy chain (Myhc) proteins. Sorted cells were then analyzed for their differentiation potential. PrP+ cells from beating embryoid bodies (EBs) frequently included nascent Myhc+ cardiomyocytes. Cultured PrP+ cells further differentiated, giving rise to cardiac troponin I+ definitive cardiomyocytes with either an atrial or a ventricular identity. These cells were electrophysiologically functional and able to survive in vivo after transplantation. Combining PrP with a second marker, platelet-derived growth factor receptor (PDGFR)alpha, enabled us to identify an earlier cardiomyogenic population from prebeating EBs, the PrP+PDGFRalpha+ (PRa) cells. The Myhc- PRa cells expressed cardiac transcription factors, such as Nkx2.5, T-box transcription factor 5, and Isl1 (islet LIM homeobox 1), although they were not completely committed. In mouse embryos, PRa cells in cardiac crescent at the 1 to 2 somite stage were Myhc+, whereas they were Myhc- at headfold stages. PRa cells clonally expanded in methlycellulose cultures. Furthermore, single Myhc- PRa cell-derived colonies contained both cardiac and smooth muscle cells. Thus, PrP demarcates a population of bipotential cardiomyogenic progenitor cells that can differentiate into cardiac or smooth muscle cells.

Bifunctional Ag@SiO 2 /Au Nanoparticles for Probing Sequential Catalytic Reactions by Surface-Enhanced Raman Spectroscopy

DOE PAGES

Wu, Yiren; Su, Dong; Qin, Dong

2017-02-22

Here, we report the synthesis of bifunctional Ag@SiO 2/Au nanoparticles with an “islands in the sea” configuration by titrating HAuCl 4 solution into an aqueous suspension of Ag@SiO 2 core–shell nanocubes in the presence of NaOH, ascorbic acid, and poly(vinyl pyrrolidone) at pH 11.9. The NaOH plays an essential role in generating small pores in the SiO 2 shell in situ, followed by the epitaxial deposition of Au from the Ag surface through the pores, leading to the formation of Au islands (6–12 nm in size) immersed in a SiO 2 sea. Furthermore, by controlling the amount of HAuCl 4more » titrated into the reaction system, the Au islands can be made to pass through and protrude from the SiO 2 shell, embracing catalytic activity toward the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. And while the Ag in the core provides a strong surface-enhanced Raman scattering activity, the SiO 2 sea helps maintain the Au component as compact, isolated, and stabilized islands. The Ag@SiO 2/Au nanoparticles can serve as a bifunctional probe to monitor the stepwise Au-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by NaBH 4 and Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4'-dimercaptoazobenzene by the O 2 from air in the same reaction system.« less

Bifunctional Ag@SiO 2 /Au Nanoparticles for Probing Sequential Catalytic Reactions by Surface-Enhanced Raman Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Yiren; Su, Dong; Qin, Dong

Here, we report the synthesis of bifunctional Ag@SiO 2/Au nanoparticles with an “islands in the sea” configuration by titrating HAuCl 4 solution into an aqueous suspension of Ag@SiO 2 core–shell nanocubes in the presence of NaOH, ascorbic acid, and poly(vinyl pyrrolidone) at pH 11.9. The NaOH plays an essential role in generating small pores in the SiO 2 shell in situ, followed by the epitaxial deposition of Au from the Ag surface through the pores, leading to the formation of Au islands (6–12 nm in size) immersed in a SiO 2 sea. Furthermore, by controlling the amount of HAuCl 4more » titrated into the reaction system, the Au islands can be made to pass through and protrude from the SiO 2 shell, embracing catalytic activity toward the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. And while the Ag in the core provides a strong surface-enhanced Raman scattering activity, the SiO 2 sea helps maintain the Au component as compact, isolated, and stabilized islands. The Ag@SiO 2/Au nanoparticles can serve as a bifunctional probe to monitor the stepwise Au-catalyzed reduction of 4-nitrothiophenol to 4-aminothiophenol by NaBH 4 and Ag-catalyzed oxidation of 4-aminothiophenol to trans-4,4'-dimercaptoazobenzene by the O 2 from air in the same reaction system.« less

Fusions between green fluorescent protein and beta-glucuronidase as sensitive and vital bifunctional reporters in plants.

PubMed

Quaedvlieg, N E; Schlaman, H R; Admiraal, P C; Wijting, S E; Stougaard, J; Spaink, H P

1998-07-01

By fusing the genes encoding green fluorescent protein (GFP) and beta-glucuronidase (GUS) we have created a set of bifunctional reporter constructs which are optimized for use in transient and stable expression studies in plants. This approach makes it possible to combine the advantage of GUS, its high sensitivity in histochemical staining, with the advantages of GFP as a vital marker. The fusion proteins were functional in transient expression studies in tobacco using either DNA bombardment or potato virus X as a vector, and in stably transformed Arabidopsis thaliana and Lotus japonicus plants. The results show that high level of expression does not interfere with efficient stable transformation in A. thaliana and L. japonicus. Using confocal laser scanning microscopy we show that the fusion constructs are very suitable for promoter expression studies in all organs of living plants, including root nodules. The use of these reporter constructs in the model legume L. japonicus offers exciting new possibilities for the study of the root nodulation process.

Fusions between green fluorescent protein and beta-glucuronidase as sensitive and vital bifunctional reporters in plants.

PubMed

Quaedvlieg, N E; Schlaman, H R; Admiraal, P C; Wijting, S E; Stougaard, J; Spaink, H P

1998-11-01

By fusing the genes encoding green fluorescent protein (GFP) and beta-glucuronidase (GUS) we have created a set of bifunctional reporter constructs which are optimized for use in transient and stable expression studies in plants. This approach makes it possible to combine the advantage of GUS, its high sensitivity in histochemical staining, with the advantages of GFP as a vital marker. The fusion proteins were functional in transient expression studies in tobacco using either DNA bombardment or potato virus X as a vector, and in stably transformed Arabidopsis thaliana and Lotus japonicus plants. The results show that high level of expression does not interfere with efficient stable transformation in A. thaliana and L. japonicus. Using confocal laser scanning microscopy we show that the fusion constructs are very suitable for promoter expression studies in all organs of living plants, including root nodules. The use of these reporter constructs in the model legume L. japonicus offers exciting new possibilities for the study of the root nodulation process.

Variation in primary and culture-expanded cells derived from connective tissue progenitors in human bone marrow space, bone trabecular surface and adipose tissue.

PubMed

Qadan, Maha A; Piuzzi, Nicolas S; Boehm, Cynthia; Bova, Wesley; Moos, Malcolm; Midura, Ronald J; Hascall, Vincent C; Malcuit, Christopher; Muschler, George F

2018-03-01

Connective tissue progenitors (CTPs) embody the heterogeneous stem and progenitor cell populations present in native tissue. CTPs are essential to the formation and remodeling of connective tissue and represent key targets for tissue-engineering and cell-based therapies. To better understand and characterize CTPs, we aimed to compare the (i) concentration and prevalence, (ii) early in vitro biological behavior and (iii) expression of surface-markers and transcription factors among cells derived from marrow space (MS), trabecular surface (TS), and adipose tissues (AT). Cancellous-bone and subcutaneous-adipose tissues were collected from 8 patients. Cells were isolated and cultured. Colony formation was assayed using Colonyze software based on ASTM standards. Cell concentration ([Cell]), CTP concentration ([CTP]) and CTP prevalence (P CTP ) were determined. Attributes of culture-expanded cells were compared based on (i) effective proliferation rate and (ii) expression of surface-markers CD73, CD90, CD105, SSEA-4, SSEA-3, SSEA-1/CD15, Cripto-1, E-Cadherin/CD324, Ep-CAM/CD326, CD146, hyaluronan and transcription factors Oct3/4, Sox-2 and Nanog using flow cytometry. Mean [Cell], [CTP] and P CTP were significantly different between MS and TS samples (P = 0.03, P = 0.008 and P= 0.0003), respectively. AT-derived cells generated the highest mean total cell yield at day 6 of culture-4-fold greater than TS and more than 40-fold greater than MS per million cells plated. TS colonies grew with higher mean density than MS colonies (290 ± 11 versus 150 ± 11 cell per mm 2 ; P = 0.0002). Expression of classical-mesenchymal stromal cell (MSC) markers was consistently recorded (>95%) from all tissue sources, whereas all the other markers were highly variable. The prevalence and biological potential of CTPs are different between patients and tissue sources and lack variation in classical MSC markers. Other markers are more likely to discriminate differences between cell populations in biological performance. Understanding the underlying reasons for variation in the concentration, prevalence, marker expression and biological potential of CTPs between patients and source tissues and determining the means of managing this variation will contribute to the rational development of cell-based clinical diagnostics and targeted cell-based therapies. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Pharmacokinetics and pharmacodynamics of CD4-anchoring bi-functional fusion inhibitor in monkeys.

PubMed

Liu, Xingrong; Ou, Ying C; Zhang, Jun; Ahene, Ago; Clark, Douglas; Hsieh, Su-Chun; Cooper, Matthew; Ji, Changhua

2014-03-01

This study was to characterize the pharmacokinetics (PK) and pharmacodynamics (PD) of a chimeric protein, CD4-anchoring bi-functional fusion inhibitor (CD4-BFFI), in monkeys and assess the feasibility for HIV-1 treatment in humans. The serum concentrations of CD4-BFFI and CD4 receptors were determined and modeled using a target-mediated drug disposition (TMDD) model following intravenous administration of 1 or 10 mg/kg in monkeys. In vitro CD4 internalization was examined in human peripheral blood mononuclear cells. Noncompartmental analysis showed a decrease in clearance (1.35 to 0.563 mL/h/kg) and an increase in half-lives (35 to 50 h) with increasing doses. Dose-dependent CD4 occupancy was observed. The TMDD model reasonably captured the PK/PD profiles and suggested greater degradation rate constant for the free CD4 than the bound CD4. In vitro assay showed CD4-BFFI did not reduce the internalization of cell surface CD4. The simulated serum concentrations of CD4-BFFI were 20-fold above its in vitro IC50 for HIV-1 at 3 mg/kg weekly or biweekly following subcutaneous administration in humans. The TMDD modeling and in vitro CD4 internalization study indicate that CD4-BFFI does not induce CD4 internalization and CD4-BFFI short half-life is likely due to normal CD4 internalization. The simulated human PK supports CD4-BFFI as a promising anti-HIV-1 agent.

Insight into the epitaxial encapsulation of Pd catalysts in an oriented metalloporphyrin network thin film for tandem catalysis.

PubMed

Vohra, M Ismail; Li, De-Jing; Gu, Zhi-Gang; Zhang, Jian

2017-06-14

A palladium catalyst (Pd-Cs) encapsulated metalloporphyrin network PIZA-1 thin film with bifunctional properties has been developed through a modified epitaxial layer-by-layer encapsulation approach. Combining the oxidation activity of Pd-Cs and the acetalization activity of the Lewis acidic sites in the PIZA-1 thin film, this bifunctional catalyst of the Pd-Cs@PIZA-1 thin film exhibits a good catalytic activity in a one-pot tandem oxidation-acetalization reaction. Furthermore, the surface components can be controlled by ending the top layer with different precursors in the thin film preparation procedures. The catalytic performances of these thin films with different surface composites were studied under the same conditions, which showed different reaction conversions. The result revealed that the surface component can influence the catalytic performance of the thin films. This epitaxial encapsulation offers a good understanding of the tandem catalysis for thin film materials and provides useful guidance to develop new thin film materials with catalytic properties.

Signal peptide cleavage is essential for surface expression of a regulatory T cell surface protein, leucine rich repeat containing 32 (LRRC32).

PubMed

Chan, Derek V; Somani, Ally-Khan; Young, Andrew B; Massari, Jessica V; Ohtola, Jennifer; Sugiyama, Hideaki; Garaczi, Edina; Babineau, Denise; Cooper, Kevin D; McCormick, Thomas S

2011-05-26

Elevated numbers of regulatory T cells (T(regs)) have been implicated in certain cancers. Depletion of T(regs) has been shown to increase anti-tumor immunity. T(regs) also play a critical role in the suppression of autoimmune responses. The study of T(regs) has been hampered by a lack of adequate surface markers. Leucine Rich Repeat Containing 32 (LRRC32), also known as Glycoprotein A Repetitions Predominant (GARP), has been postulated as a novel surface marker of activated T(regs). However, there is limited information regarding the processing of LRRC32 or the regulatory phenotype and functional activity of T(regs) expressing LRRC32. Using naturally-occurring freshly isolated T(regs), we demonstrate that low levels of LRRC32 are present intracellularly prior to activation and that freshly isolated LRRC32+ T(regs) are distinct from LRRC32- T(regs) with respect to the expression of surface CD62L. Using LRRC32 transfectants of HEK cells, we demonstrate that the N-terminus of LRRC32 is cleaved prior to expression of the protein at the cell surface. Furthermore, we demonstrate using a construct containing a deleted putative signal peptide region that the presence of a signal peptide region is critical to cell surface expression of LRRC32. Finally, mixed lymphocyte assays demonstrate that LRRC32+ T(regs) are more potent suppressors than LRRC32- T(regs). A cleaved signal peptide site in LRRC32 is necessary for surface localization of native LRRC32 following activation of naturally-occurring freshly-isolated regulatory T cells. LRRC32 expression appears to alter the surface expression of activation markers of T cells such as CD62L. LRRC32 surface expression may be useful as a marker that selects for more potent T(reg) populations. In summary, understanding the processing and expression of LRRC32 may provide insight into the mechanism of action of T(regs) and the refinement of immunotherapeutic strategies aimed at targeting these cells.

Proteomic Definitions of Mesenchymal Stem Cells

PubMed Central

Maurer, Martin H.

2011-01-01

Mesenchymal stem cells (MSCs) are pluripotent cells isolated from the bone marrow and various other organs. They are able to proliferate and self-renew, as well as to give rise to progeny of at least the osteogenic, chondrogenic, and adipogenic lineages. Despite this functional definition, MSCs can also be defined by their expression of a distinct set of cell surface markers. In the current paper, studies investigating the proteome of human MSCs are reviewed with the aim to identify common protein markers of MSCs. The proteomic analysis of MSCs revealed a distinct set of proteins representing the basic molecular inventory, including proteins for (i) cell surface markers, (ii) the responsiveness to growth factors, (iii) the reuse of developmental signaling cascades in adult stem cells, (iv) the interaction with molecules of the extracellular matrix, (v) the expression of genes regulating transcription and translation, (vi) the control of the cell number, and (vii) the protection against cellular stress. PMID:21437194

Isolation of mouse pancreatic alpha, beta, duct and acinar populations with cell surface markers.

PubMed

Dorrell, Craig; Grompe, Maria T; Pan, Fong Cheng; Zhong, Yongping; Canaday, Pamela S; Shultz, Leonard D; Greiner, Dale L; Wright, Chris V; Streeter, Philip R; Grompe, Markus

2011-06-06

Tools permitting the isolation of live pancreatic cell subsets for culture and/or molecular analysis are limited. To address this, we developed a collection of monoclonal antibodies with selective surface labeling of endocrine and exocrine pancreatic cell types. Cell type labeling specificity and cell surface reactivity were validated on mouse pancreatic sections and by gene expression analysis of cells isolated using FACS. Five antibodies which marked populations of particular interest were used to isolate and study viable populations of purified pancreatic ducts, acinar cells, and subsets of acinar cells from whole pancreatic tissue or of alpha or beta cells from isolated mouse islets. Gene expression analysis showed the presence of known endocrine markers in alpha and beta cell populations and revealed that TTR and DPPIV are primarily expressed in alpha cells whereas DGKB and GPM6A have a beta cell specific expression profile. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures

PubMed Central

Wiklander, Oscar P. B.; Bostancioglu, R. Beklem; Welsh, Joshua A.; Zickler, Antje M.; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W.; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O.; Mohammad, Dara K.; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z.; Jones, Jennifer C.; EL Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell’s activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Immunomodulatory properties of carbon nanotubes are able to compensate immune function dysregulation caused by microgravity conditions

NASA Astrophysics Data System (ADS)

Crescio, Claudia; Orecchioni, Marco; Ménard-Moyon, Cécilia; Sgarrella, Francesco; Pippia, Proto; Manetti, Roberto; Bianco, Alberto; Delogu, Lucia Gemma

2014-07-01

Spaceflights lead to dysregulation of the immune cell functionality affecting the expression of activation markers and cytokine production. Short oxidized multi-walled carbon nanotubes functionalized by 1,3-dipolar cycloaddition have been reported to activate immune cells. In this Communication we have performed surface marker assays and multiplex ELISA on primary monocytes and T cells under microgravity. We have discovered that carbon nanotubes, through their immunostimulatory properties, are able to fight spaceflight immune system dysregulations.Spaceflights lead to dysregulation of the immune cell functionality affecting the expression of activation markers and cytokine production. Short oxidized multi-walled carbon nanotubes functionalized by 1,3-dipolar cycloaddition have been reported to activate immune cells. In this Communication we have performed surface marker assays and multiplex ELISA on primary monocytes and T cells under microgravity. We have discovered that carbon nanotubes, through their immunostimulatory properties, are able to fight spaceflight immune system dysregulations. Electronic supplementary information (ESI) available: Experimental section, structures of f-MWCNTs and uptake by human primary immune cells. See DOI: 10.1039/c4nr02711f

Purification and differentiation of human adipose-derived stem cells by membrane filtration and membrane migration methods

PubMed Central

Lin, Hong Reng; Heish, Chao-Wen; Liu, Cheng-Hui; Muduli, Saradaprasan; Li, Hsing-Fen; Higuchi, Akon; Kumar, S. Suresh; Alarfaj, Abdullah A.; Munusamy, Murugan A.; Hsu, Shih-Tien; Chen, Da-Chung; Benelli, Giovanni; Murugan, Kadarkarai; Cheng, Nai-Chen; Wang, Han-Chow; Wu, Gwo-Jang

2017-01-01

Human adipose-derived stem cells (hADSCs) are easily isolated from fat tissue without ethical concerns, but differ in purity, pluripotency, differentiation ability, and stem cell marker expression, depending on the isolation method. We isolated hADSCs from a primary fat tissue solution using: (1) conventional culture, (2) a membrane filtration method, (3) a membrane migration method where the primary cell solution was permeated through membranes, adhered hADSCs were cultured, and hADSCs migrated out from the membranes. Expression of mesenchymal stem cell markers and pluripotency genes, and osteogenic differentiation were compared for hADSCs isolated by different methods using nylon mesh filter membranes with pore sizes ranging from 11 to 80 μm. hADSCs isolated by the membrane migration method had the highest MSC surface marker expression and efficient differentiation into osteoblasts. Osteogenic differentiation ability of hADSCs and MSC surface marker expression were correlated, but osteogenic differentiation ability and pluripotent gene expression were not. PMID:28071738

Carbon supported MnO2-CoFe2O4 with enhanced electrocatalytic activity for oxygen reduction and oxygen evolution

NASA Astrophysics Data System (ADS)

Wang, Ying; Liu, Qing; Hu, Tianjun; Zhang, Limin; Deng, Youquan

2017-05-01

The catalyst MnO2-CoFe2O4/C was firstly synthesized via a two-step process and applied as a bifunctional electrocatalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media. The composite exhibits better bifunctional activity than CoFe2O4/C and MnO2/C. Moreover, superior durability and high methanol tolerance in alkaline media outperforms the commercial Pt/C electrocatalyst, which signifying its excellent potential for applications in metal-air batteries and alkaline fuel cells.

Transient partial permeabilization with saponin enables cellular barcoding prior to surface marker staining1

PubMed Central

Behbehani, Gregory K.; Thom, Colin; Zunder, Eli R.; Finck, Rachel; Gaudilliere, Brice; Fragiadakis, Gabriela K.; Fantl, Wendy J.; Nolan, Garry P.

2015-01-01

Fluorescent cellular barcoding and mass-tag cellular barcoding are cytometric methods that enable high sample throughput, minimize inter-sample variation, and reduce reagent consumption. Previously employed barcoding protocols require that barcoding be performed after surface marker staining, complicating combining the technique with measurement of alcohol-sensitive surface epitopes. This report describes a method of barcoding fixed cells after a transient partial permeabilization with 0.02% saponin that results in efficient and consistent barcode staining with fluorescent or mass-tagged reagents while preserving surface marker staining. This approach simplifies barcoding protocols and allows direct comparison of surface marker staining of multiple samples without concern for variations in the antibody cocktail volume, antigen-antibody ratio, or machine sensitivity. Using this protocol, cellular barcoding can be used to reliably detect subtle differences in surface marker expression. PMID:25274027

Covalent immobilisation of antibodies in Teflon-FEP microfluidic devices for the sensitive quantification of clinically relevant protein biomarkers.

PubMed

Pivetal, Jeremy; Pereira, Filipa M; Barbosa, Ana I; Castanheira, Ana P; Reis, Nuno M; Edwards, Alexander D

2017-03-13

This study reports for the first time the sensitive colorimetric and fluorescence detection of clinically relevant protein biomarkers by sandwich immunoassays using the covalent immobilisation of antibodies onto the fluoropolymer surface inside Teflon®-FEP microfluidic devices. Teflon®-FEP has outstanding optical transparency ideal for high-sensitivity colorimetric and fluorescence bioassays, however this thermoplastic is regarded as chemically inert and very hydrophobic. Covalent immobilisation can offer benefits over passive adsorption to plastic surfaces by allowing better control over antibody density, orientation and analyte binding capacity, and so we tested a range of different and novel covalent immobilisation strategies. We first functionalised the inner surface of a 10-bore, 200 μm internal diameter FEP microcapillary film with high-molecular weight polyvinyl alcohol (PVOH) without changing the outstanding optical transparency of the device delivered by the matched refractive index of FEP and water. Glutaraldehyde immobilisation was compared with the use of photoactivated linkers and NHS-ester crosslinkers for covalently immobilising capture antibodies onto PVOH. Three clinically relevant sandwich ELISAs were tested against the cytokine IL-1β, the myocardial infarct marker cardiac troponin I (cTnI), and the chronic heart failure marker brain natriuretic peptide (BNP). Overall, glutaraldehyde immobilisation was effective for BNP assays, but yielded unacceptable background for IL-1β and cTnI assays caused by direct binding of the biotinylated detection antibody to the modified PVOH surface. We found NHS-ester groups reacted with APTES-treated PVOH coated fluoropolymers. This facilitated a novel method for capture antibody immobilisation onto fluoropolymer devices using a bifunctional NHS-maleimide crosslinker. The density of covalently immobilised capture antibodies achieved using PVOH/APTES/NHS/maleimide approached levels seen with passive adsorption, and sensitive and quantitative assay performance was achieved using this method. Overall, the PVOH coating provided an excellent surface for controlled covalent antibody immobilisation onto Teflon®-FEP for performing high-sensitivity immunoassays.

CD24-Positive Cells from Normal Adult Mouse Liver Are Hepatocyte Progenitor Cells

PubMed Central

Qiu, Qiong; Hernandez, Julio Cesar; Dean, Adam M.; Rao, Pulivarthi H.

2011-01-01

The identification of specific cell surface markers that can be used to isolate liver progenitor cells will greatly facilitate experimentation to determine the role of these cells in liver regeneration and their potential for therapeutic transplantation. Previously, the cell surface marker, CD24, was observed to be expressed on undifferentiated bipotential mouse embryonic liver stem cells and 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced oval cells. Here, we describe the isolation and characterization of a rare, primary, nonhematopoietic, CD24+ progenitor cell population from normal, untreated mouse liver. By immunohistochemistry, CD24-expressing cells in normal adult mouse liver were colocalized with CK19-positive cholangiocytes. This nonhematopoietic (CD45−, Ter119−) CD24+ cell population isolated by flow cytometry represented 0.04% of liver cells and expressed several markers of liver progenitor/oval cells. The immunophenotype of nonhematopoietic CD24+ cells was CD133, Dlk, and Sca-1 high, but c-Kit, Thy-1, and CD34 low. The CD24+ cells had increased expression of CK19, epithelial cell adhesion molecule, Sox 9, and FN14 compared with the unsorted cells. Upon transplantation of nonhematopoietic CD24+ cells under the sub-capsule of the livers of Fah knockout mice, cells differentiated into mature functional hepatocytes. Analysis of X and Y chromosome complements were used to determine whether or not fusion of the engrafted cells with the recipient hepatocytes occurred. No cells were found that contained XXXY or any other combination of donor and host sex chromosomes as would be expected if cell fusion had occurred. These results suggested that CD24 can be used as a cell surface marker for isolation of hepatocyte progenitor cells from normal adult liver that are able to differentiate into hepatocytes. PMID:21361791

CD24-positive cells from normal adult mouse liver are hepatocyte progenitor cells.

PubMed

Qiu, Qiong; Hernandez, Julio Cesar; Dean, Adam M; Rao, Pulivarthi H; Darlington, Gretchen J

2011-12-01

The identification of specific cell surface markers that can be used to isolate liver progenitor cells will greatly facilitate experimentation to determine the role of these cells in liver regeneration and their potential for therapeutic transplantation. Previously, the cell surface marker, CD24, was observed to be expressed on undifferentiated bipotential mouse embryonic liver stem cells and 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced oval cells. Here, we describe the isolation and characterization of a rare, primary, nonhematopoietic, CD24+ progenitor cell population from normal, untreated mouse liver. By immunohistochemistry, CD24-expressing cells in normal adult mouse liver were colocalized with CK19-positive cholangiocytes. This nonhematopoietic (CD45-, Ter119-) CD24+ cell population isolated by flow cytometry represented 0.04% of liver cells and expressed several markers of liver progenitor/oval cells. The immunophenotype of nonhematopoietic CD24+ cells was CD133, Dlk, and Sca-1 high, but c-Kit, Thy-1, and CD34 low. The CD24+ cells had increased expression of CK19, epithelial cell adhesion molecule, Sox 9, and FN14 compared with the unsorted cells. Upon transplantation of nonhematopoietic CD24+ cells under the sub-capsule of the livers of Fah knockout mice, cells differentiated into mature functional hepatocytes. Analysis of X and Y chromosome complements were used to determine whether or not fusion of the engrafted cells with the recipient hepatocytes occurred. No cells were found that contained XXXY or any other combination of donor and host sex chromosomes as would be expected if cell fusion had occurred. These results suggested that CD24 can be used as a cell surface marker for isolation of hepatocyte progenitor cells from normal adult liver that are able to differentiate into hepatocytes.

DNA "nano-claw": logic-based autonomous cancer targeting and therapy.

PubMed

You, Mingxu; Peng, Lu; Shao, Na; Zhang, Liqin; Qiu, Liping; Cui, Cheng; Tan, Weihong

2014-01-29

Cell types, both healthy and diseased, can be classified by inventories of their cell-surface markers. Programmable analysis of multiple markers would enable clinicians to develop a comprehensive disease profile, leading to more accurate diagnosis and intervention. As a first step to accomplish this, we have designed a DNA-based device, called "Nano-Claw". Combining the special structure-switching properties of DNA aptamers with toehold-mediated strand displacement reactions, this claw is capable of performing autonomous logic-based analysis of multiple cancer cell-surface markers and, in response, producing a diagnostic signal and/or targeted photodynamic therapy. We anticipate that this design can be widely applied in facilitating basic biomedical research, accurate disease diagnosis, and effective therapy.

Rapid and sensitive phenotypic marker detection on breast cancer cells using surface-enhanced Raman scattering (SERS) imaging.

PubMed

Lee, Sangyeop; Chon, Hyangah; Lee, Jiyoung; Ko, Juhui; Chung, Bong Hyun; Lim, Dong Woo; Choo, Jaebum

2014-01-15

We report a surface-enhanced Raman scattering (SERS)-based cellular imaging technique to detect and quantify breast cancer phenotypic markers expressed on cell surfaces. This technique involves the synthesis of SERS nano tags consisting of silica-encapsulated hollow gold nanospheres (SEHGNs) conjugated with specific antibodies. Hollow gold nanospheres (HGNs) enhance SERS signal intensity of individual particles by localizing surface electromagnetic fields through pinholes in the hollow particle structures. This capacity to enhance imaging at the level of single molecules permits the use of HGNs to detect specific biological markers expressed in living cancer cells. In addition, silica encapsulation greatly enhances the stability of nanoparticles. Here we applied a SERS-based imaging technique using SEHGNs in the multiplex imaging of three breast cancer cell phenotypes. Expression of epidermal growth factor (EGF), ErbB2, and insulin-like growth factor-1 (IGF-1) receptors were assessed in the MDA-MB-468, KPL4 and SK-BR-3 human breast cancer cell lines. SERS imaging technology described here can be used to test the phenotype of a cancer cell and quantify proteins expressed on the cell surface simultaneously. Based on results, this technique may enable an earlier diagnosis of breast cancer than is currently possible and offer guidance in treatment. © 2013 Elsevier B.V. All rights reserved.

Preparation of highly hydrophobic cotton fabrics by modification with bifunctional silsesquioxanes in the sol-gel process

NASA Astrophysics Data System (ADS)

Przybylak, Marcin; Maciejewski, Hieronim; Dutkiewicz, Agnieszka

2016-11-01

The surface modification of cotton fabrics was carried out using two types of bifunctional fluorinated silsesquioxanes with different ratios of functional groups. The modification was performed either by one- or two-step process. Two methods, the sol-gel and the dip coating method were used in different configurations. The heat treatment and the washing process were applied after modification. The wettability of cotton fabric was evaluated by measuring water contact angles (WCA). Changes in the surface morphology were examined by scanning electron microscopy (SEM, SEM-LFD) and atomic force microscopy (AFM). Moreover, the modified fabrics were subjected to analysis of elemental composition of the applied coatings using SEM-EDS techniques. Highly hydrophobic textiles were obtained in all cases studied and one of the modifications resulted in imparting superhydrophobic properties. Most of impregnated textiles remained hydrophobic even after multiple washing process which shows that the studied modification is durable.

Synthesis of Bifunctional Fe3O4@SiO2-Ag Magnetic-Plasmonic Nanoparticles by an Ultrasound Assisted Chemical Method

NASA Astrophysics Data System (ADS)

Chu, Dung Tien; Sai, Doanh Cong; Luu, Quynh Manh; Tran, Hong Thi; Quach, Truong Duy; Kim, Dong Hyun; Nguyen, Nam Hoang

2017-06-01

Bifunctional magnetic-plasmonic nanoparticles (NPs)—Fe3O4@SiO2-Ag were successfully synthesized by an ultrasound assisted chemical method. Silver ions were absorbed and then reduced by sodium borohydride on the surface of 3-aminopropyltriethoxysilane (APTES) functionalized silica-coated magnetic NPs, then they were reduced under the influence of a 200 W ultrasonic wave for 60 min. When the amount of precursor silver ions increased, the relative intensity of diffraction peaks of silver crystals in all samples increased with the atomic ratio of silver/iron increasing from 0.208 to 0.455 and saturation magnetization ( M s) decreasing from 44.68 emu/g to 34.74 emu/g. The NPs have superparamagnetic properties and strong surface plasmon absorption at 420 nm, which make these particles promising for biomedical applications.

Further insights into the characterization of equine adipose tissue-derived mesenchymal stem cells.

PubMed

Raabe, Oksana; Shell, Katja; Würtz, Antonia; Reich, Christine Maria; Wenisch, Sabine; Arnhold, Stefan

2011-08-01

Adipose tissue-derived stem cells (ADSCs) represent a promising subpopulation of adult stem cells for tissue engineering applications in veterinary medicine. In this study we focused on the morphological and molecular biological properties of the ADSCs. The expression of stem cell markers Oct4, Nanog and the surface markers CD90 and CD105 were detected using RT-PCR. ADSCs showed a proliferative potential and were capable of adipogenic and osteogenic differentiation. Expression of Alkaline phosphatase (AP), phosphoprotein (SPP1), Runx2 and osteocalcin (OC) mRNA were positive in osteogenic lineages and peroxisome proliferator activated receptor (Pparγ2) mRNA was positive in adipogenic lineages. ADSCs show stem cell and surface marker profiles and differentiation characteristics that are similar to but distinct from other adult stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs). The availability of an easily accessible and reproducible cell source may greatly facilitate the development of stem cell based tissue engineering and therapies for regenerative equine medicine.

Biomarkers for evaluation of mast cell and basophil activation.

PubMed

Kabashima, Kenji; Nakashima, Chisa; Nonomura, Yumi; Otsuka, Atsushi; Cardamone, Chiara; Parente, Roberta; De Feo, Giulia; Triggiani, Massimo

2018-03-01

Mast cells and basophils play a pathogenetic role in allergic, inflammatory, and autoimmune disorders. These cells have different development, anatomical location and life span but share many similarities in mechanisms of activation and type of mediators. Mediators secreted by mast cells and basophils correlate with clinical severity in asthma, chronic urticaria, anaphylaxis, and other diseases. Therefore, effective biomarkers to measure mast cell and basophil activation in vivo could potentially have high diagnostic and prognostic values. An ideal biomarker should be specific for mast cells or basophils, easily and reproducibly detectable in blood or biological fluids and should be metabolically stable. Markers of mast cell and basophil include molecules secreted by stimulated cells and surface molecules expressed upon activation. Some markers, such as histamine and lipid mediators are common to mast cells and basophils whereas others, such as tryptase and other proteases, are relatively specific for mast cells. The best surface markers of activation expressed on mast cells and basophils are CD63 and CD203. While these mediators and surface molecules have been associated to a variety of diseases, none of them fulfills requirements for an optimal biomarker and search for better indicators of mast cell/basophil activation in vivo is ongoing. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Blue two-photon fluorescence metal cluster probe precisely marking cell nuclei of two cell lines.

PubMed

Wang, Yaling; Cui, Yanyan; Liu, Ru; Wei, Yueteng; Jiang, Xinglu; Zhu, Huarui; Gao, Liang; Zhao, Yuliang; Chai, Zhifang; Gao, Xueyun

2013-11-25

A bifunctional peptide was designed to in situ reduce Cu ions and anchor a Cu cluster. The peptide-Cu cluster probe, mainly composed of Cu14, emitted blue two-photon fluorescence under femtosecond laser excitation. Most important, the probe can specifically mark the nuclei of HeLa and A549 cells, respectively.

Polarization-dependent bi-functional metasurface for directive radiation and diffusion-like scattering

NASA Astrophysics Data System (ADS)

Cui, Li; Wang, Wenjun; Ding, Guowen; Chen, Ke; Zhao, Junming; Jiang, Tian; Zhu, Bo; Feng, Yijun

2017-11-01

In this paper, we design a bi-functional metasurface with different spatial distribution of reflection phase responses depending on the incident polarization. The metasurface with a thickness of only 0.067 λ0 (λ0 is the working wavelength) is constructed by unit cells composing two orthogonal I-shaped metallic structures, and the reflection phase for x- and y-linearly polarized incidence can be independently controlled by the geometric parameters. The metasurface can work as a flat parabolic reflector antenna with a maximum gain reaching about 22 dBi around 9.5 GHz, when it is illuminated by the x-polarized feed source of an offset open-ended waveguide antenna. Meanwhile, designed with randomly distributed reflection phases, the proposed metasurface can behave as an electromagnetic (EM) diffusion-like surface, which is capable of suppressing the backward scattering in a broadband from 8.5 GHz to 14 GHz for y-polarized incidence. By this strategy of EM functionality integration, a metasurface reflector antenna equipped with stealth technique to achieve simultaneously high gain and low backward scattering is obtained. Finally, experiments have been carried out to demonstrate this design principle, which agree with the simulation results. The proposed metasurface could offer a promising route for designing EM devices with polarization-dependent multi-functionalities.

Silicon cantilever functionalization for cellulose-specific chemical force imaging of switchgrass

DOE PAGES

Lee, Ida; Evans, Barbara R.; Foston, Marcus B.; ...

2015-05-08

A method for direct functionalization of silicon and silicon nitride cantilevers with bifunctional silanes was tested with model surfaces to determine adhesive forces for different hydrogen-bonding chemistries. Application for biomass surface characterization was tested by mapping switchgrass and isolated switchgrass cellulose in topographic and force-volume mode using a cellulose-specific cantilever.

Final Technical Report: Metal—Organic Surface Catalyst for Low-temperature Methane Oxidation: Bi-functional Union of Metal—Organic Complex and Chemically Complementary Surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tait, Steven L.

Stabilization and chemical control of transition metal centers is a critical problem in the advancement of heterogeneous catalysts to next-generation catalysts that exhibit high levels of selectivity, while maintaining strong activity and facile catalyst recycling. Supported metal nanoparticle catalysts typically suffer from having a wide range of metal sites with different coordination numbers and varying chemistry. This project is exploring new possibilities in catalysis by combining features of homogeneous catalysts with those of heterogeneous catalysts to develop new, bi-functional systems. The systems are more complex than traditional heterogeneous catalysts in that they utilize sequential active sites to accomplish the desiredmore » overall reaction. The interaction of metal—organic catalysts with surface supports and their interactions with reactants to enable the catalysis of critical reactions at lower temperatures are at the focus of this study. Our work targets key fundamental chemistry problems. How do the metal—organic complexes interact with the surface? Can those metal center sites be tuned for selectivity and activity as they are in the homogeneous system by ligand design? What steps are necessary to enable a cooperative chemistry to occur and open opportunities for bi-functional catalyst systems? Study of these systems will develop the concept of bringing together the advantages of heterogeneous catalysis with those of homogeneous catalysis, and take this a step further by pursuing the objective of a bi-functional system. The use of metal-organic complexes in surface catalysts is therefore of interest to create well-defined and highly regular single-site centers. While these are not likely to be stable in the high temperature environments (> 300 °C) typical of industrial heterogeneous catalysts, they could be applied in moderate temperature reactions (100-300 °C), made feasible by lowering reaction temperatures by better catalyst control. They also serve as easily tuned model systems for exploring the chemistry of single-site transition metals and tandem catalysts that could then be developed into a zeolite or other stable support structures. In this final technical report, three major advances our described that further these goals. The first is a study demonstrating the ability to tune the oxidation state of V single-site centers on a surface by design of the surrounding ligand field. The synthesis of the single-site centers was developed in a previous reporting period of this project and this new advance shows a distinct new ability of the systems to have a designed oxidation state of the metal center. Second, we demonstrate metal complexation at surfaces using vibrational spectroscopy and also show a metal replacement reaction on Ag surfaces. Third, we demonstrate a surface-catalyzed dehydrocyclization reaction important for metal-organic catalyst design at surfaces.« less

The Role of the Omental Microenvironment in Ovarian Cancer Metastatic Colonization

DTIC Science & Technology

2010-08-01

Cancer cells which have adhered to the surface of the omentum stain positively for this proliferative marker , confirming their viability under our ex...6 mice (Figure 1). Due to technical difficulties, we had to change some of the proposed immune cell markers for the FACS analysis. We are currently...for F4/80 (macrophage cell marker ) was even more dramatic. Representative data from the macrophage localization in milky spots after i.p injection of

Isolation and characterization of mouse innate lymphoid cells.

PubMed

Halim, Timotheus Y F; Takei, Fumio

2014-08-01

Innate lymphoid cells (ILCs) are rare populations of cytokine-producing lymphocytes and are divided into three groups, namely ILC1, ILC2, and ILC3, based on the cytokines that they produce. They comprise less than 1% of lymphocytes in mucosal tissues and express no unique cell surface markers. Therefore, they can only be identified by combinations of multiple cell surface markers and further characterized by cytokine production in vitro. Thus, multicolor flow cytometry is the only reliable method to purify and characterize ILCs. Here we describe the methods for cell preparation, flow cytometric analysis, and purification of murine ILC2 and ILC3. Copyright © 2014 John Wiley & Sons, Inc.

A novel bifunctional Ni-doped TiO2 inverse opal with enhanced SERS performance and excellent photocatalytic activity

NASA Astrophysics Data System (ADS)

Li, Xuehong; Wu, Yun; Shen, Yuhua; Sun, Yan; Yang, Ying; Xie, Anjian

2018-01-01

Three-dimensional inverse opal photonic microarray (IOPM) structure exhibits good qualities in structural regularity and interconnectivity, such as high specific surface area, large pore volume, uniform pore size, and ordered periodic construction. Here, a novel nickel-doped titanium dioxide IOPM (Ni-TiO2 IOPM) was fabricated for the first time as a bifunctional material for the applications of surface-enhanced Raman scattering (SERS) substrate and photocatalyst. The Ni doping could change the defect concentration of the substrate to enhance the SERS effect, and could increase the light absorption of the substrate in visible region. The synergistic effect of Ni doping and the periodically ordered porous structure enhanced both SERS sensitivity and photocatalytic activity. As a SERS substrate, the Ni-TiO2 IOPM exhibited highly sensitive detection capability for 4-mercaptobenzoic acid (4-MBA) at a concentration as low as 1 × 10-11 M. Under simulated sunlight, about 95% of the methylene blue (MB) was degraded within 90 min when Ni-TiO2 IOPM was used as the photocatalytst. The Ni-TiO2 IOPM prepared in this work may be a promising bifunctional SERS substrate candidate for organic sewage detection and environment protection. In addition, the fabrication strategy can be extended to synthesize other nanomaterials with orderly and porous structure.

DSG2 Is a Functional Cell Surface Marker for Identification and Isolation of Human Pluripotent Stem Cells.

PubMed

Park, Jongjin; Son, Yeonsung; Lee, Na Geum; Lee, Kyungmin; Lee, Dong Gwang; Song, Jinhoi; Lee, Jaemin; Kim, Seokho; Cho, Min Ji; Jang, Ju-Hong; Lee, Jangwook; Park, Jong-Gil; Kim, Yeon-Gu; Kim, Jang-Seong; Lee, Jungwoon; Cho, Yee Sook; Park, Young-Jun; Han, Baek Soo; Bae, Kwang-Hee; Han, Seungmin; Kang, Byunghoon; Haam, Seungjoo; Lee, Sang-Hyun; Lee, Sang Chul; Min, Jeong-Ki

2018-06-08

Pluripotent stem cells (PSCs) represent the most promising clinical source for regenerative medicine. However, given the cellular heterogeneity within cultivation and safety concerns, the development of specific and efficient tools to isolate a pure population and eliminate all residual undifferentiated PSCs from differentiated derivatives is a prerequisite for clinical applications. In this study, we raised a monoclonal antibody and identified its target antigen as desmoglein-2 (DSG2). DSG2 co-localized with human PSC (hPSC)-specific cell surface markers, and its expression was rapidly downregulated upon differentiation. The depletion of DSG2 markedly decreased hPSC proliferation and pluripotency marker expression. In addition, DSG2-negative population in hPSCs exhibited a notable suppression in embryonic body and teratoma formation. The actions of DSG2 in regulating the self-renewal and pluripotency of hPSCs were predominantly exerted through the regulation of β-catenin/Slug-mediated epithelial-to-mesenchymal transition. Our results demonstrate that DSG2 is a valuable PSC surface marker that is essential for the maintenance of PSC self-renewal. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Bioinspired Catecholic Primers for Rigid and Ductile Dental Resin Composites.

PubMed

Shin, Eeseul; Ju, Sung Won; An, Larry; Ahn, Eungjin; Ahn, Jin-Soo; Kim, Byeong-Su; Ahn, B Kollbe

2018-01-17

In the construction of dental restorative polymer composite materials, surface priming on mineral fillers is essential to improve the mechanical performance of the composites. Here we present bioinspired catechol-functionalized primers for a tougher dental resin composite containing glass fillers. The catecholic primers with different polymerizable end groups were designed and then coated on glass surfaces using a simple drop-casting or dip-coating process. The surface binding ability and possible cross-linking (coupling or chemical bridging between the glass substrate and the dental resin) of the catecholic bifunctional primers were evaluated using atomic force microscopy, contact angle measurements, and the knife shear bonding test and compared to a state-of-the-art silane-based coupling agent. Various mechanical tests including shrinkage and compression tests of the dental resin composites were also conducted. Compression tests of the composites containing the catecholic primed fillers exhibited enhanced mechanical properties, owing to the bidentate hydrogen bonding of catechol moieties to the oxide mineral surface. Furthermore, the superior biocompatibility of the primed surface was confirmed via cell attachment assay, thus providing applicability of catecholic primers for practical dental and biomedical applications.

Degradable polyethylenimine derivate coupled to a bifunctional peptide R13 as a new gene-delivery vector

PubMed Central

Liu, Kehai; Wang, Xiaoyu; Fan, Wei; Zhu, Qing; Yang, Jingya; Gao, Jing; Gao, Shen

2012-01-01

Background To solve the efficiency versus cytotoxicity and tumor-targeting problems of polyethylenimine (PEI) used as a nonviral gene delivery vector, a degradable PEI derivate coupled to a bifunctional peptide R13 was developed. Methods First, we synthesized a degradable PEI derivate by crosslinking low-molecular-weight PEI with pluronic P123, then used tumor-targeting peptide arginine-glycine-aspartate-cysteine (RGDC), in conjunction with the cell-penetrating peptide Tat (49–57), to yield a bifunctional peptide RGDC-Tat (49–57) named R13, which can improve cell selection and increase cellular uptake, and, lastly, adopted R13 to modify the PEI derivates so as to prepare a new polymeric gene vector (P123-PEI-R13). The new gene vector was characterized in terms of its chemical structure and biophysical parameters. We also investigated the specificity, cytotoxicity, and gene transfection efficiency of this vector in αvβ3-positive human cervical carcinoma Hela cells and murine melanoma B16 cells in vitro. Results The vector showed controlled degradation, strong targeting specificity to αvβ3 receptor, and noncytotoxicity in Hela cells and B16 cells at higher doses, in contrast to PEI 25 KDa. The particle size of P123-PEI-R13/DNA complexes was around 100–250 nm, with proper zeta potential. The nanoparticles can protect plasmid DNA from being digested by DNase I at a concentration of 6 U DNase I/μg DNA. The nanoparticles were resistant to dissociation induced by 50% fetal bovine serum and 600 μg/mL sodium heparin. P123-PEI-R13 also revealed higher transfection efficiency in two cell lines as compared with PEI 25 KDa. Conclusion P123-PEI-R13 is a potential candidate as a safe and efficient gene-delivery carrier for gene therapy. PMID:22412301

Evaluation of Accessory Lacrimal Gland in Muller's Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease.

PubMed

Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H; Jassim Jaboori, Assraa; Setabutr, Pete; Aakalu, Vinay K

2017-04-01

The accessory lacrimal glands (ALGs) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential, and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. ALG tissues obtained from Muller's muscle conjunctival resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2, and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Thus, we report for the first time that human ALG tissues contain precursor marker-positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES, and isolate candidate precursor cells from ALG tissue.

Profiling of normal and malignant breast tissue show CD44high/CD24low phenotype as a predominant stem/progenitor marker when used in combination with Ep-CAM/CD49f markers

PubMed Central

2013-01-01

Background Accumulating evidence supports cancer to initiate and develop from a small population of stem-like cells termed as cancer stem cells (CSC). The exact phenotype of CSC and their counterparts in normal mammary gland is not well characterized. In this study our aim was to evaluate the phenotype and function of stem/progenitor cells in normal mammary epithelial cell populations and their malignant counterparts. Methods Freshly isolated cells from both normal and malignant human breasts were sorted using 13 widely used stem/progenitor cell markers individually or in combination by multi-parametric (up to 9 colors) cell sorting. The sorted populations were functionally evaluated by their ability to form colonies and mammospheres, in vitro. Results We have compared, for the first time, the stem/progenitor markers of normal and malignant breasts side-by-side. Amongst all markers tested, we found CD44high/CD24low cell surface marker combination to be the most efficient at selecting normal epithelial progenitors. Further fractionation of CD44high/CD24low positive cells showed that this phenotype selects for luminal progenitors within Ep-CAMhigh/CD49f + cells, and enriches for basal progenitors within Ep-CAM-/low/CD49f + cells. On the other hand, primary breast cancer samples, which were mainly luminal Ep-CAMhigh, had CD44high/CD24low cells among both CD49fneg and CD49f + cancer cell fractions. However, functionally, CSC were predominantly CD49f + proposing the use of CD44high/CD24low in combination with Ep-CAM/CD49f cell surface markers to further enrich for CSC. Conclusion Our study clearly demonstrates that both normal and malignant breast cells with the CD44high/CD24low phenotype have the highest stem/progenitor cell ability when used in combination with Ep-CAM/CD49f reference markers. We believe that this extensive characterization study will help in understanding breast cancer carcinogenesis, heterogeneity and drug resistance. PMID:23768049

A study of Na(x)Pt3O4 as an O2 electrode bifunctional electrocatalyst

NASA Technical Reports Server (NTRS)

Fielder, William L.; Singer, Joseph

1991-01-01

The present study suggests that polytetrafluoroethylene (PTFE) bonded Na(X)Pt3O4 gas porous diffusion electrodes may be a viable candidate for bifunctional O2 reduction and evolution activity. The electrodes exhibited Tafel slopes of about 0.06 V/decade for both O2 reduction an evolution. For O2 reduction, the 0.06 slope doubled to 0.12 V/decade at larger current densities. Preliminary stability testing at 24 C suggest that the Na(x)Pt3O4 electrodes were relatively stable at reducing and oxidizing potentials typically encountered at the O2 electrodes in a regenerative fuel cell.

Characterization of novel biomarkers in selecting for subtype specific medulloblastoma phenotypes.

PubMed

Liang, Lisa; Aiken, Christopher; McClelland, Robyn; Morrison, Ludivine Coudière; Tatari, Nazanin; Remke, Marc; Ramaswamy, Vijay; Issaivanan, Magimairajan; Ryken, Timothy; Del Bigio, Marc R; Taylor, Michael D; Werbowetski-Ogilvie, Tamra E

2015-11-17

Major research efforts have focused on defining cell surface marker profiles for characterization and selection of brain tumor stem/progenitor cells. Medulloblastoma is the most common primary malignant pediatric brain cancer and consists of 4 molecular subgroups: WNT, SHH, Group 3 and Group 4. Given the heterogeneity within and between medulloblastoma variants, surface marker profiles may be subtype-specific. Here, we employed a high throughput flow cytometry screen to identify differentially expressed cell surface markers in self-renewing vs. non-self-renewing SHH medulloblastoma cells. The top 25 markers were reduced to 4, CD271/p75NTR/NGFR, CD106/VCAM1, EGFR and CD171/NCAM-L1, by evaluating transcript levels in SHH tumors relative to samples representing the other variants. However, only CD271/p75NTR/NGFR and CD171/NCAM-L1 maintain differential expression between variants at the protein level. Functional characterization of CD271, a low affinity neurotrophin receptor, in cell lines and primary cultures suggested that CD271 selects for lower self-renewing progenitors or stem cells. Moreover, CD271 levels were negatively correlated with expression of SHH pathway genes. Our study reveals a novel role for CD271 in SHH medulloblastoma and suggests that targeting CD271 pathways could lead to the design of more selective therapies that lessen the broad impact of current treatments on developing nervous systems.

Synthesis and radiolabeling of chelator-RNA aptamer bioconjugates with copper-64 for targeted molecular imaging

PubMed Central

Rockey, William M.; Huang, Ling; Kloepping, Kyle C.; Baumhover, Nicholas J.; Giangrande, Paloma H.; Schultz, Michael K.

2014-01-01

Ribonucleic acid (RNA) aptamers with high affinity and specificity for cancer-specific cell-surface antigens are promising reagents for targeted molecular imaging of cancer using positron emission tomography (PET). For this application, aptamers must be conjugated to chelators capable of coordinating PET-radionuclides (e.g. copper-64, 64Cu) to enable radiolabeling for in vivo imaging of tumors. This study investigates the choice of chelator and radiolabeling parameters such as pH and temperature for the development of 64Cu-labeled RNA-based targeted agents for PET imaging. The characterization and optimization of labeling conditions are described for four chelator-aptamer complexes. Three commercially available bifunctional macrocyclic chelators (1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid mono N-hydroxysuccinimide [DOTA-NHS]; S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid [p-SCN-Bn-NOTA]; and p-SCN-Bn-3,6,9,15-tetraazabicyclo [9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid [p-SCN-Bn-PCTA]), as well as the polyamino-macrocyclic diAmSar (3,6,10,13,16,19-hexaazabicyclo[6.6.6] icosane-1,8-diamine) were conjugated to A10–3.2, a RNA aptamer which has been shown to bind specifically to a prostate cancer-specific cell-surface antigen (PSMA). Although a commercial bifunctional version of diAmSar was not available, RNA conjugation with this chelator was achieved in a two-step reaction by the addition of a disuccinimidyl suberate linker. Radiolabeling parameters (e.g. pH, temperature, and time) for each chelator-RNA conjugate were assessed in order to optimize specific activity and RNA stability. Furthermore, the radiolabeled chelator-coupled RNA aptamers were evaluated for binding specificity to their target antigen. In summary, key parameters were established for optimal radiolabeling of RNA aptamers for eventual PET imaging with 64Cu. PMID:21658962

[Cordyceps sinensis enhances lymphocyte proliferation and CD markers expression in simulated microgravity environment].

PubMed

Hao, Tong; Li, Jun-Jie; Du, Zhi-Yan; Duan, Cui-Mi; Wang, Yan-Meng; Wang, Chang-Yong; Song, Jing-Ping; Wang, Lin-Jie; Li, Ying-Hui; Wang, Yan

2012-10-01

This study was aimed to explore the effect of cordyceps sinensis enhancing lymphocyte proliferation and surface CD marker expression in simulated microgravity environment. The splenic lymphocytes were separated from mice and cultured in the rotary cell culture system simulated microgravity environment. The cells were treated with different concentration of cordyceps sinensis solution (0, 6.25, 12.5, 25 and 50 µg/ml) for 24, 48 and 72 h respectively, then the cells were harvested, and analyzed for cell proliferation and the expression of cell surface markers (CD4 and CD8). The results showed that under simulated microgravity environment, the lymphocyte proliferation was inhibited. When the concentration of cordyceps sinensis was 25 or 50 µg/ml, the lymphocyte proliferation, CD4 and CD8 expressions all increased, but 50 µg/ml cordyceps sinensis could inhibit the proliferation ability with the time prolonging. It is concluded that the suitable concentration of cordyceps sinensis displayed the ability to enhance the lymphocyte proliferation and CD marker expression in simulated microgravity environment. These results may be valuable for screening drugs which can be potentially against immunosuppression under simulated microgravity.

Neighbor of Punc E 11: expression pattern of the new hepatic stem/progenitor cell marker during murine liver development.

PubMed

Schievenbusch, Stephanie; Sauer, Elisabeth; Curth, Harald-Morten; Schulte, Sigrid; Demir, Münevver; Toex, Ulrich; Goeser, Tobias; Nierhoff, Dirk

2012-09-20

We have previously identified Neighbor of Punc E 11 (Nope) as a specific cell surface marker of stem/progenitor cells in the murine fetal liver that is also expressed in hepatocellular carcinoma. Here, we focus on the differential expression pattern of Nope during murine fetal and postnatal liver development as well as in a normal and regenerating adult liver including oval cell activation. In the fetal liver, Nope shows a constantly high expression level and is a useful surface marker for the identification of Dlk, E-cadherin, and CD133-positive hepatoblasts by flow cytometry. Postnatally, Nope expression declines rapidly and remains barely detectable in the adult liver as shown by quantitative real-time reverse-transcriptase polymerase chain reaction and western blot analyses. Immunohistochemically, costainings for Nope- and epithelial-specific markers (E-cadherin), markers of early hepatoblasts (alpha-fetoprotein), and biliary marker proteins (CK19) demonstrate that Nope is initially expressed on bipotent hepatoblasts and persists thereafter on commited hepatocytic as well as cholangiocytic progenitor cells during late fetal liver development. Postnatally, Nope loses its circular expression pattern and is specifically directed to the sinusoidal membrane of early hepatocytes. While Nope is only weakly expressed on cholangiocytes in the normal adult liver, activated stem/progenitor (oval) cells clearly coexpress Nope together with the common markers A6, EpCAM, and CD24 in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine mouse model. In conclusion, Nope should be most useful in future research to define the differentiation stage of hepatic-specified cells of various sources and is a promising candidate to identify and isolate hepatic stem cells from the adult liver.

MOF-Derived Ultrathin Cobalt Phosphide Nanosheets as Efficient Bifunctional Hydrogen Evolution Reaction and Oxygen Evolution Reaction Electrocatalysts

PubMed Central

Li, Hong; Ke, Fei; Zhu, Junfa

2018-01-01

The development of a highly efficient and stable bifunctional electrocatalyst for water splitting is still a challenging issue in obtaining clean and sustainable chemical fuels. Herein, a novel bifunctional catalyst consisting of 2D transition-metal phosphide nanosheets with abundant reactive sites templated by Co-centered metal−organic framework nanosheets, denoted as CoP-NS/C, has been developed through a facile one-step low-temperature phosphidation process. The as-prepared CoP-NS/C has large specific surface area and ultrathin nanosheets morphology providing rich catalytic active sites. It shows excellent electrocatalytic performances for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic and alkaline media, with the Tafel slopes of 59 and 64 mV/dec and a current density of 10 mA/cm2 at the overpotentials of 140 and 292 mV, respectively, which are remarkably superior to those of CoP/C, CoP particles, and comparable to those of commercial noble-metal catalysts. In addition, the CoP-NS/C also shows good durability after a long-term test. PMID:29414838

Parkia pendula lectin as histochemistry marker for meningothelial tumour.

PubMed

Beltrão, E I C; Medeiros, P L; Rodrigues, O G; Figueredo-Silva, J; Valença, M M; Coelho, L C B B; Carvalho, L B

2003-01-01

Lectins have been intensively used in histochemical techniques for cell surface characterization. These proteins are involved in several biological processes and their use as histochemical markers have been evaluated since they can indicate differences in cell surfaces. Parkia pendula lectin (PpeL) was evaluated as histochemical marker for meningothelial meningioma biopsies. Tissue slices were incubated with PpeL conjugated to horseradish peroxidase (PpeL-HRP) and Concanavalin A-HRP (ConA-HPR) and the binding visualized with diaminobenzidine and hydrogen peroxide. The lectin-tissue binding was inhibited with D-glucose. PpeL showed to be a useful tool for the characterization of meningothelial tumour and clinico-pathological diagnosis.

Targeting Prostate Cancer with Bifunctional Modulators of the Androgen Receptor

DTIC Science & Technology

2013-10-01

linker lengths were prepared and assessed to determine the impact of linker length on the activity of the molecules. HEK293T cells were transfected as...M. Determination of...15 derivatives were determined experimentally by radiolabeled competition binding assays using an extract 16 from Hi5 insect cells expressing an N

Investigating Cell Surface Markers on Normal Hematopoietic Stem Cells in Three Different Niche Conditions

PubMed Central

Garg, Swati; Madkaikar, Manisha

2013-01-01

Hematopoietic stem cells are of therapeutic interest to the clinicians and researchers due to their promising assistance in management of malignant and inherited hematological conditions. Evaluation of cell surface markers using multiparametric flow cytometry is a well adapted qualitative measure of cells in question for many years. An artillery of these markers has been studied in hematological malignancies and related disorders. However, their role and differential expression on normal hematopoietic stem cells from clinically available sources is not always described carefully. In the present study, we attempted to evaluate expression of CD44, CD90, CD96 and CD123 in three clinically available sources of normal HSCs (Hematopoietic stem cells). Sources of HSCs in the present study involved umbilical cord blood (UCB), normal bone marrow (NBM) and bone marrow from idiopathic thrombocytopenic purpura (ITP) patients (IBM). CD44 is an important homing receptor while CD90 is involved in maintaining stem cell quiescent. CD96 is known to be leukemia specific marker and CD123 is involved in stem cell differentiation and survival. We observed a significant difference in expression CD44, CD90 and CD123 on normal HSCs derived from umbilical cord and ITP marrow. CD96 was highly expressed on HSCs obtained from ITP marrow. Investigating expression of these markers on normal HSCs in different niches will be helpful in correlating their function with niche condition and delineating their ‘abnormal’ expression from the normal. PMID:24386557

Investigating cell surface markers on normal hematopoietic stem cells in three different niche conditions.

PubMed

Garg, Swati; Madkaikar, Manisha; Ghosh, Kanjaksha

2013-11-01

Hematopoietic stem cells are of therapeutic interest to the clinicians and researchers due to their promising assistance in management of malignant and inherited hematological conditions. Evaluation of cell surface markers using multiparametric flow cytometry is a well adapted qualitative measure of cells in question for many years. An artillery of these markers has been studied in hematological malignancies and related disorders. However, their role and differential expression on normal hematopoietic stem cells from clinically available sources is not always described carefully. In the present study, we attempted to evaluate expression of CD44, CD90, CD96 and CD123 in three clinically available sources of normal HSCs (Hematopoietic stem cells). Sources of HSCs in the present study involved umbilical cord blood (UCB), normal bone marrow (NBM) and bone marrow from idiopathic thrombocytopenic purpura (ITP) patients (IBM). CD44 is an important homing receptor while CD90 is involved in maintaining stem cell quiescent. CD96 is known to be leukemia specific marker and CD123 is involved in stem cell differentiation and survival. We observed a significant difference in expression CD44, CD90 and CD123 on normal HSCs derived from umbilical cord and ITP marrow. CD96 was highly expressed on HSCs obtained from ITP marrow. Investigating expression of these markers on normal HSCs in different niches will be helpful in correlating their function with niche condition and delineating their 'abnormal' expression from the normal.

Analysis of Microtubule Mediated Functions of Prostate Specific Membrane Antigen

DTIC Science & Technology

2006-04-01

localization of vesicles containing these markers increased to approximately 43% (38/88) when cells are incubated with tunicamycin, indicating a role...PSMA at both plasma membrane domains following nocodazole treatment. Polarity of the basolateral marker Na,K- ATPase was unaffected by nocodazole...restricted to the apical surface facing the lumen. This staining was clearly distinct from that of the endothelial cell marker CD 34 and CD31

New markers for tracking endoderm induction and hepatocyte differentiation from human pluripotent stem cells

PubMed Central

Holtzinger, Audrey; Streeter, Philip R.; Sarangi, Farida; Hillborn, Scott; Niapour, Maryam; Ogawa, Shinichiro; Keller, Gordon

2015-01-01

The efficient generation of hepatocytes from human pluripotent stem cells (hPSCs) requires the induction of a proper endoderm population, broadly characterized by the expression of the cell surface marker CXCR4. Strategies to identify and isolate endoderm subpopulations predisposed to the liver fate do not exist. In this study, we generated mouse monoclonal antibodies against human embryonic stem cell-derived definitive endoderm with the goal of identifying cell surface markers that can be used to track the development of this germ layer and its specification to a hepatic fate. Through this approach, we identified two endoderm-specific antibodies, HDE1 and HDE2, which stain different stages of endoderm development and distinct derivative cell types. HDE1 marks a definitive endoderm population with high hepatic potential, whereas staining of HDE2 tracks with developing hepatocyte progenitors and hepatocytes. When used in combination, the staining patterns of these antibodies enable one to optimize endoderm induction and hepatic specification from any hPSC line. PMID:26493401

Isolation of major pancreatic cell types and long-term culture-initiating cells using novel human surface markers.

PubMed

Dorrell, Craig; Abraham, Stephanie L; Lanxon-Cookson, Kelsea M; Canaday, Pamela S; Streeter, Philip R; Grompe, Markus

2008-09-01

We have developed a novel panel of cell-surface markers for the isolation and study of all major cell types of the human pancreas. Hybridomas were selected after subtractive immunization of Balb/C mice with intact or dissociated human islets and assessed for cell-type specificity and cell-surface reactivity by immunohistochemistry and flow cytometry. Antibodies were identified by specific binding of surface antigens on islet (panendocrine or alpha-specific) and nonislet pancreatic cell subsets (exocrine and duct). These antibodies were used individually or in combination to isolate populations of alpha, beta, exocrine, or duct cells from primary human pancreas by FACS and to characterize the detailed cell composition of human islet preparations. They were also employed to show that human islet expansion cultures originated from nonendocrine cells and that insulin expression levels could be increased to up to 1% of normal islet cells by subpopulation sorting and overexpression of the transcription factors Pdx-1 and ngn3, an improvement over previous results with this culture system. These methods permit the analysis and isolation of functionally distinct pancreatic cell populations with potential for cell therapy.

Live single cell functional phenotyping in droplet nano-liter reactors.

PubMed

Konry, Tania; Golberg, Alexander; Yarmush, Martin

2013-11-11

While single cell heterogeneity is present in all biological systems, most studies cannot address it due to technical limitations. Here we describe a nano-liter droplet microfluidic-based approach for stimulation and monitoring of surface and secreted markers of live single immune dendritic cells (DCs) as well as monitoring the live T cell/DC interaction. This nano-liter in vivo simulating microenvironment allows delivering various stimuli reagents to each cell and appropriate gas exchanges which are necessary to ensure functionality and viability of encapsulated cells. Labeling bioassay and microsphere sensors were integrated into nano-liter reaction volume of the droplet to monitor live single cell surface markers and secretion analysis in the time-dependent fashion. Thus live cell stimulation, secretion and surface monitoring can be obtained simultaneously in distinct microenvironment, which previously was possible using complicated and multi-step in vitro and in vivo live-cell microscopy, together with immunological studies of the outcome secretion of cellular function.

Cellular and Molecular Level Responses After Radiofrequency Radiation Exposure, Alone or in Combination with X-rays or Chemicals

DTIC Science & Technology

1992-07-27

cell surface marker CD22 , which plays a role in early B-cell activation, is present within the cytoplasm of all B- cells, but expressed only on the...surface of a subpopulation of those cells. CD22 is an activation receptor associated with cell proliferation of small resting B-cells, and acts as an...adhesion molecule mediating the binding of B-cells to other hematopoietic cells (Stamenkovic & Seed, 1990). The CD22 surface glycoprotein is the putative

Relationship between Numerous Mast Cells and Early Follicular Development in Neonatal MRL/MpJ Mouse Ovaries

PubMed Central

Nakamura, Teppei; Otsuka, Saori; Ichii, Osamu; Sakata, Yuko; Nagasaki, Ken-Ichi; Hashimoto, Yoshiharu; Kon, Yasuhiro

2013-01-01

In the neonatal mouse ovary, clusters of oocytes called nests break into smaller cysts and subsequently form individual follicles. During this period, we found numerous mast cells in the ovary of MRL/MpJ mice and investigated their appearance and morphology with follicular development. The ovarian mast cells, which were already present at postnatal day 0, tended to localize adjacent to the surface epithelium. Among 11 different mouse strains, MRL/MpJ mice possessed the greatest number of ovarian mast cells. Ovarian mast cells were also found in DBA/1, BALB/c, NZW, and DBA/2 mice but rarely in C57BL/6, NZB, AKR, C3H/He, CBA, and ICR mice. The ovarian mast cells expressed connective tissue mast cell markers, although mast cells around the surface epithelium also expressed a mucosal mast cell marker in MRL/MpJ mice. Some ovarian mast cells migrated into the oocyte nests and directly contacted the compressed and degenerated oocytes. In MRL/MpJ mice, the number of oocytes in the nest was significantly lower than in the other strains, and the number of oocytes showed a positive correlation with the number of ovarian mast cells. The gene expression of a mast cell marker also correlated with the expression of an oocyte nest marker, suggesting a link between the appearance of ovarian ? 4mast cells and early follicular development. Furthermore, the expression of follicle developmental markers was significantly higher in MRL/MpJ mice than in C57BL/6 mice. These results indicate that the appearance of ovarian mast cells is a unique phenotype of neonatal MRL/MpJ mice, and that ovarian mast cells participate in early follicular development, especially nest breakdown. PMID:24124609

Bio-active molecules modified surfaces enhanced mesenchymal stem cell adhesion and proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mobasseri, Rezvan; Center for Nanofibers & Nanotechnology, Department of Mechanical Engineering, National University of Singapore, 117576; Tian, Lingling

Surface modification of the substrate as a component of in vitro cell culture and tissue engineering, using bio-active molecules including extracellular matrix (ECM) proteins or peptides derived ECM proteins can modulate the surface properties and thereby induce the desired signaling pathways in cells. The aim of this study was to evaluate the behavior of human bone marrow mesenchymal stem cells (hBM-MSCs) on glass substrates modified with fibronectin (Fn), collagen (Coll), RGD peptides (RGD) and designed peptide (R-pept) as bio-active molecules. The glass coverslips were coated with fibronectin, collagen, RGD peptide and R-peptide. Bone marrow mesenchymal stem cells were cultured on differentmore » substrates and the adhesion behavior in early incubation times was investigated using scanning electron microscopy (SEM) and confocal microscopy. The MTT assay was performed to evaluate the effect of different bio-active molecules on MSCs proliferation rate during 24 and 72 h. Formation of filopodia and focal adhesion (FA) complexes, two steps of cell adhesion process, were observed in MSCs cultured on bio-active molecules modified coverslips, specifically in Fn coated and R-pept coated groups. SEM image showed well adhesion pattern for MSCs cultured on Fn and R-pept after 2 h incubation, while the shape of cells cultured on Coll and RGD substrates indicated that they might experience stress condition in early hours of culture. Investigation of adhesion behavior, as well as proliferation pattern, suggests R-peptide as a promising bio-active molecule to be used for surface modification of substrate in supporting and inducing cell adhesion and proliferation. - Highlights: • Bioactive molecules modified surface is a strategy to design biomimicry scaffold. • Bi-functional Tat-derived peptide (R-pept) enhanced MSCs adhesion and proliferation. • R-pept showed similar influences to fibronectin on FA formation and attachment.« less

A Nanostructured Bifunctional platform for Sensing of Glucose Biomarker in Artificial Saliva: Synergy in hybrid Pt/Au surfaces.

PubMed

Raymundo-Pereira, Paulo A; Shimizu, Flávio M; Coelho, Dyovani; Piazzeta, Maria H O; Gobbi, Angelo L; Machado, Sergio A S; Oliveira, Osvaldo N

2016-12-15

We report on a bimetallic, bifunctional electrode where a platinum (Pt) surface was patterned with nanostructured gold (Au) fingers with different film thicknesses, which was functionalized with glucose oxidase (GOx) to yield a highly sensitive glucose biosensor. This was achieved by using selective adsorption of a self-assembled monolayer (SAM) onto Au fingers, which allowed GOx immobilization only onto the Au-SAM surface. This modified electrode was termed bifunctional because it allowed to simultaneously immobilize the biomolecule (GOx) on gold to catalyze glucose, and detect hydrogen peroxide on Pt sites. Optimized electrocatalytic activity was reached for the architecture Pt/Au-SAM/GOx with 50nm thickness of Au, where synergy between Pt and Au allowed for detection of hydrogen peroxide (H2O2) at a low applied potential (0V vs. Ag/AgCl). Detection was performed for H2O2 in the range between 4.7 and 102.7 nmol L(-1), with detection limit of 3.4×10(-9) mol L(-1) (3.4 nmol L(-1)) and an apparent Michaelis-Menten rate constant of 3.2×10(-6)molL(-1), which is considerably smaller than similar devices with monometallic electrodes. The methodology was validated by measuring glucose in artificial saliva, including in the presence of interferents. The synergy between Pt and Au was confirmed in electrochemical impedance spectroscopy measurements with an increased electron transfer, compared to bare Pt and Au electrodes. The approach for fabricating the reproducible bimetallic Pt/Au electrodes is entirely generic and may be explored for other types of biosensors and biodevices where advantage can be taken of the combination of the two metals. Copyright © 2016 Elsevier B.V. All rights reserved.

Hierarchically Designed 3D Holey C2N Aerogels as Bifunctional Oxygen Electrodes for Flexible and Rechargeable Zn-Air Batteries.

PubMed

Shinde, Sambhaji S; Lee, Chi Ho; Yu, Jin-Young; Kim, Dong-Hyung; Lee, Sang Uck; Lee, Jung-Ho

2018-01-23

The future of electrochemical energy storage spotlights on the designed formation of highly efficient and robust bifunctional oxygen electrocatalysts that facilitate advanced rechargeable metal-air batteries. We introduce a scalable facile strategy for the construction of a hierarchical three-dimensional sulfur-modulated holey C 2 N aerogels (S-C 2 NA) as bifunctional catalysts for Zn-air and Li-O 2 batteries. The S-C 2 NA exhibited ultrahigh surface area (∼1943 m 2 g -1 ) and superb electrocatalytic activities with lowest reversible oxygen electrode index ∼0.65 V, outperforms the highly active bifunctional and commercial (Pt/C and RuO 2 ) catalysts. Density functional theory and experimental results reveal that the favorable electronic structure and atomic coordination of holey C-N skeleton enable the reversible oxygen reactions. The resulting Zn-air batteries with liquid electrolytes and the solid-state batteries with S-C 2 NA air cathodes exhibit superb energy densities (958 and 862 Wh kg -1 ), low charge-discharge polarizations, excellent reversibility, and ultralong cycling lives (750 and 460 h) than the commercial Pt/C+RuO 2 catalysts, respectively. Notably, Li-O 2 batteries with S-C 2 NA demonstrated an outstanding specific capacity of ∼648.7 mA h g -1 and reversible charge-discharge potentials over 200 cycles, illustrating great potential for commercial next-generation rechargeable power sources of flexible electronics.

Pushing the Theoretical Limit of Li-CFx Batteries: A Tale of Bi-functional Electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rangasamy, Ezhiylmurugan; Li, Juchuan; Sahu, Gayatri

2014-01-01

In a typical battery, electrodes deliver capacities less or equal the theoretical maxima of the electrode materials.1 The inert electrolyte functions solely as the ionic conductor without contribution to the cell capacity because of its distinct mono-function in the concept of conventional batteries. Here we demonstrate that the most energy-dense Li-CFx battery2 delivers a capacity exceeding the theoretical maximum of CFx with a solid electrolyte of Li3PS4 (LPS) that has dual functions: as the inert electrolyte at the anode and the active component at the cathode. Such a bi-functional electrolyte reconciles both inert and active characteristics through a synergistic dischargemore » mechanism of CFx and LPS. Li3PS4 is known as an inactive solid electrolyte with a broad electrochemical window over 5 V.3 The synergy at the cathode is through LiF, the discharge product of CFx, which activates the electrochemical discharge of LPS at a close electrochemical potential of CFx. Therefore, the solid-state Li-CFx batteries output 126.6% energy beyond their theoretic limits without compromising the stability of the cell voltage. The extra energy comes from the electrochemical discharge of LPS, the inert electrolyte. This bi-functional electrolyte revolutionizes the concept of conventional batteries and opens a new avenue for the design of batteries with an unprecedentedly high energy density.« less

Development of a bifunctional filter for prion protein and leukoreduction of red blood cell components.

PubMed

Yokomizo, Tomo; Kai, Takako; Miura, Morikazu; Ohto, Hitoshi

2015-02-01

Leukofiltration of blood components is currently implemented worldwide as a precautionary measure against white blood cell-associated adverse effects and the potential transmission of variant Creutzfeldt-Jakob disease (vCJD). A newly developed bifunctional filter (Sepacell Prima, Asahi Kasei Medical) was assessed for prion removal, leukoreduction (LR), and whether the filter significantly affected red blood cells (RBCs). Sepacell Prima's postfiltration effects on RBCs, including hemolysis, complement activation, and RBC chemistry, were compared with those of a conventional LR filter (Sepacell Pure RC). Prion removal was measured by Western blot after spiking RBCs with microsomal fractions derived from scrapie-infected hamster brain homogenate. Serially diluted exogenous prion solutions (0.05 mL), with or without filtration, were injected intracerebrally into Golden Syrian hamsters. LR efficiency of 4.44 log with the Sepacell Prima was comparable to 4.11 log with the conventional LR filter. There were no significant differences between the two filters in hemoglobin loss, hemolysis, complement activation, and RBC biomarkers. In vitro reduction of exogenously spiked prions by the filter exceeded 3 log. The titer, 6.63 (log ID50 /mL), of prefiltration infectivity of healthy hamsters was reduced to 2.52 (log ID50 /mL) after filtration. The reduction factor was calculated as 4.20 (log ID50 ). With confirmed removal efficacy for exogenous prion protein, this new bifunctional prion and LR filter should reduce the residual risk of vCJD transmission through blood transfusion without adding complexity to component processing. © 2014 AABB.

Concurrent detection of secreted products from human lymphocytes by microengraving: cytokines and antigen-reactive antibodies

PubMed Central

Bradshaw, Elizabeth M.; Kent, Sally C.; Tripuraneni, Vinay; Orban, Tihamer; Ploegh, Hidde L.; Hafler, David A.; Love, J. Christopher

2008-01-01

Cell surface determinants, cytokines and antibodies secreted by hematopoietic cells are used to classify their lineage and function. Currently available techniques are unable to elucidate multiple secreted proteins while also assigning phenotypic surface-displayed markers to the individual living cells. Here, a soft lithographic method, microengraving, was adapted for the multiplexed interrogation of populations of individual human peripheral blood mononuclear cells for secreted cytokines (IFN-γ and IL-6), antigen-specific antibodies, and lineage-specific surface-expressed markers. Application of the method to a clinical sample from a recent onset Type 1 diabetic subject with a positive titer of anti-insulin antibodies showed that ~0.58% of circulating CD19+ B cells secreted proinsulin-reactive antibodies of the IgG isotype and 2–3% of circulating cells secreted IL-6. These data demonstrate the utility of microengraving for interrogating multiple phenotypes of single human cells concurrently and for detecting rare populations of cells by their secreted products. PMID:18675591

Bis-(3'-5')-cyclic dimeric GMP-linked quorum sensing controls swarming in Vibrio parahaemolyticus.

PubMed

Trimble, Michael J; McCarter, Linda L

2011-11-01

Movement over and colonization of surfaces are important survival strategies for bacteria, and many find it advantageous to perform these activities as a group, using quorum sensing to sample population size and synchronize behavior. It is puzzling however, that swarming-proficient and virulent strains of Vibrio parahaemolyticus are silenced for the vibrio archetypal pathway of quorum sensing. Here we describe the S-signal, a pheromone that can be communicated between cells in coculture to regulate surface colonization. This signal was harvested in cell-free supernatants and demonstrated to stimulate swarming gene expression at low cell density. The S-signal was generated by the pyridoxal phosphate-dependent aminotransferase ScrA; signal reception required the periplasmic binding protein ScrB and the membrane-bound GGDEF-EAL domain-containing protein ScrC. ScrC is a bifunctional enzyme that has the ability to form and degrade the second messenger bis-(3'-5') cyclic dimeric GMP (c-di-GMP). ScrA in neighboring cells was able to alter the activity of ScrC in a ScrB-dependent manner, transforming ScrC's repressing ability to inducing activity with respect to swarming. Conversely, cell-cell signaling repressed capsule gene expression. In summary, we report that quorum sensing can stimulate swarming in V. parahaemolyticus; it does so via an alternative pathway capable of generating an autoinducing signal that influences c-di-GMP, thereby expanding the lexicon and language of cell-cell communication.

Surface Position, Not Signaling from Surrounding Maternal Tissues, Specifies Aleurone Epidermal Cell Fate in Maize[OA

PubMed Central

Gruis, Darren (Fred); Guo, Hena; Selinger, David; Tian, Qing; Olsen, Odd-Arne

2006-01-01

Maize (Zea mays) endosperm consists of an epidermal-like surface layer of aleurone cells, an underlying body of starchy endosperm cells, and a basal layer of transfer cells. To determine whether surrounding maternal tissues perform a role in specifying endosperm cell fates, a maize endosperm organ culture technique was established whereby the developing endosperm is completely removed from surrounding maternal tissues. Using cell type-specific fluorescence markers, we show that aleurone cell fate specification occurs exclusively in response to surface position and does not require specific, continued maternal signal input. The starchy endosperm and aleurone cell fates are freely interchangeable throughout the lifespan of the endosperm, with internalized aleurone cells converting to starchy endosperm cells and with starchy endosperm cells that become positioned at the surface converting to aleurone cells. In contrast to aleurone and starchy endosperm cells, transfer cells fail to develop in in vitro-grown endosperm, supporting earlier indications that maternal tissue interaction is required to fully differentiate this cell type. Several parameters confirm that the maize endosperm organ cultures described herein retain the main developmental features of in planta endosperm, including fidelity of aleurone mutant phenotypes, temporal and spatial control of cell type-specific fluorescent markers, specificity of cell type transcripts, and control of mitotic cell divisions. PMID:16698897

The expression of the class 1 glucose transporter isoforms in human embryonic stem cells, and the potential use of GLUT2 as a marker for pancreatic progenitor enrichment.

PubMed

Segev, Hana; Fishman, Betina; Schulman, Rita; Itskovitz-Eldor, Joseph

2012-07-01

Even before the first appearance of the developing pancreas, glucose is the major substrate in the growing embryo. The transport of glucose across cell membranes is facilitated by a family of membranal glucose transporters (GLUT). We analyzed changes in expression of class 1 glucose transporters (GLUT1-4) during human embryonic stem cell (hESC) and human induced pluripotent stem cell (hiPSC) differentiation, from undifferentiated cells to 28-day-old embryoid bodies (EBs). We also examined the potential use of GLUT2 as a marker for differentiating pancreatic progenitor cells. Using quantitative real time polymerase chain reaction (qPCR), western blot, and immunofluorescence, we observed enhanced expression of GLUT1 and GLUT2 during differentiation, but only minor change in GLUT3 expression. GLUT4 expression was found to be very low both at the RNA and in the protein levels. Expression of the early pancreatic transcription factor, pancreatic duodenal homeobox gene 1 (PDX1), correlated with GLUT2 expression, suggesting the potential use of GLUT2 as a surface marker for tracking pancreatic precursor cells. After sorting EBs according to their membranal GLUT2 expression, GLUT2 and PDX1 expression were found elevated, as was expression of other endodermal markers such as PAX4, NGN3, CXCR4, and SOX17. This simple method may be used to differentiate embryonic stem cells and to isolate from them, using GLUT2 as a surface marker, an enriched pancreatic progenitor cell population in order to achieve insulin-producing cells. The sorted GLUT2 cells may potentially be used in the future as insulin-producing cells for beta cell therapies.

A Dual-Action Armed Replicating Adenovirus for the Treatment of Osteoblastic Bone Metastases of Prostate Cancer

DTIC Science & Technology

2007-03-01

ligand), a membrane-bound cytokine expressed in osteoblasts/stromal cells, which binds to RANK, a cell- surface protein present on osteoclast...cocultures were incubated for 10 days and then the culture medium was employed in an ELISA to detect the osteoclast marker , tartrate- resistant acid...bone marrow stromal cells and osteoclast precursor cells. Ten days post-infection, expression of the osteoclast marker enzyme TRAP was determined

Evaluation of Accessory Lacrimal Gland in Muller’s Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease

PubMed Central

Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H.; Jaboori, Assraa Jassim; Setabutr, Pete; Aakalu, Vinay K.

2017-01-01

Purpose The accessory lacrimal glands (ALG) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. Materials and Methods ALG tissues obtained from Muller’s Muscle Conjunctival Resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Results Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2 and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Conclusions Thus, we report for the first time that human ALG tissues contain precursor marker positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES and isolate candidate precursor cells from ALG tissue. PMID:27612554

Adsorption of 2 Chloroethyl Ethyl Sulfide on Silica: Binding Mechanism and Energy of a Bifunctional Hydrogen-Bond Acceptor at the Gas Surface Interface

DTIC Science & Technology

2014-11-19

C. A. S.; Sumpter, K. B.; Wagner, G. W.; Rice, J. S. Degradation of the Blister Agent Sulfur Mustard, Bis(2-chloroethyl) Sulfide, on Concrete . J...SECURITY CLASSIFICATION OF: This work investigates the fundamental nature of sulfur mustard surface adsorption by characterizing interfacial hydrogen...nature of sulfur mustard surface adsorption by characterizing interfacial hydrogen bonding and other intermolecular forces for the surrogate molecule

EMMPRIN (CD147) is induced by C/EBPβ and is differentially expressed in ALK+ and ALK- anaplastic large-cell lymphoma.

PubMed

Schmidt, Janine; Bonzheim, Irina; Steinhilber, Julia; Montes-Mojarro, Ivonne A; Ortiz-Hidalgo, Carlos; Klapper, Wolfram; Fend, Falko; Quintanilla-Martínez, Leticia

2017-09-01

Anaplastic lymphoma kinase-positive (ALK+) anaplastic large-cell lymphoma (ALCL) is characterized by expression of oncogenic ALK fusion proteins due to the translocation t(2;5)(p23;q35) or variants. Although genotypically a T-cell lymphoma, ALK+ ALCL cells frequently show loss of T-cell-specific surface antigens and expression of monocytic markers. C/EBPβ, a transcription factor constitutively overexpressed in ALK+ ALCL cells, has been shown to play an important role in the activation and differentiation of macrophages and is furthermore capable of transdifferentiating B-cell and T-cell progenitors to macrophages in vitro. To analyze the role of C/EBPβ for the unusual phenotype of ALK+ ALCL cells, C/EBPβ was knocked down by RNA interference in two ALK+ ALCL cell lines, and surface antigen expression profiles of these cell lines were generated using a Human Cell Surface Marker Screening Panel (BD Biosciences). Interesting candidate antigens were further analyzed by immunohistochemistry in primary ALCL ALK+ and ALK- cases. Antigen expression profiling revealed marked changes in the expression of the activation markers CD25, CD30, CD98, CD147, and CD227 after C/EBPβ knockdown. Immunohistochemical analysis confirmed a strong, membranous CD147 (EMMPRIN) expression in ALK+ ALCL cases. In contrast, ALK- ALCL cases showed a weaker CD147 expression. CD274 or PD-L1, an immune inhibitory receptor ligand, was downregulated after C/EBPβ knockdown. PD-L1 also showed stronger expression in ALK+ ALCL compared with ALK- ALCL, suggesting an additional role of C/EBPβ in ALK+ ALCL in generating an immunosuppressive environment. Finally, no expression changes of T-cell or monocytic markers were detected. In conclusion, surface antigen expression profiling demonstrates that C/EBPβ plays a critical role in the activation state of ALK+ ALCL cells and reveals CD147 and PD-L1 as important downstream targets. The multiple roles of CD147 in migration, adhesion, and invasion, as well as T-cell activation and proliferation suggest its involvement in the pathogenesis of ALCL.

Subnanometer Cobalt-Hydroxide-Anchored N-Doped Carbon Nanotube Forest for Bifunctional Oxygen Catalyst.

PubMed

Kim, Ji Eun; Lim, Joonwon; Lee, Gil Yong; Choi, Sun Hee; Maiti, Uday Narayan; Lee, Won Jun; Lee, Ho Jin; Kim, Sang Ouk

2016-01-27

Electrochemical oxygen redox reactions are the crucial elements for energy conversion and storage including fuel cells and metal air batteries. Despite tremendous research efforts, developing high-efficient, low-cost, and durable bifunctional oxygen catalysts remains a major challenge. We report a new class of hybrid material consisting of subnanometer thick amorphous cobalt hydroxide anchored on NCNT as a durable ORR/OER bifunctional catalyst. Although amorphous cobalt species-based catalysts are known as good OER catalysts, hybridizing with NCNT successfully enhanced ORR activity by promoting a 4e reduction pathway. Abundant charge carriers in amorphous cobalt hydroxide are found to trigger the superior OER activity with high current density and low Tafel slope as low as 36 mV/decade. A remarkably high OER turnover frequency (TOF) of 2.3 s(-1) at an overpotential of 300 mV was obtained, one of the highest values reported so far. Moreover, the catalytic activity was maintained over 120 h of cycling. The unique subnanometer scale morphology of amorphous hydroxide cobalt species along with intimate cobalt species-NCNT interaction minimizes the deactivation of catalyst during prolonged repeated cycles.

Ductal cancers of the pancreas frequently express markers of gastrointestinal epithelial cells.

PubMed

Sessa, F; Bonato, M; Frigerio, B; Capella, C; Solcia, E; Prat, M; Bara, J; Samloff, I M

1990-06-01

It has been found by immunohistochemical staining that antigens normally found in gastric and/or intestinal epithelial cells are expressed in most differentiated duct cell carcinomas of the pancreas. Among 88 such tumors, 93% and 92%, respectively, expressed M1 and cathepsin E, markers of gastric surface-foveolar epithelial cells, 51% expressed pepsinogen II, a marker of gastroduodenal mucopeptic cells, 48% expressed CAR-5, a marker of colorectal epithelial cells, and 35% expressed M3SI, a marker of small intestinal goblet cells. Most of the tumors also expressed normal pancreatic duct antigens; 97% expressed DU-PAN-2, and 59% expressed N-terminus gastrin-releasing peptide. In agreement with these findings, electron microscopy revealed malignant cells with fine structural features of gastric foveolar cells, gastric mucopeptic cells, intestinal goblet cells, intestinal columnar cells, pancreatic duct epithelial cells, and cells with features of more than one cell type. Normal pancreatic duct epithelium did not express any marker of gastrointestinal epithelial cells, whereas such benign lesions as mucinous cell hypertrophy and papillary hyperplasia commonly expressed gut-type antigens but rarely expressed pancreatic duct cell markers. By contrast, lesions characterized by atypical papillary hyperplasia commonly expressed both gastric and pancreatic duct cell markers. Metaplastic pyloric-type glands expressed pepsinogen II and, except for their expression of cathepsin E, were indistinguishable from normal pyloric glands. In marked contrast, the immunohistochemical and ultrastructural features of 14 ductuloacinar cell tumors were those of cells lining terminal ductules, centroacinar cells, and/or acinar cells; none expressed any gut-type antigen. The results indicate that gastrointestinal differentiation is common in both benign and malignant lesions of pancreatic duct epithelium and suggest that duct cell carcinomas are histogenetically related to gastric- and intestinal-type metaplastic changes of epithelial cells lining the main and interlobular ducts of the pancreas.

Gap Junction Protein Connexin 43 Serves as a Negative Marker for a Stem Cell-Containing Population of Human Limbal Epithelial Cells

PubMed Central

Chen, Zhuo; Evans, W. Howard; Pflugfelder, Stephen C.; Li, De-Quan

2010-01-01

This study evaluated whether the gap junction protein connexin (Cx) 43 could serve as a negative cell surface marker for human corneal epithelial stem cells. Cx43 expression was evaluated in corneo-limbal tissue and primary limbal epithelial cultures. Immunofluorescent staining and laser scanning confocal microscopy showed that Cx43 was strongly expressed in the corneal and limbal suprabasal epithelial cells, but the basal cells of the limbal epithelium were negative. Cx43 antibody stained mainly large cells but not small cells in primary limbal epithelial cultures. As determined by semiquantitative reverse transcription polymerase chain reaction (PCR) and real-time PCR, Cx43 mRNA was more abundant in the corneal than limbal epithelia, and it was expressed in higher levels in mature limbal epithelial cultures. Using GAP11, a rabbit polyclonal antibody against the Cx32 extracellular loop 2 (151–187), a sequence that is highly homologous in Cx43, the Cx43dim and Cx43bright cells were selected from primary limbal epithelial cultures by fluorescence-activated cell sorting and were evaluated for stem cell properties. These Cx43dim and Cx43bright cells were confirmed by their expression levels of Cx43 protein and mRNA. The Cx43dim cells were found to contain higher percentages of slow-cycling bromodeoxyuridine (BrdU)-label retaining cells and the cells that were positive for stem cell-associated markers p63, ABCG2, and integrin β1 and negative for differentiation markers K3 and involucrin. The Cx43dim cells possessed a greater proliferative potential than Cx43bright cells and nonfractionated cells as evaluated by BrdU incorporation, colony-forming efficiency, and growth capacity. Our findings suggest that human limbal basal cells do not express connexin 43, which could serve as a negative cell surface marker for the stem cell-containing population of human limbal epithelial cells. PMID:16424398

Micropost microenvironments for studying luminal-basal lineage commitment of breast cancer cells

NASA Astrophysics Data System (ADS)

Kesavaraju, Anand; Qing, Bo; Jabart, Eric; Labarge, Mark; Sohn, Lydia

2013-03-01

MCF-7 breast cancer cells were plated onto polydimethylsiloxane (PDMS) microposts in order to examine the effects of the microenvironment on cell lineage. Different stiffnesses and sizes of the microposts are postulated to impact cell surface marker expression levels. We will provide preliminary results analyzing CD271 and focal adhesion markers such as vinculin. 3D shear flow will also be applied to the microposts to study how external mechanical stimuli affect cancer cells within their microenvironment.

Superparamagnetic Au-Fe3O4 nanoparticles: one-pot synthesis, biofunctionalization and toxicity evaluation

NASA Astrophysics Data System (ADS)

Pariti, A.; Desai, P.; Maddirala, S. K. Y.; Ercal, N.; Katti, K. V.; Liang, X.; Nath, M.

2014-09-01

Superparamagnetic Au-Fe3O4 bifunctional nanoparticles have been synthesized using a single step hot-injection precipitation method. The synthesis involved using Fe(CO)5 as iron precursor and HAuCl4 as gold precursor in the presence of oleylamine and oleic acid. Oleylamine helps in reducing Au3+ to Au0 seeds which simultaneously oxidizes Fe(0) to form Au-Fe3O4 bifunctional nanoparticles. Triton® X-100 was employed as a highly viscous solvent to prevent agglomeration of Fe3O4 nanoparticles. Detailed characterization of these nanoparticles was performed by using x-ray powder diffraction, transmission electron microscopy, scanning tunneling electron microscopy, UV-visible spectroscopy, Mössbauer and magnetometry studies. To evaluate these nanoparticles’ applicability in biomedical applications, L-cysteine was attached to the Au-Fe3O4 nanoparticles and cytotoxicity of Au-Fe3O4 nanoparticles was tested using CHO cells by employing MTS assay. L-cysteine modified Au-Fe3O4 nanoparticles were qualitatively characterized using Fourier transform infrared spectroscopy and Raman spectroscopy; and quantitatively using acid ninhydrin assay. Investigations reveal that that this approach yields Au-Fe3O4 bifunctional nanoparticles with an average particle size of 80 nm. Mössbauer studies indicated the presence of Fe in Fe3+ in A and B sites (tetrahedral and octahedral, respectively) and Fe2+ in B sites (octahedral). Magnetic measurements also indicated that these nanoparticles were superparamagnetic in nature due to Fe3O4 region. The saturation magnetization for the bifunctional nanoparticles was observed to be ˜74 emu g-1, which is significantly higher than the previously reported Fe3O4 nanoparticles. Mössbauer studies indicated that there was no significant Fe(0) impurity that could be responsible for the superparamagnetic nature of these nanoparticles. None of the investigations showed any presence of other impurities such as Fe2O3 and FeOOH. These Au-Fe3O4 bifunctional nanoparticles showed no significant cytotoxicity to the CHO cells up to 48 h even at concentrations of 1 mg ml-1 making them suitable for biomedical applications such as local heat generators (hyperthermia) for cancer treatment and drug delivery vehicles.

Downregulation of Melanoma Cell Adhesion Molecule (MCAM/CD146) Accelerates Cellular Senescence in Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells.

PubMed

Jin, Hye Jin; Kwon, Ji Hye; Kim, Miyeon; Bae, Yun Kyung; Choi, Soo Jin; Oh, Wonil; Yang, Yoon Sun; Jeon, Hong Bae

2016-04-01

Therapeutic applications of mesenchymal stem cells (MSCs) for treating various diseases have increased in recent years. To ensure that treatment is effective, an adequate MSC dosage should be determined before these cells are used for therapeutic purposes. To obtain a sufficient number of cells for therapeutic applications, MSCs must be expanded in long-term cell culture, which inevitably triggers cellular senescence. In this study, we investigated the surface markers of human umbilical cord blood-derived MSCs (hUCB-MSCs) associated with cellular senescence using fluorescence-activated cell sorting analysis and 242 cell surface-marker antibodies. Among these surface proteins, we selected the melanoma cell adhesion molecule (MCAM/CD146) for further study with the aim of validating observed expression differences and investigating the associated implications in hUCB-MSCs during cellular senescence. We observed that CD146 expression markedly decreased in hUCB-MSCs following prolonged in vitro expansion. Using preparative sorting, we found that hUCB-MSCs with high CD146 expression displayed high growth rates, multilineage differentiation, expression of stemness markers, and telomerase activity, as well as significantly lower expression of the senescence markers p16, p21, p53, and senescence-associated β-galactosidase, compared with that observed in hUCB-MSCs with low-level CD146 expression. In contrast, CD146 downregulation with small interfering RNAs enhanced the senescence phenotype. In addition, CD146 suppression in hUCB-MSCs caused downregulation of other cellular senescence regulators, including Bmi-1, Id1, and Twist1. Collectively, our results suggest that CD146 regulates cellular senescence; thus, it could be used as a therapeutic marker to identify senescent hUCB-MSCs. One of the fundamental requirements for mesenchymal stem cell (MSC)-based therapies is the expansion of MSCs during long-term culture because a sufficient number of functional cells is required. However, long-term growth inevitably induces cellular senescence, which potentially causes poor clinical outcomes by inducing growth arrest and the loss of stem cell properties. Thus, the identification of markers for evaluating the status of MSC senescence during long-term culture may enhance the success of MSC-based therapy. This study provides strong evidence that CD146 is a novel and useful marker for predicting senescence in human umbilical cord blood-derived MSCs (hUCB-MSCs), and CD146 can potentially be applied in quality-control assessments of hUCB-MSC-based therapy. ©AlphaMed Press.

Local suppression of contact hypersensitivity in mice by a new bifunctional psoralen, 4,4',5'-trimethylazapsoralen, and UVA radiation.

PubMed

Aubin, F; Dall'Acqua, F; Kripke, M L

1991-07-01

Although psoralens plus UVA radiation (320-400 nm) have been widely used for the treatment of dermatologic diseases, the toxic effects of these agents have led investigators to develop new photochemotherapeutic compounds. One such compound is 4,4',5'-trimethylazapsoralen (TMAP), a new bifunctional molecule. The purpose of this study was to examine the immunologic side effects of repeated treatment of C3H mice with TMAP plus UVA radiation. During this treatment, the number of ATPase+, la+, and Thy-1+ dendritic epidermal cells greatly decreased in the treated site, despite the lack of phototoxicity. The reduction in the number of detectable cutaneous immune cells was accompanied by a decrease in the induction of contact hypersensitivity to dinitrofluorobenzene applied to the treated skin, an impairment in the antigen-presenting activity of draining lymph node cells, and the presence of suppressor lymphoid cells in the spleen of unresponsive mice. Treatment with UVA radiation alone also reduced the number of ATPase+, Ia+, and Thy-1+ cells in the skin, but did not cause any detectable alterations in immune function. This implies that morphologic alterations in these cells do not necessarily indicate loss of function. Thus, although TMAP in combination with UVA radiation is not overtly phototoxic, it is highly immunosuppressive in mice.

Skeletal myogenic differentiation of human urine-derived cells as a potential source for skeletal muscle regeneration.

PubMed

Chen, Wei; Xie, Minkai; Yang, Bin; Bharadwaj, Shantaram; Song, Lujie; Liu, Guihua; Yi, Shanhong; Ye, Gang; Atala, Anthony; Zhang, Yuanyuan

2017-02-01

Stem cells are regarded as possible cell therapy candidates for skeletal muscle regeneration. However, invasive harvesting of those cells can cause potential harvest-site morbidity. The goal of this study was to assess whether human urine-derived stem cells (USCs), obtained through non-invasive procedures, can differentiate into skeletal muscle linage cells (Sk-MCs) and potentially be used for skeletal muscle regeneration. In this study, USCs were harvested from six healthy individuals aged 25-55. Expression profiles of cell-surface markers were assessed by flow cytometry. To optimize the myogenic differentiation medium, we selected two from four different types of myogenic differentiation media to induce the USCs. Differentiated USCs were identified with myogenic markers by gene and protein expression. USCs were implanted into the tibialis anterior muscles of nude mice for 1 month. The results showed that USCs displayed surface markers with positive staining for CD24, CD29, CD44, CD73, CD90, CD105, CD117, CD133, CD146, SSEA-4 and STRO-1, and negative staining for CD14, CD31, CD34 and CD45. After myogenic differentiation, a change in morphology was observed from 'rice-grain'-like cells to spindle-shaped cells. The USCs expressed specific Sk-MC transcripts and protein markers (myf5, myoD, myosin, and desmin) after being induced with different myogenic culture media. Implanted cells expressed Sk-MC markers stably in vivo. Our findings suggest that USCs are able to differentiate into the Sk-MC lineage in vitro and after being implanted in vivo. Thus, they might be a potential source for cell injection therapy in the use of skeletal muscle regeneration. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Identification of cell surface glycoprotein markers for glioblastoma-derived stem-like cells using a lectin microarray and LC-MS/MS approach

PubMed Central

He, Jintang; Liu, Yashu; Xie, Xiaolei; Zhu, Thant; Soules, Mary; DiMeco, Francesco; Vescovi, Angelo L.; Fan, Xing; Lubman, David M.

2010-01-01

Despite progress in the treatment of glioblastoma, more than 95% of patients suffering from this disease still die within two years. Recent findings support the belief that cancer stem-like cells are responsible for tumor formation and ongoing growth. Here a method combining lectin microarray and LC-MS/MS was used to discover the cell surface glycoprotein markers of a glioblastoma-derived stem-like cell line. Lectin microarray analysis of cell surface glycans showed that two galactose-specific lectins Trichosanthes kirilowii agglutinin (TKA) and Peanut agglutinin (PNA) could distinguish the stem-like glioblastoma neurosphere culture from a traditional adherent glioblastoma cell line. Agarose-bound TKA and PNA were used to capture the glycoproteins from the two cell cultures, which were analyzed by LC-MS/MS. The glycoproteins were quantified by spectral counting, resulting in the identification of 12 and 11 potential glycoprotein markers from the TKA and PNA captured fractions respectively. Almost all of these proteins were membrane proteins. Differential expression was verified by Western blotting analysis of 6 interesting proteins, including the up-regulated Receptor-type tyrosine-protein phosphatase zeta, Tenascin-C, Chondroitin sulfate proteoglycan NG2, Podocalyxin-like protein 1 and CD90, and the down-regulated CD44. An improved understanding of these proteins may be important for earlier diagnosis and better therapeutic targeting of glioblastoma. PMID:20235609

Functional Analysis of CD28/B7 and CD40/CD40L Costimulation During the in vivo Type 2 Immune Response

DTIC Science & Technology

1995-10-06

these activation markers on B cells and changes in B cell size (forward light scatter) were analyzed by flow cytometry (Figure 7). B cell surface B7...activation ofnaive CD4+ Th cells requires two signals delivered from antigen presenting cells (APes). The engagement ofthe T cell surface receptor...shown that T cell surface ii molecule CD28, and its homologue CTLA-4, can provide costimulatory signals to 10 cells when they interact with their ligands

Chemical and Molecular Biological Aspects of Alkylhydrazine-Induced Carcinogenesis in Human Cells in Vitro. Revised

DTIC Science & Technology

1984-04-01

weights using the following phage DNA markers : lambda, T2 and T7. The number of alkaline labile sites (breaks due to apurinic sites and phosphotriesters...exhibit cell invasiveness in chick embryo skin, human malignancy specific cell- surface antigenic determinants (19), and produce tumors in pre...they eluted from the column, were identified by co-chromatographed markers , (Chart 2). When randomly proliferating cells were treated with either 1,1-DMH

Lycopersicon esculentum lectin is a marker of transient amplifying cells in in vitro cultures of isolated limbal stem cells.

PubMed

Vergallo, C; Fonseca, T; Pizzi, G; Dini, L

2010-08-01

The maintenance of a healthy corneal epithelium under both normal and wound healing conditions is achieved by a population of stem cells (SCs) located in the basal epithelium at the corneoscleral limbus. In the light of the development of strategies for reconstruction of the ocular surface in patients with limbal stem cell deficiency, a major challenge in corneal SCs biology remains the ability to identify stem cells in situ and in vitro. To date, not so much markers exist for the identification of different phenotypes. CESCs (corneal epithelial stem cells) isolated from limbal biopsies were maintained in primary culture for 14 days and stained with Hoechst and a panel of FITC-conjugated lectins. All lectins, with the exception of Lycopersicon esculentum, labelled CESCs irrespective of the degree of differentiation. Lycopersicon esculentum, that binds N-acetylglucosamine oligomers, labelled intensely only the surface of TACs (single corneal epithelial stem cells better than colonial cells). These results suggest that Lycopersicon esculentum lectin is a useful and easy-to-use marker for the in vitro identification of TACs (transient amplifying cells) in cultures of isolated CESCs. Copyright 2010. Published by Elsevier Ltd.

Fabrication and Characterization of Luminescent Magnetic Bifunctional Nanocomposite Based on TbPO4·H2O Nanowires and Fe3O4 Nanoparticles

NASA Astrophysics Data System (ADS)

Huong, Nguyen Thanh; Hung, Nguyen Manh; Lien, Pham Thi; Van, Nguyen Duc; Nam, Pham Hong; Binh, Nguyen Thanh; Minh, Le Quoc

2016-07-01

The fabrication and properties of luminescent magnetic bifunctional nanocomposites comprised of TbPO4·H2O nanowires as a core and magnetite nanoparticles as a shell are presented. TbPO4·H2O nanowires were synthesized by a microwave-assisted method while the grafting process of freshly-formed superparamagnetic magnetite nanoparticles on the surface of luminescent nanowires was carried out by a co-precipitate method. The effects of the Fe3O4/TbPO4·H2O mass ratio on the luminescent and magnetic properties of the obtained nanocomposite were also investigated. The results showed that, for the optimized bifunctional nanocomposites, green luminescent emissions at 488 nm, 542 nm, 585 nm, 620 nm and superparamagnetic behavior with saturation magnetization M s of 6 emu/g were achieved. With a hyperthermia temperature of ~43.5°C under an alternating current (AC) magnetic field, the obtained TbPO4·H2O/Fe3O4 nanocomposite was expected to be used for both optical probing and hyperthermia cancer treatments in biomedical applications.

Effect of carbon supports on RhRe bifunctional catalysts for selective hydrogenolysis of tetrahydropyran-2-methanol

DOE PAGES

Karanjkar, Pranav U.; Burt, Samuel P.; Chen, Xiaoli; ...

2016-09-12

Tetrahydropyran-2-methanol undergoes selective C–O–C hydrogenolysis to produce 1,6-hexanediol using a bifunctional RhRe (reducible metal with an oxophilic promoter) catalyst supported on Vulcan XC-72 carbon (VXC) with >90% selectivity. This RhRe/VXC catalyst is stable over 40 h of reaction in a continuous flow fixed bed reactor. The hydrogenolysis activity of RhRe/VXC is two orders-of-magnitude higher than that of RhRe supported on Norit Darco 12X40 activated carbon (NDC). STEM–EDS analysis reveals that, compared to the RhRe/VXC catalyst, the Re and Rh component metals are segregated on the surface of the low activity RhRe/NDC catalyst, suggesting that Rh and Re in close proximitymore » (“bimetallic” particles) are required for an active hydrogenolysis catalyst. Differences in metal distribution on the carbon surfaces are, in turn, linked to the properties of the carbons: NDC has both a higher surface area and surface oxygen content. Thus, the low areal density of Rh and Re precursors on the high area NDC and/or interactions of the precursors with its O functional groups may interfere with the formation of the bimetallic species required for an active catalyst.« less

Feline Glycoprotein A Repetitions Predominant Anchors Transforming Growth Factor Beta on the Surface of Activated CD4+CD25+ Regulatory T Cells and Mediates AIDS Lentivirus-Induced T Cell Immunodeficiency

PubMed Central

Miller, Michelle M.; Fogle, Jonathan E.; Ross, Peter

2013-01-01

Abstract Using the feline immunodeficiency virus (FIV) model for AIDS-lentivirus infection, our laboratory has previously demonstrated that T regulatory (Treg) cell-mediated immune T and B cell dysfunction contributes to lentivirus persistence and chronic disease through membrane bound transforming growth factor beta (mTGFb). Studying Treg cells in the context of infection has been problematic as no inducible marker for activated Treg cells had been identified. However, recent reports in human Treg studies have described a novel protein, glycoprotein A repetitions predominant (GARP), as a unique marker of activated human Treg cells that anchors mTGFb. Herein we extend these studies to the feline Treg system, identifying feline GARP and demonstrating that human and feline GARP proteins are homologous in structure, expression pattern, and ability to form a complex with TGFb. We further demonstrate that GARP and TGFb form a complex on the surface of activated Treg cells and that these GARP+TGFb+ Treg cells are highly efficient suppressor cells. Analysis of expression of this Treg activation marker in the FIV-AIDS model reveals an up-regulation of GARP expressing Treg cells during chronic FIV infection. We demonstrate that the GARP+ Treg cells from FIV-infected cats suppress T helper cells in vivo and that blocking GARP or TGFb eliminates this suppression. These data suggest that GARP is expressed in complex with TGFb on the surface of activated Treg cells and plays an important role in TGFb+ Treg-mediated T cell immune suppression during lentivirus infection. PMID:23373523

Feline glycoprotein A repetitions predominant anchors transforming growth factor beta on the surface of activated CD4(+)CD25(+) regulatory T cells and mediates AIDS lentivirus-induced T cell immunodeficiency.

PubMed

Miller, Michelle M; Fogle, Jonathan E; Ross, Peter; Tompkins, Mary B

2013-04-01

Using the feline immunodeficiency virus (FIV) model for AIDS-lentivirus infection, our laboratory has previously demonstrated that T regulatory (Treg) cell-mediated immune T and B cell dysfunction contributes to lentivirus persistence and chronic disease through membrane bound transforming growth factor beta (mTGFb). Studying Treg cells in the context of infection has been problematic as no inducible marker for activated Treg cells had been identified. However, recent reports in human Treg studies have described a novel protein, glycoprotein A repetitions predominant (GARP), as a unique marker of activated human Treg cells that anchors mTGFb. Herein we extend these studies to the feline Treg system, identifying feline GARP and demonstrating that human and feline GARP proteins are homologous in structure, expression pattern, and ability to form a complex with TGFb. We further demonstrate that GARP and TGFb form a complex on the surface of activated Treg cells and that these GARP(+)TGFb(+) Treg cells are highly efficient suppressor cells. Analysis of expression of this Treg activation marker in the FIV-AIDS model reveals an up-regulation of GARP expressing Treg cells during chronic FIV infection. We demonstrate that the GARP(+) Treg cells from FIV-infected cats suppress T helper cells in vivo and that blocking GARP or TGFb eliminates this suppression. These data suggest that GARP is expressed in complex with TGFb on the surface of activated Treg cells and plays an important role in TGFb(+) Treg-mediated T cell immune suppression during lentivirus infection.

Live single cell functional phenotyping in droplet nano-liter reactors

NASA Astrophysics Data System (ADS)

Konry, Tania; Golberg, Alexander; Yarmush, Martin

2013-11-01

While single cell heterogeneity is present in all biological systems, most studies cannot address it due to technical limitations. Here we describe a nano-liter droplet microfluidic-based approach for stimulation and monitoring of surfaceand secreted markers of live single immune dendritic cells (DCs) as well as monitoring the live T cell/DC interaction. This nano-liter in vivo simulating microenvironment allows delivering various stimuli reagents to each cell and appropriate gas exchanges which are necessary to ensure functionality and viability of encapsulated cells. Labeling bioassay and microsphere sensors were integrated into nano-liter reaction volume of the droplet to monitor live single cell surface markers and secretion analysis in the time-dependent fashion. Thus live cell stimulation, secretion and surface monitoring can be obtained simultaneously in distinct microenvironment, which previously was possible using complicated and multi-step in vitro and in vivo live-cell microscopy, together with immunological studies of the outcome secretion of cellular function.

Isolation, Identification, and Culture of Human Lymphatic Endothelial Cells.

PubMed

Lokmic, Zerina

2016-01-01

A protocol describing the isolation of foreskin lymphatic endothelial cells (LECs) and lymphatic malformation lymphatic endothelial cells (LM LECs) is presented herein. To isolate LECs and LM LECs, tissues are mechanically disrupted to make a single-cell suspension, which is then enzymatically digested in dispase and collagenase type II. LECs and LM LECs, in the resulting single-cell suspension, are then sequentially labeled with antibodies recognizing fibroblast and endothelial cell surface antigens CD34 and CD31 and separated from the remaining components in the cell suspension by capture with magnetic beads. Viable LECs and LM LECs are then seeded and expanded on fibronectin-coated flasks. LEC and LM LEC purity is determined immunohistochemically using cell surface markers CD31, CD34, podoplanin, VEGFR-3 and nuclear marker PROX-1. Cells whose purity is >98 % are used for experiments between passage 4 and 6.

[Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-31

Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

(Bifunctional chelates of Rh-105, Au-199, and other metallic radionuclides as potential radiotherapeutic agents)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-01-01

Progress during this period is reported under the following headings: Diethylenetriamine based and related bifunctional chelating agents and their complexation with Rh-105, Au-198, Pd-109, cu-67, In-111, and Co-57; studies of Pd-109, Rh-105 and Tc-99m with bifunctional chelates based on phenylenediamine; establishment of an appropriate protein assay method for conjugated proteins; studies of new bifunctional Bi, Tri and tetradentate amine oxime ligands with Rh-105; IgG and antibody B72.3 conjugation studies by HPLC Techniques with bifunctional metal chelates; and progress on ligand systems for Au(III).

Bifunctional NaYF4:Er3+/Yb3+ submicron rods, implemented in quantum dot sensitized solar cell(Conference Presentation)

NASA Astrophysics Data System (ADS)

Guerrero, J. Pablo; Cerdán Pasarán, Andrea; López-Luke, Tzarara; Ramachari, D.; Esparza, Diego; De la Rosa Cruz, Elder; Romero Arellano, Victor Hugo

2016-09-01

In this work are presented the results obtained with solar cells sensitized with quantum dots of cadmium sulphide (CdS) incorporating luminescent materials (NaYF4:Yb/Er). The study revealed that through using a bifunctional layer of NaYF4:Yb/Er submicron rods, the infrared radiation is absorbed in 980nm to generate luminescence in the visible region to 530nm, under the UP-conversion process, in the same way simultaneously, NaYF4:Yb/Er layer causes scattering toward the quantum dots, the emission and scattering generated by this material is reabsorbed by the QD-CdS, and these in turn are absorbing in its range of solar radiation absorption, Thus generates an increase in the electron injection into the semiconductor of TiO2. The results of a cell incorporating NaYF4: Yb/Er at 0.07M shown photoconversion efficiencies of 3.39% improving efficiency with respect to the reference solar cell without using NaYF4: Yb/Er of 1.99%. The obtained values of current and voltage showed a strong dependence of the percentage of NaYF4 Yb/Er, and the mechanism of incorporation of this material.

MTBE OXIDATION BY BIFUNCTIONAL ALUMINUN

EPA Science Inventory

Bifunctional aluminum, prepared by sulfating zero-valent aluminum with sulfuric acid, is an innovative extension of zero-valent metal (ZVM) technology for ground water remediation. Bifunctional aluminum has a dual functionality of simultaneously decomposing both reductively- an...

MTBE OXIDATION BY BIFUNCTIONAL ALUMINUM

EPA Science Inventory

Bifunctional aluminum, prepared by sulfating zero-valent aluminum with sulfuric acid, has a dual functionality of simultaneously decomposing both reductively- and oxidatively-degradable contaminants. In this work, the use of bifunctional aluminum for the degradation of methyl te...

Effects of Different Cell-Detaching Methods on the Viability and Cell Surface Antigen Expression of Synovial Mesenchymal Stem Cells.

PubMed

Tsuji, Kunikazu; Ojima, Miyoko; Otabe, Koji; Horie, Masafumi; Koga, Hideyuki; Sekiya, Ichiro; Muneta, Takeshi

2017-06-09

Flow cytometric analysis of cell surface antigens is a powerful tool for the isolation and characterization of stem cells residing in adult tissues. In contrast to the collection of hematopoietic stem cells, the process of enzymatic digestion is usually necessary to prepare mesenchymal stem cells (MSCs) suspensions, which can influence the expression of cell surface markers. In this study, we examined the effects of various cell-detaching reagents and digestion times on the expression of stem cell-related surface antigens and MSC functions. Human MSCs were detached from dishes using four different reagents: trypsin, TrypLE, collagenase, and a nonenzymatic cell dissociation reagent (C5789; Sigma-Aldrich). Following dissociation reagent incubations ranging from 5 to 120 min, cell surface markers were analyzed by flow cytometry. Trypsin and TrypLE quickly dissociated the cells within 5 min, while collagenase and C5789 required 60 min to obtain maximum cell yields. C5789 significantly decreased cell viability at 120 min. Trypsin treatment significantly reduced CD44+, CD55+, CD73+, CD105+, CD140a+, CD140b+, and CD201+ cell numbers within 30 min. Collagenase treatment reduced CD140a expression by 30 min. In contrast, TrypLE treatment did not affect the expression of any cell surface antigens tested by 30 min. Despite the significant loss of surface antigen expression after 60 min of treatment with trypsin, adverse effects of enzymatic digestion on multipotency of MSCs were limited. Overall, our data indicated that TrypLE is advantageous over other cell dissociation reagents tested for the rapid preparation of viable MSC suspensions.

Characterization and Classification of Mesenchymal Stem Cells in Several Species Using Surface Markers for Cell Therapy Purposes.

PubMed

Ghaneialvar, Hori; Soltani, Leila; Rahmani, Hamid Reza; Lotfi, Abbas Sahebghadam; Soleimani, Masoud

2018-01-01

Mesenchymal stem cells are multipotent cells capable of replicating as undifferentiated cells, and have the potential of differentiating into mesenchymal tissue lineages such as osteocytes, adipocytes and chondrocytes. Such lineages can then be used in cell therapy. The aim of present study was to characterize bone marrow derived mesenchymal stem cells in four different species, including: sheep, goat, human and mouse. Human bone-marrow mesenchymal stem cells were purchased, those of sheep and goat were isolated from fetal bone marrow, and those of mouse were collected by washing bone cavity of femur and tibia with DMEM/F12. Using flow-cytometry, they were characterized by CD surface antigens. Furthermore, cells of third passage were examined for their osteogenic and adipogenic differentiation potential by oil red and alizarin red staining respectively. According to the results, CD markers studied in the four groups of mesenchymal stem cells showed a different expression. Goat and sheep expressed CD44 and CD166, and weakly expressed CD34, CD45, CD105 and CD90. Similarly, human and mouse mesenchymal cells expressed CD44, CD166, CD105 and CD90 whereas the expression of CD34 and CD45 was negative. In conclusion, although all mesenchymal stem cells display plastic adherence and tri-lineage differentiation, not all express the same panel of surface antigens described for human mesenchymal stem cells. Additional panel of CD markers are necessary to characterize regenerative potential and possible application of these stem cells in regenerative medicine and implantology.

mAb C19 targets a novel surface marker for the isolation of human cardiac progenitor cells from human heart tissue and differentiated hESCs.

PubMed

Leung, Hau Wan; Moerkamp, Asja T; Padmanabhan, Jayanthi; Ng, Sze-Wai; Goumans, Marie-José; Choo, Andre

2015-05-01

Cardiac progenitor cells (CPCs) have been isolated from adult and developing hearts using an anti-mouse Sca-1 antibody. However, the absence of a human Sca-1 homologue has hampered the clinical application of the CPCs. Therefore, we generated novel monoclonal antibodies (mAbs) specifically raised against surface markers expressed by resident human CPCs. Here, we explored the suitability of one of these mAbs, mAb C19, for the identification, isolation and characterization of CPCs from fetal heart tissue and differentiating cultures of human embryonic stem cells (hESCs). Using whole-cell immunization, mAbs were raised against Sca-1+ CPCs and screened for reactivity to various CPC lines by flow cytometry. mAb C19 was found to be specific for Sca-1+ CPCs, with high cell surface binding capabilities. mAb C19 stained small stem-like cells in cardiac tissue sections. Moreover, during differentiation of hESCs towards cardiomyocytes, a transient population of cells with mAb C19 reactivity was identified and isolated using magnetic-activated cell sorting. Their cell fate was tracked and found to improve cardiomyocyte purity from hESC-derived cultures. mAb C19+ CPCs, from both hESC differentiation and fetal heart tissues, were maintained and expanded in culture, while retaining their CPC-like characteristics and their ability to further differentiate into cardiomyocytes by stimulation with TGFβ1. Finally, gene expression profiling of these mAb C19+ CPCs suggested a highly angiogenic nature, which was further validated by cell-based angiogenesis assays. mAb C19 is a new surface marker for the isolation of multipotent CPCs from both human heart tissues and differentiating hESCs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecular cloning and characterization of markers and cytokines for equid myeloid cells.

PubMed

Steinbach, Falko; Stark, Robert; Ibrahim, Sherif; Gawad, Eman Abd-El; Ludwig, Hanns; Walter, Jakob; Commandeur, Ulrich; Mauel, Susanne

2005-10-18

The myeloid cell system comprises of monocytes, macrophages (MPhi), dendritic cells (DC), Kupffer cells, osteoclasts or microglia and is also known as the mononuclear phagocytic system (MPS). Essential cytokines to differentiate or activate these cells include GM-CSF or IL-4. Important markers for characterization include CD1, CD14, CD68, CD163 and CD206. All these markers, however, were not cloned or further characterized in equids by use of monoclonal antibodies earlier. To overcome this problem with the present study, two approaches were used. First, we cloned equine cytokines and markers, and second we analyzed cross-reactivity of human homologues or anti-human monoclonal antibodies. For cloning of equine cytokines and markers, we used degenerate primers delineated from other species, or equine-specific primers based on previous information in Genbank. Flow cytometry was used to determine the expression of markers on myeloid cells. Cross-reactivity could be shown for anti-human CD14, CD163 and mannose receptor (CD206) mAbs. Surface markers such as CD1 and CD68 that distinguish MPhi and DC were cloned and sequenced. According to blast homology, equine CD1a and CD1b could be identified and distinguished. With the resulting information, dendritic cells and macrophages of horses may be characterized.

Systemic surfaceome profiling identifies target antigens for immune-based therapy in subtypes of advanced prostate cancer

PubMed Central

Lee, John K.; Bangayan, Nathanael J.; Chai, Timothy; Smith, Bryan A.; Pariva, Tiffany E.; Yun, Sangwon; Vashisht, Ajay; Zhang, Qingfu; Park, Jung Wook; Corey, Eva; Huang, Jiaoti; Wohlschlegel, James; Witte, Owen N.

2018-01-01

Prostate cancer is a heterogeneous disease composed of divergent molecular and histologic subtypes, including prostate adenocarcinoma (PrAd) and neuroendocrine prostate cancer (NEPC). While PrAd is the major histology in prostate cancer, NEPC can evolve from PrAd as a mechanism of treatment resistance that involves a transition from an epithelial to a neurosecretory cancer phenotype. Cell surface markers are often associated with specific cell lineages and differentiation states in normal development and cancer. Here, we show that PrAd and NEPC can be broadly discriminated by cell-surface profiles based on the analysis of prostate cancer gene expression datasets. To overcome a dependence on predictions of human cell-surface genes and an assumed correlation between mRNA levels and protein expression, we integrated transcriptomic and cell-surface proteomic data generated from a panel of prostate cancer cell lines to nominate cell-surface markers associated with these cancer subtypes. FXYD3 and CEACAM5 were validated as cell-surface antigens enriched in PrAd and NEPC, respectively. Given the lack of effective treatments for NEPC, CEACAM5 appeared to be a promising target for cell-based immunotherapy. As a proof of concept, engineered chimeric antigen receptor T cells targeting CEACAM5 induced antigen-specific cytotoxicity in NEPC cell lines. Our findings demonstrate that the surfaceomes of PrAd and NEPC reflect unique cancer differentiation states and broadly represent vulnerabilities amenable to therapeutic targeting. PMID:29686080

Expression, crystallization and preliminary crystallographic studies of a novel bifunctional N-­acetylglutamate synthase/kinase from Xanthomonas campestris homologous to vertebrate N-acetylglutamate synthase

PubMed Central

Shi, Dashuang; Caldovic, Ljubica; Jin, Zhongmin; Yu, Xiaolin; Qu, Qiuhao; Roth, Lauren; Morizono, Hiroki; Hathout, Yetrib; Allewell, Norma M.; Tuchman, Mendel

2006-01-01

A novel N-acetylglutamate synthase/kinase bifunctional enzyme of arginine biosynthesis that was homologous to vertebrate N-acetylglutamate synthases was identified in Xanthomonas campestris. The protein was overexpressed, purified and crystallized. The crystals belong to the hexagonal space group P6222, with unit-cell parameters a = b = 134.60, c = 192.11 Å, and diffract to about 3.0 Å resolution. Selenomethionine-substituted recombinant protein was produced and selenomethionine substitution was verified by mass spectroscopy. Multiple anomalous dispersion (MAD) data were collected at three wavelengths at SER-CAT, Advanced Photon Source, Argonne National Laboratory. Structure determination is under way using the MAD phasing method. PMID:17142901

Simple, mild, one-step labelling of proteins with gallium-68 using a tris(hydroxypyridinone) bifunctional chelator: a 68Ga-THP-scFv targeting the prostate-specific membrane antigen.

PubMed

Nawaz, Saima; Mullen, Gregory E D; Sunassee, Kavitha; Bordoloi, Jayanta; Blower, Philip J; Ballinger, James R

2017-10-25

Labelling proteins with gallium-68 using bifunctional chelators is often problematic because of unsuitably harsh labelling conditions such as low pH or high temperature and may entail post-labelling purification. To determine whether tris(hydroxypyridinone) (THP) bifunctional chelators offer a potential solution to this problem, we have evaluated the labelling and biodistribution of a THP conjugate with a new single-chain antibody against the prostate-specific membrane antigen (PSMA), an attractive target for staging prostate cancer (PCa). A single-chain variable fragment (scFv) of J591, a monoclonal antibody that recognises an external epitope of PSMA, was prepared in order to achieve biokinetics matched to the half-life of gallium-68. The scFv, J591c-scFv, was engineered with a C-terminal cysteine. J591c-scFv was produced in HEK293T cells and purified by size-exclusion chromatography. A maleimide THP derivative (THP-mal) was coupled site-specifically to the C-terminal cysteine residue. The THP-mal-J591c-scFv conjugate was labelled with ammonium acetate-buffered gallium-68 from a 68 Ge/ 68 Ga generator at room temperature and neutral pH. The labelled conjugate was evaluated in the PCa cell line DU145 and its PSMA-overexpressing variant in vitro and xenografted in SCID mice. J591c-scFv was produced in yields of 4-6 mg/l culture supernatant and efficiently coupled with the THP-mal bifunctional chelator. Labelling yields > 95% were achieved at room temperature following incubation of 5 μg conjugate with gallium-68 for 5 min without post-labelling purification. 68 Ga-THP-mal-J591c-scFv was stable in serum and showed selective binding to the DU145-PSMA cell line, allowing an IC50 value of 31.5 nM to be determined for unmodified J591c-scFv. Serial PET/CT imaging showed rapid, specific tumour uptake and clearance via renal elimination. Accumulation in DU145-PSMA xenografts at 90 min post-injection was 5.4 ± 0.5%ID/g compared with 0.5 ± 0.2%ID/g in DU145 tumours (n = 4). The bifunctional chelator THP-mal enabled simple, rapid, quantitative, one-step room temperature radiolabelling of a protein with gallium-68 at neutral pH without a need for post-labelling purification. The resultant gallium-68 complex shows high affinity for PSMA and favourable in vivo targeting properties in a xenograft model of PCa.

Altered β-catenin expression related to cancer progression on actinic cheilitis and squamous cell carcinoma of the lip.

PubMed

Schussel, Juliana L; Pinto, Décio Dos Santos; Martins, Marília Trierveiler

2011-02-01

β-Catenin is a bifunctional protein related to cell adhesion and gene transcription when activated by Wnt pathway. Altered expression of β-catenin was related to loss of differentiation, more aggressive phenotype, increase of tumor invasion, and poor prognosis in a number of different cancers. Actinic cheilitis is caused by excessive exposure to ultraviolet radiation and has a high potential to suffer malignant transformation into squamous cell carcinoma (SCC) of the lip, the most frequent oral malignancy. Studies of oral cancer have shown the correlation of β-catenin expression and oral SCC prognosis, and loss of membrane expression may be considered as a potential marker for early tumor recurrence. Thirty-five cases of actinic cheilitis and 12 cases of SCC of the lip were select and submitted to immunohistochemical staining using β-catenin antibody. β-Catenin was positive on the membrane for all cases. Eighty-five percent of actinic cheilitis cases showed cytoplasmatic staining, and 22% nuclear staining. Eighty-three percent of SCC was positive for β-catenin, and none of them had nuclear staining. Cytoplasmatic and nuclear staining of β-catenin on studied cases point to pathway alterations. Results demonstrated that β-catenin expression is altered on epithelial dysplasia, and it is related to degree of alterations. Copyright © 2011 Elsevier Inc. All rights reserved.

Polymer-coated surface enhanced Raman scattering (SERS) gold nanoparticles for multiplexed labeling of chronic lymphocytic leukemia cells

NASA Astrophysics Data System (ADS)

MacLaughlin, Christina M.; Parker, Edward P. K.; Walker, Gilbert C.; Wang, Chen

2012-01-01

The ease and flexibility of functionalization and inherent light scattering properties of plasmonic nanoparticles make them suitable contrast agents for measurement of cell surface markers. Immunophenotyping of lymphoproliferative disorders is traditionally undertaken using fluorescence detection methods which have a number of limitations. Herein, surface-enhanced Raman scattering (SERS) gold nanoparticles conjugated to monoclonal antibodies are used for the selective targeting of CD molecules on the surface of chronic lymphocytic leukemia (CLL) cells. Raman-active reporters were physisorbed on to the surface of 60 nm spherical Au nanoparticles, the particles were coated with 5kDa polyethylene glycol (PEG) including functionalities for conjugation to monoclonal IgG1 antibodies. A novel method for quantifying the number of antibodies bound to SERS probes on an individual basis as opposed to obtaining averages from solution was demonstrated using metal dots in transmission electron microscopy (TEM). The specificity of the interaction between SERS probes and surface CD molecules of CLL cells was assessed using Raman spectroscopy and dark field microscopy. An in-depth study of SERS probe targeting to B lymphocyte marker CD20 was undertaken, and proof-of-concept targeting using different SERS nanoparticle dyes specific for cell surface CD19, CD45 and CD5 demonstrated using SERS spectroscopy.

Cellular basis for neonatally induced T-suppressor activity. Primary B cell maturation is blocked by suppressor-helper interactions restricted by loci on chromosome 12

PubMed Central

1985-01-01

The cellular mechanism and genetic restriction of neonatally induced HA- specific suppressor T (Ts) cells have been examined. The in vivo effect of these Ts cells on antibody production, primary B cell proliferation, B cell surface marker changes, and helper T (Th) cell priming during primary responses to HA have been determined. The results indicate that, although antigen-induced B cell proliferative responses and surface marker changes occur in the presence of Ts cells, differentiation to Ig secretion, and long-lived memory B cell production are prevented. Further, antigen-specific Th cell priming is completely ablated by Ts cells, suggesting that Ts act by preventing the delivery of Th signals required for both the later stages of primary B cell maturation, and the formation of memory B cell populations. Finally, in vivo cell mixing experiments using congenic mice indicate that this Ts-Th interaction is restricted by loci on mouse chromosome 12. PMID:2580040

Development of Novel Bifunctional Compounds that Induce Apoptosis in Prostate Cancer Cells

DTIC Science & Technology

2006-02-01

were different from those of other alkylating agents used in chemotherapy. The apoptotic responses of prostate cancer cells suggested that the 11β... alkylating DNA Damaging Agent Tethered to an Androgen Receptor Ligand. Chemistry & Biology 12; 779-787. Personnel Supported Dr. Robert Croy...our work was the design of DNA-damag- ing agents that disrupt both DNA repair and signaling pathways in prostate tumor cells. A DNA alkylator (N,N

Compact and highly stable quantum dots through optimized aqueous phase transfer

NASA Astrophysics Data System (ADS)

Tamang, Sudarsan; Beaune, Grégory; Poillot, Cathy; De Waard, Michel; Texier-Nogues, Isabelle; Reiss, Peter

2011-03-01

A large number of different approaches for the aqueous phase transfer of quantum dots have been proposed. Surface ligand exchange with small hydrophilic thiols, such as L-cysteine, yields the lowest particle hydrodynamic diameter. However, cysteine is prone to dimer formation, which limits colloidal stability. We demonstrate that precise pH control during aqueous phase transfer dramatically increases the colloidal stability of InP/ZnS quantum dots. Various bifunctional thiols have been applied. The formation of disulfides, strongly diminishing the fluorescence QY has been prevented through addition of appropriate reducing agents. Bright InP/ZnS quantum dots with a hydrodynamic diameter <10 nm and long-term stability have been obtained. Finally we present in vitro studies of the quantum dots functionalized with the cell-penetrating peptide maurocalcine.

Mouse ES cells have a potential to differentiate into odontoblast-like cells using hanging drop method.

PubMed

Kawai, R; Ozeki, N; Yamaguchi, H; Tanaka, T; Nakata, K; Mogi, M; Nakamura, H

2014-05-01

We examined whether mouse embryonic stem (ES) cells can differentiate into odontoblast-like cells without epithelial-mesenchymal interaction. Cells were cultured by the 'hanging drop' method using a collagen type-I scaffold (CS) combined with bone morphogenetic protein (BMP)-4 (CS/BMP-4). Expression of odontoblast-related mRNA and protein, and cell proliferation were performed by reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence staining and WST-1 assay, respectively. Cells potently expressed odontoblast-related cell marker mRNAs following induction of odontoblastic differentiation. Dentin sialophosphoprotein, a marker of mature odontoblasts, was strongly expressed in differentiated ES cells. The cells also acquired an odontoblast-like functional phenotype, as evidenced by the appearance of alkaline phosphatase activity and calcification. The cell-surface expression of α2, α6, αV and αVβ3 integrin proteins was rapidly upregulated in differentiated cells. Finally, anti-α2 integrin antibody suppressed the expression of odontoblastic markers in cells grown using this culture system, suggesting that α2 integrin expression in ES cells triggers their differentiation into odontoblast-like cells. Mouse ES cells cultured by the 'hanging drop' method are able to differentiate into cells with odontoblast-specific physiological functions and cell-surface integrin protein expression. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A bi-functional antibody-receptor domain fusion protein simultaneously targeting IGF-IR and VEGF for degradation

PubMed Central

Shen, Yang; Zeng, Lin; Novosyadlyy, Ruslan; Forest, Amelie; Zhu, Aiping; Korytko, Andrew; Zhang, Haifan; Eastman, Scott W; Topper, Michael; Hindi, Sagit; Covino, Nicole; Persaud, Kris; Kang, Yun; Burtrum, Douglas; Surguladze, David; Prewett, Marie; Chintharlapalli, Sudhakar; Wroblewski, Victor J; Shen, Juqun; Balderes, Paul; Zhu, Zhenping; Snavely, Marshall; Ludwig, Dale L

2015-01-01

Bi-specific antibodies (BsAbs), which can simultaneously block 2 tumor targets, have emerged as promising therapeutic alternatives to combinations of individual monoclonal antibodies. Here, we describe the engineering and development of a novel, human bi-functional antibody-receptor domain fusion molecule with ligand capture (bi-AbCap) through the fusion of the domain 2 of human vascular endothelial growth factor receptor 1 (VEGFR1) to an antibody directed against insulin-like growth factor – type I receptor (IGF-IR). The bi-AbCap possesses excellent stability and developability, and is the result of minimal engineering. Beyond potent neutralizing activities against IGF-IR and VEGF, the bi-AbCap is capable of cross-linking VEGF to IGF-IR, leading to co-internalization and degradation of both targets by tumor cells. In multiple mouse xenograft tumor models, the bi-AbCap improves anti-tumor activity over individual monotherapies. More importantly, it exhibits superior inhibition of tumor growth, compared with the combination of anti-IGF-IR and anti-VEGF therapies, via powerful blockade of both direct tumor cell growth and tumor angiogenesis. The unique “capture-for-degradation” mechanism of the bi-AbCap is informative for the design of next-generation bi-functional anti-cancer therapies directed against independent signaling pathways. The bi-AbCap design represents an alternative approach to the creation of dual-targeting antibody fusion molecules by taking advantage of natural receptor-ligand interactions. PMID:26073904

Novel 16-substituted bifunctional derivatives of huperzine B: multifunctional cholinesterase inhibitors

PubMed Central

Shi, Yu-fang; Zhang, Hai-yan; Wang, Wei; Fu, Yan; Xia, Yu; Tang, Xi-can; Bai, Dong-lu; He, Xu-chang

2009-01-01

Aim: To design novel bifunctional derivatives of huperzine B (HupB) based on the concept of dual binding site of acetylcholinesterase (AChE) and evaluate their pharmacological activities for seeking new drug candidates against Alzheimer's disease (AD). Methods: Novel 16-substituted bifunctional derivatives of HupB were synthesized through chemical reactions. The inhibitory activities of the derivatives toward AChE and butyrylcholinesterase (BuChE) were determined in vitro by modified Ellman's method. Cell viability was quantified by the reduction of MTT. Results: A new preparative method was developed for the generation of 16-substituted derivatives of HupB, and pharmacological trials indicated that the derivatives were multifunctional cholinesterase inhibitors targeting both AChE and BuChE. Among the derivatives tested, 9c, 9e, 9f, and 9i were 480 to 1360 times more potent as AChE inhibitors and 370 to 1560 times more potent as BuChE inhibitors than the parent HupB. Further preliminary pharmacological trials of derivatives 9c and 9i were performed, including examining the mechanism of AChE inhibition, the substrate kinetics of the enzyme inhibition, and protection against hydrogen peroxide (H2O2)-induced cytotoxicity in PC12 cells. Conclusion: Preliminary pharmacological evaluation indicated that 16-substituted derivatives of HupB, particularly 9c and 9i, would be potentially valuable new drug candidates for AD therapy, and further exploration is needed to evaluate their pharmacological and clinical efficacies. PMID:19578388

Exocytosis of vacuolar apical compartment (VAC): a cell-cell contact controlled mechanism for the establishment of the apical plasma membrane domain in epithelial cells

PubMed Central

1988-01-01

The vacuolar apical compartment (VAC) is an organelle found in Madin- Darby canine kidney (MDCK) cells with incomplete intercellular contacts by incubation in 5 microM Ca++ and in cells without contacts (single cells in subconfluent culture); characteristically, it displays apical biochemical markers and microvilli and excludes basolateral markers (Vega-Salas, D. E., P. J. I. Salas, and E. Rodriguez-Boulan. 1987. J. Cell Biol. 104:1249-1259). The apical surface of cells kept under these culture conditions is immature, with reduced numbers of microvilli and decreased levels of an apical biochemical marker (184 kD), which is, however, still highly polarized (Vega-Salas, D. E., P. J. I. Salas, D. Gundersen, and E. Rodriguez-Boulan. 1987. J. Cell Biol. 104:905-916). We describe here the morphological stages of VAC exocytosis which ultimately lead to the establishment of a differentiated apical domain. Addition of 1.8 mM Ca++ to monolayers developed in 5 microM Ca++ causes the rapid (20-40 min) fusion of VACs with the plasma membrane and their accessibility to external antibodies, as demonstrated by immunofluorescence, immunoperoxidase EM, and RIA with antibodies against the 184-kD apical plasma membrane marker. Exocytosis occurs towards areas of cell-cell contact in the developing lateral surface where they form intercellular pockets; fusion images are always observed immediately adjacent to the incomplete junctional bands detected by the ZO-1 antibody (Stevenson, B. R., J. D. Siliciano, M. S. Mooseker, and D. A. Goodenough. 1986. J. Cell Biol. 103:755-766). Blocks of newly incorporated VAC microvilli and 184-kD protein progressively move from intercellular ("primitive" lateral) spaces towards the microvilli-poor free cell surface. The definitive lateral domain is sealed behind these blocks by the growing tight junctional fence. These results demonstrate a fundamental role of cell-cell contact-mediated VAC exocytosis in the establishment of epithelial surface polarity. Because isolated stages (intercellular pockets) of the stereotyped sequence of events triggered by the establishment of intercellular contacts in MDCK cells have been reported during normal differentiation of intestine epithelium (Colony, P. C., and M. R. Neutra. 1983. Dev. Biol. 97:349-363), we speculate that the mechanism we describe here plays an important role in the establishment of epithelial cell polarity in vivo. PMID:3053735

Hydrazinonicotinamide prolongs quantum dot circulation and reduces reticuloendothelial system clearance by suppressing opsonization and phagocyte engulfment

NASA Astrophysics Data System (ADS)

Jung, Kyung-Ho; Park, Jin Won; Paik, Jin-Young; Lee, Eun Jeong; Choe, Yearn Seong; Lee, Kyung-Han

2012-12-01

In this study, we investigated the effects of hydrazinonicotinamide (HYNIC)—a bifunctional crosslinker widely used to 99mTc radiolabel protein and nanoparticles for imaging studies—on quantum dot opsonization, macrophage engulfment and in vivo kinetics. In streptavidin-coated quantum dots (SA-QDots), conjugation with HYNIC increased the net negative charge without affecting the zeta potential. Confocal microscopy and fluorescence-activated cell sorting showed HYNIC attachment to suppress SA-QDot engulfment by macrophages. Furthermore, HYNIC conjugation suppressed surface opsonization by serum protein including IgG. When intravenously injected into mice, HYNIC conjugation significantly prolonged the circulation of SA-QDots and reduced their hepatosplenic uptake. Diminished reticuloendothelial system clearance of SA-QDots and aminoPEG-QDots by HYNIC conjugation was also demonstrated by in vivo and ex vivo optical imaging. The effects of HYNIC on the opsonization, phagocytosis and in vivo kinetics of quantum dots were reversed by removal of the hydrazine component from HYNIC. Thus, surface functionalization with HYNIC can improve the in vivo kinetics of quantum dots by reducing phagocytosis via suppression of surface opsonization.

Correlative Light-Electron Microscopy of Lipid-Encapsulated Fluorescent Nanodiamonds for Nanometric Localization of Cell Surface Antigens.

PubMed

Hsieh, Feng-Jen; Chen, Yen-Wei; Huang, Yao-Kuan; Lee, Hsien-Ming; Lin, Chun-Hung; Chang, Huan-Cheng

2018-02-06

Containing an ensemble of nitrogen-vacancy centers in crystal matrices, fluorescent nanodiamonds (FNDs) are a new type of photostable markers that have found wide applications in light microscopy. The nanomaterial also has a dense carbon core, making it visible to electron microscopy. Here, we show that FNDs encapsulated in biotinylated lipids (bLs) are useful for subdiffraction imaging of antigens on cell surface with correlative light-electron microscopy (CLEM). The lipid encapsulation enables not only good dispersion of the particles in biological buffers but also high specific labeling of live cells. By employing the bL-encapsulated FNDs to target CD44 on HeLa cell surface through biotin-mediated immunostaining, we obtained the spatial distribution of these antigens by CLEM with a localization accuracy of ∼50 nm in routine operations. A comparative study with dual-color imaging, in which CD44 was labeled with FND and MICA/MICB was labeled with Alexa Fluor 488, demonstrated the superior performance of FNDs as fluorescent fiducial markers for CLEM of cell surface antigens.

Widespread Non-Hematopoietic Tissue Distribution by Transplanted Human Progenitor Cells with High Aldehyde Dehydrogenase Activity

PubMed Central

Hess, David A.; Craft, Timothy P.; Wirthlin, Louisa; Hohm, Sarah; Zhou, Ping; Eades, William C.; Creer, Michael H.; Sands, Mark S.; Nolta, Jan A.

2011-01-01

Transplanted adult progenitor cells distribute to peripheral organs and can promote endogenous cellular repair in damaged tissues. However, development of cell-based regenerative therapies has been hindered by the lack of pre-clinical models to efficiently assess multiple organ distribution and difficulty defining human cells with regenerative function. After transplantation into beta-glucuronidase (GUSB)-deficient NOD/SCID/MPSVII mice, we characterized the distribution of lineage depleted human umbilical cord blood-derived cells purified by selection using high aldehyde dehydrogenase activity (ALDH) with CD133 co-expression. ALDHhi or ALDHhiCD133+ cells produced robust hematopoietic reconstitution, and variable levels of tissue distribution in multiple organs. GUSB+ donor cells that co-expressed human (HLA-A,B,C) and hematopoietic (CD45+) cell surface markers were the primary cell phenotype found adjacent to the vascular beds of several tissues, including islet and ductal regions of mouse pancreata. In contrast, variable phenotypes were detected in the chimeric liver, with HLA+/CD45+ cells demonstrating robust GUSB expression adjacent to blood vessels, and CD45−/HLA− cells with diluted GUSB expression predominant in the liver parenchyma. However, true non-hematopoietic human (HLA+/CD45−) cells were rarely detected in other peripheral tissues, suggesting that these GUSB+/HLA−/CD45− cells in the liver were a result of downregulated human surface marker expression in vivo, not widespread seeding of non-hematopoietic cells. However, relying solely on continued expression of cell surface markers, as employed in traditional xenotransplantation models, may underestimate true tissue distribution. ALDH-expressing progenitor cells demonstrated widespread and tissue-specific distribution of variable cellular phenotypes, indicating that these adult progenitor cells should be explored in transplantation models of tissue damage. PMID:18055447

Markers of nonselective and specific NK cell activation.

PubMed

Fogel, Leslie A; Sun, Michel M; Geurs, Theresa L; Carayannopoulos, Leonidas N; French, Anthony R

2013-06-15

NK cell activation is controlled by the integration of signals from cytokine receptors and germline-encoded activation and inhibitory receptors. NK cells undergo two distinct phases of activation during murine CMV (MCMV) infection: a nonselective phase mediated by proinflammatory cytokines and a specific phase driven by signaling through Ly49H, an NK cell activation receptor that recognizes infected cells. We sought to delineate cell surface markers that could distinguish NK cells that had been activated nonselectively from those that had been specifically activated through NK cell receptors. We demonstrated that stem cell Ag 1 (Sca-1) is highly upregulated during viral infections (to an even greater extent than CD69) and serves as a novel marker of early, nonselective NK cell activation. Indeed, a greater proportion of Sca-1(+) NK cells produced IFN-γ compared with Sca-1(-) NK cells during MCMV infection. In contrast to the universal upregulation of Sca-1 (as well as KLRG1) on NK cells early during MCMV infection, differential expression of Sca-1, as well as CD27 and KLRG1, was observed on Ly49H(+) and Ly49H(-) NK cells late during MCMV infection. Persistently elevated levels of KLRG1 in the context of downregulation of Sca-1 and CD27 were observed on NK cells that expressed Ly49H. Furthermore, the differential expression patterns of these cell surface markers were dependent on Ly49H recognition of its ligand and did not occur solely as a result of cellular proliferation. These findings demonstrate that a combination of Sca-1, CD27, and KLRG1 can distinguish NK cells nonselectively activated by cytokines from those specifically stimulated through activation receptors.

Graphene-cobaltite-Pd hybrid materials for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells.

PubMed

Sharma, Chandra Shekhar; Awasthi, Rahul; Singh, Ravindra Nath; Sinha, Akhoury Sudhir Kumar

2013-12-14

Hybrid materials comprising of Pd, MCo2O4 (where M = Mn, Co or Ni) and graphene have been prepared for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells. Structural and electrochemical characterizations were carried out using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, chronoamperometry and cyclic, CO stripping, and linear sweep voltammetries. The study revealed that all the three hybrid materials are active for both methanol oxidation (MOR) and oxygen reduction (ORR) reactions in 1 M KOH. However, the Pd-MnCo2O4/GNS hybrid electrode exhibited the greatest MOR and ORR activities. This active hybrid electrode has also outstanding stability under both MOR and ORR conditions, while Pt- and other Pd-based catalysts undergo degradation under similar experimental conditions. The Pd-MnCo2O4/GNS hybrid catalyst exhibited superior ORR activity and stability compared to even Pt in alkaline solutions.

Analyses of functions of an anti-PD-L1/TGFβR2 bispecific fusion protein (M7824).

PubMed

Jochems, Caroline; Tritsch, Sarah R; Pellom, Samuel Troy; Su, Zhen; Soon-Shiong, Patrick; Wong, Hing C; Gulley, James L; Schlom, Jeffrey

2017-09-26

M7824 (MSB0011359C) is a novel first-in-class bifunctional fusion protein consisting of a fully human IgG1 anti-PD-L1 monoclonal antibody (with structural similarities to avelumab) linked to the extracellular domain of two TGFβ receptor 2 (TGFβR2) molecules serving as a TGFβ Trap. Avelumab has demonstrated clinical activity in a range of human cancers and has been approved by the Food and Drug Administration for the therapy of Merkel cell and bladder carcinomas. Preclinical studies have shown this anti-PD-L1 is capable of mediating antibody-dependent cell-mediated cytotoxicity (ADCC). In the studies reported here, it is shown that M7824 is also capable of mediating ADCC of a wide range of human carcinoma cells in vitro , employing natural killer (NK) cells as effectors, albeit not as potent as anti-PD-L1 employing some tumor cells as targets. The addition of the IL-15 superagonist fusion protein complex ALT-803 enhanced the ADCC capacity of both anti-PD-L1 and M7824, and to levels that both agents now demonstrated similar levels of ADCC of tumor cells. TGFβ is a known immunosuppressive entity. Studies reported here show TGFβ1 induced reduction of several NK activation markers as well as reduction of endogenous NK lytic activity and NK-mediated ADCC of tumor cells. These phenomena could be reduced or mitigated, however, by M7824, but not by anti-PD-L1. M7824, but not anti-PD-L1, was also shown to reduce the immunosuppressive activity of regulatory T cells on human CD4 + T-cell proliferation. These studies thus demonstrate the dual functionalities of M7824 and provide the rationale for its further clinical development.

Functionalized magnetic-fluorescent hybrid nanoparticles for cell labelling.

PubMed

Lou, Lei; Yu, Ke; Zhang, Zhengli; Li, Bo; Zhu, Jianzhong; Wang, Yiting; Huang, Rong; Zhu, Ziqiang

2011-05-01

A facile method of synthesizing 60 nm magnetic-fluorescent core-shell bifunctional nanocomposites with the ability to label cells is presented. Hydrophobic trioctylphosphine oxide (TOPO)-capped CdSe@ZnS quantum dots (QDs) were assembled on polyethyleneimine (PEI)-coated Fe(3)O(4) nanoparticles (MNP). Polyethyleneimine was utilized for the realization of multifunction, including attaching 4 nm TOPO capped CdSe@ZnS quantum dots onto magnetite particles, altering the surface properties of quantum dots from hydrophobic to hydrophilic as well as preventing the formation of large aggregates. Results show that these water-soluble hybrid nanocomposites exhibit good colloidal stability and retain good magnetic and fluorescent properties. Because TOPO-capped QDs are assembled instead of their water-soluble equivalents, the nanocomposites are still highly luminescent with no shift in the PL peak position and present long-term fluorescence stability. Moreover, TAT peptide (GRKKRRQRRRPQ) functionalized hybrid nanoparticles were also studied due to their combined magnetic enrichment and optical detection for cell separation and rapid cell labelling. A cell viability assay revealed good biocompatibility of these hybrid nanoparticles. The potential application of the new magnetic-fluorescent nanocomposites in biological and medicine is demonstrated. © The Royal Society of Chemistry 2011

Ligand-Binding Properties and Conformational Dynamics of Autolysin Repeat Domains in Staphylococcal Cell Wall Recognition

PubMed Central

Zoll, Sebastian; Schlag, Martin; Shkumatov, Alexander V.; Rautenberg, Maren; Svergun, Dmitri I.; Götz, Friedrich

2012-01-01

The bifunctional major autolysin Atl plays a key role in staphylococcal cell separation. Processing of Atl yields catalytically active amidase (AM) and glucosaminidase (GL) domains that are each fused to repeating units. The two repeats of AM (R1 and R2) target the enzyme to the septum, where it cleaves murein between dividing cells. We have determined the crystal structure of R2, which reveals that each repeat folds into two half-open β-barrel subunits. We further demonstrate that lipoteichoic acid serves as a receptor for the repeats and that this interaction depends on conserved surfaces in each subunit. Small-angle X-ray scattering of the mature amidase reveals the presence of flexible linkers separating the AM, R1, and R2 units. Different levels of flexibility for each linker provide mechanistic insights into the conformational dynamics of the full-length protein and the roles of its components in cell wall association and catalysis. Our analysis supports a model in which the repeats direct the catalytic AM domain to the septum, where it can optimally perform the final step of cell division. PMID:22609916

Biological response on a titanium implant-grade surface functionalized with modular peptides☆

PubMed Central

Yazici, H.; Fong, H.; Wilson, B.; Oren, E.E.; Amos, F.A.; Zhang, H.; Evans, J.S.; Snead, M.L.; Sarikaya, M.; Tamerler, C.

2015-01-01

Titanium (Ti) and its alloys are among the most successful implantable materials for dental and orthopedic applications. The combination of excellent mechanical and corrosion resistance properties makes them highly desirable as endosseous implants that can withstand a demanding biomechanical environment. Yet, the success of the implant depends on its osteointegration, which is modulated by the biological reactions occurring at the interface of the implant. A recent development for improving biological responses on the Ti-implant surface has been the realization that bifunctional peptides can impart material binding specificity not only because of their molecular recognition of the inorganic material surface, but also through their self-assembly and ease of biological conjugation properties. To assess peptide-based functionalization on bioactivity, the present authors generated a set of peptides for implant-grade Ti, using cell surface display methods. Out of 60 unique peptides selected by this method, two of the strongest titanium binding peptides, TiBP1 and TiBP2, were further characterized for molecular structure and adsorption properties. These two peptides demonstrated unique, but similar molecular conformations different from that of a weak binder peptide, TiBP60. Adsorption measurements on a Ti surface revealed that their disassociation constants were 15-fold less than TiBP60. Their flexible and modular use in biological surface functionalization were demonstrated by conjugating them with an integrin recognizing peptide motif, RGDS. The functionalization of the Ti surface by the selected peptides significantly enhanced the bioactivity of osteoblast and fibroblast cells on implant-grade materials. PMID:23159566

Transcriptional Networks in Single Perivascular Cells Sorted from Human Adipose Tissue Reveal a Hierarchy of Mesenchymal Stem Cells.

PubMed

Hardy, W Reef; Moldovan, Nicanor I; Moldovan, Leni; Livak, Kenneth J; Datta, Krishna; Goswami, Chirayu; Corselli, Mirko; Traktuev, Dmitry O; Murray, Iain R; Péault, Bruno; March, Keith

2017-05-01

Adipose tissue is a rich source of multipotent mesenchymal stem-like cells, located in the perivascular niche. Based on their surface markers, these have been assigned to two main categories: CD31 - /CD45 - /CD34 + /CD146 - cells (adventitial stromal/stem cells [ASCs]) and CD31 - /CD45 - /CD34 - /CD146 + cells (pericytes [PCs]). These populations display heterogeneity of unknown significance. We hypothesized that aldehyde dehydrogenase (ALDH) activity, a functional marker of primitivity, could help to better define ASC and PC subclasses. To this end, the stromal vascular fraction from a human lipoaspirate was simultaneously stained with fluorescent antibodies to CD31, CD45, CD34, and CD146 antigens and the ALDH substrate Aldefluor, then sorted by fluorescence-activated cell sorting. Individual ASCs (n = 67) and PCs (n = 73) selected from the extremities of the ALDH-staining spectrum were transcriptionally profiled by Fluidigm single-cell quantitative polymerase chain reaction for a predefined set (n = 429) of marker genes. To these single-cell data, we applied differential expression and principal component and clustering analysis, as well as an original gene coexpression network reconstruction algorithm. Despite the stochasticity at the single-cell level, covariation of gene expression analysis yielded multiple network connectivity parameters suggesting that these perivascular progenitor cell subclasses possess the following order of maturity: (a) ALDH br ASC (most primitive); (b) ALDH dim ASC; (c) ALDH br PC; (d) ALDH dim PC (least primitive). This order was independently supported by specific combinations of class-specific expressed genes and further confirmed by the analysis of associated signaling pathways. In conclusion, single-cell transcriptional analysis of four populations isolated from fat by surface markers and enzyme activity suggests a developmental hierarchy among perivascular mesenchymal stem cells supported by markers and coexpression networks. Stem Cells 2017;35:1273-1289. © 2017 AlphaMed Press.

The Cell Surface Markers Expression in Postmenopausal Women and Relation to Obesity and Bone Status.

PubMed

Horváthová, Mira; Ilavská, Silvia; Štefíková, Kornélia; Szabová, Michaela; Krivošíková, Zora; Jahnová, Eva; Tulinská, Jana; Spustová, Viera; Gajdoš, Martin

2017-07-11

The age-related changes and hormonal deprivation in postmenopausal women are associated with the immune response alteration. The excessive fat accumulation, local and systemic inflammation may lead to dysregulation in immune function and relevant health problems, including obesity and osteoporosis. We analyzed the expression of cell surface markers in the venous blood specimens, stained with fluorophores-conjugated monoclonal antibodies and analysed by multicolour flow cytometry. The significant changes of cytotoxic, naive, and memory T-lymphocytes, plasmacytoid dendritic cells (DCs) were in postmenopausal women versus fertile women. Body mass index (BMI) affected markedly the cell surface expression of CD265/RANK. Osteoporosis is linked to reduced percentage of plasmacytoid DCs, and elevated natural Treg cells ( p < 0.05). The confounding factors such as women age, BMI, bone mineral density (BMD), waist size and tissue fat affect the expression of RANK on myeloid DCs and CD40L on T-lymphocytes that might be the immunophenotypic modulators after menopause.

The Cell Surface Markers Expression in Postmenopausal Women and Relation to Obesity and Bone Status

PubMed Central

Horváthová, Mira; Ilavská, Silvia; Štefíková, Kornélia; Szabová, Michaela; Krivošíková, Zora; Jahnová, Eva; Tulinská, Jana; Spustová, Viera; Gajdoš, Martin

2017-01-01

The age-related changes and hormonal deprivation in postmenopausal women are associated with the immune response alteration. The excessive fat accumulation, local and systemic inflammation may lead to dysregulation in immune function and relevant health problems, including obesity and osteoporosis. We analyzed the expression of cell surface markers in the venous blood specimens, stained with fluorophores-conjugated monoclonal antibodies and analysed by multicolour flow cytometry. The significant changes of cytotoxic, naive, and memory T-lymphocytes, plasmacytoid dendritic cells (DCs) were in postmenopausal women versus fertile women. Body mass index (BMI) affected markedly the cell surface expression of CD265/RANK. Osteoporosis is linked to reduced percentage of plasmacytoid DCs, and elevated natural Treg cells (p < 0.05). The confounding factors such as women age, BMI, bone mineral density (BMD), waist size and tissue fat affect the expression of RANK on myeloid DCs and CD40L on T-lymphocytes that might be the immunophenotypic modulators after menopause. PMID:28696349

Cobalt phosphide based nanostructures as bifunctional electrocatalysts for low temperature alkaline water splitting

DOE PAGES

Lambert, Timothy N.; Vigil, Julian A.; Christensen, Ben

2016-08-22

Cobalt phosphide based thin films and nanoparticles were prepared by the thermal phosphidation of spinel Co 3O 4 precursor films and nanoparticles, respectively. CoP films were prepared with overall retention of the Co 3O 4 nanoplatelet morphology while the spherical/cubic Co 3O 4 and Ni 0.15Co 2.85O 4 nanoparticles were converted to nanorods or nanoparticles, respectively. The inclusion of nickel in the nanoparticles resulted in a 2.5 fold higher surface area leading to higher gravimetric performance. In each case high surface area structures were obtained with CoP as the primary phase. All materials were found to act as effective bifunctionalmore » electrocatalysts for both the HER and the OER and compared well to commercial precious metal benchmark materials in alkaline electrolyte. As a result, a symmetrical water electrolysis cell prepared from the CoP-based film operated at a low overpotential of 0.41-0.51 V.« less

Unveiling NIR Aza-Boron-Dipyrromethene (BODIPY) Dyes as Raman Probes: Surface-Enhanced Raman Scattering (SERS)-Guided Selective Detection and Imaging of Human Cancer Cells.

PubMed

Adarsh, Nagappanpillai; Ramya, Adukkadan N; Maiti, Kaustabh Kumar; Ramaiah, Danaboyina

2017-10-12

The development of new Raman reporters has attracted immense attention in diagnostic research based on surface enhanced Raman scattering (SERS) techniques, which is a well established method for ultrasensitive detection through molecular fingerprinting and imaging. Herein, for the first time, we report the unique and efficient Raman active features of the selected aza-BODIPY dyes 1-6. These distinctive attributes could be extended at the molecular level to allow detection through SERS upon adsorption onto nano-roughened gold surface. Among the newly revealed Raman reporters, the amino substituted derivative 4 showed high signal intensity at very low concentrations (ca. 0.4 μm for 4-Au). Interestingly, an efficient nanoprobe has been constructed by using gold nanoparticles as SERS substrate, and 4 as the Raman reporter (4-Au@PEG), which unexpectedly showed efficient recognition of three human cancer cells (lung: A549, cervical: HeLa, Fibrosarcoma: HT-1080) without any specific surface marker. We observed well reflected and resolved Raman mapping and characteristic signature peaks whereas, such recognition was not observed in normal fibroblast (3T3L1) cells. To confirm these findings, a SERS nanoprobe was conjugated with a specific tumour targeting marker, EGFR (Epidermal Growth Factor Receptor), a well known targeted agent for Human Fibrosarcoma (HT1080). This nanoprobe efficiently targeted the surface marker of HT1080 cells, threreby demonstrating its use as an ultrasensitive Raman probe for detection and targeted imaging, leaving normal cells unaffected. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

CD24 tracks divergent pluripotent states in mouse and human cells

PubMed Central

Shakiba, Nika; White, Carl A.; Lipsitz, Yonatan Y.; Yachie-Kinoshita, Ayako; Tonge, Peter D; Hussein, Samer M. I.; Puri, Mira C.; Elbaz, Judith; Morrissey-Scoot, James; Li, Mira; Munoz, Javier; Benevento, Marco; Rogers, Ian M.; Hanna, Jacob H.; Heck, Albert J. R.; Wollscheid, Bernd; Nagy, Andras; Zandstra, Peter W

2015-01-01

Reprogramming is a dynamic process that can result in multiple pluripotent cell types emerging from divergent paths. Cell surface protein expression is a particularly desirable tool to categorize reprogramming and pluripotency as it enables robust quantification and enrichment of live cells. Here we use cell surface proteomics to interrogate mouse cell reprogramming dynamics and discover CD24 as a marker that tracks the emergence of reprogramming-responsive cells, while enabling the analysis and enrichment of transgene-dependent (F-class) and -independent (traditional) induced pluripotent stem cells (iPSCs) at later stages. Furthermore, CD24 can be used to delineate epiblast stem cells (EpiSCs) from embryonic stem cells (ESCs) in mouse pluripotent culture. Importantly, regulated CD24 expression is conserved in human pluripotent stem cells (PSCs), tracking the conversion of human ESCs to more naive-like PSC states. Thus, CD24 is a conserved marker for tracking divergent states in both reprogramming and standard pluripotent culture. PMID:26076835

Radiation Response of Cancer Stem-Like Cells From Established Human Cell Lines After Sorting for Surface Markers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Assar, Osama; Muschel, Ruth J.; Mantoni, Tine S.

2009-11-15

Purpose: A subpopulation of cancer stem-like cells (CSLC) is hypothesized to exist in different cancer cell lines and to mediate radioresistance in solid tumors. Methods and Materials: Cells were stained for CSLC markers and sorted (fluorescence-activated cell sorter/magnetic beads) to compare foci and radiosensitivity of phosphorylated histone H2AX at Ser 139 (gamma-H2AX) in sorted vs. unsorted populations in eight cell lines from different organs. CSLC properties were examined using anchorage-independent growth and levels of activated Notch1. Validation consisted of testing tumorigenicity and postirradiation enrichment of CSLC in xenograft tumors. Results: The quantity of CSLC was generally in good agreement withmore » primary tumors. CSLC from MDA-MB-231 (breast) and Panc-1 and PSN-1 (both pancreatic) cells had fewer residual gamma-H2AX foci than unsorted cells, pointing to radioresistance of CSLC. However, only MDA-MB-231 CSLC were more radioresistant than unsorted cells. Furthermore, MDA-MB-231 CSLC showed enhanced anchorage-independent growth and overexpression of activated Notch1 protein. The expression of cancer stem cell surface markers in the MDA-MB-231 xenograft model was increased after exposure to fractionated radiation. In contrast to PSN-1 cells, a growth advantage for MDA-MB-231 CSLC xenograft tumors was found compared to tumors arising from unsorted cells. Conclusions: CSLC subpopulations showed no general radioresistant phenotype, despite the quantities of CSLC subpopulations shown to correspond relatively well in other reports. Likewise, CSLC characteristics were found in some but not all of the tested cell lines. The reported problems in testing for CSLC in cell lines may be overcome by additional techniques, beyond sorting for markers.« less

Leucine-rich Repeat Neuronal Protein 1 Regulates Differentiation of Embryonic Stem Cells by Posttranslational Modifications of Pluripotency Factors.

PubMed

Liao, Chien Huang; Wang, Ya-Hui; Chang, Wei-Wei; Yang, Bei-Chia; Wu, Tsai-Jung; Liu, Wei-Li; Yu, Alice L; Yu, John

2018-06-11

Stem cell surface markers may facilitate a better understanding of stem cell biology through molecular function studies or serve as tools to monitor the differentiation status and behavior of stem cells in culture or tissue. Thus, it is important to identify additional, novel stem cell markers. We used glycoproteomics to discover surface glycoproteins on human embryonic stem cells (hESCs) that may be useful stem cell markers. We found that a surface glycoprotein, leucine-rich repeat neuronal protein 1 (LRRN1), is expressed abundantly on the surface of hESCs prior to differentiation into embryoid bodies (EBs). Silencing of LRRN1 with short hairpin RNA (shLRRN1) in hESCs resulted in decreased capacity of self-renewal, and skewed differentiation toward endoderm/mesoderm lineages in vitro and in vivo. Meanwhile, the protein expression levels of the pluripotency factors OCT4, NANOG and SOX2 were reduced. Interestingly, the mRNA levels of these pluripotency factors were not affected in LRRN1 silenced cells, but protein half-lives were substantially shortened. Furthermore, we found LRRN1 silencing led to nuclear export and proteasomal degradation of all three pluripotency factors. In addition, the effects on nuclear export were mediated by AKT phosphorylation. These results suggest that LRRN1 plays an important role in maintaining the protein stability of pluripotency factors through AKT phosphorylation, thus maintaining hESC self-renewal capacity and pluripotency. Overall, we found that LRRN1 contributes to pluripotency of hESC by preventing translocation of OCT4, NANOG and SOX2 from nucleus to cytoplasm, thereby lessening their post-translational modification and degradation. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

Laser-modified titanium surfaces enhance the osteogenic differentiation of human mesenchymal stem cells.

PubMed

Bressel, Tatiana A B; de Queiroz, Jana Dara Freires; Gomes Moreira, Susana Margarida; da Fonseca, Jéssyca T; Filho, Edson A; Guastaldi, Antônio Carlos; Batistuzzo de Medeiros, Silvia Regina

2017-11-28

Titanium surfaces have been modified by various approaches with the aim of improving the stimulation of osseointegration. Laser beam (Yb-YAG) treatment is a controllable and flexible approach to modifying surfaces. It creates a complex surface topography with micro and nano-scaled patterns, and an oxide layer that can improve the osseointegration of implants, increasing their usefulness as bone implant materials. Laser beam irradiation at various fluences (132, 210, or 235 J/cm 2 ) was used to treat commercially pure titanium discs to create complex surface topographies. The titanium discs were investigated by scanning electron microscopy, X-ray diffraction, and measurement of contact angles. The surface generated at a fluence of 235 J/cm 2 was used in the biological assays. The behavior of mesenchymal stem cells from an umbilical cord vein was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, a mineralization assay, and an alkaline phosphatase activity assay and by carrying out a quantitative real-time polymerase chain reaction for osteogenic markers. CHO-k1 cells were also exposed to titanium discs in the MTT assay. The best titanium surface was that produced by laser beam irradiation at 235 J/cm 2 fluence. Cell proliferation analysis revealed that the CHO-k1 and mesenchymal stem cells behaved differently. The laser-processed titanium surface increased the proliferation of CHO-k1 cells, reduced the proliferation of mesenchymal stem cells, upregulated the expression of the osteogenic markers, and enhanced alkaline phosphatase activity. The laser-treated titanium surface modulated cellular behavior depending on the cell type, and stimulated osteogenic differentiation. This evidence supports the potential use of laser-processed titanium surfaces as bone implant materials, and their use in regenerative medicine could promote better outcomes.

Monoclonal antibodies to the equine CD2 T lymphocyte marker, to a pan-granulocyte/monocyte marker and to a unique pan-B lymphocyte marker.

PubMed

Tumas, D B; Brassfield, A L; Travenor, A S; Hines, M T; Davis, W C; McGuire, T C

1994-12-01

Murine monoclonal antibodies, HB88A, B29A and DH59B separately identify the CD2 T lymphocyte molecule, a unique pan-B lymphocyte surface marker and a pan-granulocyte/monocyte surface molecule, respectively, in the horse. Specificity was shown by two-color immunofluorescent flow cytometry and immunofluorescent microscopy. MAb HB88A reacted with a 52 kDa pan-T lymphocyte molecule present on 75% +/- 7 of peripheral blood lymphocytes (PBL) (n = 15 horses). It also reacted with lymphocytes restricted to T lymphocyte dependent areas of lymph node and spleen. Specificity of mAb HB88A to CD2 was demonstrated by its reactivity to COS7 cells which expressed a transfected 1.5 kb equine lymphocyte c-DNA clone having 77.5% overall sequence homology with human CD2 c-DNA. MAb B29A reacted with a pan-B lymphocyte specific cell surface complex, 143, 72, 50, 40, 27 and 14.5 kDa, present on 19% +/- 7 of PBL (n = 15 horses). This complex has not been described in the horse or other species. MAb DH59B reacted with a 96 kDa pan-granulocyte/monocyte specific surface protein and identified macrophages and Kupffer cells in equine tissue sections. Together these mAbs can be used to identify and quantitate the major constituents of equine leukocytes.

A stem cell apostasy: A tale of 4 H words

PubMed Central

Quesenberry, Peter J.; Goldberg, Laura R.; Dooner, Mark S.

2014-01-01

The field of hematopoietic stem cell biology has become increasingly dominated by the pursuit and study of highly purified populations of hematopoietic stem cells (HSCs). Such HSCs are typically isolated based on their cell surface marker expression patterns and ultimately defined by their multipotency and capacity for self-generation. However, even with progressively more stringent stem cell separation techniques, the resultant HSC population remains heterogeneous with respect to both self-renewal and differentiation capacity. Critical studies on un-separated whole bone marrow (WBM) have definitively shown that long-term engraftable hematopoietic stem cells are in active cell cycle and thus continually changing phenotype. Therefore, they cannot be purified by current approaches dependent on stable surface epitope expression because the surface markers are continually changing as well. These critical cycling cells are discarded with current stem cell purifications. Despite this, research defining such characteristics as self-renewal capacity, lineage-commitment, bone marrow niches, and proliferative state of HSCs continues to focus predominantly on this small sub-population of purified marrow cells. This review discusses the research leading to the hierarchical model of hematopoiesis and questions the dogmas pertaining to HSC quiescence and purification. PMID:25183450

Giant cells around bone biomaterials: Osteoclasts or multi-nucleated giant cells?

PubMed

Miron, Richard J; Zohdi, Hamoon; Fujioka-Kobayashi, Masako; Bosshardt, Dieter D

2016-12-01

Recently accumulating evidence has put into question the role of large multinucleated giant cells (MNGCs) around bone biomaterials. While cells derived from the monocyte/macrophage lineage are one of the first cell types in contact with implanted biomaterials, it was originally thought that specifically in bone tissues, all giant cells were bone-resorbing osteoclasts whereas foreign body giant cells (FBGCs) were found associated with a connective tissue foreign body reaction resulting in fibrous encapsulation and/or material rejection. Despite the great majority of bone grafting materials routinely found with large osteoclasts, a special subclass of bone biomaterials has more recently been found surrounded by large giant cells virtually incapable of resorbing bone grafts even years after their implantation. While original hypotheses believed that a 'foreign body reaction' may be taking place, histological data retrieved from human samples years after their implantation have put these original hypotheses into question by demonstrating better and more stable long-term bone volume around certain bone grafts. Exactly how or why this 'special' subclass of giant cells is capable of maintaining long-term bone volume, or methods to scientifically distinguish them from osteoclasts remains extremely poorly studied. The aim of this review article was to gather the current available literature on giant cell markers and differences in expression patterns between osteoclasts and MNGCs utilizing 19 specific markers including an array of CD-cell surface markers. Furthermore, the concept of now distinguishing between pro-inflammatory M1-MNGCs (previously referred to as FBGCs) as well as wound-healing M2-MNGCs is introduced and discussed. This review article presents 19 specific cell-surface markers to distinguish between osteoclasts and MNGCs including an array of CD-cell surface markers. Furthermore, the concept of now distinguishing between pro-inflammatory M1-MNGCs (often previously referred to as FBGCs) as well as wound-healing M2-MNGCs is introduced and discussed. The proposed concepts and guidelines aims to guide the next wave of research facilitating the differentiation between osteoclast/MNGCs formation, as well as provides the basis for increasing our understanding of the exact function of MNGCs in bone tissue/biomaterial homeostasis. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Expression of surface markers on the human monocytic leukaemia cell line, THP-1, as indicators for the sensitizing potential of chemicals.

PubMed

An, Susun; Kim, Seoyoung; Huh, Yong; Lee, Tae Ryong; Kim, Han-Kon; Park, Kui-Lea; Eun, Hee Chul

2009-04-01

Evaluation of skin sensitization potential is an important part of the safety assessment of cosmetic ingredients and topical drugs. Recently, evaluation of changes in surface marker expression induced in dendritic cells (DC) or DC surrogate cell lines following exposure to chemicals represents one approach for in vitro test methods. The study aimed to test the change of expression patterns of surface markers on THP-1 cells by chemicals as a predictive in vitro method for contact sensitization. We investigated the expression of CD54, CD86, CD83, CD80, and CD40 after a 1-day exposure to sensitizers (1-chloro-2,4-dinitrobenzene; 2,4-dinitrofluorobenzene; benzocaine; 5-chloro-2-methyl-4-isothiazolin-3-one; hexyl cinnamic aldehyde; eugenol; nickel sulfate hexahydrate; potassium dichromate; cobalt sulfate; 2-mercaptobenzothiazole; and ammonium tetrachloroplatinate) and non-sensitizers (sodium lauryl sulfate, benzalkonium chloride, lactic acid, salicylic acid, isopropanol, and dimethyl sulphoxide). The test concentrations were 0.1x, 0.5x, and 1x of the 50% inhibitory concentration, and the relative fluorescence intensity was used as an expression indicator. By evaluating the expression patterns of CD54, CD86, and CD40, we could classify the chemicals as sensitizers or non-sensitizers, but CD80 and CD83 showed non-specific patterns of expression. These data suggest that the THP-1 cells are good model for screening contact sensitizers and CD40 could be a useful marker complementary to CD54 and CD86.

The influence of rat mesenchymal stem cell CD44 surface markers on cell growth, fibronectin expression, and cardiomyogenic differentiation on silk fibroin - Hyaluronic acid cardiac patches.

PubMed

Yang, Ming-Chia; Chi, Nai-Hsin; Chou, Nai-Kuan; Huang, Yi-You; Chung, Tze-Wen; Chang, Yu-Lin; Liu, Hwa-Chang; Shieh, Ming-Jium; Wang, Shoei-Shen

2010-02-01

Since MSCs contain an abundant of CD44 surface markers, it is of interesting to investigate whether CD44 on rat MSC (rMSCs) influenced cell growth, fibronectin expression and cardiomyogenic differentiation on new SF/HA cardiac patches. For this investigation, we examined the influences of rMSCs with or without a CD44-blockage treatment on the aforementioned issues after they were cultivated, and further induced by 5-aza on SF and SF/HA patches. The results showed that the relative growth rates of rMSCs cultured on cultural wells, SF/HA patches without or with a CD44-blockage treatment were 100%, 208.9+/-7.1 (%) or 48.4+/-6.0 (%) (n=3, for all), respectively, after five days of cultivations. Moreover, rMSCs cultivated on SF/HA patches highly promoted fibronectin expressions (e.g., 1.8x10(5)/cell, in fluorescent intensity) while cells with a CD44-blockage treatment markedly diminished the expressions (e.g., 1.1x10(4)/cell, in fluorescent intensity) on same patches. For investigating possible influences of CD44 surface markers of rMSCs on their cardiomyogenic differentiation, the expressions of specific cardiac genes of cells were examined by using real-time PCR analysis. The results indicated that 5-aza inducing rMSCs significantly promoted the expressions of Gata4, Nkx2.5, Tnnt2 and Actc1 genes (all, P<0.01 or better, n=3) on SF/HA patches compared with those expressions on SF patches and for cells with a CD44-blockage treatment on SF/HA patches. Furthermore, the intensity of the expressions of cardiotin and connexin 43 of 5-aza inducing rMSCs were markedly higher than those of cells with a CD44-blockage treatment after they were cultured on SF/HA patches. Through this study, we reported that CD44 surface markers of rMSCs highly influenced the proliferations, fibronectin expressions and cardiomyogenic differentiation of rMSCs cultivated on cardiac SF/HA patches.

Pore-formation by adenylate cyclase toxoid activates dendritic cells to prime CD8+ and CD4+ T cells.

PubMed

Svedova, Martina; Masin, Jiri; Fiser, Radovan; Cerny, Ondrej; Tomala, Jakub; Freudenberg, Marina; Tuckova, Ludmila; Kovar, Marek; Dadaglio, Gilles; Adkins, Irena; Sebo, Peter

2016-04-01

The adenylate cyclase toxin-hemolysin (CyaA) of Bordetella pertussis is a bi-functional leukotoxin. It penetrates myeloid phagocytes expressing the complement receptor 3 and delivers into their cytosol its N-terminal adenylate cyclase enzyme domain (~400 residues). In parallel, ~1300 residue-long RTX hemolysin moiety of CyaA forms cation-selective pores and permeabilizes target cell membrane for efflux of cytosolic potassium ions. The non-enzymatic CyaA-AC(-) toxoid, has repeatedly been successfully exploited as an antigen delivery tool for stimulation of adaptive T-cell immune responses. We show that the pore-forming activity confers on the CyaA-AC(-) toxoid a capacity to trigger Toll-like receptor and inflammasome signaling-independent maturation of CD11b-expressing dendritic cells (DC). The DC maturation-inducing potency of mutant toxoid variants in vitro reflected their specifically enhanced or reduced pore-forming activity and K(+) efflux. The toxoid-induced in vitro phenotypic maturation of DC involved the activity of mitogen activated protein kinases p38 and JNK and comprised increased expression of maturation markers, interleukin 6, chemokines KC and LIX and granulocyte-colony-stimulating factor secretion, prostaglandin E2 production and enhancement of chemotactic migration of DC. Moreover, i.v. injected toxoids induced maturation of splenic DC in function of their cell-permeabilizing capacity. Similarly, the capacity of DC to stimulate CD8(+) and CD4(+) T-cell responses in vitro and in vivo was dependent on the pore-forming activity of CyaA-AC(-). This reveals a novel self-adjuvanting capacity of the CyaA-AC(-) toxoid that is currently under clinical evaluation as a tool for delivery of immunotherapeutic anti-cancer CD8(+) T-cell vaccines into DC.

REDUCTIVE ACTIVATION OF DIOXYGEN FOR DEGRADATION OF METHYL TERT-BUTYL ETHER BY BIFUNCTION

EPA Science Inventory

Bifunctional aluminum is prepared by sulfating aluminum metal with sulfuric acid. The use of bifunctional aluminum to degrade methyl tert-butyl ether (MTBE) in the presence of dioxygen has been examined using batch systems. Primary degradation products were tert-butyl alcohol, ...

Framework Stability of Nanocrystalline NaY in Aqueous Solution at Varying pH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petushkov, Anton; Freeman, Jasmine; Larsen, Sarah C.

Nanocrystalline zeolites (with crystal sizes of less than 50 nm) are versatile, porous nanomaterials with potential applications in a broad range of areas including bifunctional catalysis, drug delivery, environmental protection, and sensing, to name a few. The characterization of the properties of nanocrystalline zeolites on a fundamental level is critical to the realization of these innovative applications. Nanocrystalline zeolites have unique surface chemistry that is distinct from conventional microcrystalline zeolite materials and that will result in novel applications. In the proposed work, magnetic resonance techniques (solid state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR)) will be used tomore » elucidate the structure and reactivity of nanocrystalline zeolites and to motivate bifunctional applications. Density functional theory (DFT) calculations will enhance data interpretation through chemical shift, quadrupole coupling constant, g-value and hyperfine calculations.« less

Hepatic oval cells express the hematopoietic stem cell marker Thy-1 in the rat.

PubMed

Petersen, B E; Goff, J P; Greenberger, J S; Michalopoulos, G K

1998-02-01

Hepatic oval cells (HOC) are a small subpopulation of cells found in the liver when hepatocyte proliferation is inhibited and followed by some type of hepatic injury. HOC can be induced to proliferate using a 2-acetylaminofluorene (2-AAF)/hepatic injury (i.e., CCl4, partial hepatectomy [PHx]) protocol. These cells are believed to be bipotential, i.e., able to differentiate into hepatocytes or bile ductular cells. In the past, isolation of highly enriched populations of these cells has been difficult. Thy-1 is a cell surface marker used in conjunction with CD34 and lineage-specific markers to identify hematopoietic stem cells. Thy-1 antigen is not normally expressed in adult liver, but is expressed in fetal liver, presumably on the hematopoietic cells. We report herein that HOC express high levels of Thy-1. Immunohistochemistry revealed that the cells expressing Thy-1 were indeed oval cells, because they also expressed alpha-fetoprotein (AFP), gamma-glutamyl transpeptidase (GGT), cytokeratin 19 (CK-19), OC.2, and OV-6, all known markers for oval cell identification. In addition, the Thy-1+ cells were negative for desmin, a marker specific for Ito cells. Using Thy-1 antibody as a new marker for the identification of oval cells, a highly enriched population was obtained. Using flow cytometric methods, we isolated a 95% to 97% pure Thy-1+ oval cell population. Our results indicate that cell sorting using Thy-1 could be an attractive tool for future studies, which would facilitate both in vivo and in vitro studies of HOC.

Expression pattern of pluripotent markers in different embryonic developmental stages of buffalo (Bubalus bubalis) embryos and putative embryonic stem cells generated by parthenogenetic activation.

PubMed

Singh, Karn P; Kaushik, Ramakant; Garg, Veena; Sharma, Ruchi; George, Aman; Singh, Manoj K; Manik, Radhey S; Palta, Prabhat; Singla, Suresh K; Chauhan, Manmohan S

2012-12-01

In this study, we describe the production of buffalo parthenogenetic blastocysts and subsequent isolation of parthenogenetic embryonic stem cell (PGESC)-like cells. PGESC colonies exhibited dome-shaped morphology and were clearly distinguishable from the feeder layer cells. Different stages of development of parthenogenetic embryos and derived embryonic stem cell (ESC)-like cells expressed key ESC-specific markers, including OCT-4, NANOG, SOX-2, FOXD3, REX-1, STAT-3, TELOMERASE, NUCLEOSTEMIN, and cMYC. Immunofluorescence-based studies revealed that the PGESCs were positive for surface-based pluripotent markers, viz., SSEA-3, SSEA-4, TRA 1-80, TRA 1-60, CD-9, and CD-90 and exhibited high alkaline phosphatase (ALP) activity. PGEC cell-like cells formed embryoid body (EB)-like structures in hanging drop cultures and when cultured for extended period of time spontaneously differentiated into derivatives of three embryonic germ layers as confirmed by RT-PCR for ectodermal (CYTOKERATIN8, NF-68), mesodermal (MSX1, BMP-4, ASA), and endodermal markers (AFP, HNF-4, GATA-4). Differentiation of PGESCs toward the neuronal lineage was successfully directed by supplementation of serum-containing media with retinoic acid. Our results indicate that the isolated ESC-like cells from parthenogenetic blastocyst hold properties of ESCs and express markers of pluripotency. The pluripotency markers were also expressed by early cleavage-stage of buffalo embryos.

Hollow TiO2@Co9S8 Core–Branch Arrays as Bifunctional Electrocatalysts for Efficient Oxygen/Hydrogen Production

PubMed Central

Deng, Shengjue; Zhong, Yu; Zeng, Yinxiang; Wang, Yadong; Wang, Xiuli; Tu, Jiangping

2017-01-01

Abstract Designing ever more efficient and cost‐effective bifunctional electrocatalysts for oxygen/hydrogen evolution reactions (OER/HER) is greatly vital and challenging. Here, a new type of binder‐free hollow TiO2@Co9S8 core–branch arrays is developed as highly active OER and HER electrocatalysts for stable overall water splitting. Hollow core–branch arrays of TiO2@Co9S8 are readily realized by the rational combination of crosslinked Co9S8 nanoflakes on TiO2 core via a facile and powerful sulfurization strategy. Arising from larger active surface area, richer/shorter transfer channels for ions/electrons, and reinforced structural stability, the as‐obtained TiO2@Co9S8 core–branch arrays show noticeable exceptional electrocatalytic performance, with low overpotentials of 240 and 139 mV at 10 mA cm−2 as well as low Tafel slopes of 55 and 65 mV Dec−1 for OER and HER in alkaline medium, respectively. Impressively, the electrolysis cell based on the TiO2@Co9S8 arrays as both cathode and anode exhibits a remarkably low water splitting voltage of 1.56 V at 10 mA cm−2 and long‐term durability with no decay after 10 d. The versatile fabrication protocol and smart branch‐core design provide a new way to construct other advanced metal sulfides for energy conversion and storage. PMID:29593976

Hollow TiO2@Co9S8 Core-Branch Arrays as Bifunctional Electrocatalysts for Efficient Oxygen/Hydrogen Production.

PubMed

Deng, Shengjue; Zhong, Yu; Zeng, Yinxiang; Wang, Yadong; Wang, Xiuli; Lu, Xihong; Xia, Xinhui; Tu, Jiangping

2018-03-01

Designing ever more efficient and cost-effective bifunctional electrocatalysts for oxygen/hydrogen evolution reactions (OER/HER) is greatly vital and challenging. Here, a new type of binder-free hollow TiO 2 @Co 9 S 8 core-branch arrays is developed as highly active OER and HER electrocatalysts for stable overall water splitting. Hollow core-branch arrays of TiO 2 @Co 9 S 8 are readily realized by the rational combination of crosslinked Co 9 S 8 nanoflakes on TiO 2 core via a facile and powerful sulfurization strategy. Arising from larger active surface area, richer/shorter transfer channels for ions/electrons, and reinforced structural stability, the as-obtained TiO 2 @Co 9 S 8 core-branch arrays show noticeable exceptional electrocatalytic performance, with low overpotentials of 240 and 139 mV at 10 mA cm -2 as well as low Tafel slopes of 55 and 65 mV Dec -1 for OER and HER in alkaline medium, respectively. Impressively, the electrolysis cell based on the TiO 2 @Co 9 S 8 arrays as both cathode and anode exhibits a remarkably low water splitting voltage of 1.56 V at 10 mA cm -2 and long-term durability with no decay after 10 d. The versatile fabrication protocol and smart branch-core design provide a new way to construct other advanced metal sulfides for energy conversion and storage.

Ovarian cancer stem cells.

PubMed

Zeimet, A G; Reimer, D; Sopper, S; Boesch, M; Martowicz, A; Roessler, J; Wiedemair, A M; Rumpold, H; Untergasser, G; Concin, N; Hofstetter, G; Muller-Holzner, E; Fiegl, H; Marth, C; Wolf, D; Pesta, M; Hatina, J

2012-01-01

Because of its semi-solid character in dissemination and growth, advanced ovarian cancer with its hundreds of peritoneal tumor nodules and plaques appears to be an excellent in vivo model for studying the cancer stem cell hypothesis. The most important obstacle, however, is to adequately define and isolate these tumor-initiating cells endowed with the properties of anoikis-resistance and unlimited self-renewal. Until now, no universal single marker or marker constellation has been found to faithfully isolate (ovarian) cancer stem cells. As these multipotent cells are known to possess highly elaborated efflux systems for cytotoxic agents, these pump systems have been exploited to outline putative stem cells as a side-population (SP) via dye exclusion analysis. Furthermore, the cells in question have been isolated via flow cytometry on the basis of cell surface markers thought to be characteristic for stem cells.In the Vienna variant of the ovarian cancer cell line A2780 a proof-of-principle model with both a stable SP and a stable ALDH1A1+ cell population was established. Double staining clearly revealed that both cell fractions were not identical. Of note, A2780V cells were negative for expression of surface markers CD44 and CD117 (c-kit). When cultured on monolayers of healthy human mesothelial cells, green-fluorescence-protein (GFP)-transfected SP of A2780V exhibited spheroid-formation, whereas non-side-population (NSP) developed a spare monolayer growing over the healthy mesothelium. Furthermore, A2780V SP was found to be partially resistant to platinum. However, this resistance could not be explained by over-expression of the "excision repair cross-complementation group 1" (ERCC1) gene, which is essentially involved in the repair of platinated DNA damage. ERCC1 was, nonetheless, over-expressed in A2780V cells grown as spheres under stem cell-selective conditions as compared to adherent monolayers cultured under differentiating conditions. The same was true for the primary ovarian cancer cells B-57.In summary our investigations indicate that even in multi-passaged cancer cell lines hierarchic government of growth and differentiation is conserved and that the key cancer stem cell population may be composed of small overlapping cell fractions defined by various arbitrary markers.

Expression of pericardial fluid T-cells and related inflammatory cytokines in patients with chronic heart failure.

PubMed

Iskandar, Reinard; Liu, Shengchen; Xiang, Fei; Chen, Wen; Li, Liangpeng; Qin, Wei; Huang, Fuhua; Chen, Xin

2017-05-01

Pericardial fluid, as a biochemical indicator of heart status, directly indicates pathological alteration to the heart. The accumulation of pericardial fluid can be attributed to an underlying systemic or local inflammatory process. However, the pericardial fluid expression of cellular surface markers, as well as several cytokines in chronic heart failure (CHF), remain unclear. In order to evaluate these issues further the pericardial fluid expression of several cytokines and the surface expression of activity markers between CHF patients and non-heart failure (NHF) patients were analyzed. The pericardial fluid expression of cytokines was measured by immunofluorescence and biomarker of plasma N-terminal propeptide of B-type natriuretic peptide (NT-proBNP), while pericardial fluid levels of soluble glycoprotein 130 (sgp130) were analyzed by ELISA in 50 CHF and 24 NHF patients. In addition, the surface expression of activation markers for T-cells was measured by immunohistochemistry. Patients with CHF demonstrated increased levels of plasma NT-proBNP and pericardial fluid sgp130. Surface expression of cellular activation markers CD25 and Foxp3 in the pericardial fluid was increased in patients with CHF. Moreover, the pro- and anti-inflammatory cytokines interferon (IFN)-γ, interleukin (IL)-6 and IL-10 in patients with CHF also demonstrated an increased expression within its pericardial fluid. In addition, there was infiltration of inflammatory cells and enhanced expression of inflammatory cytokines in the pericardial fluid of patients with CHF, which may reflect T cell activation, suggesting that systemic inflammation is important in the progression of CHF. This evidence could indicate a possible novel target for future therapeutics and prevention of CHF.

[Stem cells: searching predisposition to cardiac commitment by surface markers expression].

PubMed

Lara-Martínez, Luis A; Gutiérrez-Villegas, Ingrid; Arenas-Luna, Victor M; Hernández-Gutierrez, Salomón

2018-01-05

It is well-known that cardiovascular diseases are the leading cause of death worldwide, and represent an important economic burden to health systems. In an attempt to solve this problem, stem cell therapy has emerged as a therapeutic option. Within the last 20 years, a great variety of stem cells have been used in different myocardial infarction models. Up until now, the use of cardiac stem cells (CSCs) has seemed to be the best option, but the inaccessibility and scarcity of these cells make their use unreliable. Additionally, there is a high risk as they have to be obtained directly from the heart of the patient. Unlike CSCs, adult stem cells originating from bone marrow or adipose tissue, among others, appear to be an attractive option due to their easier accessibility and abundance, but particularly due to the probable existence of cardiac progenitors among their different sub-populations. In this review an analysis is made of the surface markers present in CSCs compared with other adult stem cells. This suggested the pre-existence of cells sharing specific surface markers with CSCs, a predictable immunophenotype present in some cells, although in low proportions, and with a potential of cardiac differentiation that could be similar to CSCs, thus increasing their therapeutic value. This study highlights new perspectives regarding MSCs that would enable some of these sub-populations to be differentiated at cardiac tissue level. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Mammary collective cell migration involves transient loss of epithelial features and individual cell migration within the epithelium

PubMed Central

Ewald, Andrew J.; Huebner, Robert J.; Palsdottir, Hildur; Lee, Jessie K.; Perez, Melissa J.; Jorgens, Danielle M.; Tauscher, Andrew N.; Cheung, Kevin J.; Werb, Zena; Auer, Manfred

2012-01-01

Normal mammary morphogenesis involves transitions between simple and multilayered epithelial organizations. We used electron microscopy and molecular markers to determine whether intercellular junctions and apico-basal polarity were maintained in the multilayered epithelium. We found that multilayered elongating ducts had polarized apical and basal tissue surfaces both in three-dimensional culture and in vivo. However, individual cells were only polarized on surfaces in contact with the lumen or extracellular matrix. The basolateral marker scribble and the apical marker atypical protein kinase C zeta localized to all interior cell membranes, whereas PAR3 displayed a cytoplasmic localization, suggesting that the apico-basal polarity was incomplete. Despite membrane localization of E-cadherin and β-catenin, we did not observe a defined zonula adherens connecting interior cells. Instead, interior cells were connected through desmosomes and exhibited complex interdigitating membrane protrusions. Single-cell labeling revealed that individual cells were both protrusive and migratory within the epithelial multilayer. Inhibition of Rho kinase (ROCK) further reduced intercellular adhesion on apical and lateral surfaces but did not disrupt basal tissue organization. Following morphogenesis, segregated membrane domains were re-established and junctional complexes re-formed. We observed similar epithelial organization during mammary morphogenesis in organotypic culture and in vivo. We conclude that mammary epithelial morphogenesis involves a reversible, spatially limited, reduction in polarity and intercellular junctions and active individualistic cell migration. Our data suggest that reductions in polarity and adhesion during breast cancer progression might reflect partial recapitulation of a normal developmental program. PMID:22344263

Controllable Construction of Core-Shell Polymer@Zeolitic Imidazolate Frameworks Fiber Derived Heteroatom-Doped Carbon Nanofiber Network for Efficient Oxygen Electrocatalysis.

PubMed

Zhao, Yingxuan; Lai, Qingxue; Zhu, Junjie; Zhong, Jia; Tang, Zeming; Luo, Yan; Liang, Yanyu

2018-05-01

Designing rational nanostructures of metal-organic frameworks based carbon materials to promote the bifunctional catalytic activity of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly desired but still remains a great challenge. Herein, an in situ growth method to achieve 1D structure-controllable zeolitic imidazolate frameworks (ZIFs)/polyacrylonitrile (PAN) core/shell fiber (PAN@ZIFs) is developed. Subsequent pyrolysis of this precursor can obtain a heteroatom-doped carbon nanofiber network as an efficient bifunctional oxygen electrocatalyst. The electrocatalytic performance of derived carbon nanofiber is dominated by the structures of PAN@ZIFs fiber, which is facilely regulated by efficiently controlling the nucleation and growth process of ZIFs on the surface of polymer fiber as well as optimizing the components of ZIFs. Benefiting from the core-shell structures with appropriate dopants and porosity, as-prepared catalysts show brilliant bifunctional ORR/OER catalytic activity and durability. Finally, the rechargeable Zn-air battery assembled from the optimized catalyst (CNF@Zn/CoNC) displays a peak power density of 140.1 mW cm -2 , energy density of 878.9 Wh kg Zn -1 , and excellent cyclic stability over 150 h, giving a promising performance in realistic application. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly Efficient and Robust Nickel Phosphides as Bifunctional Electrocatalysts for Overall Water-Splitting.

PubMed

Li, Jiayuan; Li, Jing; Zhou, Xuemei; Xia, Zhaoming; Gao, Wei; Ma, Yuanyuan; Qu, Yongquan

2016-05-04

To search for the efficient non-noble metal based and/or earth-abundant electrocatalysts for overall water-splitting is critical to promote the clean-energy technologies for hydrogen economy. Herein, we report nickel phosphide (NixPy) catalysts with the controllable phases as the efficient bifunctional catalysts for water electrolysis. The phases of NixPy were determined by the temperatures of the solid-phase reaction between the ultrathin Ni(OH)2 plates and NaH2PO2·H2O. The NixPy with the richest Ni5P4 phase synthesized at 325 °C (NixPy-325) delivered efficient and robust catalytic performance for hydrogen evolution reaction (HER) in the electrolytes with a wide pH range. The NixPy-325 catalysts also exhibited a remarkable performance for oxygen evolution reaction (OER) in a strong alkaline electrolyte (1.0 M KOH) due to the formation of surface NiOOH species. Furthermore, the bifunctional NixPy-325 catalysts enabled a highly performed overall water-splitting with ∼100% Faradaic efficiency in 1.0 M KOH electrolyte, in which a low applied external potential of 1.57 V led to a stabilized catalytic current density of 10 mA/cm(2) over 60 h.

Generation of Mesenchymal-Like Stem Cells From Urine in Pediatric Patients.

PubMed

He, W; Zhu, W; Cao, Q; Shen, Y; Zhou, Q; Yu, P; Liu, X; Ma, J; Li, Y; Hong, K

2016-01-01

Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine. Traditionally, the procedures of MSC isolation are usually invasive and time-consuming. Urine is merely a body waste, and recent studies have suggested that urine represents an alternative source of stem cells. We, therefore, determined whether the possibility of isolating mesenchymal-like stem cells was practical from human urine. A total of 16 urine samples were collected from pediatric patients. Urine-derived cells were isolated, expanded, and identified for specific cell surface markers using flow cytometry. Cell morphology was observed by microscopy. Osteogenic and adipogenic differentiation potential were determinded by culturing cells in specific induction medium, and assessed by alkaline phosphatase and oil red O stainings, respectively. Clones were established and passaged successfully from primary cultures of urine cells. Cultured urine-derived cells at passage 3 were fusiform and arranged with certain directionality. Urine-derived cells at passage 5 displayed expressions of cell surface markers (CD29, CD105, CD166, CD90, and CD13). There was no expression of the general hematopoietic cell markers (CD45, CD34, and HLA-DR). Under in vitro induction conditions, urine-derived cells at passage 5 were able to differentiate into osteoblasts, but not adipocytes. Urine may be a noninvasive source for mesenchymal-like stem cells. These cells could potentially provide a new source of autologous stem cells for regenerative medicine and cell therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Aminoadipate semialdehyde synthase mRNA knockdown reduces the lysine requirement of a mouse hepatic cell line

USDA-ARS?s Scientific Manuscript database

a-Aminoadipate d-semialdehyde synthase (AASS) is the bifunctional enzyme containing the lysine a-ketoglutarate reductase (LKR) and saccharopine dehydrogenase activities responsible for the first two steps in the irreversible catabolism of lysine. A rare disease in humans, familial hyperlysinemia, c...

T cell exhaustion: from pathophysiological basics to tumor immunotherapy.

PubMed

Catakovic, Kemal; Klieser, Eckhard; Neureiter, Daniel; Geisberger, Roland

2017-01-05

The immune system is capable of distinguishing between danger- and non-danger signals, thus inducing either an appropriate immune response against pathogens and cancer or inducing self-tolerance to avoid autoimmunity and immunopathology. One of the mechanisms that have evolved to prevent destruction by the immune system, is to functionally silence effector T cells, termed T cell exhaustion, which is also exploited by viruses and cancers for immune escape In this review, we discuss some of the phenotypic markers associated with T cell exhaustion and we summarize current strategies to reinvigorate exhausted T cells by blocking these surface marker using monoclonal antibodies.

An analytical study of reduced-gravity flow dynamics

NASA Technical Reports Server (NTRS)

Bradshaw, R. D.; Kramer, J. L.; Zich, J. L.

1976-01-01

Addition of surface tension forces to a marker-and-cell code and the performance of four incompressible fluid simulations in reduced gravity, were studied. This marker-and-cell code has a variable grid capability with arbitrary curved boundaries and time dependent acceleration fields. The surface tension logic includes a spline fit of surface marker particles as well as contact angle logic for straight and curved wall boundaries. Three types of flow motion were simulated with the improved code: impulsive settling in a model Centaur LH2 tank, continuous settling in a model and full scale Centaur LO2 tank and mixing in a Centaur LH2 tank. The impulsive settling case confirmed a drop tower analysis which indicated more orderly fluid collection flow patterns with this method providing a potential savings in settling propellants. In the LO2 tank, fluid collection and flow simulation into the thrust barrel were achieved. The mixing simulation produced good results indicating both the development of the flow field and fluid interface behavior.

The usefulness of three-dimensional cell culture in induction of cancer stem cells from esophageal squamous cell carcinoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujiwara, Daisuke; Kato, Kazunori, E-mail: kzkatou@juntendo.ac.jp; Department of Atopy Research Center, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421

2013-05-17

Highlights: •Spheroids were created from esophageal carcinoma cells using NanoCulture® Plates. •The proportion of strongly ALDH-positive cells increased in 3-D culture. •Expression of cancer stem cell-related genes was enhanced in 3-D culture. •CA-9 expression was enhanced, suggesting hypoxia had been induced in 3-D culture. •Drug resistance was increased. 3-D culture is useful for inducing cancer stem cells. -- Abstract: In recent years, research on resistance to chemotherapy and radiotherapy in cancer treatment has come under the spotlight, and researchers have also begun investigating the relationship between resistance and cancer stem cells. Cancer stem cells are assumed to be present inmore » esophageal cancer, but experimental methods for identification and culture of these cells have not yet been established. To solve this problem, we created spheroids using a NanoCulture® Plate (NCP) for 3-dimensional (3-D) cell culture, which was designed as a means for experimentally reproducing the 3-D structures found in the body. We investigated the potential for induction of cancer stem cells from esophageal cancer cells. Using flow cytometry we analyzed the expression of surface antigen markers CD44, CD133, CD338 (ABCG2), CD318 (CDCP1), and CD326 (EpCAM), which are known cancer stem cell markers. None of these surface antigen markers showed enhanced expression in 3-D cultured cells. We then analyzed aldehyde dehydrogenase (ALDH) enzymatic activity using the ALDEFLUOR reagent, which can identify immature cells such as stem cells and precursor cells. 3-D-cultured cells were strongly positive for ALDH enzyme activity. We also analyzed the expression of the stem cell-related genes Sox-2, Nanog, Oct3/4, and Lin28 using RT-PCR. Expression of Sox-2, Nanog, and Lin28 was enhanced. Analysis of expression of the hypoxic surface antigen marker carbonic anhydrase-9 (CA-9), which is an indicator of cancer stem cell induction and maintenance, revealed that CA-9 expression was enhanced, suggesting that hypoxia had been induced. Comparison of cancer drug resistance using cisplatin and doxorubicin in 3-D-cultured esophageal cancer cells showed that cancer drug resistance had increased. These results indicate that 3-D culture of esophageal squamous cell carcinoma lines is a useful method for inducing cancer stem cells.« less

Catalytic activity of nanostructured Au: Scale effects versus bimetallic/bifunctional effects in low-temperature CO oxidation on nanoporous Au

PubMed Central

Wang, Lu-Cun; Zhong, Yi; Jin, Haijun; Widmann, Daniel; Weissmüller, Jörg

2013-01-01

Summary The catalytic properties of nanostructured Au and their physical origin were investigated by using the low-temperature CO oxidation as a test reaction. In order to distinguish between structural effects (structure–activity correlations) and bimetallic/bifunctional effects, unsupported nanoporous gold (NPG) samples prepared from different Au alloys (AuAg, AuCu) by selective leaching of a less noble metal (Ag, Cu) were employed, whose structure (surface area, ligament size) as well as their residual amount of the second metal were systematically varied by applying different potentials for dealloying. The structural and chemical properties before and after 1000 min reaction were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic behavior was evaluated by kinetic measurements in a conventional microreactor and by dynamic measurements in a temporal analysis of products (TAP) reactor. The data reveal a clear influence of the surface contents of residual Ag and Cu species on both O2 activation and catalytic activity, while correlations between activity and structural parameters such as surface area or ligament/crystallite size are less evident. Consequences for the mechanistic understanding and the role of the nanostructure in these NPG catalysts are discussed. PMID:23503603

Endocytosis and interaction of poly (amidoamine) dendrimers with Caco-2 cells.

PubMed

Kitchens, Kelly M; Foraker, Amy B; Kolhatkar, Rohit B; Swaan, Peter W; Ghandehari, Hamidreza

2007-11-01

To investigate the internalization and subcellular trafficking of fluorescently labeled poly (amidoamine) (PAMAM) dendrimers in intestinal cell monolayers. PAMAM dendrimers with positive or negative surface charge were conjugated to fluorescein isothiocyanate (FITC) and visualized for colocalization with endocytosis markers using confocal microscopy. Effect of concentration, generation and charge on the morphology of microvilli was observed using transmission electron microscopy. Both cationic and anionic PAMAM dendrimers internalized within 20 min, and differentially colocalized with endocytosis markers clathrin, EEA-1, and LAMP-1. Transmission electron microscopy analysis showed a concentration-, generation- and surface charge-dependent effect on microvilli morphology. These studies provide visual evidence that endocytic mechanism(s) contribute to the internalization and subcellular trafficking of PAMAM dendrimers across the intestinal cells, and that appropriate selection of PAMAM dendrimers based on surface charge, concentration and generation number allows the application of these polymers for oral drug delivery.

Multi-cellular human bronchial models exposed to diesel exhaust particles: assessment of inflammation, oxidative stress and macrophage polarization.

PubMed

Ji, Jie; Upadhyay, Swapna; Xiong, Xiaomiao; Malmlöf, Maria; Sandström, Thomas; Gerde, Per; Palmberg, Lena

2018-05-02

Diesel exhaust particles (DEP) are a major component of outdoor air pollution. DEP mediated pulmonary effects are plausibly linked to inflammatory and oxidative stress response in which macrophages (MQ), epithelial cells and their cell-cell interaction plays a crucial role. Therefore, in this study we aimed at studying the cellular crosstalk between airway epithelial cells with MQ and MQ polarization following exposure to aerosolized DEP by assessing inflammation, oxidative stress, and MQ polarization response markers. Lung mucosa models including primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI) were co-cultured without (PBEC-ALI) and with MQ (PBEC-ALI/MQ). Cells were exposed to 12.7 μg/cm 2 aerosolized DEP using XposeALI ® . Control (sham) models were exposed to clean air. Cell viability was assessed. CXCL8 and IL-6 were measured in the basal medium by ELISA. The mRNA expression of inflammatory markers (CXCL8, IL6, TNFα), oxidative stress (NFKB, HMOX1, GPx) and MQ polarization markers (IL10, IL4, IL13, MRC1, MRC2 RETNLA, IL12 andIL23) were measured by qRT-PCR. The surface/mRNA expression of TLR2/TLR4 was detected by FACS and qRT-PCR. In PBEC-ALI exposure to DEP significantly increased the secretion of CXCL8, mRNA expression of inflammatory markers (CXCL8, TNFα) and oxidative stress markers (NFKB, HMOX1, GPx). However, mRNA expressions of these markers (CXCL8, IL6, NFKB, and HMOX1) were reduced in PBEC-ALI/MQ models after DEP exposure. TLR2 and TLR4 mRNA expression increased after DEP exposure in PBEC-ALI. The surface expression of TLR2 and TLR4 on PBEC was significantly reduced in sham-exposed PBEC-ALI/MQ compared to PBEC-ALI. After DEP exposure surface expression of TLR2 was increased on PBEC of PBEC-ALI/MQ, while TLR4 was decreased in both models. DEP exposure resulted in similar expression pattern of TLR2/TLR4 on MQ as in PBEC. In PBEC-ALI/MQ, DEP exposure increased the mRNA expression of anti-inflammatory M2 macrophage markers (IL10, IL4, IL13, MRC1, MRC2). The cellular interaction of PBEC with MQ in response to DEP plays a pivotal role for MQ phenotypic alteration towards M2-subtypes, thereby promoting an efficient resolution of the inflammation. Furthermore, this study highlighted the fact that cell-cell interaction using multicellular ALI-models combined with an in vivo-like inhalation exposure system is critical in better mimicking the airway physiology compared with traditional cell culture systems.

Mesenchymal stem cells reside in anterior cruciate ligament remnants in situ.

PubMed

Fu, Weili; Li, Qi; Tang, Xin; Chen, Gang; Zhang, Chenghao; Li, Jian

2016-07-01

It has been reported that the anterior cruciate ligament (ACL) has certain self-healing ability after acute injury or with primary suture repair. Many studies have confirmed that a remnant preservation technique with ACL reconstruction contributes to biological augmentation for ACL healing. However, it remains unclear whether mesenchymal stem cells (MSC) reside in ACL remnants in situ. The aim of this study was to investigate the methods of culture and identification of MSC derived from the remnants of ACL rupture patients and to analyse these MSC's properties. The cells of ACL remnants from the ACL rupture patients were isolated by the methods of enzymatic digestion and cultured in vitro to the third passage under the microscope to observe their morphology and growth status. The third passage of isolated cells was analysed for the identification of immunophenotype, osteogenic, adipogenic and chondrogenic differentiation. On the third to fifth days of in vitro culture, a few cells of long fusiform shape appeared and were adherent to the plastic walls. On the sixth to ninth days, cells clustered and colonies were observed. The third passage cells showed uniform cell morphology and good proliferation, with appearance of the typical surface markers of MSC, CD29, CD44, CD90 and CD105. The surface markers of CD34 and CD45 of haematopoietic stem cells were not expressed. Under appropriate conditions of in vitro culture, isolated cells could be differentiated into osteoblasts that deposit mineralised matrix and express early osteogenic markers, adipocytes that accumulate lipid droplets in cytoplasm and chondrocytes that secrete chondrogenic-specific matrix aggrecan and collagen II. Real-time polymerase chain reaction (PCR) analysis demonstrated that the specific mRNA expression of osteogenesis, adipogenesis and chondrogenesis increased significantly compared with the control groups at day zero. Stem cells derived in situ from the human ACL stump were successfully isolated and characterised. Those isolated cells were identified as MSC according to their adherent ability, morphology, surface markers and multilineage differentiation potential. MSC derived from ACL remnants could be a potential source of seeding cells for ligament regeneration.

Isolation of a circulating CD45−, CD34dim cell population and validation of their endothelial phenotype

PubMed Central

Tropea, Margaret M.; Harper, Bonnie J. A.; Graninger, Grace M.; Phillips, Terry M.; Ferreyra, Gabriela; Mostowski, Howard S.; Danner, Robert L.; Suffredini, Anthony F.; Solomon, Michael A.

2016-01-01

Summary Accurately detecting circulating endothelial cells (CECs) is important since their enumeration has been proposed as a biomarker to measure injury to the vascular endothelium. However, there is no single methodology for determining CECs in blood, making comparison across studies difficult. Many methods for detecting CECs rely on characteristic cell surface markers and cell viability indicators, but lack secondary validation. Here, a CEC population in healthy adult human subjects was identified by flow cytometry as CD45−, CD34dim that is comparable to a previously described CD45−, CD31bright population. In addition, nuclear staining with 7-aminoactinomycin D (7-AAD) was employed as a standard technique to exclude dead cells. Unexpectedly, the CD45−, CD34dim, 7-AAD− CECs lacked surface detectable CD146, a commonly used marker of CECs. Furthermore, light microscopy revealed this cell population to be composed primarily of large cells without a clearly defined nucleus. Nevertheless, immunostains still demonstrated the presence of the lectin Ulex europaeus and van Willebrand factor. Ultramicro analytical immunochemistry assays for the endothelial cell proteins CD31, CD34, CD62E, CD105, CD141, CD144 and vWF indicated these cells possess an endothelial phenotype. However, only a small amount of RNA, which was mostly degraded, could be isolated from these cells. Thus the majority of CECs in healthy individuals as defined by CD45−, CD34dim, and 7-AAD− have shed their CD146 surface marker and are senescent cells without an identifiable nucleus and lacking RNA of sufficient quantity and quality for transcriptomal analysis. This study highlights the importance of secondary validation of CEC identification. PMID:25057108

Induction of 26S proteasome subunit PSMB5 by the bifunctional inducer 3-methylcholanthrene through the Nrf2-ARE, but not the AhR/Arnt-XRE, pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwak, Mi-Kyoung; Kensler, Thomas W.

The 26S proteasome is responsible for degradation of abnormal intracellular proteins, including oxidatively damaged proteins and may play a role as a component of a cellular antioxidative system. However, little is known about regulation of proteasome expression. In the present study, regulation of proteasome expression by the bifunctional enzyme inducer and a specific signaling pathway for this regulation were investigated in murine neuroblastoma cells. Expression of catalytic core subunits including PSMB5 and peptidase activities of the proteasome were elevated following incubation with 3-methylcholanthrene (3-MC). Studies using reporter genes containing the murine Psmb5 promoter showed that transcriptional activity of this genemore » was enhanced by 3-MC. Overexpression of AhR/Arnt did not affect activation of the Pmsb5 promoter by 3-MC and deletion of the xenobiotic response elements (XREs) from this promoter exerted modest effects on inducibility in response to 3-MC. However, mutation of the proximal AREs of the Psmb5 promoter largely abrogated its inducibility by 3-MC. In addition, this promoter showed a blunted response toward 3-MC in the absence of nrf2; 3-MC incubation increased nuclear levels of Nrf2 only in wild-type cells. Collectively, these results indicate that expression of proteasome subunit PSMB5 is modulated by bifunctional enzyme inducers in a manner independent of the AhR/Arnt-XRE pathway but dependent upon the Nrf2-ARE pathway.« less

Two-step protocol for isolation and culture of cardiospheres.

PubMed

Chen, Lijuan; Pan, Yaohua; Zhang, Lan; Wang, Yingjie; Weintraub, Neal; Tang, Yaoliang

2013-01-01

Cardiac progenitor cells (CPC) are a unique pool of progenitor cells residing in the heart that play an important role in cardiac homeostasis and physiological cardiovascular cell turnover during acute myocardial infarction (MI). Transplanting CPC into the heart has shown promise in two recent clinical trials of cardiac repair (SCIPIO & CADUCEUS). CSCs were originally isolated directly from enzymatically digested hearts followed by cell sorting using stem cell markers. However, long exposure to enzymatic digestion can affect the integrity of stem cell markers on the cell surface and also compromise stem cell function. Here, we describe a two-step procedure in which a large number of intact cardiac progenitor cells can be purified from small amount of heart tissue.

Water-medium and solvent-free organic reactions over a bifunctional catalyst with Au nanoparticles covalently bonded to HS/SO3H functionalized periodic mesoporous organosilica.

PubMed

Zhu, Feng-Xia; Wang, Wei; Li, He-Xing

2011-08-03

An operationally simple approach for the preparation of a new class of bifunctional Au nanoparticle-acid catalysts has been developed. In situ reduction of Au(3+) with HS-functionalized periodic mesoporous organosilicas (PMOs) creates robust, fine Au nanoparticles and concomitantly produces a sulfonic acid moiety strongly bonded to PMOs. Characterizations of the nanostructures reveal that Au nanoparticles are formed with uniformed, narrow size distribution around 1-2 nm, which is very critical for essential catalytic activities. Moreover, the Au nanoparticles are mainly attached onto the pore surface rather than onto the outer surface with ordered mesoporous channels, allowing for maximal exposure to reaction substrates while minimizing Au nanoparticle leaching. Their higher S(BET), V(P), and D(P) than either the Au-HS-PMO(Et) or the Au/SO(3)H-PMO(Et) render the catalyst with comparably even higher catalytic efficiency than its homogeneous counterparts. Furthermore, the unique amphiphilic compartment of the Au-HS/SO(3)H-PMO(Et) nanostructures enables organic reactions to proceed efficiently in a pure aqueous solution without using any organic solvents or even without water. As demonstrated experimentally, remarkably, the unique bifunctional Au-HS/SO(3)H-PMO(Et) catalyst displays higher efficiencies in promoting water-medium alkyne hydration, intramolecular hydroamination, styrene oxidation, and three-component coupling reactions and even the solvent-free alkyne hydration process than its homogeneous catalysts. The robust catalyst can be easily recycled and used repetitively at least 10 times without loss of catalytic efficiency. These features render the catalyst particularly attractive in the practice of organic synthesis in an environmentally friendly manner.

Tissue non-specific alkaline phosphatase production by human dental pulp stromal cells is enhanced by high density cell culture.

PubMed

Tomlinson, Matthew J; Dennis, Caitriona; Yang, Xuebin B; Kirkham, Jennifer

2015-08-01

The cell surface hydrolase tissue non-specific alkaline phosphatase (TNAP) (also known as MSCA-1) is used to identify a sub-population of bone marrow stromal cells (BMSCs) with high mineralising potential and is found on subsets of cells within the dental pulp. We aim to determine whether TNAP is co-expressed by human dental pulp stromal cells (hDPSCs) alongside a range of BMSC markers, whether this is an active form of the enzyme and the effects of culture duration and cell density on its expression. Cells from primary dental pulp and culture expanded hDPSCs expressed TNAP. Subsequent analyses revealed persistent TNAP expression and co-expression with BMSC markers such as CD73 and CD90. Flow cytometry and biochemical assays showed that increased culture durations and cell densities enhanced TNAP expression by hDPSCs. Arresting the hDPSC cell cycle also increased TNAP expression. These data confirm that TNAP is co-expressed by hDPSCs together with other BMSC markers and show that cell density affects TNAP expression levels. We conclude that TNAP is a potentially useful marker for hDPSC selection especially for uses in mineralised tissue regenerative therapies.

Investigating Evolutionary Conservation of Dendritic Cell Subset Identity and Functions

PubMed Central

Vu Manh, Thien-Phong; Bertho, Nicolas; Hosmalin, Anne; Schwartz-Cornil, Isabelle; Dalod, Marc

2015-01-01

Dendritic cells (DCs) were initially defined as mononuclear phagocytes with a dendritic morphology and an exquisite efficiency for naïve T-cell activation. DC encompass several subsets initially identified by their expression of specific cell surface molecules and later shown to excel in distinct functions and to develop under the instruction of different transcription factors or cytokines. Very few cell surface molecules are expressed in a specific manner on any immune cell type. Hence, to identify cell types, the sole use of a small number of cell surface markers in classical flow cytometry can be deceiving. Moreover, the markers currently used to define mononuclear phagocyte subsets vary depending on the tissue and animal species studied and even between laboratories. This has led to confusion in the definition of DC subset identity and in their attribution of specific functions. There is a strong need to identify a rigorous and consensus way to define mononuclear phagocyte subsets, with precise guidelines potentially applicable throughout tissues and species. We will discuss the advantages, drawbacks, and complementarities of different methodologies: cell surface phenotyping, ontogeny, functional characterization, and molecular profiling. We will advocate that gene expression profiling is a very rigorous, largely unbiased and accessible method to define the identity of mononuclear phagocyte subsets, which strengthens and refines surface phenotyping. It is uniquely powerful to yield new, experimentally testable, hypotheses on the ontogeny or functions of mononuclear phagocyte subsets, their molecular regulation, and their evolutionary conservation. We propose defining cell populations based on a combination of cell surface phenotyping, expression analysis of hallmark genes, and robust functional assays, in order to reach a consensus and integrate faster the huge but scattered knowledge accumulated by different laboratories on different cell types, organs, and species. PMID:26082777

CXCR6 identifies a putative population of retained human lung T cells characterised by co-expression of activation markers.

PubMed

Morgan, Angela J; Guillen, Cristina; Symon, Fiona A; Birring, Surinder S; Campbell, James J; Wardlaw, Andrew J

2008-01-01

Expressions of activation markers have been described on the surface of T cells in the blood and the lung in both health and disease. We have studied the distribution of activation markers on human lung T cells and have found that only certain populations exist. Importantly, the presence or absence of some markers appears to predict those of others, in particular cells which express CD103 also express CD49a and CD69, whereas cells which do not express CD69 also do not express CD49a or CD103. In view of the paucity of activation marker expression in the peripheral blood, we have hypothesised that these CD69+, CD49a+, and CD103+ (triple positive) cells are retained in the lung, possess effector function (IFNgamma secretion) and express particular chemokine receptors which allow them to be maintained in this environment. We have found that the ability of the triple negative cells to secrete IFNgamma is significantly less than the triple positive cells, suggesting that the expression of activation markers can highlight a highly specialised effector cell. We have studied the expression of 14 chemokine receptors and have found that the most striking difference between the triple negative cells and the triple positive cells is the expression of CXCR6 with 12.8+/-9.8% of triple negative cells expressing CXCR6 compared to 89.5+/-5.5% of triple positive cells. We propose therefore that CXCR6 may play an important role in the retention of T cells within the lung.

Confirmation of Pig-a mutation in flow cytometry-identified CD48-deficient T-lymphocytes from F344 rats.

PubMed

Revollo, Javier; Pearce, Mason G; Petibone, Dayton M; Mittelstaedt, Roberta A; Dobrovolsky, Vasily N

2015-05-01

The Pig-a assay is used for monitoring somatic cell mutation in laboratory animals and humans. The assay detects haematopoietic cells deficient in glycosylphosphatidylinositol (GPI)-anchored protein surface markers using flow cytometry. However, given that synthesis of the protein markers (and the expression of their genes) is independent of the expression of the X-linked Pig-a gene and the function of its enzyme product, the deficiency of markers at the surface of the cells may be caused by a number of events (e.g. by mutation or epigenetic silencing in the marker gene itself or in any of about two dozen autosomal genes involved in the synthesis of GPI). Here we provide direct evidence that the deficiency of the GPI-anchored surface marker CD48 in rat T-cells is accompanied by mutation in the endogenous X-linked Pig-a gene. We treated male F344 rats with N-ethyl-N-nitrosourea (ENU), and established colonies from flow cytometry-identified and sorted CD48-deficient spleen T-lymphocytes. Molecular analysis confirmed that the expanded sorted cells have mutations in the Pig-a gene. The spectrum of Pig-a mutation in our model was consistent with the spectrum of ENU-induced mutation determined in other in vivo models, mostly base-pair substitutions at A:T with the mutated T on the non-transcribed strand of Pig-a genomic DNA. We also used next generation sequencing to derive a similar mutational spectrum from a pool of 64 clones developed from flow-sorted CD48-deficient lymphocytes. Our findings confirm that Pig-a assays detect what they are designed to detect-gene mutation in the Pig-a gene. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

New electrocatalysts for unitized regenerative fuel cell: Pt-Ir alloy deposited on the proton exchange membrane surface by impregnation-reduction method.

PubMed

Wan, Chieh-Hao; Wu, Chun-Lin; Lin, Meng-Tsun; Shih, Chihhsiong

2010-07-01

In this paper, a modified technique to prepare Pt-Ir catalyst layer on the proton exchange membrane (PEM) surface using the impregnation-reduction (IR) method is proposed to improve the electrocatalytic activity as well as the life cycle of the bifunctional oxygen electrode (BOE). The resulted electrocatalysts were characterized by the Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Electron Probe Micro-Analysis (EPMA), and Transmission Electron Microscope (TEM). The electrocatalytic properties of the Pt-Ir layer on PEM surface for the oxygen reduction and water oxidation reactions as well as the life cycle of MEA were investigated. Experimental results showed that the Ir particles were dispersed densely in the platinum layer through the modified IR technique. The atomic ratio of Pt over Ir elements was 9:1, and the resulted thickness of the obtained Pt-Ir catalyst layer was about 1.0 microm. The Pt-Ir catalyst layer was composed of Pt layer doped with Ir nano-particles comprising nano Pt-Ir alloy phase. The large surface area of Ir core with Pt shell particles and the presence of nano Pt-Ir alloy phase led to a higher electrocatalytic activity of BOE. Due to the good binding between the Nafion membrane and the Pt-Ir alloy catalyst, as well as the composite structure of the resulted Pt-Ir, the life cycle of Unitized Regenerative Fuel Cell (URFC) is improved through this novel BOE.

Sers Imaging of Nasopharyngeal Carcinoma Markers Using an Antibody-Conjugated Gold Nanoparticles Probe

NASA Astrophysics Data System (ADS)

Li, J.-H.; Du, Y.; Feng, G.-K.; Du, Y.-B.; Zhou, Y.-Q.; Zeng, M.-S.

2017-11-01

Surface-enhanced Raman scattering (SERS) nanotags as an ultrasensitive nanoprobe is becoming popular for the detection of biomarkers. Herein, antibody-conjugated gold nanoparticles (AuNPs) were used to target LMP2A in an LMP2A-infected CNE2 cell line. SERS maps showed that the LMP2A was distributed around the cell, which was consistent with the results of immunofl uorescence staining in the previous report. This location could be due to the specific binding of the bioconjugated nanotags to the receptors on the cell surface. However, the CNE2 cell line without LMP2A-infected showed no detectable signal at 1044 cm-1. The results demonstrated the potential feasibility of AuNPs nanotags as highly sensitive probes conjugated at the subcellular level for detection and localization of cancer markers in nasopharyngeal carcinoma (NPC).

Human Uterine Leiomyoma Stem/Progenitor Cells Expressing CD34 and CD49b Initiate Tumors In Vivo

PubMed Central

Ono, Masanori; Moravek, Molly B.; Coon, John S.; Navarro, Antonia; Monsivais, Diana; Dyson, Matthew T.; Druschitz, Stacy A.; Malpani, Saurabh S.; Serna, Vanida A.; Qiang, Wenan; Chakravarti, Debabrata; Kim, J. Julie; Bulun, Serdar E.

2015-01-01

Context: Uterine leiomyoma is the most common benign tumor in reproductive-age women. Using a dye-exclusion technique, we previously identified a side population of leiomyoma cells exhibiting stem cell characteristics. However, unless mixed with mature myometrial cells, these leiomyoma side population cells did not survive or grow well in vitro or in vivo. Objective: The objective of this study was to identify cell surface markers to isolate leiomyoma stem/progenitor cells. Design: Real-time PCR screening was used to identify cell surface markers preferentially expressed in leiomyoma side population cells. In vitro colony-formation assay and in vivo tumor-regeneration assay were used to demonstrate functions of leiomyoma stem/progenitor cells. Results: We found significantly elevated CD49b and CD34 gene expression in side population cells compared with main population cells. Leiomyoma cells were sorted into three populations based on the expression of CD34 and CD49b: CD34+/CD49b+, CD34+/CD49b−, and CD34−/CD49b− cells, with the majority of the side population cells residing in the CD34+/CD49b+ fraction. Of these populations, CD34+/CD49b+ cells expressed the lowest levels of estrogen receptor-α, progesterone receptor, and α-smooth muscle actin, but the highest levels of KLF4, NANOG, SOX2, and OCT4, confirming their more undifferentiated status. The stemness of CD34+/CD49b+ cells was also demonstrated by their strongest in vitro colony-formation capacity and in vivo tumor-regeneration ability. Conclusions: CD34 and CD49b are cell surface markers that can be used to enrich a subpopulation of leiomyoma cells possessing stem/progenitor cell properties; this technique will accelerate efforts to develop new therapies for uterine leiomyoma. PMID:25658015

Fat-associated lymphoid cluster in Cyprinus carpio: Characterisation and its relation with peritoneal haemangiosarcoma.

PubMed

Madera-Sandoval, Ruth L; Reyes-Maldonado, Elba; Dzul-Caamal, Ricardo; Gallegos-Rangel, Esperanza; Domínguez-López, María Lilia; García-Latorre, Ethel; Vega-López, Armando

2015-06-01

FALC cells are natural helper cells producing Th2-type cytokines, which express c-kit, Sca-1, IL7R and CD45 in mouse and human. These cells are involved in allergic responses and contribute to the inflammatory reactions of adipose tissue; however, a lack of information prevails about the presence of these cells in other species. The aim of the study was to identify and characterise FALC cells in the common carp (Cyprinus carpio) using immunohistochemistry and molecular biology techniques as well as to explore their relationships with their microenvironment. Histological description of the FALC was performed using H&E and polyclonal antibodies were used against cell-surface markers such as c-kit, Sca-1 and CD45. Furthermore, gene expression of c-kit, Sca-1 and IL7R was assessed. C. carpio FALC cells express the same surface markers reported in FALC of the mouse at both the pre- and post-transcriptional level. By exposure to the soluble fraction of helminths, FALC cells produce abundant Th2 cytokines (IL-5, IL-6 and IL-13) but do not synthesise IL-1α. Additionally, FALC cells probably participate in vascular remodelling of the intestine vessels, inducing tumours because a malignant haemangiosarcoma in the peritoneal cavity was found. In this tumour, abundant FALC with their characteristic cell-surface markers were detected. The findings of this study suggest the involvement of some proto-oncogenes such as c-kit and Sca-1, and the deregulation of Src kinases modulated by CD45 present in C. carpio FALC with the ontogeny of peritoneal haemangiosarcoma in this fish species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sulfur mustard induced mast cell degranulation in mouse skin is inhibited by a novel anti-inflammatory and anticholinergic bifunctional prodrug.

PubMed

Joseph, Laurie B; Composto, Gabriella M; Perez, Roberto M; Kim, Hong-Duck; Casillas, Robert P; Heindel, Ned D; Young, Sherri C; Lacey, Carl J; Saxena, Jaya; Guillon, Christophe D; Croutch, Claire R; Laskin, Jeffrey D; Heck, Diane E

2018-09-01

Sulfur mustard (SM, bis(2-chloroethyl sulfide) is a potent vesicating agent known to cause skin inflammation, necrosis and blistering. Evidence suggests that inflammatory cells and mediators that they generate are important in the pathogenic responses to SM. In the present studies we investigated the role of mast cells in SM-induced skin injury using a murine vapor cup exposure model. Mast cells, identified by toluidine blue staining, were localized in the dermis, adjacent to dermal appendages and at the dermal/epidermal junction. In control mice, 48-61% of mast cells were degranulated. SM exposure (1.4g/m 3 in air for 6min) resulted in increased numbers of degranulated mast cells 1-14days post-exposure. Treatment of mice topically with an indomethacin choline bioisostere containing prodrug linked by an aromatic ester-carbonate that targets cyclooxygenases (COX) enzymes and acetylcholinesterase (1% in an ointment) 1-14days after SM reduced skin inflammation and injury and enhanced tissue repair. This was associated with a decrease in mast cell degranulation from 90% to 49% 1-3days post SM, and from 84% to 44% 7-14days post SM. These data suggest that reduced inflammation and injury in response to the bifunctional indomethacin prodrug may be due, at least in part, to abrogating mast cell degranulation. The use of inhibitors of mast cell degranulation may be an effective strategy for mitigating skin injury induced by SM. Copyright © 2017 Elsevier B.V. All rights reserved.

Semiconductor nanocrystals covalently bound to solid inorganic surfaces using self-assembled monolayers

DOEpatents

Alivisatos, A. Paul; Colvin, Vicki L.

1998-01-01

Methods are described for attaching semiconductor nanocrystals to solid inorganic surfaces, using self-assembled bifunctional organic monolayers as bridge compounds. Two different techniques are presented. One relies on the formation of self-assembled monolayers on these surfaces. When exposed to solutions of nanocrystals, these bridge compounds bind the crystals and anchor them to the surface. The second technique attaches nanocrystals already coated with bridge compounds to the surfaces. Analyses indicate the presence of quantum confined clusters on the surfaces at the nanolayer level. These materials allow electron spectroscopies to be completed on condensed phase clusters, and represent a first step towards synthesis of an organized assembly of clusters. These new products are also disclosed.

High levels of E4-PHA-reactive oligosaccharides: potential as marker for cells with characteristics of hepatic progenitor cells.

PubMed

Sasaki, Nozomi; Moriwaki, Kenta; Uozumi, Naofumi; Noda, Katsuhisa; Taniguchi, Naoyuki; Kameyama, Akihiko; Narimatsu, Hisashi; Takeishi, Shunsaku; Yamada, Masao; Koyama, Nobuto; Miyoshi, Eiji

2009-12-01

Oligosaccharides serve as markers of the cell surface and have been used as certain kinds of tumor markers. In the present study, we established a simple method for isolating hepatic progenitor cells using a lectin, which recognizes a characteristic oligosaccharide structure. Rat liver epithelial (RLE) cells, which have been established as a hepatic stem-like cell, were used to identify characteristic oligosaccharide structures on hepatic stem cells. As a result from lectin micro array, several types of lectin including E4-PHA were identified to bind RLE cells specifically. Furthermore, lectin blot and lectin flow cytometry analyses showed that binding to E(4)-PHA lectin was significantly increased in RLE cells, compared to hepatocytes, and hepatoma cells. The induction of differentiation into a hepatocyte lineage of RLE cells by treatment with Oncostatin M and dexamethasone resulted in a decrease in E(4)-PHA binding. Using an E(4)-PHA column, we succeeded in isolating hepatic stem cells from LEC (Long-Evans with cinnamon coat color) rat livers with fluminant hepatitis. The characteristics of the established cells were similar to RLE cells and had a potential of proliferating in rat liver. These results suggest that oligosaccharides can serve as a novel marker for the isolation of the hepatic progenitor cells.

Construction of Engineered Bifunctional Enzymes and Their Overproduction in Aspergillus niger for Improved Enzymatic Tools To Degrade Agricultural By-Products

PubMed Central

Levasseur, Anthony; Navarro, David; Punt, Peter J.; Belaïch, Jean-Pierre; Asther, Marcel; Record, Eric

2005-01-01

Two chimeric enzymes, FLX and FLXLC, were designed and successfully overproduced in Aspergillus niger. FLX construct is composed of the sequences encoding the feruloyl esterase A (FAEA) fused to the endoxylanase B (XYNB) of A. niger. A C-terminal carbohydrate-binding module (CBM family 1) was grafted to FLX, generating the second hybrid enzyme, FLXLC. Between each partner, a hyperglycosylated linker was included to stabilize the constructs. Hybrid proteins were purified to homogeneity, and molecular masses were estimated to be 72 and 97 kDa for FLX and FLXLC, respectively. Integrity of hybrid enzymes was checked by immunodetection that showed a single form by using antibodies raised against FAEA and polyhistidine tag. Physicochemical properties of each catalytic module of the bifunctional enzymes corresponded to those of the free enzymes. In addition, we verified that FLXLC exhibited an affinity for microcrystalline cellulose (Avicel) with binding parameters corresponding to a Kd of 9.9 × 10−8 M for the dissociation constant and 0.98 μmol/g Avicel for the binding capacity. Both bifunctional enzymes were investigated for their capacity to release ferulic acid from natural substrates: corn and wheat brans. Compared to free enzymes FAEA and XYNB, a higher synergistic effect was obtained by using FLX and FLXLC for both substrates. Moreover, the release of ferulic acid from corn bran was increased by using FLXLC rather than FLX. This result confirms a positive role of the CBM. In conclusion, these results demonstrated that the fusion of naturally free cell wall hydrolases and an A. niger-derived CBM onto bifunctional enzymes enables the increase of the synergistic effect on the degradation of complex substrates. PMID:16332795

Controlling the Interfacial Environment in the Electrosynthesis of MnOx Nanostructures for High-Performance Oxygen Reduction/Evolution Electrocatalysis.

PubMed

Hosseini-Benhangi, Pooya; Kung, Chun Haow; Alfantazi, Akram; Gyenge, Elöd L

2017-08-16

High-performance, nonprecious metal bifunctional electrocatalysts for the oxygen reduction and evolution reactions (ORR and OER, respectively) are of great importance for rechargeable metal-air batteries and regenerative fuel cells. A comprehensive study based on statistical design of experiments is presented to investigate and optimize the surfactant-assisted structure and the resultant bifunctional ORR/OER activity of anodically deposited manganese oxide (MnO x ) catalysts. Three classes of surfactants are studied: anionic (sodium dodecyl sulfate, SDS), non-ionic (t-octylphenoxypolyethoxyethanol, Triton X-100), and cationic (cetyltrimethylammonium bromide, CTAB). The adsorption of surfactants has two main effects: increased deposition current density due to higher Mn 2+ and Mn 3+ concentrations at the outer Helmholtz plane (Frumkin effect on the electrodeposition kinetics) and templating of the MnO x nanostructure. CTAB produces MnO x with nanoneedle (1D) morphology, whereas nanospherical- and nanopetal-like morphologies are obtained with SDS and Triton, respectively. The bifunctional performance is assessed based on three criteria: OER/ORR onset potential window (defined at 2 and -2 mA cm -2 ) and separately the ORR and OER mass activities. The best compromise among these three criteria is obtained either with Triton X-100 deposited catalyst composed of MnOOH and Mn 3 O 4 or SDS deposited catalyst containing a combination of α- and β-MnO 2 , MnOOH, and Mn 3 O 4 .The interaction effects among the deposition variables (surfactant type and concentration, anode potential, Mn 2+ concentration, and temperature) reveal the optimal strategy for high-activity bifunctional MnO x catalyst synthesis. Mass activities for OER and ORR up to 49 A g -1 (at 1556 mV RHE ) and -1.36 A g -1 (at 656 mV RHE ) are obtained, respectively.

Bifunctional Nitrogen-Doped Microporous Carbon Microspheres Derived from Poly(o-methylaniline) for Oxygen Reduction and Supercapacitors.

PubMed

He, Yanzhen; Han, Xijiang; Du, Yunchen; Song, Bo; Xu, Ping; Zhang, Bin

2016-02-17

Heteroatom-doped carbon materials have attracted significant attention because of their applications in oxygen reduction reaction (ORR) and supercapacitors. Here we demonstrate a facile poly(o-methylaniline)-derived fabrication of bifunctional microporous nitrogen-doped carbon microspheres (NCMSs) with high electrocatalytic activity and stability for ORR and energy storage in supercapacitors. At a pyrolysis temperature of 900 °C, the highly dispersed NCMSs present a high surface area (727.1 m(2) g(-1)), proper total content of doping N, and high concentration of quaternary N, which exhibit superior electrocatalytic activities for ORR to the commercial Pt/C catalysts, high specific capacitance (414 F g(-1)), and excellent durability, making them very promising for advanced energy conversion and storage. The presented conducting polymer-derived strategy may provide a new way for the fabrication of heteroatom-doped carbon materials for energy device applications.

Experimental Proof of the Bifunctional Mechanism for the Hydrogen Oxidation in Alkaline Media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jingkun; Ghoshal, Shraboni; Bates, Michael K.

Realization of the hydrogen economy relies on effective hydrogen production, storage, and utilization. The slow kinetics of hydrogen evolution and oxidation reaction (HER/HOR) in alkaline media limits many practical applications involving hydrogen generation and utilization, and how to overcome this fundamental limitation remains debatable. Here we present a kinetic study of the HOR on representative catalytic systems in alkaline media. Electrochemical measurements show that the HOR rate of Pt-Ru/C and Ru/C systems is decoupled to their hydrogen binding energy (HBE), challenging the current prevailing HBE mechanism. The alternative bifunctional mechanism is verified by combined electrochemical and in situ spectroscopic data,more » which provide convincing evidence for the presence of hydroxy groups on surface Ru sites in the HOR potential region and its key role in promoting the rate-determining Volmer step. The conclusion presents important references for design and selection of HOR catalysts.« less

Experimental Proof of the Bifunctional Mechanism for the Hydrogen Oxidation in Alkaline Media

DOE PAGES

Li, Jingkun; Ghoshal, Shraboni; Bates, Michael K.; ...

2017-10-16

Realization of the hydrogen economy relies on effective hydrogen production, storage, and utilization. The slow kinetics of hydrogen evolution and oxidation reaction (HER/HOR) in alkaline media limits many practical applications involving hydrogen generation and utilization, and how to overcome this fundamental limitation remains debatable. Here we present a kinetic study of the HOR on representative catalytic systems in alkaline media. Electrochemical measurements show that the HOR rate of Pt-Ru/C and Ru/C systems is decoupled to their hydrogen binding energy (HBE), challenging the current prevailing HBE mechanism. The alternative bifunctional mechanism is verified by combined electrochemical and in situ spectroscopic data,more » which provide convincing evidence for the presence of hydroxy groups on surface Ru sites in the HOR potential region and its key role in promoting the rate-determining Volmer step. The conclusion presents important references for design and selection of HOR catalysts.« less

Boehmite-An Efficient and Recyclable Acid-Base Bifunctional Catalyst for Aldol Condensation Reaction.

PubMed

Reshma, P C Rajan; Vikneshvaran, Sekar; Velmathi, Sivan

2018-06-01

In this work boehmite was used as an acid-base bifunctional catalyst for aldol condensation reactions of aromatic aldehydes and ketones. The catalyst was prepared by simple sol-gel method using Al(NO3)3·9H2O and NH4OH as precursors. The catalyst has been characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), UV-visible spectroscopy (DRS), BET surface area analyses. Boehmite is successfully applied as catalyst for the condensation reaction between 4-nitrobenzaldehyde and acetone as a model substrate giving α, β-unsaturated ketones without any side product. The scope of the reaction is extended for various substituted aldehydes. A probable mechanism has been suggested to explain the cooperative behavior of the acidic and basic sites. The catalyst is environmentally friendly and easily recovered from the reaction mixture. Also the catalyst is reusable up to 3 catalytic cycles.

Activation of Poly(ADP-Ribose) Polymerase by Sulfur Mustard in Hela Cell Cultures

DTIC Science & Technology

1993-05-13

i O : DUTiC-TID INTRODUCTION Sulfur mustard ( 2,2’-dichlorodiethyl sulfide or HD) is a bifunctional alkylating agent which reacts with a wide variety...of biological molecules. It is a strong alkylating agent of purine bases in DNA (Kohn 1983). Early studies strongly implicate DNA as a principal...cells have previously demonstrated stimulation of PADPRP activity following exposure to a monofunctional alkylating agent , methylnitrosourea (MNU

Analyses of cell surface molecules on hepatic stem/progenitor cells in mouse fetal liver.

PubMed

Kakinuma, Sei; Ohta, Haruhiko; Kamiya, Akihide; Yamazaki, Yuji; Oikawa, Tsunekazu; Okada, Ken; Nakauchi, Hiromitsu

2009-07-01

Hepatic stem/progenitor cells possess active proliferative ability and the capacity for differentiation into hepatic and cholangiocytic lineages. Our group and others have shown that a prospectively defined population in mid-gestational fetal liver contains hepatic stem/progenitor cells. However, the phenotypes of such cells are incompletely elucidated. We analyzed the profile of cell-surface molecules on primary hepatic stem/progenitor cells. Expression of cell surface molecules on primary hepatic stem/progenitor cells in mouse mid-gestational fetal liver was analyzed using flow cytometric multicolor analyses and colony-formation assays. The potential of the cells for liver repopulation was examined by transplantation assay. We found that CD13 (aminopeptidase N) was detected on the cells of the previously reported (Dlk/Pref-1(+)) hepatic stem/progenitor fraction. Colony-formation assays revealed that the CD13(+) fraction, compared with the Dlk(+) fraction, of non-hematopoietic cells in fetal liver was enriched in hepatic stem/progenitor cells. Transplantation assay showed the former fraction exhibited repopulating potential in regenerating liver. Moreover, flow cytometric analysis for over 90 antigens demonstrated enrichment of hepatic stem/progenitor cells using several positive selection markers, including (hitherto unknown) CD13, CD73, CD106, and CD133. Our data indicated that CD13 is a positive selection marker for hepatic stem/progenitor cells in mid-gestational fetal liver.

Behavior of Human Bone Marrow-Derived Mesenchymal Stem Cells on Various Titanium-Based Coatings

PubMed Central

Qu, Chengjuan; Kaitainen, Salla; Kröger, Heikki; Lappalainen, Reijo; Lammi, Mikko J.

2016-01-01

The chemical composition and texture of titanium coatings can influence the growth characteristics of the adhered cells. An enhanced proliferation of the human mesenchymal stem cells (hMSCs) would be beneficial. The present study was aimed to investigate whether titanium deposited at different atmospheres would affect the cell growth properties, cellular morphology, and expression of surface markers of hMSCs. Titanium-based coatings were deposited on silicon wafers under oxygen, nitrogen, or argon atmospheres by ultra-short pulsed laser deposition using two different gas pressures followed by heating at 400 °C for 2 h. The characteristics of the coated surfaces were determined via contact angle, zeta potential, and scanning electron microscopy (SEM) techniques. Human MSCs were cultivated on differently coated silicon wafers for 48 h. Subsequently, the cell proliferation rates were analyzed with an MTT assay. The phenotype of hMSCs was checked via immunocytochemical stainings of MSC-associated markers CD73, CD90, and CD105, and the adhesion, spreading, and morphology of hMSCs on coated materials via SEM. The cell proliferation rates of the hMSCs were similar on all coated silicon wafers. The hMSCs retained the MSC phenotype by expressing MSC-associated markers and fibroblast-like morphology with cellular projections. Furthermore, no significant differences could be found in the size of the cells when cultured on all various coated surfaces. In conclusion, despite certain differences in the contact angles and the zeta potentials of various titanium-based coatings, no single coating markedly improved the growth characteristics of hMSCs. PMID:28773947

Design of bifunctional metasurface based on independent control of transmission and reflection.

PubMed

Zhuang, Yaqiang; Wang, Guangming; Cai, Tong; Zhang, Qingfeng

2018-02-05

Multifunctional metasurface integrating different functions can significantly save the occupied space, although most of bifunctional metasurfaces reported to date only control the wave in either reflection or transmission regime. In this paper, we propose a scheme that allows one to independently control the reflection and transmission wavefront under orthogonal polarizations. For demonstration, we design a bifunctional metasurface that simultaneously realizes a diffusion reflection and a focusing transmission. The diffusion reflection is realized using a random phase distribution, which was implemented by randomly arranging two basic coding unit cells with the aid of an ergodic algorithm. Meanwhile, the hyperbolic phase distribution was designed to realize the focusing functionality in the transmission regime. To further show the potential applications, a high-gain lens antenna was designed by assembling the proposed metasurface with a proper feed. Both simulation and measurement results have been carried out, and the agreement between the two results demonstrates the validity of the performance as expected. The backward scattering can be reduced more than 5 dB within 6.4-10 GHz compared with the metallic plate. Moreover, the lens antenna has a gain of 20 dB (with around 13 dB enhancement in comparison with the bare feeding antenna) and an efficiency of 32.5%.

Bifunctional chelating agent for the design and development of site specific radiopharmaceuticals and biomolecule conjugation strategy

DOEpatents

Katti, Kattesh V.; Prabhu, Kandikere R.; Gali, Hariprasad; Pillarsetty, Nagavara Kishore; Volkert, Wynn A.

2003-10-21

There is provided a method of labeling a biomolecule with a transition metal or radiometal in a site specific manner to produce a diagnostic or therapeutic pharmaceutical compound by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radio metal or a transition metal, and covalently linking the resulting metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. Also provided is a method of synthesizing the --PR.sub.2 containing biomolecules by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radiometal or a transition metal, and covalently linking the resulting radio metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. There is provided a therapeutic or diagnostic agent comprising a --PR.sub.2 containing biomolecule.

Heterogeneous Bimetallic Phosphide/Sulfide Nanocomposite for Efficient Solar-Energy-Driven Overall Water Splitting.

PubMed

Xin, Yanmei; Kan, Xiang; Gan, Li-Yong; Zhang, Zhonghai

2017-10-24

Solar-driven overall water splitting is highly desirable for hydrogen generation with sustainable energy sources, which need efficient, earth-abundant, robust, and bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we propose a heterogeneous bimetallic phosphide/sulfide nanocomposite electrocatalyst of NiFeSP on nickel foam (NiFeSP/NF), which shows superior electrocatalytic activity of low overpotentials of 91 mV at -10 mA cm -2 for HER and of 240 mV at 50 mA cm -2 for OER in 1 M KOH solution. In addition, the NiFeSP/NF presents excellent overall water splitting performance with a cell voltage as low as 1.58 V at a current density of 10 mA cm -2 . Combining with a photovoltaic device of a Si solar cell or integrating into photoelectrochemical (PEC) systems, the bifunctional NiFeSP/NF electrocatalyst implements unassisted solar-driven water splitting with a solar-to-hydrogen conversion efficiency of ∼9.2% and significantly enhanced PEC performance, respectively.

Cancer Immunotherapy Using Virus-like Particles | NCI Technology Transfer Center | TTC

Cancer.gov

A considerable effort has been devoted to identifying and targeting specific extracellular cancer markers using antibody based therapies. However, diminished access to new cancer cell surface markers has limited the development of corresponding antibodies. NCI Technology Transfer Center is seeking to license cancer immunotherapy using virus-like particles.

The hitchhikers guide to cancer stem cell theory: markers, pathways and therapy.

PubMed

Fábián, Ákos; Vereb, György; Szöllősi, János

2013-01-01

Cancer stem cell (CSC) biology is a rapidly developing field within cancer research. CSCs are postulated to be a unique cell population exclusively capable of infinite self renewal, multilineage differentiation and with ability to evade conventional cytotoxic cancer therapy. These traits distinguish CSCs from their more differentiated counterparts, which possess only limited or no potential for self renewal and tumor initiation. Therefore, CSCs would be the driving motor of malignant growth and therapy resistance. Accordingly, successful cancer treatment would need to eliminate this highly potent group of cells, since even small residual numbers would suffice to recapitulate the disease after therapy. Putative CSCs has been identified in a broad range of human malignancies and several cell surface markers have been associated with their stem cell phenotype. Despite all efforts, a pure CSC population has not been isolated and often in vitro clonogenic and in vivo tumorigenic potential is found in several cell populations with occasionally contradictory surface marker signatures. Here, we give a brief overview of recent advances in CSC theory, including the signaling pathways in CSCs that also appear crucial for stem cells homeostasis in normal tissues. We discuss evidence for the interaction of CSCs with the stromal tumor environment. Finally, we review the emerging potentially effective CSC-targeted treatment strategies and their future role in therapy. Copyright © 2012 International Society for Advancement of Cytometry.

Immunologic reconstitution during PEG-ADA therapy in an unusual mosaic ADA deficient patient.

PubMed

Liu, Ping; Santisteban, Ines; Burroughs, Lauri M; Ochs, Hans D; Torgerson, Troy R; Hershfield, Michael S; Rawlings, David J; Scharenberg, Andrew M

2009-02-01

We report detailed genetic and immunologic studies in a patient diagnosed with adenosine deaminase (ADA) deficiency and combined immune deficiency at age 5 years. At the time of diagnosis, although all other lymphocyte subsets were depleted, circulating CD8(+) T cells with a terminally differentiated phenotype were abundant and expressed normal ADA activity due to a reversion mutation in a CD8(+) T cell or precursor. Over the first 9 months of replacement therapy with PEG-ADA, the patient steadily accumulated mature naïve CD4(+) and CD8(+) T cells, as well as CD4(+)/FOXP3(+) regulatory T cells, consistent with restoration of a functional cellular immune system. While CD19(+) naïve B cells also accumulated in response to PEG-ADA therapy, a high proportion of these B cells exhibited an immature surface marker phenotype even after 9 months, and immunization with neoantigen bacteriophage varphiX174 demonstrated a markedly subnormal humoral immune response. Our observations in this single patient have important implications for gene therapy of human ADA deficiency, as they indicate that ADA expression within even a large circulating lymphocyte population may not be sufficient to support adequate immune reconstitution. They also suggest that an immature surface marker phenotype of the peripheral B cell compartment may be a useful surrogate marker for incomplete humoral immune reconstitution during enzyme replacement, and possibly other forms of hematopoietic cell therapies.

Expression of CD markers' in immune thrombocytopenic purpura: prognostic approaches.

PubMed

Behzad, Masumeh Maleki; Asnafi, Ali Amin; Jaseb, Kaveh; Jalali Far, Mohammad Ali; Saki, Najmaldin

2017-12-01

Immune Thrombocytopenic Purpura (ITP) is a common autoimmune bleeding disorder characterized by a reduction in peripheral blood platelet counts. In this disease, autoantibodies (Auto-Abs) are produced against platelet GPIIb/GPIIIa by B cells, which require interaction with T cells. In this review, the importance of B and T lymphocytes in ITP prognosis has been studied. Relevant literature was identified by a PubMed search (1990-2016) of English-language papers using the terms B and T lymphocyte, platelet, CD markers and immune thrombocytopenic purpura. T and B lymphocytes are the main immune cells in the body. Defective function causes disrupted balance of different subgroups of lymphocytes, and abnormal expression of surface markers of these cells results in self-tolerance dysfunction, as well as induction of Auto-Abs against platelet glycoproteins (PG). Given the role of B and T cells in production of autoantibodies against PG, it can be stated that the detection of changes in CD markers' expression in these cells can be a good approach for assessing prognosis in ITP patients. © 2017 APMIS. Published by John Wiley & Sons Ltd.

Tailoring bifunctional hybrid organic–inorganic nanoadsorbents by the choice of functional layer composition probed by adsorption of Cu2+ ions

PubMed Central

Tomina, Veronika V; Melnyk, Inna V; Zub, Yuriy L; Kareiva, Aivaras; Vaclavikova, Miroslava; Kessler, Vadim G

2017-01-01

Spherical silica particles with bifunctional (≡Si(CH2)3NH2/≡SiCH3, ≡Si(CH2)3NH2/≡Si(CH2)2(CF2)5CF3) surface layers were produced by a one-step approach using a modified Stöber method in three-component alkoxysilane systems, resulting in greatly increased contents of functional components. The content of functional groups and thermal stability of the surface layers were analyzed by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, and 13C and 29Si solid-state NMR spectroscopy revealing their composition and organization. The fine chemical structure of the surface in the produced hybrid adsorbent particles and the ligand distribution were further investigated by electron paramagnetic resonance (EPR) and electron spectroscopy of diffuse reflectance (ESDR) spectroscopy using Cu2+ ion coordination as a probe. The composition and structure of the emerging surface complexes were determined and used to provide an insight into the molecular structure of the surfaces. It was demonstrated that the introduction of short hydrophobic (methyl) groups improves the kinetic characteristics of the samples during the sorption of copper(II) ions and promotes fixation of aminopropyl groups on the surface of silica microspheres. The introduction of long hydrophobic (perfluoroctyl) groups changes the nature of the surface, where they are arranged in alternately hydrophobic/hydrophilic patches. This makes the aminopropyl groups huddled and less active in the sorption of metal cations. The size and aggregation/morphology of obtained particles was optimized controlling the synthesis conditions, such as concentrations of reactants, basicity of the medium, and the process temperature. PMID:28243572

Optical Deformability as New Diagnostic Cell Marker

NASA Astrophysics Data System (ADS)

Guck, Jochen; Lincoln, Bryan; Schinkinger, Stefan; Wottawah, Falk; Moore, Samantha; Ananthakrishnan, Revathi; Kas, Josef

2002-03-01

The optical stretcher is a novel laser tool that can deform individual cells in rapid succession. When a cell is trapped between two counterpropagating laser beams the optically induced surface forces stretch the cell along the laser axis. The degree of stretching depends on the optical properties, which determine the forces, as well as the mechanical properties, which govern the response of the cell to the forces. Our results show that different cells can be distinguished based on their optical deformability, which naturally suggests using the optical deformability of cells as a novel cell marker. Many diseases are reflected in an altered cytoskeleton, which leads to a different optical deformability. An important example is the malignant transformation of cells, which is accompanied by a decrease in cytoskeletal integrity and, consequently, cell elasticity. Using optical deformability as cell marker holds the promise of earlier detection and improved diagnosis of cancer. In this context, the optical stretcher can be used as a diagnostic device to detect and sort abnormal cells. Future applications in the study of the normal differentiation of cells from stem cells to mature cells are envisioned.

Nuclear CD38 in retinoic acid-induced HL-60 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yalcintepe, Leman; Albeniz, Isil; Adin-Cinar, Suzan

2005-02-01

The cell surface antigen, CD38, is a 45-kDa transmembrane protein which is predominantly expressed on hematopoietic cells during differentiation. As a bifunctional ectoenzyme, it catalyzes the synthesis of cyclic ADP-ribose (cADPR) from NAD{sup +} and hydrolysis of either NAD{sup +} or cADPR to ADP-ribose. All-trans-retinoic acid (RA) is a potent and specific inducer of CD38 in myeloid cells. In this report, we demonstrate that the nuclei of RA-treated human HL-60 myeloblastic cells reveal enzymatic activities inherent to CD38. Thus, GDP-ribosyl cyclase and NAD{sup +} glycohydrolase activities in the nuclear fraction increased very significantly in response to incubation with RA. Withmore » Western blotting, we detected in the nuclear protein fraction from RA-treated cells a {approx}43-kDa protein band which was reactive with the CD38-specific monoclonal antibody OKT10. The expression of CD38 in HL-60 nuclei was also shown with FACScan analysis. RA treatment gave rise to an increase in in vitro ADP ribosylation of the {approx}43-kDa nuclear protein. Moreover, nuclei isolated from RA-treated HL-60 cells revealed calcium release in response to cADPR, whereas a similar response was not observed in control nuclei. These results suggest that CD38 is expressed in HL-60 cell nuclei during RA-induced differentiation.« less

Conservation of spermatogonial stem cell marker expression in undifferentiated felid spermatogonia.

PubMed

Vansandt, Lindsey M; Livesay, Janelle L; Dickson, Melissa Joy; Li, Lei; Pukazhenthi, Budhan S; Keefer, Carol L

2016-09-01

Spermatogonial stem cells (SSCs) are distinct in their ability to self-renew, transmit genetic information, and persist throughout the life of an individual. These characteristics make SSCs a useful tool for addressing diverse challenges such as efficient transgenic production in nonrodent, biomedical animal models, or preservation of the male genome for species in which survival of frozen-thawed sperm is low. A requisite first step to access this technology in felids is the establishment of molecular markers. This study was designed to evaluate, in the domestic cat (Felis catus), the expression both in situ and following enrichment in vitro of six genes (GFRA1, GPR125, ZBTB16, POU5F1, THY1, and UCHL1) that had been previously identified as SSC markers in other species. Antibodies for surface markers glial cell line-derived neurotrophic factor family receptor alpha 1, G protein-coupled receptor 125, and thymus cell antigen 1 could not be validated, whereas Western blot analysis of prepubertal, peripubertal, and adult cat testis confirmed protein expression for the intracellular markers ubiquitin carboxy-terminal hydrolase 1, zinc finger and BTB domain-containing protein 16, and POU domain, class 5, transcription factor 1. Colocalization of the markers by immunohistochemistry revealed that several cells within the subpopulation adjacent to the basement membrane of the seminiferous tubules and identified morphologically as spermatogonia, expressed all three intracellular markers. Studies performed on cheetah (Acinonyx jubatus) and Amur leopard (Panthera pardus orientalis) testis exhibited a conserved expression pattern in protein molecular weights, relative abundance, and localization of positive cells within the testis. The expression of the three intracellular SSC marker proteins in domestic and wild cat testes confirms conservation of these markers in felids. Enrichment of marker transcripts after differential plating was also observed. These markers will facilitate further studies in cell enrichment and IVC of felid SSCs enabling both production of transgenic domestic cats and preservation of the male genome from rare and endangered felids. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrasensitive Detection of Low-Abundance Surface-Marker Protein using Isothermal Rolling Circle Amplification in Microfluidic Nano-Liter Platform

PubMed Central

Konry, Tania; Yarmush, Joel M.; Irimia, Daniel

2011-01-01

With advances in immunology and cancer biology, there is an unmet need for increasingly sensitive systems to monitor the expression of specific cell markers for the development of new diagnostic and therapeutic tools. To address this challenge, we have applied a highly sensitive labeling method that translates antigen-antibody recognition processes into DNA detection event that can be greatly amplified via isothermal Rolling Circle Amplification (RCA). By merging the single-molecule detection power of RCA reaction with microfluidic technology we were able to demonstrate that identification of specific protein markers can be achieved on tumor cell surface in miniaturized nano-liter reaction droplets. Furthermore, this combined approach of signal amplification in a microfluidic format could extend the utility of existing methods by reducing sample and reagent consumption and enhancing the sensitivities and specificities for various applications, including early diagnosis of cancer. PMID:21294269

A novel two-step procedure to expand Sca-1+ cells clonally

PubMed Central

Tang, Yao Liang; Shen, Leping; Qian, Keping; Phillips, M. Ian

2007-01-01

Resident cardiac stem cells (CSCs) are characterized by their capacity to self-renew in culture, and are multi-potent for forming normal cell types in hearts. CSCs were originally isolated directly from enzymatically digested hearts using stem cell markers. However, long exposure to enzymatic digestion can affect the integrity of stem cell markers on the cell surface, and also compromise stem cell function. Alternatively resident CSCs can migrate from tissue explant and form cardiospheres in culture. However, fibroblast contamination can easily occur during CSC culture. To avoid these problems, we developed a two-step procedure by growing the cells before selecting the Sca1+ cells and culturing in cardiac fibroblast conditioned medium, they avoid fibroblast overgrowth. PMID:17577582

Superparamagnetic nanoparticles for cancer diagnostics and therapeutics

NASA Astrophysics Data System (ADS)

Kohler, Nathan

2005-11-01

This dissertation describes the development of a magnetic nanoparticle conjugate that can potentially serve as both a contrast enhancement agent in magnetic resonance imaging (MRI) and as a drug carrier in controlled drug release, targeted for cancer diagnostics and therapeutics. In this work, we developed a unique method to synthesize well-dispersed 10-nm superparamagnetic iron oxide nanoparticles (SPION) without using chemical surfactants. This approach is especially advantageous for subsequent surface modification of nanoparticles with functional coatings. To target the SPION for cancer cells in vivo to facilitate MRI contrast enhancement of tumors, we immobilized folic acid on the particle surface. Folic acid is a low molecular weight growth factor over-expressed on many forms of cancer. The covalent immobilization of folic acid to the nanoparticle surface was characterized with FTIR and the intracellular uptake of the folic acid nanoparticles was visualized with scanning confocal microscopy. To use SPION for controlled drug release, we immobilized methotrexate (MTX), a chemotherapeutic drug, to the nanoparticle surface. MTX-modified nanoparticles have several combined advantages including real-time monitoring of drug delivery using MRI, higher intracellular concentrations of methotrexate that increase cellular cytotoxicity, and reduced non-specific uptake by healthy cells within the body. We successfully conducted drug release experiments demonstrating that MTX was released under low pH conditions that mimic the intracellular conditions in the lysozome. To assess cellular cytotoxicity, we tested MTX-nanoparticle conjugates in human breast cancer cells (MCF-7), human cervical cancer cells (HeLa), and glioma cells (9L), and showed that the drug efficacy of MTX-nanoparticle conjugates was similar to that of free MTX. To improve nanoparticle circulation time and intracellular uptake, we developed a novel bifunctional poly(ethylene glycol) (PEG) SAM capable of reducing protein adsorption and particle agglomeration in vivo. The trifluoroethylester-terminal PEG SAM is compatible with oxide surfaces through silanization and ligand functionalization of the chain terminus through amidation. The structure of the silane was characterized by FTIR and NMR. Immobilization of the SAM on the particle surface and ligand grafting of folic acid was confirmed by FTIR and visualized with TEM.

Asialoglycoprotein receptor 1 is a specific cell-surface marker for isolating hepatocytes derived from human pluripotent stem cells

PubMed Central

Peters, Derek T.; Henderson, Christopher A.; Warren, Curtis R.; Friesen, Max; Xia, Fang; Becker, Caroline E.; Musunuru, Kiran; Cowan, Chad A.

2016-01-01

ABSTRACT Hepatocyte-like cells (HLCs) are derived from human pluripotent stem cells (hPSCs) in vitro, but differentiation protocols commonly give rise to a heterogeneous mixture of cells. This variability confounds the evaluation of in vitro functional assays performed using HLCs. Increased differentiation efficiency and more accurate approximation of the in vivo hepatocyte gene expression profile would improve the utility of hPSCs. Towards this goal, we demonstrate the purification of a subpopulation of functional HLCs using the hepatocyte surface marker asialoglycoprotein receptor 1 (ASGR1). We analyzed the expression profile of ASGR1-positive cells by microarray, and tested their ability to perform mature hepatocyte functions (albumin and urea secretion, cytochrome activity). By these measures, ASGR1-positive HLCs are enriched for the gene expression profile and functional characteristics of primary hepatocytes compared with unsorted HLCs. We have demonstrated that ASGR1-positive sorting isolates a functional subpopulation of HLCs from among the heterogeneous cellular population produced by directed differentiation. PMID:27143754

Bidirectional immobilization of affinity-tagged cytochrome c on electrode surfaces.

PubMed

Schröper, Florian; Baumann, Arnd; Offenhäusser, Andreas; Mayer, Dirk

2010-08-07

Here, we report a new strategy for the directed bivalent immobilization of cyt c on or between gold electrodes. C-terminal modification with cys- or his-tag did not affect the functional integrity of the protein. In combination with electrostatic protein binding, these tags enable a bifunctional immobilization between two electrodes or alternatively one electrode and interacting enzymes.

Label-free screening of niche-to-niche variation in satellite stem cells using functionalized pores

NASA Astrophysics Data System (ADS)

Chapman, Matthew R.; Balakrishnan, Karthik; Conboy, Michael J.; Mohanty, Swomitra; Jabart, Eric; Huang, Haiyan; Hack, James; Conboy, Irina M.; Sohn, Lydia L.

2012-02-01

Combinations of surface markers are currently used to identify muscle satellite cells. Using pores functionalized with specific antibodies and measuring the transit time of cells passing through these pores, we discovered remarkable heterogeneity in the expression of these markers in muscle (satellite) stem cells that reside in different single myofibers. Microniche-specific variation in stem cells of the same organ has not been previously described, as bulk analysis does not discriminate between separate myofibers or even separate hind-leg muscle groups. We found a significant population of Sca-1+ satellite cells that form myotubes, thereby demonstrating the myogenic potential of Sca-1+ cells, which are currently excluded in bulk sorting. Finally, using our label-free pore screening technique, we have been able to quantify directly surface expression of Notch1 without activation of the Notch pathway. We show for the first time Notch1-expression heterogeneity in unactivated satellite cells. The discovery of fiber-to-fiber variations prompts new research into the reasons for such diversity in muscle stem cells.

Facile formation of 2D Co2P@Co3O4 microsheets through in-situ toptactic conversion and surface corrosion: Bifunctional electrocatalysts towards overall water splitting

NASA Astrophysics Data System (ADS)

Yao, Lihua; Zhang, Nan; Wang, Yin; Ni, Yuanman; Yan, Dongpeng; Hu, Changwen

2018-01-01

Exploring efficient non-precious electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for many renewable energy conversion processes. In this work, we report that 2D Co2P@Co3O4 microsheets can be prepared through an in-situ toptactic conversion from single-crystal β-Co(OH)2 microplatelets, associated with a surface phosphatization and corrosion process. The resultant Co2P@Co3O4 2D hybrid materials can further serve as self-supported bifunctional catalytic electrodes to drive the overall water splitting for HER and OER simultaneously, with low overpotentials and high long-term stability. Furthermore, a water electrolyzer based on Co2P@Co3O4 hybrid as both anode and cathode is fabricated, which achieves 10 mA cm-2 current at only 1.57 V during water splitting process. Therefore, this work provides a facile strategy to obtain 2D Co2P-based micro/nanostructures, which act as low-cost and highly active electrocatalysts towards overall water splitting application.

A new route for degradation of volatile organic compounds under visible light: using the bifunctional photocatalyst Pt/TiO2-xNx in H2-O2 atmosphere.

PubMed

Li, Danzhen; Chen, Zhixin; Chen, Yilin; Li, Wenjuan; Huang, Hanjie; He, Yunhui; Fu, Xianzhi

2008-03-15

The bifunctional photocatalyst Pt/TiO2-xNx has been successfully prepared by wet impregnation. The properties of Pt/ TiO2-xNx have been investigated by diffuse reflectance spectra, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, a photoluminescence technique with terephthalic acid, and electric field induced surface photovoltage spectra. The photocatalytic activity of the sample was evaluated by the decomposition of volatile organic pollutants (VOCs) in a H2-O2 atmosphere under visible light irradiation. The results demonstrated that nitrogen-doped and platinum-modified TiO2 in a H2-O2 atmosphere could enormously increase the quantum efficiency of the photocatalytic system with excellent photocatalytic activity and high catalytic stability. The increased quantum efficiency can be explained by enhanced separation efficiency of photogenerated electron-hole pairs, higher interface electron transfer rate, and an increased number of surface hydroxyl radicals in the photocatalytic process. A mechanism was proposed to elucidate the degradation of VOCs over PtTiO(2-x)Nx in a H2-O2 atmosphere under visible light irradiation.

The CD11a and Endothelial Protein C Receptor Marker Combination Simplifies and Improves the Purification of Mouse Hematopoietic Stem Cells

PubMed Central

Karimzadeh, Alborz; Scarfone, Vanessa M.; Varady, Erika; Chao, Connie; Grathwohl, Karin; Fathman, John W.; Fruman, David A.; Serwold, Thomas

2018-01-01

Abstract Hematopoietic stem cells (HSCs) are the self‐renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish them from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, endothelial protein C receptor (EPCR), can be used to effectively identify and purify HSCs. We introduce a new two‐color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist's toolkit improves the purity of and simplifies isolation of HSCs. stem cells translational medicine 2018;7:468–476 PMID:29543389

A Paracrine Mechanism Accelerating Expansion of Human Induced Pluripotent Stem Cell-Derived Hepatic Progenitor-Like Cells

PubMed Central

Tsuruya, Kota; Chikada, Hiromi; Ida, Kinuyo; Anzai, Kazuya; Kagawa, Tatehiro; Inagaki, Yutaka; Mine, Tetsuya

2015-01-01

Hepatic stem/progenitor cells in liver development have a high proliferative potential and the ability to differentiate into both hepatocytes and cholangiocytes. In this study, we focused on the cell surface molecules of human induced pluripotent stem (iPS) cell-derived hepatic progenitor-like cells (HPCs) and analyzed how these molecules modulate expansion of these cells. Human iPS cells were differentiated into immature hepatic lineage cells by cytokines. In addition to hepatic progenitor markers (CD13 and CD133), the cells were coimmunostained for various cell surface markers (116 types). The cells were analyzed by flow cytometry and in vitro colony formation culture with feeder cells. Twenty types of cell surface molecules were highly expressed in CD13+CD133+ cells derived from human iPS cells. Of these molecules, CD221 (insulin-like growth factor receptor), which was expressed in CD13+CD133+ cells, was quickly downregulated after in vitro expansion. The proliferative ability was suppressed by a neutralizing antibody and specific inhibitor of CD221. Overexpression of CD221 increased colony-forming ability. We also found that inhibition of CD340 (erbB2) and CD266 (fibroblast growth factor-inducible 14) signals suppressed proliferation. In addition, both insulin-like growth factor (a ligand of CD221) and tumor necrosis factor-like weak inducer of apoptosis (a ligand of CD266) were provided by feeder cells in our culture system. This study revealed the expression profiles of cell surface molecules in human iPS cell-derived HPCs and that the paracrine interactions between HPCs and other cells through specific receptors are important for proliferation. PMID:25808356

A Paracrine Mechanism Accelerating Expansion of Human Induced Pluripotent Stem Cell-Derived Hepatic Progenitor-Like Cells.

PubMed

Tsuruya, Kota; Chikada, Hiromi; Ida, Kinuyo; Anzai, Kazuya; Kagawa, Tatehiro; Inagaki, Yutaka; Mine, Tetsuya; Kamiya, Akihide

2015-07-15

Hepatic stem/progenitor cells in liver development have a high proliferative potential and the ability to differentiate into both hepatocytes and cholangiocytes. In this study, we focused on the cell surface molecules of human induced pluripotent stem (iPS) cell-derived hepatic progenitor-like cells (HPCs) and analyzed how these molecules modulate expansion of these cells. Human iPS cells were differentiated into immature hepatic lineage cells by cytokines. In addition to hepatic progenitor markers (CD13 and CD133), the cells were coimmunostained for various cell surface markers (116 types). The cells were analyzed by flow cytometry and in vitro colony formation culture with feeder cells. Twenty types of cell surface molecules were highly expressed in CD13(+)CD133(+) cells derived from human iPS cells. Of these molecules, CD221 (insulin-like growth factor receptor), which was expressed in CD13(+)CD133(+) cells, was quickly downregulated after in vitro expansion. The proliferative ability was suppressed by a neutralizing antibody and specific inhibitor of CD221. Overexpression of CD221 increased colony-forming ability. We also found that inhibition of CD340 (erbB2) and CD266 (fibroblast growth factor-inducible 14) signals suppressed proliferation. In addition, both insulin-like growth factor (a ligand of CD221) and tumor necrosis factor-like weak inducer of apoptosis (a ligand of CD266) were provided by feeder cells in our culture system. This study revealed the expression profiles of cell surface molecules in human iPS cell-derived HPCs and that the paracrine interactions between HPCs and other cells through specific receptors are important for proliferation.

Differential Expression Levels of Integrin α6 Enable the Selective Identification and Isolation of Atrial and Ventricular Cardiomyocytes.

PubMed

Wiencierz, Anne Maria; Kernbach, Manuel; Ecklebe, Josephine; Monnerat, Gustavo; Tomiuk, Stefan; Raulf, Alexandra; Christalla, Peter; Malan, Daniela; Hesse, Michael; Bosio, Andreas; Fleischmann, Bernd K; Eckardt, Dominik

2015-01-01

Central questions such as cardiomyocyte subtype emergence during cardiogenesis or the availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, current methodologies do not allow for a transgene-free selective isolation of atrial or ventricular cardiomyocytes due to the lack of subtype specific cell surface markers. In order to develop cell surface marker-based isolation procedures for cardiomyocyte subtypes, we performed an antibody-based screening on embryonic mouse hearts. Our data indicate that atrial and ventricular cardiomyocytes are characterized by differential expression of integrin α6 (ITGA6) throughout development and in the adult heart. We discovered that the expression level of this surface marker correlates with the intracellular subtype-specific expression of MLC-2a and MLC-2v on the single cell level and thereby enables the discrimination of cardiomyocyte subtypes by flow cytometry. Based on the differential expression of ITGA6 in atria and ventricles during cardiogenesis, we developed purification protocols for atrial and ventricular cardiomyocytes from mouse hearts. Atrial and ventricular identities of sorted cells were confirmed by expression profiling and patch clamp analysis. Here, we introduce a non-genetic, antibody-based approach to specifically isolate highly pure and viable atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This will facilitate in-depth characterization of the individual cellular subsets and support translational research applications.

Differential Expression Levels of Integrin α6 Enable the Selective Identification and Isolation of Atrial and Ventricular Cardiomyocytes

PubMed Central

Wiencierz, Anne Maria; Kernbach, Manuel; Ecklebe, Josephine; Monnerat, Gustavo; Tomiuk, Stefan; Raulf, Alexandra; Christalla, Peter; Malan, Daniela; Hesse, Michael; Bosio, Andreas; Fleischmann, Bernd K.; Eckardt, Dominik

2015-01-01

Rationale Central questions such as cardiomyocyte subtype emergence during cardiogenesis or the availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, current methodologies do not allow for a transgene-free selective isolation of atrial or ventricular cardiomyocytes due to the lack of subtype specific cell surface markers. Methods and Results In order to develop cell surface marker-based isolation procedures for cardiomyocyte subtypes, we performed an antibody-based screening on embryonic mouse hearts. Our data indicate that atrial and ventricular cardiomyocytes are characterized by differential expression of integrin α6 (ITGA6) throughout development and in the adult heart. We discovered that the expression level of this surface marker correlates with the intracellular subtype-specific expression of MLC-2a and MLC-2v on the single cell level and thereby enables the discrimination of cardiomyocyte subtypes by flow cytometry. Based on the differential expression of ITGA6 in atria and ventricles during cardiogenesis, we developed purification protocols for atrial and ventricular cardiomyocytes from mouse hearts. Atrial and ventricular identities of sorted cells were confirmed by expression profiling and patch clamp analysis. Conclusion Here, we introduce a non-genetic, antibody-based approach to specifically isolate highly pure and viable atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This will facilitate in-depth characterization of the individual cellular subsets and support translational research applications. PMID:26618511

Therapeutic Effect of Human Adipose Tissue-Derived Mesenchymal Stem Cells in Experimental Corneal Failure Due to Limbal Stem Cell Niche Damage.

PubMed

Galindo, Sara; Herreras, José M; López-Paniagua, Marina; Rey, Esther; de la Mata, Ana; Plata-Cordero, María; Calonge, Margarita; Nieto-Miguel, Teresa

2017-10-01

Limbal stem cells are responsible for the continuous renewal of the corneal epithelium. The destruction or dysfunction of these stem cells or their niche induces limbal stem cell deficiency (LSCD) leading to visual loss, chronic pain, and inflammation of the ocular surface. To restore the ocular surface in cases of bilateral LSCD, an extraocular source of stem cells is needed to avoid dependence on allogeneic limbal stem cells that are difficult to obtain, isolate, and culture. The aim of this work was to test the tolerance and the efficacy of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) to regenerate the ocular surface in two experimental models of LSCD that closely resemble different severity grades of the human pathology. hAT-MSCs transplanted to the ocular surface of the partial and total LSCD models developed in rabbits were well tolerated, migrated to inflamed tissues, reduced inflammation, and restrained the evolution of corneal neovascularization and corneal opacity. The expression profile of the corneal epithelial cell markers CK3 and E-cadherin, and the limbal epithelial cell markers CK15 and p63 was lost in the LSCD models, but was partially recovered after hAT-MSC transplantation. For the first time, we demonstrated that hAT-MSCs improve corneal and limbal epithelial phenotypes in animal LSCD models. These results support the potential use of hAT-MSCs as a novel treatment of ocular surface failure due to LSCD. hAT-MSCs represent an available, non-immunogenic source of stem cells that may provide therapeutic benefits in addition to reduce health care expenses. Stem Cells 2017;35:2160-2174. © 2017 AlphaMed Press.

Use of Adipose Derived Stem Cells to Treat Large Bone Defects. Addendum

DTIC Science & Technology

2009-07-01

optimal delivery . We have also completed characterization of our segmental defect model, including analysis of vascular ingrowth during defect healing...cells seeded in 1.2% Keltone alginate at a density of 12-15x106cells/ml were loaded on 24-well transwell insert membranes [6]. Once hydrogel discs...process from tissue culture plates and hydrogels does not alter the surface phenotype. Gene expression of surface markers and proteins associated with

Isolation of Small SSEA-4-Positive Putative Stem Cells from the Ovarian Surface Epithelium of Adult Human Ovaries by Two Different Methods

PubMed Central

Virant-Klun, Irma; Skutella, Thomas; Hren, Matjaz; Gruden, Kristina; Cvjeticanin, Branko; Vogler, Andrej; Sinkovec, Jasna

2013-01-01

The adult ovarian surface epithelium has already been proposed as a source of stem cells and germinal cells in the literature, therefore it has been termed the “germinal epithelium”. At present more studies have confirmed the presence of stem cells expressing markers of pluripotency in adult mammalian ovaries, including humans. The aim of this study was to isolate a population of stem cells, based on the expression of pluripotency-related stage-specific embryonic antigen-4 (SSEA-4) from adult human ovarian surface epithelium by two different methods: magnetic-activated cell sorting and fluorescence-activated cell sorting. Both methods made it possible to isolate a similar, relatively homogenous population of small, SSEA-4-positive cells with diameters of up to 4 μm from the suspension of cells retrieved by brushing of the ovarian cortex biopsies in reproductive-age and postmenopausal women and in women with premature ovarian failure. The immunocytochemistry and genetic analyses revealed that these small cells—putative stem cells—expressed some primordial germ cell and pluripotency-related markers and might be related to the in vitro development of oocyte-like cells expressing some oocyte-specific transcription factors in the presence of donated follicular fluid with substances important for oocyte growth and development. The stemness of these cells needs to be further researched. PMID:23509763

Macroscale cobalt-MOFs derived metallic Co nanoparticles embedded in N-doped porous carbon layers as efficient oxygen electrocatalysts

NASA Astrophysics Data System (ADS)

Lu, Hai-Sheng; Zhang, Haimin; Liu, Rongrong; Zhang, Xian; Zhao, Huijun; Wang, Guozhong

2017-01-01

Metal-organic frameworks (MOFs) materials have aroused great research interest in different areas owing to their unique properties, such as high surface area, various composition, well-organized framework and controllable porous structure. Controllable fabrication of MOFs materials at macro-scale may be more promising for their large-scale practical applications. Here we report the synthesis of macro-scale Co-MOFs crystals using 1,3,5-benzenetricarboxylic acid (H3BTC) linker in the presence of Co2+, triethylamine (TEA) and nonanoic acid by a facile solvothermal reaction. Further, the as-fabricated Co-MOFs as precursor was pyrolytically treated at different temperatures in N2 atmosphere to obtain metallic Co nanoparticles embedded in N-doped porous carbon layers (denoted as Co@NPC). The results demonstrate that the Co-MOFs derived sample obtained at 900 °C (Co@NPC-900) shows a porous structure (including micropore and mesopore) with a surface area of 110.8 m2 g-1 and an N doping level of 1.62 at.% resulted from TEA in the pyrolysis process. As electrocatalyst, the Co@NPC-900 exhibits bifunctional electrocatalytic activities toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media which are key reactions in some renewable energy technologies such as fuel cells and rechargeable metal-air batteries. The results indicate that the Co@NPC-900 can afford an onset potential of 1.50 V (vs. RHE) and a potential value of 1.61 V (vs. RHE) at a current density of 10 mA cm-2 for ORR and OER with high applicable stability, respectively. The efficient catalytic activity of Co@NPC-900 as bifunctional oxygen electrocatalyst can be ascribed to N doping and embedded metallic Co nanoparticles in carbon structure providing catalytic active sites and porous structure favourable for electrocatalysis-related mass transport.

Ni/CdS bifunctional Ti@TiO2 core-shell nanowire electrode for high-performance nonenzymatic glucose sensing.

PubMed

Guo, Chunyan; Huo, Huanhuan; Han, Xu; Xu, Cailing; Li, Hulin

2014-01-07

In this work, a Ni/CdS bifunctional Ti@TiO2 core-shell nanowire electrode with excellent electrochemical sensing property was successfully constructed through a hydrothermal and electrodeposition method. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to confirm the synthesis and characterize the morphology of the as-prepared samples. The results revealed that the CdS layer between Ni and TiO2 plays an important role in the uniform nucleation and the following growth of highly dispersive Ni nanoparticle on the Ti@TiO2 core-shell nanowire surface. The bifunctional nanostructured electrode was applied to construct an electrochemical nonenzymatic sensor for the reliable detection of glucose. Under optimized conditions, this nonenzymatic glucose sensor displayed a high sensitivity up to 1136.67 μA mM(-1) cm(-2), a wider liner range of 0.005-12 mM, and a lower detection limit of 0.35 μM for glucose oxidation. The high dispersity of Ni nanoparticles, combined with the anti-poisoning faculty against the intermediate derived from the self-cleaning ability of CdS under the photoexcitation, was considered to be responsible for these enhanced electrochemical performances. Importantly, favorable reproducibility and long-term performance were also obtained thanks to the robust frameworks. All these results indicate this novel electrode is a promising candidate for nonenzymatic glucose sensing.

Synthesis and characterization of ZnS@Fe3O4 fluorescent-magnetic bifunctional nanospheres

NASA Astrophysics Data System (ADS)

Koc, Kenan; Karakus, Baris; Rajar, Kausar; Alveroglu, Esra

2017-10-01

Herein, we synthesized and characterized fluorescent and super paramagnetic ZnS@Fe3O4 nanospheres. First, (3-mercaptopropyl) trimethoxysilane (MPS) capped ZnS quantum dots (QDs) and SiO2 coated Fe3O4 nanoparticles were synthesized separately by using solution growth and co-precipitation techniques. After synthesis and characterization of these two nanoparticles, they were conglutinated together in a nano sized sphere. The QDs were attached to the surface of the Fe3O4 nanoparticles by Sisbnd Osbnd Si bonds and so Sisbnd Osbnd Si bonds created a SiO2 network around the nanoparticles during the formation of the ZnS@Fe3O4 nanospheres. The synthesized MPS capped ZnS fluorescent QDs, SiO2 coated magnetite super paramagnetic nanoparticles and ZnS@Fe3O4 fluorescent-magnetic bifunctional nanospheres were characterized by using UV-Vis Absorption Spectroscopy, Fluorescence Spectroscopy, X-ray analysis, Vibrating Sample Magnetometer analysis, Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope and Energy-dispersive X-ray spectroscopy. ZnS@Fe3O4 bifunctional nanospheres were shown to retain the magnetic properties of magnetite, while exhibiting the luminescent optical properties of ZnS nanoparticles. The combination of fluorescent and magnetic behaviors of nano composites make them useful for potential applications in the field of bio-medical and environmental.

Three-dimensional low Reynolds number flows with a free surface

NASA Technical Reports Server (NTRS)

Degani, D.; Gutfinger, C.

1977-01-01

The two-dimensional leveling problem (Degani, Gutfinger, 1976) is extended to three dimensions in the case where the flow Re number is very low and attention is paid to the free surface boundary condition with surface tension effects included. The no-slip boundary condition on the wall is observed. The numerical solution falls back on the Marker and Cell (MAC) method (Harlow and Welch, 1965) with the computation region divided into a finite number of stationary rectangular cells (or boxes in the 3-D case) and fluid flow traverses the cells (or boxes).

Multifunctional Hybrid Multilayer Gate Dielectrics with Tunable Surface Energy for Ultralow-Power Organic and Amorphous Oxide Thin-Film Transistors.

PubMed

Byun, Hye-Ran; You, Eun-Ah; Ha, Young-Geun

2017-03-01

For large-area, printable, and flexible electronic applications using advanced semiconductors, novel dielectric materials with excellent capacitance, insulating property, thermal stability, and mechanical flexibility need to be developed to achieve high-performance, ultralow-voltage operation of thin-film transistors (TFTs). In this work, we first report on the facile fabrication of multifunctional hybrid multilayer gate dielectrics with tunable surface energy via a low-temperature solution-process to produce ultralow-voltage organic and amorphous oxide TFTs. The hybrid multilayer dielectric materials are constructed by iteratively stacking bifunctional phosphonic acid-based self-assembled monolayers combined with ultrathin high-k oxide layers. The nanoscopic thickness-controllable hybrid dielectrics exhibit the superior capacitance (up to 970 nF/cm 2 ), insulating property (leakage current densities <10 -7 A/cm 2 ), and thermal stability (up to 300 °C) as well as smooth surfaces (root-mean-square roughness <0.35 nm). In addition, the surface energy of the hybrid multilayer dielectrics are easily changed by switching between mono- and bifunctional phosphonic acid-based self-assembled monolayers for compatible fabrication with both organic and amorphous oxide semiconductors. Consequently, the hybrid multilayer dielectrics integrated into TFTs reveal their excellent dielectric functions to achieve high-performance, ultralow-voltage operation (< ± 2 V) for both organic and amorphous oxide TFTs. Because of the easily tunable surface energy, the multifunctional hybrid multilayer dielectrics can also be adapted for various organic and inorganic semiconductors, and metal gates in other device configurations, thus allowing diverse advanced electronic applications including ultralow-power and large-area electronic devices.

In vitro differentiation of adipose-tissue-derived mesenchymal stem cells into neural retinal cells through expression of human PAX6 (5a) gene.

PubMed

Rezanejad, Habib; Soheili, Zahra-Soheila; Haddad, Farhang; Matin, Maryam M; Samiei, Shahram; Manafi, Ali; Ahmadieh, Hamid

2014-04-01

The neural retina is subjected to various degenerative conditions. Regenerative stem-cell-based therapy holds great promise for treating severe retinal degeneration diseases, although many drawbacks remain to be overcome. One important problem is to gain authentically differentiated cells for replacement. Paired box 6 protein (5a) (PAX6 (5a)) is a highly conserved master control gene that has an essential role in the development of the vertebrate visual system. Human adipose-tissue-derived stem cell (hADSC) isolation was performed by using fat tissues and was confirmed by the differentiation potential of the cells into adipocytes and osteocytes and by their surface marker profile. The coding region of the human PAX6 (5a) gene isoform was cloned and lentiviral particles were propagated in HEK293T. The differentiation of hADSCs into retinal cells was characterized by morphological characteristics, quantitative real-time reverse transcription plus the polymerase chain reaction (qPCR) and immunocytochemistry (ICC) for some retinal cell-specific and retinal pigmented epithelial (RPE) cell-specific markers. hADSCs were successfully isolated. Flow cytometric analysis of surface markers indicated the high purity (~97 %) of isolated hADSCs. After 30 h of post-transduction, cells gradually showed the characteristic morphology of neuronal cells and small axon-like processes emerged. qPCR and ICC confirmed the differentiation of some neural retinal cells and RPE cells. Thus, PAX6 (5a) transcription factor expression, together with medium supplemented with fibronectin, is able to induce the differentiation of hADSCs into retinal progenitors, RPE cells and photoreceptors.

Avian Follicular and Interdigitating Dendritic Cells: Isolation and Morphologic, Phenotypic, and Functional Analyses

USDA-ARS?s Scientific Manuscript database

An antiserum against Eimeria tenella sporozoites was used to localize and isolate Ag-binding cells in intestinal cecal tonsils of parasite-infected chickens. Based on their tissue localization, ultrastructural features, and expression of surface markers, two subpopulations of cells were isolated, C...

Preparation and preclinical evaluation of a 68Ga-labelled c(RGDfK) conjugate comprising the bifunctional chelator NODIA-Me.

PubMed

Läppchen, Tilman; Holland, Jason P; Kiefer, Yvonne; Bartholomä, Mark D

2018-01-01

We recently developed a chelating platform based on the macrocycle 1,4,7-triazacyclononane with up to three, five-membered azaheterocyclic arms for the development of 68 Ga- and 64 Cu-based radiopharmaceuticals. Here, a 68 Ga-labelled conjugate comprising the bifunctional chelator NODIA-Me in combination with the α v ß 3 -targeting peptide c(RGDfK) has been synthesized and characterized. The primary aim was to evaluate further the potential of our NODIA-Me chelating system for the development of 68 Ga-labelled radiotracers. The BFC NODIA-Me was conjugated to c(RGDfK) by standard peptide chemistry to obtain the final bioconjugate NODIA-Me-c(RGDfK) 3 in 72% yield. Labelling with [ 68 Ga]GaCl 3 was accomplished in a fully automated, cGMP compliant process to give [ 68 Ga]3 in high radiochemical yield (98%) and moderate specific activity (~ 8 MBq nmol- 1 ). Incorporation of the Ga-NODIA-Me chelate to c(RGDfK) 2 had only minimal influence on the affinity to integrin α v ß 3 (IC 50 values [ nat Ga]3 = 205.1 ± 1.4 nM, c(RGDfK) 2 = 159.5 ± 1.3 nM) as determined in competitive cell binding experiments in U-87 MG cell line. In small-animal PET imaging and ex vivo biodistribution studies, the radiotracer [ 68 Ga]3 showed low uptake in non-target organs and specific tumor uptake in U-87 MG tumors. The results suggest that the bifunctional chelator NODIA-Me is an interesting alternative to existing ligands for the development of 68 Ga-labelled radiopharmaceuticals.

Engineering yeast with bifunctional minicellulosome and cellodextrin pathway for co-utilization of cellulose-mixed sugars.

PubMed

Fan, Li-Hai; Zhang, Zi-Jian; Mei, Sen; Lu, Yang-Yang; Li, Mei; Wang, Zai-Yu; Yang, Jian-Guo; Yang, Shang-Tian; Tan, Tian-Wei

2016-01-01

Consolidated bioprocessing (CBP), integrating cellulase production, cellulose saccharification, and fermentation into one step has been widely considered as the ultimate low-cost configuration for producing second-generation fuel ethanol. However, the requirement of a microbial strain able to hydrolyze cellulosic biomass and convert the resulting sugars into high-titer ethanol limits CBP application. In this work, cellulolytic yeasts were developed by engineering Saccharomyces cerevisiae with a heterologous cellodextrin utilization pathway and bifunctional minicellulosomes. The cell-displayed minicellulosome was two-scaffoldin derived, and contained an endoglucanase and an exoglucanase, while the intracellular cellodextrin pathway consisted of a cellodextrin transporter and a β-glucosidase, which mimicked the unique cellulose-utilization system in Clostridium thermocellum and allowed S. cerevisiae to degrade and use cellulose without glucose inhibition/repression on cellulases and mixed-sugar uptake. Consequently, only a small inoculation of the non-induced yeast cells was required to efficiently co-convert both cellulose and galactose to ethanol in a single-step co-fermentation process, achieving a high specific productivity of ~62.61 mg cellulosic ethanol/g cell·h from carboxymethyl cellulose and ~56.37 mg cellulosic ethanol/g cell·h from phosphoric acid-swollen cellulose. Our work provides a versatile engineering strategy for co-conversion of cellulose-mixed sugars to ethanol by S. cerevisiae, and the achievements in this work may further promote cellulosic biofuel production.

Analysis of the surface expression of c-kit and occurrence of the c-kit Asp816Val activating mutation in T cells, B cells, and myelomonocytic cells in patients with mastocytosis.

PubMed

Akin, C; Kirshenbaum, A S; Semere, T; Worobec, A S; Scott, L M; Metcalfe, D D

2000-02-01

The Asp816Val c-kit activating mutation is detectable in the peripheral blood cells of some patients with mastocytosis and in lesional skin biopsies obtained from adult patients with urticaria pigmentosa. These observations led to the conclusion that this mutation is present in mast cells and mast cell precursors that express c-kit. However, the distribution of the Asp816Val mutation among hematopoietic lineages is unknown. To determine the distribution of the Asp816Val mutation among hematopoietic lineages and to explore its relationship to clinical disease, we examined cells bearing differentiation markers for myelomonocytic cells as well as T and B lymphocytes, in both peripheral blood and bone marrow obtained from patients with mastocytosis. The presence of Asp816Val c-kit mutation in cells magnetically sorted from peripheral blood or bone marrow according to surface differentiation markers was studied by reverse transcriptase polymerase chain reaction (RT-PCR) restriction fragment length polymorphism (RFLP) analysis. The surface expression of c-kit was determined by flow cytometry. The mutation was detectable by RT-PCR in at least one cell lineage in the bone marrow in 7 of 7 patients examined and in the peripheral blood of 11 of 11 adult patients with urticaria pigmentosa and indolent disease. The mutation was identified most frequently in B cells and myeloid cells. Flow cytometric analysis demonstrated that the differentiated cells expressing mutated c-kit were negative for surface KIT. These results are consistent with the conclusion that the c-kit Asp816Val mutation occurs in an early progenitor cell and is carried by myelomonocytic cells, T cells, and B cells in addition to mast cells. However, unlike mast cells, these myelomonocytic cells, T cells, and B cells do not concomitantly express surface c-kit and thus may be less susceptible to the effects of this mutation.

The CD11a and Endothelial Protein C Receptor Marker Combination Simplifies and Improves the Purification of Mouse Hematopoietic Stem Cells.

PubMed

Karimzadeh, Alborz; Scarfone, Vanessa M; Varady, Erika; Chao, Connie; Grathwohl, Karin; Fathman, John W; Fruman, David A; Serwold, Thomas; Inlay, Matthew A

2018-06-01

Hematopoietic stem cells (HSCs) are the self-renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish them from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, endothelial protein C receptor (EPCR), can be used to effectively identify and purify HSCs. We introduce a new two-color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist's toolkit improves the purity of and simplifies isolation of HSCs. Stem Cells Translational Medicine 2018;7:468-476. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Murine hepatocellular carcinoma derived stem cells reveal epithelial-to-mesenchymal plasticity.

PubMed

Jayachandran, Aparna; Shrestha, Ritu; Dhungel, Bijay; Huang, I-Tao; Vasconcelos, Marianna Yumi Kawashima; Morrison, Brian J; Ramlogan-Steel, Charmaine A; Steel, Jason C

2017-09-26

To establish a model to enrich and characterize stem-like cells from murine normal liver and hepatocellular carcinoma (HCC) cell lines and to further investigate stem-like cell association with epithelial-to-mesenchymal transition (EMT). In this study, we utilized a stem cell conditioned serum-free medium to enrich stem-like cells from mouse HCC and normal liver cell lines, Hepa 1-6 and AML12, respectively. We isolated the 3-dimensional spheres and assessed their stemness characteristics by evaluating the RNA levels of stemness genes and a cell surface stem cell marker by quantitative reverse transcriptase-PCR (qRT-PCR). Next, we examined the relationship between stem cells and EMT using qRT-PCR. Three-dimensional spheres were enriched by culturing murine HCC and normal hepatocyte cell lines in stem cell conditioned serum-free medium supplemented with epidermal growth factor, basic fibroblast growth factor and heparin sulfate. The 3-dimensional spheres had enhanced stemness markers such as Klf4 and Bmi1 and hepatic cancer stem cell (CSC) marker Cd44 compared to parental cells grown as adherent cultures. We report that epithelial markers E-cadherin and ZO-1 were downregulated, while mesenchymal markers Vimentin and Fibronectin were upregulated in 3-dimensional spheres. The 3-dimensional spheres also exhibited changes in expression of Snai , Zeb and Twist family of EMT transcription factors. Our novel method successfully enriched stem-like cells which possessed an EMT phenotype. The isolation and characterization of murine hepatic CSCs could establish a precise target for the development of more effective therapies for HCC.

3D-printed bioceramic scaffolds with antibacterial and osteogenic activity.

PubMed

Zhang, Yongliang; Zhai, Dong; Xu, Mengchi; Yao, Qingqiang; Zhu, Huiying; Chang, Jiang; Wu, Chengtie

2017-06-20

Bacterial infection poses a significant risk with the wide application of bone graft materials. Designing bone grafts with good antibacterial performance and excellent bone-forming activity is of particular significance for bone tissue engineering. In our study, a 3D printing method was used to prepare β-tricalcium phosphate (β-TCP) bioceramic scaffolds. Silver (Ag) nanoparticles were uniformly dispersed on graphene oxide (GO) to form a homogeneous nanocomposite (named Ag@GO) with different Ag-to-graphene oxide mass ratios, with this being synthesized via the liquid chemical reduction approach. Ag@GO nanocomposites were successfully modified on the β-TCP scaffolds by a simple soaking method to achieve bifunctional biomaterials with antibacterial and osteogenic activity. The prepared scaffolds possessed a connected network with triangle pore morphology and the surfaces of the β-TCP scaffolds were uniformly modified by the Ag@GO nanocomposite layers. The Ag content in the scaffolds was controlled by changing the coating times and concentration of the Ag@GO nanocomposites. The antibacterial activity of the scaffolds was assessed with Gram-negative bacteria (Escherichia coli, E. coli). The results demonstrated that the scaffolds with Ag@GO nanocomposites presented excellent antibacterial activity. In addition, the scaffolds coated with Ag@GO nanocomposites conspicuously accelerated the osteogenic differentiation of rabbit bone marrow stromal cells by improving their alkaline phosphatase activity and bone-related gene expression (osteopontin, runt-related transcription factor 2, osteocalcin and bone sialoprotein). This study demonstrates that bifunctional scaffolds with a combination of antibacterial and osteogenic activity can be achieved for the reconstruction of large-bone defects while preventing or treating infections.

Differential expression of E-cadherin at the surface of rat beta-cells as a marker of functional heterogeneity.

PubMed

Bosco, Domenico; Rouiller, Dominique G; Halban, Philippe A

2007-07-01

The aim of this study was to assess whether the expression of E-cadherin at the surface of rat beta-cells is regulated by insulin secretagogues and correlates with insulin secretion. When cultured under standard conditions, virtually all beta-cells expressed E-cadherin observed by immunofluorescence, but heterogeneous staining was observed. Using fluorescence-activated cell sorting (FACS), two beta-cell sub-populations were sorted: one that was poorly labeled ('ECad-low') and another that was highly labeled ('ECad-high'). After 1-h stimulation with 16.7 mM glucose, insulin secretion (reverse hemolytic plaque assay) from individual ECad-high beta-cells was higher than that from ECad-low beta-cells. Ca2+-dependent beta-cell aggregation was increased at 16.7 mM glucose when compared with 2.8 mM glucose. E-cadherin at the surface of beta-cells was increased after 18 h at 11.1 and 22.2 mM glucose when compared with 2.8 mM glucose, with the greatest increase at 22.2 mM glucose + 0.5 mM isobutylmethylxanthine (IBMX). While no labeling was detected on freshly trypsinized cells, the proportion of stained cells increased in a time-dependent manner during culture for 1, 3, and 24 h. This recovery was faster when cells were incubated at 16.7 vs 2.8 mM glucose. Cycloheximide inhibited expression of E-cadherin at 2.8 mM glucose, but not at 16.7 mM, while depolymerization of actin by either cytochalasin B or latrunculin B increased surface E-cadherin at low glucose. In conclusion, these results show that expression of E-cadherin at the surface of islet beta-cells is controlled by secretagogues including glucose, correlates with insulin secretion, and can serve as a surface marker of beta-cell function.

Metal-Organic Frameworks as Highly Active Electrocatalysts for High-Energy Density, Aqueous Zinc-Polyiodide Redox Flow Batteries.

PubMed

Li, Bin; Liu, Jian; Nie, Zimin; Wang, Wei; Reed, David; Liu, Jun; McGrail, Pete; Sprenkle, Vincent

2016-07-13

The new aqueous zinc-polyiodide redox flow battery (RFB) system with highly soluble active materials as well as ambipolar and bifunctional designs demonstrated significantly enhanced energy density, which shows great potential to reduce RFB cost. However, the poor kinetic reversibility and electrochemical activity of the redox reaction of I3(-)/I(-) couples on graphite felts (GFs) electrode can result in low energy efficiency. Two nanoporous metal-organic frameworks (MOFs), MIL-125-NH2 and UiO-66-CH3, that have high surface areas when introduced to GF surfaces accelerated the I3(-)/I(-) redox reaction. The flow cell with MOF-modified GFs serving as a positive electrode showed higher energy efficiency than the pristine GFs; increases of about 6.4% and 2.7% occurred at the current density of 30 mA/cm(2) for MIL-125-NH2 and UiO-66-CH3, respectively. Moreover, UiO-66-CH3 is more promising due to its excellent chemical stability in the weakly acidic electrolyte. This letter highlights a way for MOFs to be used in the field of RFBs.

Avidin-conjugated calcium phosphate nanoparticles as a modular targeting system for the attachment of biotinylated molecules in vitro and in vivo.

PubMed

van der Meer, Selina Beatrice; Knuschke, Torben; Frede, Annika; Schulze, Nina; Westendorf, Astrid M; Epple, Matthias

2017-07-15

Avidin was covalently conjugated to the surface of calcium phosphate nanoparticles, coated with a thin silica shell and terminated by sulfhydryl groups (diameter of the solid core about 50nm), with a bifunctional crosslinker connecting the amino groups of avidin to the sulfhydryl group on the nanoparticle surface. This led to a versatile nanoparticle system where all kinds of biotinylated (bio-)molecules can be easily attached to the surface by the non-covalent avidin-biotin-complex formation. It also permits the attachment of different biomolecules on the same nanoparticle (heteroavidity), creating a modular system for specific applications in medicine and biology. The variability of the binding to the nanoparticle surface of the was demonstrated with various biotinylated molecules, i.e. fluorescent dyes and antibodies. The accessibility of the conjugated avidin was demonstrated by a fluorescence-quenching assay. About 2.6 binding sites for biotin were accessible on each avidin tetramer. Together with a number of about 240 avidin tetramer units per nanoparticle, this offers about 600 binding sites for biotin on each nanoparticle. The uptake of fluorescently labelled avidin-conjugated calcium phosphate nanoparticles by HeLa cells showed the co-localization of fluorescent avidin and fluorescent biotin, indicating the stability of the complex under cell culture conditions. CD11c-antibody functionalized nanoparticles specifically targeted antigen-presenting immune cells (dendritic cells; DCs) in vitro and in vivo (mice) with high efficiency. Calcium phosphate nanoparticles have turned out to be very useful transporters for biomolecules into cells, both in vitro and in vivo. However, their covalent surface functionalization with antibodies, fluorescent dyes, or proteins requires a separate chemical synthesis for each kind of surface molecule. We have therefore developed avidin-terminated calcium phosphate nanoparticles to which all kinds of biotinylated molecules can be easily attached, also as a mixture of two or more molecules. This non-covalent bond is stable both in cell culture and after injection into mice in vivo. Thus, we have created a highly versatile system for many applications, from the delivery of biomolecules over the targeting of cells and tissue to in vivo imaging. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effect of cryopreservation on delineation of immune cell subpopulations in tumor specimens as determinated by multiparametric single cell mass cytometry analysis.

PubMed

Kadić, Elma; Moniz, Raymond J; Huo, Ying; Chi, An; Kariv, Ilona

2017-02-02

Comprehensive understanding of cellular immune subsets involved in regulation of tumor progression is central to the development of cancer immunotherapies. Single cell immunophenotyping has historically been accomplished by flow cytometry (FC) analysis, enabling the analysis of up to 18 markers. Recent advancements in mass cytometry (MC) have facilitated detection of over 50 markers, utilizing high resolving power of mass spectrometry (MS). This study examined an analytical and operational feasibility of MC for an in-depth immunophenotyping analysis of the tumor microenvironment, using the commercial CyTOF™ instrument, and further interrogated challenges in managing the integrity of tumor specimens. Initial longitudinal studies with frozen peripheral blood mononuclear cells (PBMCs) showed minimal MC inter-assay variability over nine independent runs. In addition, detection of common leukocyte lineage markers using MC and FC detection confirmed that these methodologies are comparable in cell subset identification. An advanced multiparametric MC analysis of 39 total markers enabled a comprehensive evaluation of cell surface marker expression in fresh and cryopreserved tumor samples. This comparative analysis revealed significant reduction of expression levels of multiple markers upon cryopreservation. Most notably myeloid derived suppressor cells (MDSC), defined by co-expression of CD66b + and CD15 + , HLA-DR dim and CD14 - phenotype, were undetectable in frozen samples. These results suggest that optimization and evaluation of cryopreservation protocols is necessary for accurate biomarker discovery in frozen tumor specimens.

ABCG2 Is a Selectable Marker for Enhanced Multilineage Differentiation Potential in Periodontal Ligament Stem Cells

PubMed Central

Szepesi, Áron; Matula, Zsolt; Szigeti, Anna; Várady, György; Szabó, Gyula; Uher, Ferenc; Sarkadi, Balázs

2015-01-01

Periodontal ligament stem cells (PDLSCs) provide an important source for tissue regeneration and may become especially useful in the formation of osteogenic seeds. PDLSCs can be cultured, expanded, and differentiated in vitro; thus, they may be applied in the long-term treatment of the defects in the dental regions. Here we studied numerous potential markers allowing the selection of human PDLSCs with a maximum differentiation potential. We followed the expression of the ATP-binding cassette subfamily G member 2 (ABCG2) membrane transporter protein and isolated ABCG2-expressing cells by using a monoclonal antibody, recognizing the transporter at the cell surface in intact cells. The expression of the ABCG2 protein, corresponding to the so-called side-population phenotype in various tissue-derived stem cells, was found to be a useful marker for the selection of PDLSCs with enhanced osteogenic, chondrogenic, and adipogenic differentiation. These findings may have important applications in achieving efficient dental tissue regeneration by using stem cells from extracted teeth. PMID:25101689

Bifunctional nanoparticles for surface-enhanced Raman spectroscopy-based leukemia biomarker detection

NASA Astrophysics Data System (ADS)

Mehn, Dora; Morasso, Carlo; Vanna, Renzo; Schiumarini, Domitilla; Bedoni, Marzia; Ciceri, Fabio; Gramatica, Furio

2014-03-01

The Wilms tumor gene (WT1) is a biomarker overexpressed in more than 90% of acute myeloid leukemia patients. Fast and sensitive detection of the WT1 in blood samples would allow monitoring of the minimal residual disease during clinical remission and would permit early detection of a potential relapse in acute myeloid leukemia. In this work, Surface Enhanced Raman Spectroscopy (SERS) based detection of the WT1 sequence using bifunctional, magnetic core - gold shell nanoparticles is presented. The classical co-precipitation method was applied to generate magnetic nanoparticles which were coated with a gold shell after modification with aminopropyltriethoxy silane and subsequent deposition of gold nanoparticle seeds. Simple hydroquinone based reduction procedure was applied for the shell growing in water based reaction mixture at room temperature. Thiolated ssDNA probes of the WT1 sequence were immobilized as capture oligonucleotides on the gold surface. Malachite green was applied both for testing the amplification performance of the core-shell colloidal SERS substrate and also as label dye of the target DNA sequence. The SERS enhancer efficacy of the core-shell nanomaterial was compared with the efficacy of classical spherical gold particles produced using the conventional citrate reduction method. The core-shell particles were found not only to provide an opportunity for facile separation in a heterogeneous reaction system but also to be superior regarding robustness as SERS enhancers.

Glucose biosensor from covalent immobilization of chitosan-coupled carbon nanotubes on polyaniline-modified gold electrode.

PubMed

Wan, Dong; Yuan, Shaojun; Li, G L; Neoh, K G; Kang, E T

2010-11-01

An amperometric glucose biosensor was prepared using polyaniline (PANI) and chitosan-coupled carbon nanotubes (CS-CNTs) as the signal amplifiers and glucose oxidase (GOD) as the glucose detector on a gold electrode (the Au-g-PANI-c-(CS-CNTs)-GOD biosensor). The PANI layer was prepared via oxidative graft polymerization of aniline from the gold electrode surface premodified by self-assembled monolayer of 4-aminothiophenol. CS-CNTs were covalently coupled to the PANI-modified gold substrate using glutaradehyde as a bifunctional linker. GOD was then covalently bonded to the pendant hydroxyl groups of chitosan using 1,4-carbonyldiimidazole as the bifunctional linker. The surface functionalization processes were ascertained by X-ray photoelectron spectroscopy (XPS) analyses. The field emission scanning electron microscopy (FESEM) images of the Au-g-PANI-c-(CS-CNTs) electrode revealed the formation of a three-dimensional surface network structure. The electrode could thus provide a more spatially biocompatible microenvironment to enhance the amount and biocatalytic activity of the immobilized enzyme and to better mediate the electron transfer. The resulting Au-g-PANI-c-(CS-CNTs)-GOD biosensor exhibited a linear response to glucose in the concentration range of 1-20 mM, good sensitivity (21 μA/(mM·cm(2))), good reproducibility, and retention of >80% of the initial response current after 2 months of storage.

Nano-molybdenum carbide/carbon nanotubes composite as bifunctional anode catalyst for high-performance Escherichia coli-based microbial fuel cell.

PubMed

Wang, Yaqiong; Li, Bin; Cui, Dan; Xiang, Xingde; Li, Weishan

2014-01-15

A novel electrode, carbon felt-supported nano-molybdenum carbide (Mo2C)/carbon nanotubes (CNTs) composite, was developed as platinum-free anode of high performance microbial fuel cell (MFC). The Mo2C/CNTs composite was synthesized by using the microwave-assisted method with Mo(CO)6 as a single source precursor and characterized by using X-ray diffraction and transmission electron microscopy. The activity of the composite as anode electrocatalyst of MFC based on Escherichia coli (E. coli) was investigated with cyclic voltammetry, chronoamperometry, and cell discharge test. It is found that the carbon felt electrode with 16.7 wt% Mo Mo2C/CNTs composite exhibits a comparable electrocatalytic activity to that with 20 wt% platinum as anode electrocatalyst. The superior performance of the developed platinum-free electrode can be ascribed to the bifunctional electrocatalysis of Mo2C/CNTs for the conversion of organic substrates into electricity through bacteria. The composite facilitates the formation of biofilm, which is necessary for the electron transfer via c-type cytochrome and nanowires. On the other hand, the composite exhibits the electrocatalytic activity towards the oxidation of hydrogen, which is the common metabolite of E. coli. © 2013 Elsevier B.V. All rights reserved.

Biomarkers of Nanoparticles Impact on Biological Systems

NASA Astrophysics Data System (ADS)

Mikhailenko, V.; Ieleiko, L.; Glavin, A.; Sorochinska, J.

Studies of nanoscale mineral fibers have demonstrated that the toxic and carcinogenic effects are related to the surface area and surface activity of inhaled particles. Particle surface characteristics are considered to be key factors in the generation of free radicals and reactive oxygen species and are related to the development of apoptosis or cancer. Existing physico-chemical methods do not always allow estimation of the nanoparticles impact on organismal and cellular levels. The aim of this study was to develop marker system for evaluation the toxic and carcinogenic effects of nanoparticles on cells. The markers are designed with respect to important nanoparticles characteristics for specific and sensitive assessment of their impact on biological system. We have studied DNA damage, the activity of xanthine oxidoreductase influencing the level of free radicals, bioenergetic status, phospholipids profile and formation of 1H-NMR-visible mobile lipid domains in Ehrlich carcinoma cells. The efficiency of the proposed marker system was tested in vivo and in vitro with the use of C60 fullerene nanoparticles and multiwalled carbon nanotubes. Our data suggest that multiwalled carbon nanotubes and fullerene C60 may pose genotoxic effect, change energy metabolism and membrane structure, alter free radical level via xanthine oxidase activation and cause mobile lipid domains formation as determined in vivo and in vitro studies on Ehrlich carcinoma cells.

Strategies for the preparation of bifunctional gadolinium(III) chelators

PubMed Central

Frullano, Luca; Caravan, Peter

2012-01-01

The development of gadolinium chelators that can be easily and readily linked to various substrates is of primary importance for the development high relaxation efficiency and/or targeted magnetic resonance imaging (MRI) contrast agents. Over the last 25 years a large number of bifunctional chelators have been prepared. For the most part, these compounds are based on ligands that are already used in clinically approved contrast agents. More recently, new bifunctional chelators have been reported based on complexes that show a more potent relaxation effect, faster complexation kinetics and in some cases simpler synthetic procedures. This review provides an overview of the synthetic strategies used for the preparation of bifunctional chelators for MRI applications. PMID:22375102

Notch Signaling Is Involved in Neurogenic Commitment of Human Periodontal Ligament-Derived Mesenchymal Stem Cells

PubMed Central

Osathanon, Thanaphum; Manokawinchoke, Jeeranan; Nowwarote, Nunthawan; Aguilar, Panuroot; Palaga, Tanapat

2013-01-01

Notch signaling plays critical roles in stem cells by regulating cell fate determination and differentiation. The aim of this study was to evaluate the participation of Notch signaling in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells (hPDLSCs) and to examine the ability to control differentiation of these cells using modified surfaces containing affinity immobilized Notch ligands. Neurogenic induction of hPDLSCs was performed via neurosphere formation. Cells were aggregated and form spheres as early 1 day in culture. In addition, the induced cells exhibited increased mRNA and protein expression of neuronal markers that is, β3-tubulin and neurofilament. During neuronal differentiation, a significant increase of Hes1 and Hey1 mRNA expression was noted. Using pharmacological inhibition (γ-secretase inhibitor) or genetic manipulation (overexpression of dominant negative mastermind-like transcription co-activators), neurosphere formation was attenuated and a marked decrease in neurogenic mRNA expression was observed. To confirm the role of Notch signaling in neuronal differentiation of hPDLSCs, the Notch ligand, Jagged-1, is bound to the surface using an affinity immobilization technique. The hPDLSC cultured on a Jagged-1-modified surface had increased expression of Notch signaling target genes, Hes-1 and Hey-1, confirming the activity and potency of surface-bound Jagged-1. Further, hPDLSC on surface-bound Jagged-1 under serum-free conditions showed multiple long and thin neurite-like extensions, and an increase in the expression of neurogenic mRNA markers was observed. Pretreatment of the cells with γ-secretase inhibitor, DAPT, before seeding on the Jagged-1-modified surface blocked development of the neurite-like morphology. Together, the results in this study suggest the involvement of Notch signaling in neurogenic commitment of hPDLSCs. PMID:23379739

Nanotechnology for the detection and kill of circulating tumor cells

NASA Astrophysics Data System (ADS)

Gao, Yang; Yuan, Zhou

2014-09-01

Circulating tumor cells (CTCs) represent a surrogate biomarker of hematogenous metastases and thus could be considered as a `liquid biopsy' which reveals metastasis in action. But it is absolutely a challenge to detect CTCs due to their extreme rarity. At present, the most common principle is to take advantage of the epithelial surface markers of CTCs which attach to a specific antibody. Antibody-magnetic nanobeads combine with the epithelial surface markers, and then the compound is processed by washing, separation, and detection. However, a proportion of CTC antigen expressions are down-regulated or lost in the process of epithelial-mesenchymal transition (EMT), and thus, this part of CTCs cannot be detected by classical detection methods such as CellSearch. To resolve this problem, some multiple-marker CTC detections have been developed rapidly. Additionally, nanotechnology is a promising approach to kill CTCs with high efficiency. Implantable nanotubes coated with apoptosis-promoting molecules improve the disease-free survival and overall survival. The review introduces some novel CTC detection techniques and therapeutic methods by virtue of nanotechnology to provide a better knowledge of the progress about CTC study.

Structural and electrochemical characterization of carbon supported Pt-Pr catalysts for direct ethanol fuel cells prepared using a modified formic acid method in a CO atmosphere.

PubMed

Corradini, Patricia Gon; Antolini, Ermete; Perez, Joelma

2013-07-28

Pt-Pr/C electrocatalysts were prepared using a modified formic acid method, and their activity for carbon monoxide and ethanol oxidation was compared to Pt/C. No appreciable alloy formation was detected by XRD analysis. By TEM measurements it was found that Pt particle size increases with an increasing Pr content in the catalysts and with decreasing metal precursor addition time. XPS measurements indicated Pt segregation on the catalyst surface and the presence of Pr2O3 and PrO2 oxides. The addition of Pr increased the electro-catalytic activity of Pt for both CO and CH3CH2OH oxidation. The enhanced activity of Pt-Pr/C catalysts was ascribed to both an electronic effect, caused by the presence of Pr2O3, and the bi-functional mechanism, caused by the presence of PrO2.

Semiconductor nanocrystals covalently bound to solid inorganic surfaces using self-assembled monolayers

DOEpatents

Alivisatos, A.P.; Colvin, V.L.

1998-05-12

Methods are described for attaching semiconductor nanocrystals to solid inorganic surfaces, using self-assembled bifunctional organic monolayers as bridge compounds. Two different techniques are presented. One relies on the formation of self-assembled monolayers on these surfaces. When exposed to solutions of nanocrystals, these bridge compounds bind the crystals and anchor them to the surface. The second technique attaches nanocrystals already coated with bridge compounds to the surfaces. Analyses indicate the presence of quantum confined clusters on the surfaces at the nanolayer level. These materials allow electron spectroscopies to be completed on condensed phase clusters, and represent a first step towards synthesis of an organized assembly of clusters. These new products are also disclosed. 10 figs.

Characterization of a Distinct Population of Circulating Human Non-Adherent Endothelial Forming Cells and Their Recruitment via Intercellular Adhesion Molecule-3

PubMed Central

Thompson, Emma J.; Barrett, Jeffrey M.; Tooley, Katie; Sen, Shaundeep; Sun, Wai Yan; Grose, Randall; Nicholson, Ian; Levina, Vitalina; Cooke, Ira; Talbo, Gert; Lopez, Angel F.; Bonder, Claudine S.

2012-01-01

Circulating vascular progenitor cells contribute to the pathological vasculogenesis of cancer whilst on the other hand offer much promise in therapeutic revascularization in post-occlusion intervention in cardiovascular disease. However, their characterization has been hampered by the many variables to produce them as well as their described phenotypic and functional heterogeneity. Herein we have isolated, enriched for and then characterized a human umbilical cord blood derived CD133+ population of non-adherent endothelial forming cells (naEFCs) which expressed the hematopoietic progenitor cell markers (CD133, CD34, CD117, CD90 and CD38) together with mature endothelial cell markers (VEGFR2, CD144 and CD31). These cells also expressed low levels of CD45 but did not express the lymphoid markers (CD3, CD4, CD8) or myeloid markers (CD11b and CD14) which distinguishes them from ‘early’ endothelial progenitor cells (EPCs). Functional studies demonstrated that these naEFCs (i) bound Ulex europaeus lectin, (ii) demonstrated acetylated-low density lipoprotein uptake, (iii) increased vascular cell adhesion molecule (VCAM-1) surface expression in response to tumor necrosis factor and (iv) in co-culture with mature endothelial cells increased the number of tubes, tubule branching and loops in a 3-dimensional in vitro matrix. More importantly, naEFCs placed in vivo generated new lumen containing vasculature lined by CD144 expressing human endothelial cells (ECs). Extensive genomic and proteomic analyses of the naEFCs showed that intercellular adhesion molecule (ICAM)-3 is expressed on their cell surface but not on mature endothelial cells. Furthermore, functional analysis demonstrated that ICAM-3 mediated the rolling and adhesive events of the naEFCs under shear stress. We suggest that the distinct population of naEFCs identified and characterized here represents a new valuable therapeutic target to control aberrant vasculogenesis. PMID:23144795

Functional and genomic analyses of FOXP3-transduced Jurkat-T cells as regulatory T (Treg)-like cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Joon-Young; Kim, Han-Jong; Hurt, Elaine M.

2007-10-12

FOXP3, a forkhead transcription factor is essential for the development and function of CD4{sup +}CD25{sup +} regulatory T cells (Tregs). In contrast to conversion of murine naive T cells to Tregs by transduction of Foxp3, it is controversial whether ectopic expression of FOXP3 in human CD4{sup +} T cells is sufficient for acquisition of suppressive activity. Here, we show that retroviral transduction of FOXP3 induces a Treg phenotype in human leukemic CD4{sup +} Jurkat-T cells, evidenced by increased expression of Treg-associated cell surface markers as well as inhibition of cytokine production. Furthermore, FOXP3-transduced Jurkat-T cells suppress the proliferation of humanmore » CD4{sup +}CD25{sup -} T cells. Additionally, DNA microarray analysis identifies Treg-related genes regulated by FOXP3. Our study demonstrates that enforced expression of FOXP3 confers Treg-like properties on Jurkat-T cells, which can be a convenient and efficient Treg-like cell model for further study to identify Treg cell surface markers and target genes regulated by FOXP3.« less

The Golgi localized bifunctional UDP-rhamnose/UDP-galactose transporter family of Arabidopsis

PubMed Central

Rautengarten, Carsten; Ebert, Berit; Moreno, Ignacio; Temple, Henry; Herter, Thomas; Link, Bruce; Doñas-Cofré, Daniela; Moreno, Adrián; Saéz-Aguayo, Susana; Blanco, Francisca; Mortimer, Jennifer C.; Schultink, Alex; Reiter, Wolf-Dieter; Dupree, Paul; Pauly, Markus; Heazlewood, Joshua L.; Scheller, Henrik V.; Orellana, Ariel

2014-01-01

Plant cells are surrounded by a cell wall that plays a key role in plant growth, structural integrity, and defense. The cell wall is a complex and diverse structure that is mainly composed of polysaccharides. The majority of noncellulosic cell wall polysaccharides are produced in the Golgi apparatus from nucleotide sugars that are predominantly synthesized in the cytosol. The transport of these nucleotide sugars from the cytosol into the Golgi lumen is a critical process for cell wall biosynthesis and is mediated by a family of nucleotide sugar transporters (NSTs). Numerous studies have sought to characterize substrate-specific transport by NSTs; however, the availability of certain substrates and a lack of robust methods have proven problematic. Consequently, we have developed a novel approach that combines reconstitution of NSTs into liposomes and the subsequent assessment of nucleotide sugar uptake by mass spectrometry. To address the limitation of substrate availability, we also developed a two-step reaction for the enzymatic synthesis of UDP–l-rhamnose (Rha) by expressing the two active domains of the Arabidopsis UDP–l-Rha synthase. The liposome approach and the newly synthesized substrates were used to analyze a clade of Arabidopsis NSTs, resulting in the identification and characterization of six bifunctional UDP–l-Rha/UDP–d-galactose (Gal) transporters (URGTs). Further analysis of loss-of-function and overexpression plants for two of these URGTs supported their roles in the transport of UDP–l-Rha and UDP–d-Gal for matrix polysaccharide biosynthesis. PMID:25053812

[Exendin-4 promotes paracrine action of adipose-derived stem cells through PI3K/Akt signaling pathways].

PubMed

Zhou, Hao; Yang, Junjie; Wagn, Jing; Hu, Shunying; Chen, Guanghui; Chen, Yundai

2014-10-01

To investigate the mechanism by which exendin-4 promotes paracrine secretion of cytokines by adipose-derived stem cells (ADSCs). In vitro cultured SD rat ADSCs (fourth passage) with or without exendin-4 treatment underwent flow cytometry to characterize the surface markers. MTT assay was performed to assess the proliferation of the cells exposed to different concentrations (0-20 nm/L) of exendin-4, and the paracrine secretion of cytokines (bFGF, VEGF, HGF, and IGF-1) by the ADSCs was evaluated by qPCR. The changes in the expressions of p-Akt in the cells were analyzed by Western blotting and qPCR in response to exendin-4 (10 nm/L) with or without exposure to PI3K/Akt inhibitor LY-294002 (50 nm/L); bFGF, VEGF, HGF, and IGF-1 production in the cells were detected using ELISA kits. Treatment with exendin-4 for 12 h did not affect the surface marker profile of the ADSCs but promoted the cell proliferation (P<0.05). Exendin-4 significantly increased the mRNA expressions of VEGF, bFGF, HGF, and IGF-1 in a concentration-dependent manner, and 10 nm/L was the optimum concentration (P<0.05). Exendin-4 treatment resulted in significantly increased p-Akt expressions in the ADSCs, and PI3K/Akt inhibitor not only reversed such effects of exendin-4 on p-Akt but also diminished the exendin-4- mediated up-regulation of the paracrine cytokines. Exendin-4 can concentration-dependently promote the proliferative and paracrine capacities of ADSCs partially through the PI3K/Akt signaling pathway without affecting the surface marker profile of the cells.

Transcriptome Dynamics of Developing Photoreceptors in Three‐Dimensional Retina Cultures Recapitulates Temporal Sequence of Human Cone and Rod Differentiation Revealing Cell Surface Markers and Gene Networks

PubMed Central

Kaewkhaw, Rossukon; Kaya, Koray Dogan; Brooks, Matthew; Homma, Kohei; Zou, Jizhong; Chaitankar, Vijender; Rao, Mahendra

2015-01-01

Abstract The derivation of three‐dimensional (3D) stratified neural retina from pluripotent stem cells has permitted investigations of human photoreceptors. We have generated a H9 human embryonic stem cell subclone that carries a green fluorescent protein (GFP) reporter under the control of the promoter of cone‐rod homeobox (CRX), an established marker of postmitotic photoreceptor precursors. The CRXp‐GFP reporter replicates endogenous CRX expression in vitro when the H9 subclone is induced to form self‐organizing 3D retina‐like tissue. At day 37, CRX+ photoreceptors appear in the basal or middle part of neural retina and migrate to apical side by day 67. Temporal and spatial patterns of retinal cell type markers recapitulate the predicted sequence of development. Cone gene expression is concomitant with CRX, whereas rod differentiation factor neural retina leucine zipper protein (NRL) is first observed at day 67. At day 90, robust expression of NRL and its target nuclear receptor NR2E3 is evident in many CRX+ cells, while minimal S‐opsin and no rhodopsin or L/M‐opsin is present. The transcriptome profile, by RNA‐seq, of developing human photoreceptors is remarkably concordant with mRNA and immunohistochemistry data available for human fetal retina although many targets of CRX, including phototransduction genes, exhibit a significant delay in expression. We report on temporal changes in gene signatures, including expression of cell surface markers and transcription factors; these expression changes should assist in isolation of photoreceptors at distinct stages of differentiation and in delineating coexpression networks. Our studies establish the first global expression database of developing human photoreceptors, providing a reference map for functional studies in retinal cultures. Stem Cells 2015;33:3504–3518 PMID:26235913

Potent antitumor bifunctional DNA alkylating agents, synthesis and biological activities of 3a-aza-cyclopenta[a]indenes.

PubMed

Kakadiya, Rajesh; Dong, Huajin; Lee, Pei-Chih; Kapuriya, Naval; Zhang, Xiuguo; Chou, Ting-Chao; Lee, Te-Chang; Kapuriya, Kalpana; Shah, Anamik; Su, Tsann-Long

2009-08-01

A series of bifunctional DNA interstrand cross-linking agents, bis(hydroxymethyl)- and bis(carbamates)-8H-3a-azacyclopenta[a]indene-1-yl derivatives were synthesized for antitumor evaluation. The preliminary antitumor studies revealed that these agents exhibited potent cytotoxicity in vitro and antitumor therapeutic efficacy against human tumor xenografts in vivo. Furthermore, these derivatives have little or no cross-resistance to either Taxol or Vinblastine. Remarkably, complete tumor remission in nude mice bearing human breast carcinoma MX-1 xenograft by 13a,b and 14g,h and significant suppression against prostate adenocarcinoma PC3 xenograft by 13b were achieved at the maximum tolerable dose with relatively low toxicity. In addition, these agents induce DNA interstrand cross-linking and substantial G2/M phase arrest in human non-small lung carcinoma H1299 cells. The current studies suggested that these agents are promising candidates for preclinical studies.

Human immunotoxicologic markers of chemical exposures: preliminary validation studies.

PubMed

Wartenberg, D; Laskin, D; Kipen, H

1993-01-01

The circulating cells of the immune system are sensitive to environmental contaminants, and effects are often manifested as changes in the cell surface differentiation antigens of affected populations of cells, particularly lymphocytes. In this investigation, we explore the likelihood that variation in the expression of the surface markers of immune cells can be used as an index of exposure to toxic chemicals. We recruited 38 healthy New Jersey men to study pesticides effects: 19 orchard farmers (high exposure); 13 berry farmers (low exposure); and 6 hardware store owners (no exposure). Immunophenotyping was performed assaying the following cell surface antigens: CD2, CD4, CD8, CD14, CD20, CD26, CD29, CD45R, CD56, and PMN. Data were analyzed using univariate and multivariate methods. There were no significant differences among the groups with respect to routine medical histories, physical examinations, or routine laboratory parameters. No striking differences between groups were seen in univariate tests. Multivariate tests suggested some differences among groups and limited ability to correctly classify individuals based on immunophenotyping results. Immunophenotyping represents a fruitful area of research for improved exposure classification. Work is needed both on mechanistic understanding of the patterns observed and on the statistical interpretation of these patterns.

Burn-injury affects gut-associated lymphoid tissues derived CD4+ T cells.

PubMed

Fazal, Nadeem; Shelip, Alla; Alzahrani, Alhusain J

2013-01-01

After scald burn-injury, the intestinal immune system responds to maintain immune balance. In this regard CD4+T cells in Gut-Associated Lymphoid Tissues (GALT), like mesenteric lymph nodes (MLN) and Peyer's patches (PP) respond to avoid immune suppression following major injury such as burn. Therefore, we hypothesized that the gut CD4+T cells become dysfunctional and turn the immune homeostasis towards depression of CD4+ T cell-mediated adaptive immune responses. In the current study we show down regulation of mucosal CD4+ T cell proliferation, IL-2 production and cell surface marker expression of mucosal CD4+ T cells moving towards suppressive-type. Acute burn-injury lead to up-regulation of regulatory marker (CD25+), down regulation of adhesion (CD62L, CD11a) and homing receptor (CD49d) expression, and up-regulation of negative co-stimulatory (CTLA-4) molecule. Moreover, CD4+CD25+ T cells of intestinal origin showed resistance to spontaneous as well as induced apoptosis that may contribute to suppression of effector CD4+ T cells. Furthermore, gut CD4+CD25+ T cells obtained from burn-injured animals were able to down-regulate naïve CD4+ T cell proliferation following adoptive transfer of burn-injured CD4+CD25+ T cells into sham control animals, without any significant effect on cell surface activation markers. Together, these data demonstrate that the intestinal CD4+ T cells evolve a strategy to promote suppressive CD4+ T cell effector responses, as evidenced by enhanced CD4+CD25+ T cells, up-regulated CTLA-4 expression, reduced IL-2 production, tendency towards diminished apoptosis of suppressive CD4+ T cells, and thus lose their natural ability to regulate immune homeostasis following acute burn-injury and prevent immune paralysis.

Morphology, cell viability, karyotype, expression of surface markers and plasticity of three human primary cell line cultures before and after the cryostorage in LN2 and GN2.

PubMed

Del Pino, Alberto; Ligero, Gertrudis; López, María B; Navarro, Héctor; Carrillo, Jose A; Pantoll, Siobhan C; Díaz de la Guardia, Rafael

2015-02-01

Primary cell line cultures from human skin biopsies, adipose tissue and tumor tissue are valuable samples for research and therapy. In this regard, their derivation, culture, storage, transport and thawing are important steps to be studied. Towards this end, we wanted to establish the derivation, and identify the culture characteristics and the loss of viability of three human primary cell line cultures (human adult dermal fibroblasts (hADFs), human adult mesenchymal stem cells (hMSCs), and primary culture of tumor cells from lung adenocarcinoma (PCTCLA)). Compared to fresh hADFs, hMSCs and PCTCLA, thawed cells stored in a cryogenic Dewar tanks with liquid nitrogen (LN2), displayed 98.20% ± 0.99, 95.40% ± 1.41 and 93.31% ± 3.83 of cell viability, respectively. Thawed cells stored in a Dry Vapor Shipper container with gas phase (GN2), for 20 days, in addition displayed 4.61% ± 2.78, 3.70% ± 4.09 and 9.13% ± 3.51 of average loss of cells viability, respectively, showing strong correlation between the loss of viability in hADFs and the number of post-freezing days in the Dry Vapor Shipper. No significant changes in morphological characteristics or in the expression of surface markers (being hADFs, hMSCs and PCTCLA characterized by positive markers CD73+; CD90+; CD105+; and negative markers CD14-; CD20-; CD34-; and CD45-; n=2) were found. Chromosome abnormalities in the karyotype were not found. In addition, under the right conditions hMSCs were differentiated into adipogenic, osteogenic and chondrogenic lineages in vitro. In this paper, we have shown the characteristics of three human primary cell line cultures when they are stored in LN2 and GN2. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization of the Murine Myeloid Precursor Cell Line MuMac-E8

PubMed Central

Fricke, Stephan; Riemschneider, Sina; Kohlschmidt, Janine; Hilger, Nadja; Fueldner, Christiane; Knauer, Jens; Sack, Ulrich; Emmrich, Frank; Lehmann, Jörg

2014-01-01

Starting point for the present work was the assumption that the cell line MuMac-E8 represents a murine cell population with stem cell properties. Preliminary studies already pointed to the expression of stem-cell associated markers and a self-regenerative potential of the cells. The cell line MuMac-E8 should be examined for their differential stage within stem cell hierarchy. MuMac-E8 cells were derived from a chimeric mouse model of arthritis. It could be shown that MuMac-E8 cells express mRNA of some genes associated with pluripotent stem cells (Nanog, Nucleostemin), of genes for hematopoietic markers (EPCR, Sca-1, CD11b, CD45), for the mesenchymal marker CD105 and of genes for the neural markers Pax-6 and Ezrin. In methylcellulose and May-Grünwald-Giemsa staining, hematopoietic colonies were obtained but the hematopoietic system of lethally irradiated mice could not be rescued. Osteogenic differentiation was not detectable. Thus, it became evident that MuMac-E8 represents not a stem cell line. However, MuMac-E8 cells expressed several myeloid surface markers (i.e. CD11b, F4/80, CD14, CD64), showed phagocytosis and is capable of producing nitric oxide. Thus, this cell line seems to be arrested an advanced stage of myeloid differentiation. Adherence data measured by impedance-based real-time cell analysis together with cell morphology data suggested that MuMac-E8 represents a new macrophage precursor cell line exhibiting weak adherence. This cell line is suitable as an in-vitro model for testing of macrophage functions. Moreover, it might be also useful for differentiation or reprogramming studies. PMID:25546418

Isolation of pancreatic progenitor cells with the surface marker of hematopoietic stem cells.

PubMed

Ma, Fengxia; Chen, Fang; Chi, Ying; Yang, Shaoguang; Lu, Shihong; Han, Zhongchao

2012-01-01

To isolate pancreatic progenitor cells with the surface markers of hematopoietic stem cells, the expression of stem cell antigen (Sca-1) and c-Kit and the coexpression of them with pancreatic duodenal homeobox-1 (PDX-1), neurogenin 3 (Ngn3), and insulin were examined in murine embryonic pancreas. Then different pancreatic cell subpopulations were isolated by magnet-activated cell sorting. Isolated cells were cultured overnight in hanging drops. When cells formed spheres, they were laid on floating filters at the air/medium interface. With this new culture system, pancreatic progenitor cells were induced to differentiate to endocrine and exocrine cells. It was shown that c-Kit and Sca-1 were expressed differently in embryonic pancreas at 12.5, 15.5, and 17.5 days of gestation. The expression of c-Kit and Sca-1 was the highest at 15.5 days of gestation. c-Kit rather than Sca-1 coexpressed with PDX-1, Ngn3, and insulin. Cells differentiated from c-Kit-positive cells contained more insulin-producing cells and secreted more insulin in response to glucose stimulation than that from c-Kit-negative cells. These results suggested that c-Kit could be used to isolate pancreatic progenitor cells and our new culture system permitted pancreatic progenitor cells to differentiate to mature endocrine cells.

CD146 Expression Influences Periapical Cyst Mesenchymal Stem Cell Properties.

PubMed

Paduano, Francesco; Marrelli, Massimo; Palmieri, Francesca; Tatullo, Marco

2016-10-01

Recent studies have identified a new human dental derived progenitor cell population with multi-lineage differentiation potential referred to as human periapical cyst mesenchymal stem cells (hPCy-MSCs). In the present study, we compared two subpopulations of hPCy-MSCs characterised by the low or high expression of CD146 to establish whether this expression can regulate their stem cell properties. Using flow cytometry, we evaluated the stem cell marker profile of hPCy-MSCs during passaging. Furthermore, CD146 Low and CD146 High cells were sorted by magnetic beads and subsequently both cell populations were evaluated for differences in their proliferation, self-renewal, stem cell surface markers, stemness genes expression and osteogenic differentiation potential.We found that hPCy-MSCs possessed a stable expression of several mesenchymal stem cell surface markers, whereas CD146 expression declined during passaging.In addition, sorted CD146 Low cells proliferated significantly faster, displayed higher colony-forming unit-fibroblast capacity and showed higher expression of Klf4 when compared to the CD146 High subset. Significantly, the osteogenic potential of hPCy-MSCs was greater in the CD146 Low than in CD146 High population. These results demonstrate that CD146 is spontaneously downregulated with passaging at both mRNA and protein levels and that the high expression of CD146 reduces the proliferative, self-renewal and osteogenic differentiation potential of hPCy-MSCs. In conclusion, our study demonstrates that changes in the expression of CD146 can influence the stem cell properties of hPCy-MSCs.

Anterior cruciate ligament- and hamstring tendon-derived cells: in vitro differential properties of cells involved in ACL reconstruction.

PubMed

Ghebes, Corina Adriana; Kelder, Cindy; Schot, Thomas; Renard, Auke J; Pakvis, Dean F M; Fernandes, Hugo; Saris, Daniel B

2017-04-01

Anterior cruciate ligament (ACL) reconstruction involves the replacement of the torn ligament with a new graft, often a hamstring tendon (HT). Described as similar, the ACL and HT have intrinsic differences related to their distinct anatomical locations. From a cellular perspective, identifying these differences represents a step forward in the search for new cues that enhance recovery after the reconstruction. The purpose of this study was to characterize the phenotype and multilineage potential of ACL- and HT-derived cells. ACL- and HT-derived cells were isolated from tissue harvest from patients undergoing total knee arthroplasty (TKA) or ACL reconstruction. In total, three ACL and three HT donors were investigated. Cell morphology, self-renewal potential (CFU-F), surface marker profiling, expression of tendon/ligament-related markers (PCR) and multilineage potential were analysed for both cell types; both had fibroblast-like morphology and low self-renewal potential. No differences in the expression of tendon/ligament-related genes or a selected set of surface markers were observed between the two cell types. However, differences in their multilineage potential were observed: while ACL-derived cells showed a high potential to differentiate into chondrocytes and adipocytes, but not osteoblasts, HT-derived cells showed poor potential to form adipocytes, chondrocytes and osteoblasts. Our results demonstrated that HT-derived cells have low multilineage potential compared to ACL-derived cells, further highlighting the need for extrinsic signals to fully restore the function of the ACL upon reconstruction. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Immunologic reconstitution during PEG-ADA therapy in an unusual mosaic ADA-deficient patient

PubMed Central

Liu, Ping; Santisteban, Ines; Burroughs, Laurie M.; Ochs, Hans D.; Torgerson, Troy R.; Hershfield, Michael S.; Rawlings, David J.; Scharenberg, Andrew M.

2009-01-01

We report detailed genetic and immunologic studies in a patient diagnosed with adenosine deaminase (ADA) deficiency and combined immune deficiency at age 5 years. At the time of diagnosis, although all other lymphocyte subsets were depleted, circulating CD8+ T cells with a terminally differentiated phenotype were abundant and expressed normal ADA activity due to a reversion mutation in a CD8+ T cell or precursor. Over the first 9 months of replacement therapy with PEG-ADA, the patient steadily accumulated mature naïve CD4+ and CD8+ T cells, as well as CD4+/FOXP3+ regulatory T cells, consistent with restoration of a functional cellular immune system. While CD19+ naïve B cells also accumulated in response to PEG-ADA therapy, a high proportion of these B cells exhibited an immature surface marker phenotype even after 9 months, and immunization with neoantigen bacteriophage φX174 demonstrated a markedly subnormal humoral immune response. Our observations in this single patient have important implications for gene therapy of human ADA deficiency, as they indicate that ADA expression within even a large circulating lymphocyte population may not be sufficient to support adequate immune reconstitution. They also suggest that an immature surface marker phenotype of the peripheral B cell compartment may be a useful surrogate marker for incomplete humoral immune reconstitution during enzyme replacement, and possibly other forms of hematopoietic cell therapies. PMID:18952502

Increase of CD69, CD161 and CD94 on NK cells in women with recurrent spontaneous abortion and in vitro fertilization failure.

PubMed

Ghafourian, Mehri; Karami, Najmeh; Khodadadi, Ali; Nikbakht, Roshan

2014-06-01

Recurrent spontaneous abortion (RSA) and in vitro fertilization (IVF) failure with unknown causes are the controversial issues that are probably related to the immune system. To compare circulating NK cells expressing activation and inhibition surface markers between patients with RSA and IVF failure with those of healthy multiparous and successful IVF control women, respectively. In this case-control study peripheral blood samples were collected from 43 patients who included 23 women with RSA and 20 with IVF failure, plus 43 healthy control women comprising of 36 normal multiparous women and seven women with successful IVF. The expression of CD69, CD94 and CD161 surface markers on CD56+NK cells were assessed using specific monoclonal antibodies by flowcytometry. The percentage of NK cells increased significantly in patients with RSA and in women with IVF failure in comparison to healthy multiparous and successful IVF control groups (p<0.001). The overall expression of CD69, CD94, CD161 were also increased significantly on NK cells in both patient groups compared to control groups (p<0.001). Elevated expression of CD69 and CD161 on NK cells can be considered as immunological risk markers in RSA and IVF failure. However, it is not clear if high expression of CD94 on peripheral blood NK cells is related to abnormal activity of endometrial NK cells.

Semiconducting organic-inorganic nanocomposites by intimately tethering conjugated polymers to inorganic tetrapods

NASA Astrophysics Data System (ADS)

Jung, Jaehan; Yoon, Young Jun; Lin, Zhiqun

2016-04-01

Semiconducting organic-inorganic nanocomposites were judiciously crafted by placing conjugated polymers in intimate contact with inorganic tetrapods via click reaction. CdSe tetrapods were first synthesized by inducing elongated arms from CdSe zincblende seeds through seed-mediated growth. The subsequent effective inorganic ligand treatment, followed by reacting with short bifunctional ligands, yielded azide-functionalized CdSe tetrapods (i.e., CdSe-N3). Finally, the ethynyl-terminated conjugated polymer poly(3-hexylthiophene) (i.e., P3HT-&z.tbd;) was tethered to CdSe-N3 tetrapods via a catalyst-free alkyne-azide cycloaddition, forming intimate semiconducting P3HT-CdSe tetrapod nanocomposites. Intriguingly, the intimate contact between P3HT and CdSe tetrapod was found to not only render the effective dispersion of CdSe tetrapods in the P3HT matrix, but also facilitate the efficient electronic interaction between these two semiconducting constituents. The successful anchoring of P3HT chains onto CdSe tetrapods was substantiated through Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy measurements. Moreover, the absorption and photoluminescence studies further corroborated the intimate tethering between P3HT and CdSe tetrapods. The effect of the type of bifunctional ligands (i.e., aryl vs. aliphatic ligands) and the size of tetrapods on the device performance of hybrid organic-inorganic solar cells was also scrutinized. Interestingly, P3HT-CdSe tetrapod nanocomposites produced via the use of an aryl bifunctional ligand (i.e., 4-azidobenzoic acid) exhibited an improved photovoltaic performance compared to that synthesized with their aliphatic ligand counterpart (i.e., 5-bromovaleric acid). Clearly, the optimal size of CdSe tetrapods ensuring the effective charge transport in conjunction with the good dispersion of CdSe tetrapods rendered an improved device performance. We envision that the click-reaction strategy enabled by capitalizing on two consecutive effective ligand exchanges (i.e., inorganic ligand treatment and subsequent bifunctional ligand exchange) to yield intimately connected organic-inorganic nanocomposites provides a unique platform for developing functional optoelectronic devices.Semiconducting organic-inorganic nanocomposites were judiciously crafted by placing conjugated polymers in intimate contact with inorganic tetrapods via click reaction. CdSe tetrapods were first synthesized by inducing elongated arms from CdSe zincblende seeds through seed-mediated growth. The subsequent effective inorganic ligand treatment, followed by reacting with short bifunctional ligands, yielded azide-functionalized CdSe tetrapods (i.e., CdSe-N3). Finally, the ethynyl-terminated conjugated polymer poly(3-hexylthiophene) (i.e., P3HT-&z.tbd;) was tethered to CdSe-N3 tetrapods via a catalyst-free alkyne-azide cycloaddition, forming intimate semiconducting P3HT-CdSe tetrapod nanocomposites. Intriguingly, the intimate contact between P3HT and CdSe tetrapod was found to not only render the effective dispersion of CdSe tetrapods in the P3HT matrix, but also facilitate the efficient electronic interaction between these two semiconducting constituents. The successful anchoring of P3HT chains onto CdSe tetrapods was substantiated through Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy measurements. Moreover, the absorption and photoluminescence studies further corroborated the intimate tethering between P3HT and CdSe tetrapods. The effect of the type of bifunctional ligands (i.e., aryl vs. aliphatic ligands) and the size of tetrapods on the device performance of hybrid organic-inorganic solar cells was also scrutinized. Interestingly, P3HT-CdSe tetrapod nanocomposites produced via the use of an aryl bifunctional ligand (i.e., 4-azidobenzoic acid) exhibited an improved photovoltaic performance compared to that synthesized with their aliphatic ligand counterpart (i.e., 5-bromovaleric acid). Clearly, the optimal size of CdSe tetrapods ensuring the effective charge transport in conjunction with the good dispersion of CdSe tetrapods rendered an improved device performance. We envision that the click-reaction strategy enabled by capitalizing on two consecutive effective ligand exchanges (i.e., inorganic ligand treatment and subsequent bifunctional ligand exchange) to yield intimately connected organic-inorganic nanocomposites provides a unique platform for developing functional optoelectronic devices. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00269b

Construction of genetically engineered M13K07 helper phage for simultaneous phage display of gold binding peptide 1 and nuclear matrix protein 22 ScFv antibody.

PubMed

Fatemi, Farnaz; Amini, Seyed Mohammad; Kharrazi, Sharmin; Rasaee, Mohammad Javad; Mazlomi, Mohammad Ali; Asadi-Ghalehni, Majid; Rajabibazl, Masoumeh; Sadroddiny, Esmaeil

2017-11-01

The most common techniques of antibody phage display are based on the use of M13 filamentous bacteriophages. This study introduces a new genetically engineered M13K07 helper phage displaying multiple copies of a known gold binding peptide on p8 coat proteins. The recombinant helper phages were used to rescue a phagemid vector encoding the p3 coat protein fused to the nuclear matrix protein 22 (NMP22) ScFv antibody. Transmission electron microscopy (TEM), UV-vis absorbance spectroscopy, and field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDX) analysis revealed that the expression of gold binding peptide 1 (GBP1) on major coat protein p8 significantly enhances the gold-binding affinity of M13 phages. The recombinant bacteriophages at concentrations above 5×10 4 pfu/ml red-shifted the UV-vis absorbance spectra of gold nanoparticles (AuNPs); however, the surface plasmon resonance of gold nanoparticles was not changed by the wild type bacteriophages at concentrations up to 10 12 pfu/ml. The phage ELISA assay demonstrated the high affinity binding of bifunctional bacteriophages to NMP22 antigen at concentrations of 10 5 and 10 6 pfu/ml. Thus, the p3 end of the bifunctional bacteriophages would be able to bind to specific target antigen, while the AuNPs were assembled along the coat of virus for signal generation. Our results indicated that the complex of antigen-bacteriophages lead to UV-vis spectral changes of AuNPs and NMP22 antigen in concentration range of 10-80μg/ml can be detected by bifunctional bacteriophages at concentration of 10 4 pfu/ml. The ability of bifunctional bacteriophages to bind to antigen and generate signal at the same time, makes this approach applicable for identifying different antigens in immunoassay techniques. Copyright © 2017 Elsevier B.V. All rights reserved.

Investigation of Glutaric Anhydride as an Electrolyte Additive for Graphite/LiNi 0.5 Mn 0.3 Co 0.2 O 2 Full Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peebles, Cameron; He, Meinan; Feng, Zhenxing

The effects of glutaric anhydride (GA) as an electrolyte additive for graphite/LiNi0.5Mn0.3Co0.2O2 full cells operating between 3.0-4.4 V were investigated. Linear scan voltammetry (LSV) revealed that GA preferentially oxidized prior to the carbonate-based electrolyte while Li/graphite half cells revealed that GA can suppress electrolyte decomposition on the graphite electrode giving rise to the bifunctional nature of this additive. The addition of both 0.5 and 1.0 wt% of GA into the carbonate-based electrolyte resulted in superior cycling performance compared to the baseline electrolyte as demonstrated by the slight increase in initial capacities and significant increases in capacity retention over 117 cyclesmore » at C/3. Electrochemical impedance spectroscopy (EIS) showed that while the overall impedance of the GA containing cells was higher than the cells with the baseline electrolyte the change in impedance between post-formation and post-cycling was smallest for the cells containing GA. Additionally, X-ray photoelectron spectroscopy (XPS) analysis confirmed that GA decomposed on the cathode surface leading to an increase in oxygen-containing species, a decrease in LiF species and a simultaneous increase in LixPOyFz species. (C) 2016 The Electrochemical Society. All rights reserved.« less

Photochemical properties and sensor applications of modified yellow fluorescent protein (YFP) covalently attached to the surfaces of etched optical fibers (EOFs).

PubMed

Veselov, Alexey A; Abraham, Bobin George; Lemmetyinen, Helge; Karp, Matti T; Tkachenko, Nikolai V

2012-01-01

Fluorescent proteins have the inherent ability to act as sensing components which function both in vitro and inside living cells. We describe here a novel study on a covalent site-specific bonding of fluorescent proteins to form self-assembled monolayers (SAMs) on the surface of etched optical fibers (EOFs). Deposition of fluorescent proteins on EOFs gives the opportunity to increase the interaction of guided light with deposited molecules relative to plane glass surfaces. The EOF modification is carried out by surface activation using 3-aminopropylthrimethoxysilane (APTMS) and bifunctional crosslinker sulfosuccinimidyl 4-[N-maleimidomethyl]cyclohexane-1-carboxylate (sulfo-SMCC) which exposes sulfhydryl-reactive maleimide groups followed by covalent site-specific coupling of modified yellow fluorescent protein (YFP). Steady-state and fluorescence lifetime measurements confirm the formation of SAM. The sensor applications of YPF SAMs on EOF are demonstrated by the gradual increase of emission intensity upon addition of Ca(2+) ions in the concentration range from a few tens of micromolars up to a few tens of millimolars. The studies on the effect of pH, divalent cations, denaturing agents, and proteases reveal the stability of YFP on EOFs at normal physiological conditions. However, treatments with 0.5% SDS at pH 8.5 and protease trypsin are found to denaturate or cleave the YFP from fiber surfaces.

A comparative study of the structural organization of spheres derived from the adult human subventricular zone and glioblastoma biopsies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vik-Mo, Einar Osland, E-mail: e.o.vik-mo@medisin.uio.no; Department of Neurosurgery, Oslo University Hospital, Oslo; Sandberg, Cecilie

2011-04-15

Sphere forming assays have been useful to enrich for stem like cells in a range of tumors. The robustness of this system contrasts the difficulties in defining a stem cell population based on cell surface markers. We have undertaken a study to describe the cellular and organizational composition of tumorspheres, directly comparing these to neurospheres derived from the adult human subventricular zone (SVZ). Primary cell cultures from brain tumors were found to contain variable fractions of cells positive for tumor stem cell markers (CD133 (2-93%)/SSEA1 (3-15%)/CXCR4 (1-72%)). All cultures produced tumors upon xenografting. Tumorspheres contained a heterogeneous population of cells,more » but were structurally organized with stem cell markers present at the core of spheres, with markers of more mature glial progenitors and astrocytes at more peripheral location. Ultrastructural studies showed that tumorspheres contained a higher fraction of electron dense cells in the core than the periphery (36% and 19%, respectively). Neurospheres also contained a heterogeneous cell population, but did not have an organization similar to tumorspheres. Although tumorspheres clearly display irregular and neoplastic cells, they establish an organized structure with an outward gradient of differentiation. We suggest that this organization is central in maintaining the tumor stem cell pool.« less

Molecular cloning and characterization of rat sperm surface antigen 2B1, a glycoprotein implicated in sperm-zona binding.

PubMed

Hou, S T; Ma, A; Jones, R; Hall, L

1996-10-01

The rat sperm surface antigen, 2B1, that has been proposed to play a key role in sperm adhesion to the zona pellucida, has been cloned and its entire cDNA sequenced. Northern blot analysis indicates that 2B1 is encoded by a 2.2-kb RNA transcript that is abundantly expressed in the testis. The deduced protein sequence contains 512 amino-acid residues with a strong candidate signal sequence and C-terminal transmembrane domain. Data base searches reveal a high degree of sequence similarity to guinea pig, rabbit, monkey, and human PH20 sperm surface antigens, and a lower degree of similarity to honey bee and whiteface hornet venom hyaluronidases. Rat 2B1 antigen also possesses hyaluronidase activity, suggesting that it is a bifunctional protein with putative roles in the dispersion of cumulus oophorus cells as well as zona adhesion. However, while it would appear that 2B1 is the rat homologue of the guinea pig PH20 antigen, they differ in a number of important biochemical respects (including their mode of attachment to the sperm membrane and distribution between soluble and membrane-bound fractions), as well as in their localization on the sperm membrane. Expression of regions of the 2B1 protein in recombinant bacterial cells has allowed a preliminary mapping of the 2B1 epitope, and has provided more definitive information on the endoproteolytic processing of 2B1 during epididymal transit.

Autonomous molecular cascades for evaluation of cell surfaces

NASA Astrophysics Data System (ADS)

Rudchenko, Maria; Taylor, Steven; Pallavi, Payal; Dechkovskaia, Alesia; Khan, Safana; Butler, Vincent P., Jr.; Rudchenko, Sergei; Stojanovic, Milan N.

2013-08-01

Molecular automata are mixtures of molecules that undergo precisely defined structural changes in response to sequential interactions with inputs. Previously studied nucleic acid-based automata include game-playing molecular devices (MAYA automata) and finite-state automata for the analysis of nucleic acids, with the latter inspiring circuits for the analysis of RNA species inside cells. Here, we describe automata based on strand-displacement cascades directed by antibodies that can analyse cells by using their surface markers as inputs. The final output of a molecular automaton that successfully completes its analysis is the presence of a unique molecular tag on the cell surface of a specific subpopulation of lymphocytes within human blood cells.

Preservation media, durations and cell concentrations of short-term storage affect key features of human adipose-derived mesenchymal stem cells for therapeutic application.

PubMed

Zhang, Fengli; Ren, Huaijuan; Shao, Xiaohu; Zhuang, Chao; Chen, Yantian; Qi, Nianmin

2017-01-01

Adipose-derived mesenchymal stem cells (ADSCs) have shown great potential in the treatment of various diseases. However, the optimum short-term storage condition of ADSCs in 2∼8 °C is rarely reported. This study aimed at optimizing a short-term storage condition to ensure the viability and function of ADSCs before transplantation. Preservation media and durations of storage were evaluated by cell viability, apoptosis, adhesion ability and colony-forming unit (CFU) capacity of ADSCs. The abilities of cell proliferation and differentiation were used to optimize cell concentrations. Optimized preservation condition was evaluated by cell surface markers, cell cycle and immunosuppressive capacity. A total of 5% human serum albumin in multiple electrolytes (ME + HSA) was the optimized medium with high cell viability, low cluster rate, good adhesion ability and high CFU capacity of ADSCs. Duration of storage should be limited to 24 h to ensure the quality of ADSCs before transplantation. A concentration of 5 × 10 6 cells/ml was the most suitable cell concentration with low late stage apoptosis, rapid proliferation and good osteogenic and adipogenic differentiation ability. This selected condition did not change surface markers, cell cycle, indoleamine 2, 3-dioxygenase 1 (IDO1) gene expression and kynurenine (Kyn) concentration significantly. In this study, ME + HSA was found to be the best medium, most likely due to the supplement of HSA which could protect cells, the physiological pH (7.4) of ME and sodium gluconate ingredient in ME which could provide energy for cells. Duration should be limited to 24 h because of reduced nutrient supply and increased waste and lactic acid accumulation during prolonged storage. To keep cell proliferation and limit lactic acid accumulation, the proper cell concentration is 5× 10 6 cells/ml. Surface markers, cell cycle and immunosuppressive capacity did not change significantly after storage using the optimized condition, which confirmed our results that this optimized short-term storage condition of MSCs has a great potential for the application of cell therapy.

Tumor target amplification: Implications for nano drug delivery systems.

PubMed

Seidi, Khaled; Neubauer, Heidi A; Moriggl, Richard; Jahanban-Esfahlan, Rana; Javaheri, Tahereh

2018-04-10

Tumor cells overexpress surface markers which are absent from normal cells. These tumor-restricted antigenic signatures are a fundamental basis for distinguishing on-target from off-target cells for ligand-directed targeting of cancer cells. Unfortunately, tumor heterogeneity impedes the establishment of a solid expression pattern for a given target marker, leading to drastic changes in quality (availability) and quantity (number) of the target. Consequently, a subset of cancer cells remains untargeted during the course of treatment, which subsequently promotes drug-resistance and cancer relapse. Since target inefficiency is only problematic for cancer treatment and not for treatment of other pathological conditions such as viral/bacterial infections, target amplification or the generation of novel targets is key to providing eligible antigenic markers for effective targeted therapy. This review summarizes the limitations of current ligand-directed targeting strategies and provides a comprehensive overview of tumor target amplification strategies, including self-amplifying systems, dual targeting, artificial markers and peptide modification. We also discuss the therapeutic and diagnostic potential of these approaches, the underlying mechanism(s) and established methodologies, mostly in the context of different nanodelivery systems, to facilitate more effective ligand-directed cancer cell monitoring and targeting. Copyright © 2018 Elsevier B.V. All rights reserved.

The effect of different collagen modifications for titanium and titanium nitrite surfaces on functions of gingival fibroblasts.

PubMed

Ritz, U; Nusselt, T; Sewing, A; Ziebart, T; Kaufmann, K; Baranowski, A; Rommens, P M; Hofmann, Alexander

2017-01-01

Targeted modifications of the bulk implant surfaces using bioactive agents provide a promising tool for improvement of the long-term bony and soft tissue integration of dental implants. In this study, we assessed the cellular responses of primary human gingival fibroblasts (HGF) to different surface modifications of titanium (Ti) and titanium nitride (TiN) alloys with type I collagen or cyclic-RGDfK-peptide in order to define a modification improving long-term implants in dental medicine. Employing Ti and TiN implants, we compared the performance of simple dip coating and anodic immobilization of type I collagen that provided collagen layers of two different thicknesses. HGF were seeded on the different coated implants, and adhesion, proliferation, and gene expression were analyzed. Although there were no strong differences in initial cell adhesion between the groups at 2 and 4 hours, we found that all surface modifications induced higher proliferation rates as compared to the unmodified controls. Consistently, gene expression levels of cell adhesion markers (focal adhesion kinase (FAK), integrin beta1, and vinculin), cell differentiation markers (FGFR1, TGFb-R1), extracellular protein markers (type I collagen, vimentin), and cytoskeletal protein marker aktinin-1 were consistently higher in all surface modification groups at two different time points of investigation as compared to the unmodified controls. Our results indicate that simple dip coating of Ti and TiN with collagen is sufficient to induce in vitro cellular responses that are comparable to those of more reliable coating methods like anodic adsorption, chemical cross-linking, or RGD coating. TiN alloys do not possess any positive or adverse effects on HGF. Our results demonstrate a simple, yet effective, method for collagen coating on titanium implants to improve the long term integration and stability of dental implants.

Cell Homogeneity Indispensable for Regenerative Medicine by Cultured Human Corneal Endothelial Cells.

PubMed

Hamuro, Junji; Toda, Munetoyo; Asada, Kazuko; Hiraga, Asako; Schlötzer-Schrehardt, Ursula; Montoya, Monty; Sotozono, Chie; Ueno, Morio; Kinoshita, Shigeru

2016-09-01

To identify the subpopulation (SP) among heterogeneous cultured human corneal endothelial cells (cHCECs) devoid of cell-state transition applicable for cell-based therapy. Subpopulation presence in cHCECs was confirmed via surface CD-marker expression level by flow cytometry. CD markers effective for distinguishing distinct SPs were selected by analyzing those on established cHCECs with a small cell area and high cell density. Contrasting features among three typical cHCEC SPs was confirmed by PCR array for extracellular matrix (ECM). Combined analysis of CD markers was performed to identify the SP (effector cells) applicable for therapy. ZO-1 and Na+/K+ ATPase, CD200, and HLA expression were compared among heterogeneous SPs. Flow cytometry analysis identified the effector cell expressing CD166+CD105-CD44-∼+/-CD26-CD24-, but CD200-, and the presence of other SPs with CD166+ CD105-CD44+++ (CD26 and CD24, either + or -) was confirmed. PCR array revealed three distinct ECM expression profiles. Some SPs expressed ZO-1 and Na+/K+ ATPase at comparable levels with effector cells, while only one SP expressed CD200, but not on effector cells. Human leukocyte antigen expression was most reduced in the effector SP. The proportion of effector cells (E-ratio) inversely paralleled donor age and decreased during prolonged culture passages. The presence of Rho-associated protein kinase (ROCK) inhibitor increased the E-ratio in cHCECs. The average area of effector cells was approximately 200∼220 μm2, and the density of cHCECs exceeded 2500 cells/mm2. A specified cultured effector cell population sharing the surface phenotypes with mature HCECs in corneal tissues may serve as an alternative to donor corneas for the treatment of corneal endothelial dysfunction.

Pathogen-induced ubiquitin-editing enzyme A20 bifunctionally shuts off NF-κB and caspase-8-dependent apoptotic cell death

PubMed Central

Lim, Michelle C C; Maubach, Gunter; Sokolova, Olga; Feige, Michael H; Diezko, Rolf; Buchbinder, Jörn; Backert, Steffen; Schlüter, Dirk; Lavrik, Inna N; Naumann, Michael

2017-01-01

The human pathogen Helicobacter pylori infects more than half of the world’s population and is a paradigm for persistent yet asymptomatic infection but increases the risk for chronic gastritis and gastric adenocarcinoma. For successful colonization, H. pylori needs to subvert the host cell death response, which serves to confine pathogen infection by killing infected cells and preventing malignant transformation. Infection of gastric epithelial cells by H. pylori provokes direct and fast activation of the proinflammatory and survival factor NF-κB, which regulates target genes, such as CXCL8, BIRC3 and TNFAIP3. However, it is not known how H. pylori exploits NF-κB activation and suppresses the inflammatory response and host apoptotic cell death, in order to avert the innate immune response and avoid cell loss, and thereby enhance colonization to establish long-term infection. Here we assign for the first time that H. pylori and also Campylobacter jejuni-induced ubiquitin-editing enzyme A20 bifunctionally terminates NF-κB activity and negatively regulates apoptotic cell death. Mechanistically, we show that the deubiquitinylase activity of A20 counteracts cullin3-mediated K63-linked ubiquitinylation of procaspase-8, therefore restricting the activity of caspase-8. Interestingly, another inducible NF-κB target gene, the scaffold protein p62, ameliorates the interaction of A20 with procaspase-8. In conclusion, pathogen-induced de novo synthesis of A20 regulates the shut-off of the survival factor NF-κB but, on the other hand, also impedes caspase-8-dependent apoptotic cell death so as to promote the persistence of pathogens. PMID:28574503

Cobalt Nanoparticle-Embedded Porous Carbon Nanofibers with Inherent N- and F-Doping as Binder-Free Bifunctional Catalysts for Oxygen Reduction and Evolution Reactions.

PubMed

Singhal, Richa; Kalra, Vibha

2017-01-18

Efficient, low-cost, non-precious metal-based, and stable bifunctional electrocatalysts are key to various energy storage and conversion devices such as regenerative fuel cells and metal-air batteries. In this work, we report cobalt nanoparticle-embedded porous carbon nanofibers with inherent N- and F-doping as binder-free bifunctional electrocatalysts with excellent activity for both the oxygen reduction and oxygen evolution reaction (ORR/OER) in an alkaline medium. Single-step electrospinning of a solution of the polymer mixture (carbon precursor) and the cobalt precursor followed by controlled pyrolysis with an intermediate reduction step in H 2 (to reduce cobalt oxides to cobalt) was utilized to synthesize an integrated freestanding catalyst. The fabricated catalyst with effective structural and electronic interaction between the cobalt metal nanoparticles and the N- and F-doped carbon defect sites showed enhanced catalytic properties compared to the benchmark catalysts for ORR and OER (Pt, Ir, and Ru). The ORR potential at the current density of -3 mA cm -2 was 0.81 V RHE and the OER potential at a current density of 10 mA cm -2 was 1.595 V RHE , resulting in a ΔE of only 0.785 V. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stability of a Bifunctional Cu-Based Core@Zeolite Shell Catalyst for Dimethyl Ether Synthesis Under Redox Conditions Studied by Environmental Transmission Electron Microscopy and In Situ X-Ray Ptychography.

PubMed

Baier, Sina; Damsgaard, Christian D; Klumpp, Michael; Reinhardt, Juliane; Sheppard, Thomas; Balogh, Zoltan; Kasama, Takeshi; Benzi, Federico; Wagner, Jakob B; Schwieger, Wilhelm; Schroer, Christian G; Grunwaldt, Jan-Dierk

2017-06-01

When using bifunctional core@shell catalysts, the stability of both the shell and core-shell interface is crucial for catalytic applications. In the present study, we elucidate the stability of a CuO/ZnO/Al2O3@ZSM-5 core@shell material, used for one-stage synthesis of dimethyl ether from synthesis gas. The catalyst stability was studied in a hierarchical manner by complementary environmental transmission electron microscopy (ETEM), scanning electron microscopy (SEM) and in situ hard X-ray ptychography with a specially designed in situ cell. Both reductive activation and reoxidation were applied. The core-shell interface was found to be stable during reducing and oxidizing treatment at 250°C as observed by ETEM and in situ X-ray ptychography, although strong changes occurred in the core on a 10 nm scale due to the reduction of copper oxide to metallic copper particles. At 350°C, in situ X-ray ptychography indicated the occurrence of structural changes also on the µm scale, i.e. the core material and parts of the shell undergo restructuring. Nevertheless, the crucial core-shell interface required for full bifunctionality appeared to remain stable. This study demonstrates the potential of these correlative in situ microscopy techniques for hierarchically designed catalysts.

Space-Confined Earth-Abundant Bifunctional Electrocatalyst for High-Efficiency Water Splitting.

PubMed

Tang, Yanqun; Fang, Xiaoyu; Zhang, Xin; Fernandes, Gina; Yan, Yong; Yan, Dongpeng; Xiang, Xu; He, Jing

2017-10-25

Hydrogen generation from water splitting could be an alternative way to meet increasing energy demands while also balancing the impact of energy being supplied by fossil-based fuels. The efficacy of water splitting strongly depends on the performance of electrocatalysts. Herein, we report a unique space-confined earth-abundant electrocatalyst having the bifunctionality of simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), leading to high-efficiency water splitting. Outperforming Pt/C or RuO 2 catalysts, this mesoscopic, space-confined, bifunctional configuration is constructed from a monolithic zeolitic imidazolate framework@layered double hydroxide (ZIF@LDH) precursor on Ni foam. Such a confinement leads to a high dispersion of ultrafine Co 3 O 4 nanoparticles within the N-doped carbon matrix by temperature-dependent calcination of the ZIF@LDH. We demonstrate that the OER has an overpotential of 318 mV at a current density of 10 mA cm -2 , while that of HER is -106 mV @ -10 mA cm -2 . The voltage applied to a two-electrode cell for overall water splitting is 1.59 V to achieve a stable current density of 10 mA cm -2 while using the monolithic catalyst as both the anode and the cathode. It is anticipated that our space-confined method, which focuses on earth-abundant elements with structural integrity, may provide a novel and economically sound strategy for practical energy conversion applications.

Mining for osteogenic surface topographies: In silico design to in vivo osseo-integration.

PubMed

Hulshof, Frits F B; Papenburg, Bernke; Vasilevich, Aliaksei; Hulsman, Marc; Zhao, Yiping; Levers, Marloes; Fekete, Natalie; de Boer, Meint; Yuan, Huipin; Singh, Shantanu; Beijer, Nick; Bray, Mark-Anthony; Logan, David J; Reinders, Marcel; Carpenter, Anne E; van Blitterswijk, Clemens; Stamatialis, Dimitrios; de Boer, Jan

2017-08-01

Stem cells respond to the physicochemical parameters of the substrate on which they grow. Quantitative material activity relationships - the relationships between substrate parameters and the phenotypes they induce - have so far poorly predicted the success of bioactive implant surfaces. In this report, we screened a library of randomly selected designed surface topographies for those inducing osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Cell shape features, surface design parameters, and osteogenic marker expression were strongly correlated in vitro. Furthermore, the surfaces with the highest osteogenic potential in vitro also demonstrated their osteogenic effect in vivo: these indeed strongly enhanced bone bonding in a rabbit femur model. Our work shows that by giving stem cells specific physicochemical parameters through designed surface topographies, differentiation of these cells can be dictated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low CD1c + myeloid dendritic cell counts correlated with a high risk of rapid disease progression during early HIV-1 infection.

PubMed

Diao, Yingying; Geng, Wenqing; Fan, Xuejie; Cui, Hualu; Sun, Hong; Jiang, Yongjun; Wang, Yanan; Sun, Amy; Shang, Hong

2015-08-19

During early HIV-1 infection (EHI), the interaction between the immune response and the virus determines disease progression. Although CD1c + myeloid dendritic cells (mDCs) can trigger the immune response, the relationship between CD1c + mDC alteration and disease progression has not yet been defined. EHI changes in CD1c + mDC counts, surface marker (CD40, CD86, CD83) expression, and IL-12 secretion were assessed by flow cytometry in 29 patients. When compared with the normal controls, patients with EHI displayed significantly lower CD1c + mDC counts and IL-12 secretion and increased surface markers. CD1c + mDC counts were positively correlated with CD4+ T cell counts and inversely associated with viral loads. IL-12 secretion was only positively associated with CD4+ T cell counts. Rapid progressors had lower counts, CD86 expression, and IL-12 secretion of CD1c + mDCs comparing with typical progressors. Kaplan-Meier analysis and Cox regression models suggested patients with low CD1c + mDC counts (<10 cells/μL) had a 4-fold higher risk of rapid disease progression than those with high CD1c + mDC counts. However, no relationship was found between surface markers or IL-12 secretion and disease progression. During EHI, patients with low CD1c + mDC counts were more likely to experience rapid disease progression than those with high CD1c + mDC counts.

Propitious Dendritic Cu2O-Pt Nanostructured Anodes for Direct Formic Acid Fuel Cells.

PubMed

El-Nagar, Gumaa A; Mohammad, Ahmad M; El-Deab, Mohamed S; El-Anadouli, Bahgat E

2017-06-14

This study introduces a novel competent dendritic copper oxide-platinum nanocatalyst (nano-Cu 2 O-Pt) immobilized onto a glassy carbon (GC) substrate for formic acid (FA) electro-oxidation (FAO); the prime reaction in the anodic compartment of direct formic acid fuel cells (DFAFCs). Interestingly, the proposed catalyst exhibited an outstanding improvement for FAO compared to the traditional platinum nanoparticles (nano-Pt) modified GC (nano-Pt/GC) catalyst. This was evaluated from steering the reaction mechanism toward the desired direct route producing carbon dioxide (CO 2 ); consistently with mitigating the other undesired indirect pathway producing carbon monoxide (CO); the potential poison deteriorating the catalytic activity of typical Pt-based catalysts. Moreover, the developed catalyst showed a reasonable long-term catalytic stability along with a significant lowering in onset potential of direct FAO that ultimately reduces the polarization and amplifies the fuel cell's voltage. The observed catalytic enhancement was believed to originate bifunctionally; while nano-Pt represented the base for the FA adsorption, nanostructured copper oxide (nano-Cu 2 O) behaved as a catalytic mediator facilitating the charge transfer during FAO and providing the oxygen atmosphere inspiring the poison's (CO) oxidation at relatively lower potential. Surprisingly, moreover, nano-Cu 2 O induced a surface retrieval of nano-Pt active sites by capturing the poisoning CO via "a spillover mechanism" to renovate the Pt surface for the direct FAO. Finally, the catalytic tolerance of the developed catalyst toward halides' poisoning was discussed.

Mpl traffics to the cell surface through conventional and unconventional routes

PubMed Central

Cleyrat, Cédric; Darehshouri, Anza; Steinkamp, Mara P.; Vilaine, Mathias; Boassa, Daniela; Ellisman, Mark H.; Hermouet, Sylvie; Wilson, Bridget S.

2014-01-01

Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: Human Erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the ER. Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially co-localize with ER-Tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically-encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling. PMID:24931576

Cancer stem cell-targeted therapeutics and delivery strategies.

PubMed

Ahmad, Gulzar; Amiji, Mansoor M

2017-08-01

Cancer initiating or stem cells (CSCs) are a small population of cells in the tumor mass, which have been reported to be present in different types of cancers. CSCs usually reside within the tumor and are responsible for reoccurrence of cancer. The imprecise, inaccessible nature and increased efflux of conventional therapeutic drugs make these cells resistant to drugs. We discuss the specific markers for identification of these cells, role of CSCs in chemotherapy resistance and use of different therapeutic means to target them, including elucidation of specific cell markers, exploitation of different signaling pathways and use of nanotechnology. Area covered: This review covers cancer stem cell signaling which are used by these cells to maintain their quiescence, stemness and resistant phenotype, distinct cell surface markers, contribution of these cells in drug resistance, inevitability to cure cancer and use of nanotechnology to overcome this hurdle. Expert opinion: Cancer stem cells are the main culprit of our failure to cure cancer. In order to cure cancer along with other cells types in cancer, cancer stem cells need to be targeted in the tumor bed. Nanotechnology solutions can facilitate clinical translation of the therapeutics along with other emerging technologies to cure cancer.

Asialoglycoprotein receptor 1 is a specific cell-surface marker for isolating hepatocytes derived from human pluripotent stem cells.

PubMed

Peters, Derek T; Henderson, Christopher A; Warren, Curtis R; Friesen, Max; Xia, Fang; Becker, Caroline E; Musunuru, Kiran; Cowan, Chad A

2016-05-01

Hepatocyte-like cells (HLCs) are derived from human pluripotent stem cells (hPSCs) in vitro, but differentiation protocols commonly give rise to a heterogeneous mixture of cells. This variability confounds the evaluation of in vitro functional assays performed using HLCs. Increased differentiation efficiency and more accurate approximation of the in vivo hepatocyte gene expression profile would improve the utility of hPSCs. Towards this goal, we demonstrate the purification of a subpopulation of functional HLCs using the hepatocyte surface marker asialoglycoprotein receptor 1 (ASGR1). We analyzed the expression profile of ASGR1-positive cells by microarray, and tested their ability to perform mature hepatocyte functions (albumin and urea secretion, cytochrome activity). By these measures, ASGR1-positive HLCs are enriched for the gene expression profile and functional characteristics of primary hepatocytes compared with unsorted HLCs. We have demonstrated that ASGR1-positive sorting isolates a functional subpopulation of HLCs from among the heterogeneous cellular population produced by directed differentiation. © 2016. Published by The Company of Biologists Ltd.

Molecular Innovations Toward Theranostics of Aggressive Prostate Cancer

DTIC Science & Technology

2014-09-01

to develop dendrimer -based theranostic agent with prostate cancer specificity and positron emission tomography imaging capability that can prevent...laboratories to develop a new molecular medicine. The goal of this project is to construct dendrimer nanoconjuate containing a prostate specific...cell permeation peptide, peptide therapeutic(s) and bifunctional chelator for PET imaging. Dr. Simanek’s laboratory will make dendrimers that bear

Molecular Innovations Toward Theranostics of Aggressive Prostate Cancer

DTIC Science & Technology

2013-09-01

objective is to develop dendrimer -based theranostic agent with prostate cancer specificity and positron emission tomography imaging capability that...The goal of this project is to construct dendrimer nanoconjuate containing a prostate specific cell permeation peptide, peptide therapeutic(s) and...bifunctional chelator for PET imaging. Dr. Simanek’s laboratory will make dendrimers that bear functional handles for conjugation with imaging

Nanoengineered Polystyrene Surfaces with Nanopore Array Pattern Alters Cytoskeleton Organization and Enhances Induction of Neural Differentiation of Human Adipose-Derived Stem Cells.

PubMed

Jung, Ae Ryang; Kim, Richard Y; Kim, Hyung Woo; Shrestha, Kshitiz Raj; Jeon, Seung Hwan; Cha, Kyoung Je; Park, Yong Hyun; Kim, Dong Sung; Lee, Ji Youl

2015-07-01

Human adipose-derived stem cells (hADSCs) can differentiate into various cell types depending on chemical and topographical cues. One topographical cue recently noted to be successful in inducing differentiation is the nanoengineered polystyrene surface containing nanopore array-patterned substrate (NP substrate), which is designed to mimic the nanoscale topographical features of the extracellular matrix. In this study, efficacies of NP and flat substrates in inducing neural differentiation of hADSCs were examined by comparing their substrate-cell adhesion rates, filopodia growth, nuclei elongation, and expression of neural-specific markers. The polystyrene nano Petri dishes containing NP substrates were fabricated by a nano injection molding process using a nickel electroformed nano-mold insert (Diameter: 200 nm. Depth of pore: 500 nm. Center-to-center distance: 500 nm). Cytoskeleton and filopodia structures were observed by scanning electron microscopy and F-actin staining, while cell adhesion was tested by vinculin staining after 24 and 48 h of seeding. Expression of neural specific markers was examined by real-time quantitative polymerase chain reaction and immunocytochemistry. Results showed that NP substrates lead to greater substrate-cell adhesion, filopodia growth, nuclei elongation, and expression of neural specific markers compared to flat substrates. These results not only show the advantages of NP substrates, but they also suggest that further study into cell-substrate interactions may yield great benefits for biomaterial engineering.

[Ca2+]i Elevation and Oxidative Stress Induce KCNQ1 Protein Translocation from the Cytosol to the Cell Surface and Increase Slow Delayed Rectifier (IKs) in Cardiac Myocytes*

PubMed Central

Wang, Yuhong; Zankov, Dimitar P.; Jiang, Min; Zhang, Mei; Henderson, Scott C.; Tseng, Gea-Ny

2013-01-01

Our goals are to simultaneously determine the three-dimensional distribution patterns of KCNQ1 and KCNE1 in cardiac myocytes and to study the mechanism and functional implications for variations in KCNQ1/KCNE1 colocalization in myocytes. We monitored the distribution patterns of KCNQ1, KCNE1, and markers for subcellular compartments/organelles using immunofluorescence/confocal microscopy and confirmed the findings in ventricular myocytes by directly observing fluorescently tagged KCNQ1-GFP and KCNE1-dsRed expressed in these cells. We also monitored the effects of stress on KCNQ1-GFP and endoplasmic reticulum (ER) remodeling during live cell imaging. The data showed that 1) KCNE1 maintained a stable cell surface localization, whereas KCNQ1 exhibited variations in the cytosolic compartment (striations versus vesicles) and the degree of presence on the cell surface; 2) the degree of cell surface KCNQ1/KCNE1 colocalization was positively correlated with slow delayed rectifier (IKs) current density; 3) KCNQ1 and calnexin (an ER marker) shared a cytosolic compartment; and 4) in response to stress ([Ca2+]i elevation, oxidative overload, or AT1R stimulation), KCNQ1 exited the cytosolic compartment and trafficked to the cell periphery in vesicles. This was accompanied by partial ER fragmentation. We conclude that the cellular milieu regulates KCNQ1 distribution in cardiac myocytes and that stressful conditions can increase IKs by inducing KCNQ1 movement to the cell surface. This represents a hitherto unrecognized mechanism by which IKs fulfills its function as a repolarization reserve in ventricular myocytes. PMID:24142691

Dual actions of a novel bifunctional compound to lower glucose in mice with diet-induced insulin resistance

PubMed Central

Chen, Katherine; Jih, Alice; Kavaler, Sarah T.; Lagakos, William S.; Oh, Dayoung; Watkins, Steven M.

2015-01-01

Docosahexaenoic acid (DHA 22:6n-3) and salicylate are both known to exert anti-inflammatory effects. This study investigated the effects of a novel bifunctional drug compound consisting of DHA and salicylate linked together by a small molecule that is stable in plasma but hydrolyzed in the cytoplasm. The components of the bifunctional compound acted synergistically to reduce inflammation mediated via nuclear factor κB in cultured macrophages. Notably, oral administration of the bifunctional compound acted in two distinct ways to mitigate hyperglycemia in high-fat diet-induced insulin resistance. In mice with diet-induced obesity, the compound lowered blood glucose by reducing hepatic insulin resistance. It also had an immediate glucose-lowering effect that was secondary to enhanced glucagon-like peptide-1 (GLP-1) secretion and abrogated by the administration of exendin(9–39), a GLP-1 receptor antagonist. These results suggest that the bifunctional compound could be an effective treatment for individuals with type 2 diabetes and insulin resistance. This strategy could also be employed in other disease conditions characterized by chronic inflammation. PMID:26058862

Synthesis of a bifunctional cytidine derivative and its conjugation to RNA for in vitro selection of a cytidine deaminase ribozyme

PubMed Central

Rublack, Nico

2014-01-01

Summary Over the past 20 years, the generation of functional RNAs by in vitro selection has become a standard technique. Apart from aptamers for simple binding of defined ligands, also RNAs for catalysis of chemical reactions have been selected. In the latter case, a key step often is the conjugation of one of the two reactants to the library, requiring suitable strategies for terminal or internal RNA functionalization. With the aim of selecting a ribozyme for deamination of cytidine, we have set up a selection scheme involving the attachment of the cytidine acting as deamination substrate to the 3'-terminus of the RNAs in the library, and library immobilization. Here, we report the synthesis of a bifunctional cytidine derivative suitable for conjugation to RNA and linkage of the conjugated library to a streptavidine-coated surface. Successful conjugation of the cytidine derivative to the 3'-terminus of a model RNA is demonstrated. PMID:25246949

Preparation of highly fluorescent magnetic nanoparticles for analytes-enrichment and subsequent biodetection.

PubMed

Zhang, Bingbo; Chen, Bingdi; Wang, Yilong; Guo, Fangfang; Li, Zhuoquan; Shi, Donglu

2011-01-15

Bifunctional nanoparticles with highly fluorescence and decent magnetic properties have been widely used in biomedical application. In this study, highly fluorescent magnetic nanoparticles (FMNPs) with uniform size of ca. 40 nm are prepared by encapsulation of both magnetic nanoparticles (MNPs) and shell/core quantum dots (QDs) with well-designed shell structure/compositions into silica matrix via a one-pot reverse microemulsion approach. The spectral analysis shows that the FMNPs hold high fluorescent quantum yield (QY). The QYs and saturation magnetization of the FMNPs can be regulated by varying the ratio of the encapsulated QDs to MNPs. Moreover, the surface of the FMNPs can be modified to offer chemical groups for antibody conjugation for following use in target-enrichment and subsequent fluorescent detection. The in vitro immunofluorescence assay and flow cytometric analysis indicate that the bifunctional FMNPs-antibody bioconjugates are capable of target-enrichment, magnetic separation and can also be used as alternative fluorescent probes on flow cytometry for biodetection. Copyright © 2010 Elsevier Inc. All rights reserved.

Electrocatalytic performances of g-C3N4-LaNiO3 composite as bi-functional catalysts for lithium-oxygen batteries

PubMed Central

Wu, Yixin; Wang, Taohuan; Zhang, Yidie; Xin, Sen; He, Xiaojun; Zhang, Dawei; Shui, Jianglan

2016-01-01

A low cost and non-precious metal composite material g-C3N4-LaNiO3 (CNL) was synthesized as a bifunctional electrocatalyst for the air electrode of lithium-oxygen (Li-O2) batteries. The composition strategy changed the electron structure of LaNiO3 and g-C3N4, ensures high Ni3+/Ni2+ ratio and more absorbed hydroxyl on the surface of CNL that can promote the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The composite catalyst presents higher activities than the individual components g-C3N4 and LaNiO3 for both ORR and OER. In non-aqueous Li-O2 batteries, CNL shows higher capacity, lower overpotentials and better cycling stability than XC-72 carbon and LaNiO3 catalysts. Our results suggest that CNL composite is a promising cathode catalyst for Li-O2 batteries. PMID:27074882

Effects of spaceflight on levels and activity of immune cells

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald; Berry, Wallace D.; Mandel, Adrian D.; Konstantinova, Irena V.; Taylor, Gerald R.

1990-01-01

Experiments were carried out on cells from rats that had been flown on Soviet Biosputnik Cosmos 1887 to explore the effects of speceflight on immune responses. Rat bone marrow cells were examined for their response to colony stimulating factor-M. Rat spleen and bone marrow cells were stained with antibodies directed against cell surface antigenic markers. The results of the studies indicate that bone marrow cells from flown rats showed a decreased response to colony stimulating factor. There was a higher percentage of spleen cells from flown rats staining positively for pan-T-cell, suppressor-T-cell, and interleukin-2 receptor cell surface antigens. A small increase in the percentage of cells staining positively for helper-T-cell antigens was also noted. In addition, a higher percentage of cells that appeared to be part of the myelogenous population of bone marrow cells from flown rats stained positively for surface immunoglobulin.

Genomic analysis of bifunctional Class C-Class D β-lactamases in environmental bacteria.

PubMed

Silveira, Melise Chaves; Catanho, Marcos; Miranda, Antônio Basílio de

2018-01-01

β-lactamases, which are found in several bacterial species and environments, are the main cause of resistance to β-lactams in Gram-negative bacteria. In 2009, a protein (LRA-13) with two β-lactamase domains (one class C domain and one class D domain) was experimentally characterised, and an extended action spectrum against β-lactams consistent with two functional domains was found. Here, we present the results of searches in the non-redundant NCBI protein database that revealed the existence of a group of homologous bifunctional β-lactamases in the genomes of environmental bacteria. These findings suggest that bifunctional β-lactamases are widespread in nature; these findings also raise concern that bifunctional β-lactamases may be transferred to bacteria of clinical importance through lateral gene transfer mechanisms.

Segregation of two spectrin isoforms: polarized membrane-binding sites direct polarized membrane skeleton assembly.

PubMed

Dubreuil, R R; Maddux, P B; Grushko, T A; MacVicar, G R

1997-10-01

Spectrin isoforms are often segregated within specialized plasma membrane subdomains where they are thought to contribute to the development of cell surface polarity. It was previously shown that ankyrin and beta spectrin are recruited to sites of cell-cell contact in Drosophila S2 cells expressing the homophilic adhesion molecule neuroglian. Here, we show that neuroglian has no apparent effect on a second spectrin isoform (alpha beta H), which is constitutively associated with the plasma membrane in S2 cells. Another membrane marker, the Na,K-ATPase, codistributes with ankyrin and alpha beta spectrin at sites of neuroglian-mediated contact. The distributions of these markers in epithelial cells in vivo are consistent with the order of events observed in S2 cells. Neuroglian, ankyrin, alpha beta spectrin, and the Na,K-ATPase colocalize at the lateral domain of salivary gland cells. In contrast, alpha beta H spectrin is sorted to the apical domain of salivary gland and somatic follicle cells. Thus, the two spectrin isoforms respond independently to positional cues at the cell surface: in one case an apically sorted receptor and in the other case a locally activated cell-cell adhesion molecule. The results support a model in which the membrane skeleton behaves as a transducer of positional information within cells.

Substrate micropatterns produced by polymer demixing regulate focal adhesions, actin anisotropy, and lineage differentiation of stem cells.

PubMed

Vega, Sebastián L; Arvind, Varun; Mishra, Prakhar; Kohn, Joachim; Sanjeeva Murthy, N; Moghe, Prabhas V

2018-06-12

Stem cells are adherent cells whose multipotency and differentiation can be regulated by numerous microenvironmental signals including soluble growth factors and surface topography. This study describes a simple method for creating distinct micropatterns via microphase separation resulting from polymer demixing of poly(desaminotyrosyl-tyrosine carbonate) (PDTEC) and polystyrene (PS). Substrates with co-continuous (ribbons) or discontinuous (islands and pits) PDTEC regions were obtained by varying the ratio of PDTEC and sacrificial PS. Human mesenchymal stem cells (MSCs) cultured on co-continuous PDTEC substrates for 3 days in bipotential adipogenic/osteogenic (AD/OS) induction medium showed no change in cell morphology but exhibited increased anisotropic cytoskeletal organization and larger focal adhesions when compared to MSCs cultured on discontinuous micropatterns. After 14 days in bipotential AD/OS induction medium, MSCs cultured on co-continuous micropatterns exhibited increased expression of osteogenic markers, whereas MSCs on discontinuous PDTEC substrates showed a low expression of adipogenic and osteogenic differentiation markers. Substrates with graded micropatterns were able to reproduce the influence of local underlying topography on MSC differentiation, thus demonstrating their potential for high throughput analysis. This work presents polymer demixing as a simple, non-lithographic technique to produce a wide range of micropatterns on surfaces with complex geometries to influence cellular and tissue regenerative responses. Gaining a better understanding of how engineered microenvironments influence stem cell differentiation is integral to increasing the use of stem cells and materials in a wide range of tissue engineering applications. In this study, we show the range of topography obtained by polymer demixing is sufficient for investigating how surface topography affects stem cell morphology and differentiation. Our findings show that co-continuous topographies favor early (3-day) cytoskeletal anisotropy and focal adhesion maturation as well as long-term (14-day) expression of osteogenic differentiation markers. Taken together, this study presents a simple approach to pattern topographies that induce divergent responses in stem cell morphology and differentiation. Copyright © 2018. Published by Elsevier Ltd.

Characterization and differentiation of human embryonic stem cells.

PubMed

Carpenter, M K; Rosler, E; Rao, M S

2003-01-01

Cell replacement therapies have been limited by the availability of sufficient quantities of cells for transplantation. Human ES (hES) cell lines have recently been generated by several laboratories. When maintained for over 1 year in vitro, they remain karyotypically and phenotypically stable and may therefore provide an excellent source material for cell therapies. Currently, data is available for 26 hES cell lines. Although limited characterization has been performed on most of these lines, there are remarkable similarities in expression of markers. hES cell lines derived in different laboratories show similar expression profiles of surface markers, including SSEA-4, Tra-1-60, and Tra-1-81. In addition, markers associated with pluripotent cells such as OCT-4 are expressed at in all cell lines tested. These cells express high levels of telomerase and appear to have indefinite growth potential. The generation of the large quantities of cells necessary for cell replacement therapies will require a cell population which is stable over long term culture. We have characterized the properties of multiple hES cell lines that have been maintained in culture for extended periods. Quantitative analyses demonstrate that all of the cell lines examined show consistent marker expression and retain a normal karyotype after long-term culture. hES cells have been differentiated into the derivatives of all three germ layers. Specifically this includes cardiomyocytes, neural cells, hepatocyte-like cells, endothelial cells and hematopoietic progenitor cells. These data demonstrating the karyotypic and phenotypic stability of hES cells and their extensive differentiative capacity indicate that they may be an appropriate source of cells for multiple regenerative medicine applications.

Use of Hes1-GFP reporter mice to assess activity of the Hes1 promoter in bone cells under chronic inflammation

PubMed Central

Zhang, Hengwei; Sun, Wen; Li, Xing; Wang, Mengmeng; Boyce, Brendan F; Hilton, Matthew J; Xing, Lianping

2016-01-01

Notch signaling plays a critical role in maintaining bone homeostasis partially by controlling the formation of osteoblasts from mesenchymal stem cells (MSCs). We reported that TNF activates Notch signaling in MSCs which inhibits osteoblast differentiation in TNF transgenic (TNF-Tg) mice, a mouse model of chronic inflammatory arthritis. In the current study, we used Hes1-GFP and Hes1-GFP/TNF-Tg mice to study the distribution and dynamic change of Notch active cells in normal and inflammatory bone loss and mechanisms mediating their enhanced proliferation. We found that Hes1-GFP+ cells are composed of cells expressing mesenchymal, hematopoietic and endothelial surface markers. CD45−/Hes1-GFP+ cells express high levels of mesenchymal markers and form CFU-F and CFU-ALP colonies. Expansion of CFU-F colonies is associated with a rapid increase in Hes1-GFP+ cell numbers and their GFP intensity. The GFP signal is lost when a CFU-F colony differentiates into an ALP+ osteoblast colony. TNF increases the numbers of CD45−/Hes1-GFP+ cells, which are stained negatively for osteoblast marker osteocalcin and localized adjacent to endosteal and trabecular bone surfaces. CD45−/Hes1-GFP+ cells in Hes1-GFP/TNF-Tg mice have increased BrdU incorporation and PDGFRβ levels. TNF increases the number of proliferating Hes1-GFP+ cells, which is prevented by a specific PDGFRβ inhibitor. Notch inhibition blocks TNF-mediated PDGFRβ expression and cell proliferation. Thus, TNF-induced MSC proliferation is mediated by PDGFRβ signal, which works at downstream of Notch. Hes1-GFP mice can be used to assess the activation status of Notch in bone cells. PMID:27269414

Use of Hes1-GFP reporter mice to assess activity of the Hes1 promoter in bone cells under chronic inflammation.

PubMed

Zhang, Hengwei; Sun, Wen; Li, Xing; Wang, Mengmeng; Boyce, Brendan F; Hilton, Matthew J; Xing, Lianping

2016-09-01

Notch signaling plays a critical role in maintaining bone homeostasis partially by controlling the formation of osteoblasts from mesenchymal stem cells (MSCs). We reported that TNF activates Notch signaling in MSCs which inhibits osteoblast differentiation in TNF transgenic (TNF-Tg) mice, a mouse model of chronic inflammatory arthritis. In the current study, we used Hes1-GFP and Hes1-GFP/TNF-Tg mice to study the distribution and dynamic change of Notch active cells in normal and inflammatory bone loss and mechanisms mediating their enhanced proliferation. We found that Hes1-GFP+ cells are composed of cells expressing mesenchymal, hematopoietic and endothelial surface markers. CD45-/Hes1-GFP+ cells express high levels of mesenchymal markers and form CFU-F and CFU-ALP colonies. Expansion of CFU-F colonies is associated with a rapid increase in Hes1-GFP+ cell numbers and their GFP intensity. The GFP signal is lost when a CFU-F colony differentiates into an ALP+ osteoblast colony. TNF increases the numbers of CD45-/Hes1-GFP+ cells, which are stained negatively for osteoblast marker osteocalcin and localized adjacent to endosteal and trabecular bone surfaces. CD45-/Hes1-GFP+ cells in Hes1-GFP/TNF-Tg mice have increased BrdU incorporation and PDGFRβ levels. TNF increases the number of proliferating Hes1-GFP+ cells, which is prevented by a specific PDGFRβ inhibitor. Notch inhibition blocks TNF-mediated PDGFRβ expression and cell proliferation. Thus, TNF-induced MSC proliferation is mediated by PDGFRβ signal, which works at downstream of Notch. Hes1-GFP mice can be used to assess the activation status of Notch in bone cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Convergent and divergent two-dimensional coordination networks formed through substrate-activated or quenched alkynyl ligation.

PubMed

Čechal, Jan; Kley, Christopher S; Kumagai, Takashi; Schramm, Frank; Ruben, Mario; Stepanow, Sebastian; Kern, Klaus

2014-09-07

Metal coordination assemblies of the symmetric bi-functional 4,4'-di-(1,4-buta-1,3-diynyl)-benzoic acid are investigated by scanning tunnelling microscopy on metal surfaces. The formation of long-range ordered, short-range disordered and random phases depends on the competition between the convergent and divergent coordination motifs of the individual functional groups and is crucially influenced by the substrate.

Bifunctional Alkylating Agent-Induced p53 and Nonclassical Nuclear Factor kB Responses and Cell Death are Altered by Caffeic Acid Phenethyl Ester: A Potential Role for Antioxidant/Electrophilic Response-Element Signaling

DTIC Science & Technology

2007-01-01

Methods. To establish the maximal LDH 2,3,7,8-tetrachloro- activity achievable from these cells, untreated control cells were grown dibenzo-p- dioxin to the...to modulated by AhR (Miao et al., 2005). Curcumin has been induce apoptosis. CAPE may be involved in anoikis, that is, shown to compete with dioxin ...the AhR directly binds (Miao et al., 2005). adhesion kinase (Weyant et al., 2000). Also, CAPE-induced Exposure of Hepalclc7 cells to dioxin results in

Assessment of Regenerative Capacity in the Dolphin

DTIC Science & Technology

2011-10-10

surface markers. Cultured cells were also cryogenically frozen for future cell therapy treatment of dolphin skin wounds. Gene array analysis on the...Mammals, Atlantic Bottlenose Dolphin, Autologous Cell Therapy 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a...cellular therapy for dolphin skin wounds. Finally, the cells will be tested for immunogenicity to develop an allogeneic (same species, universal

Voltammetric determination of Cd2+ based on the bifunctionality of single-walled carbon nanotubes-Nafion film.

PubMed

Sun, Dong; Xie, Xiafeng; Cai, Yuepiao; Zhang, Huajie; Wu, Kangbing

2007-01-02

In the presence of Nafion, single-walled carbon nanotubes (SWNTs) were easily dispersed into ethanol, resulting in a homogeneous SWNTs/Nafion suspension. After evaporating ethanol, a SWNTs/Nafion film with bifunctionality was constructed onto glassy carbon electrode (GCE) surface. Attributing to the strong cation-exchange ability of Nafion and excellent properties of SWNTs, the SWNTs/Nafion film-coated GCE remarkably enhances the sensitivity of determination of Cd(2+). Based on this, an electrochemical method was developed for the determination of trace levels of Cd(2+) by anodic stripping voltammetry (ASV). In pH 5.0 NaAc-HAc buffer, Cd(2+) was firstly exchanged and adsorbed onto SWNTs/Nafion film surface, and then reduce at -1.10 V. During the positive potential sweep, reduced cadmium was oxidized, and a well-defined stripping peak appeared at -0.84 V, which can be used as analytical signal for Cd(2+). The linear range is found to be from 4.0 x 10(-8) to 4.0 x 10(-6) mol L(-1), and the lowest detectable concentration is estimated to be 4.0 x 10(-9) mol L(-1). Finally, this method was successfully employed to detect Cd(2+) in water samples.

Bi-functional Au/FeS (Au/Co3O4) composite for in situ SERS monitoring and degradation of organic pollutants

NASA Astrophysics Data System (ADS)

Ma, Shuzhen; Cai, Qian; Lu, Kailing; Liao, Fan; Shao, Mingwang

2016-01-01

The bi-functional Au/FeS (Au/Co3O4) composite was fabricated by in situ reducing Au nanoparticles onto the surface of FeS (Co3O4). The as-prepared FeS possessed a multi-structure composed of plenty of nanoplates, which were coated by Au nanoparticles with an average size of 47.5 nm. While the Co3O4 showed a thin hexagonal sheet containing Au nanoparticles on its surface with an average size of 79.0 nm. Both the as-prepared Au/FeS and Au/Co3O4 composites exhibited excellent SERS performance, capable of enhancing the Raman signals of R6G molecules with the enhancement factor up to 1.81 × 106 and 7.60 × 104, respectively. Moreover, Au/FeS (Au/Co3O4) composite also has been verified to have intrinsic peroxidase-like activity, which could decompose H2O2 into hydroxyl radicals and then degrade organic pollutants into small molecules. Therefore, SERS can be used to real-time and in situ monitoring the degradation process of R6G molecules, employing the Au/FeS (Au/Co3O4) composite both as SERS substrate and catalyst.

Expression of Lipid Peroxidation Markers in the Tear Film and Ocular Surface of Patients with Non-Sjogren Syndrome: Potential Biomarkers for Dry Eye Disease.

PubMed

Choi, Won; Lian, Cui; Ying, Li; Kim, Ga Eon; You, In Cheon; Park, Soo Hyun; Yoon, Kyung Chul

2016-09-01

To investigate the expression of lipid peroxidation markers in the tear film and ocular surface and their correlation with disease severity in patients with dry eye disease. The concentrations of hexanoyl-lysine (HEL), 4-hydroxy-2-nonenal (HNE), and malondialdehyde (MDA) were measured with enzyme-linked immunosorbent assays in tears obtained from 44 patients with non-Sjogren syndrome dry eye and 33 control subjects. The correlations between the marker levels and the tear film and ocular surface parameters, including tear film break-up time (BUT), Schirmer tear value, tear clearance rate, keratoepitheliopathy scores, corneal sensitivity, conjunctival goblet cell density, and symptom score, were analyzed. The expression of the lipid peroxidation markers HEL, 4-HNE, and MDA in the conjunctiva was evaluated using immunohistochemistry. The concentrations of HEL, 4-HNE, and MDA were 279.84 ± 69.98 nmol/L, 0.02 ± 0.01 μg/mL, and 3.80 ± 1.05 pmol/mg in control subjects and 283.21 ± 89.67 nmol/L (p = 0.97), 0.20 ± 0.03 μg/mL (p < 0.01), and 13.32 ± 4.03 pmol/mg (p < 0.01) in dry eye patients. 4-HNE and MDA levels significantly correlated with BUT, Schirmer tear value, tear clearance rate, keratoepitheliopathy scores, conjunctival goblet cell density, and symptom score (p < 0.05), whereas HEL levels did not correlate with these parameters. Staining intensities for 4-HNE and MDA increased in dry eye patients. The expression of late lipid peroxidation markers, 4-HNE and MDA, increases in the tear film and ocular surface of patients with dry eye. The levels correlate with various tear film and ocular surface parameters and may reflect the severity of dry eye disease.

Novel Adult Stem Cells for Peripheral Nerve Regeneration

DTIC Science & Technology

2012-09-01

were also positive for MSC surface marker CD29 and CD44 (Fig. 1F-G). However, CD29 and CD44 are also expressed in SMCs, so we will not use these non...tubulin. In addition, MVSCs were negative for perivascular MSC marker CD146 (Fig. 1H) and SMC progenitor marker Sca-1 (Fig. 1I). MVSCs were also...University of California, Berkeley, California 94720, USA. 2 UC Berkeley-UCSF Graduate Program in Bioengineering, Berkeley, California 94720, USA. 3

Decreased NK-Cell Cytotoxicity after Short Flights on the Space Shuttle

NASA Technical Reports Server (NTRS)

Mehta, Satish K.; Grimm, Elizabeth A.; Smid, Christine; Kaur, Indreshpal; Feeback, Daniel L.; Pierson, Duane L.

2000-01-01

Cytotoxic activity of natural killer (NK) cells and cell surface marker expression of peripheral blood mononuclear cells (PBMCs) isolated from 11 U.S. astronauts on two different missions were determined before and after 9 or 10 days of spaceflight aboard the space shuttle. Blood samples were collected 10 and 3 days before launch, within 3 hours after landing, and 3 days after landing. All PBMC preparations were cryopreserved and analyzed simultaneously in a 4-hour cytotoxicity "Cr-release assay using NK-sensitive K-562 target cells. Compared to preflight values, NK-cell cytotoxicity (corrected for lymphopenia observed on landing day) was significantly decreased at landing (P < 0.0125). It then apparently began to recover and approached preflight values by 3 days after landing. Consistent with decreased NK-cell cytotoxicity, significant increases from preflight values were found in plasma adrenocorticotropic hormone at landing. Plasma and urinary cortisol levels did not change significantly from preflight values. Expression of major lymphocyte surface markers (CD3, CD4, CD8, CD14, CD16, CD56), determined by flow cytometric analysis, revealed no consistent phenotypic changes in relative percent of NK or other lymphoid cells after 10 days of spaceflight.

Dissecting Stages of Human Kidney Development and Tumorigenesis with Surface Markers Affords Simple Prospective Purification of Nephron Stem Cells.

PubMed

Pode-Shakked, Naomi; Pleniceanu, Oren; Gershon, Rotem; Shukrun, Rachel; Kanter, Itamar; Bucris, Efrat; Pode-Shakked, Ben; Tam, Gal; Tam, Hadar; Caspi, Revital; Pri-Chen, Sara; Vax, Einav; Katz, Guy; Omer, Dorit; Harari-Steinberg, Orit; Kalisky, Tomer; Dekel, Benjamin

2016-03-29

When assembling a nephron during development a multipotent stem cell pool becomes restricted as differentiation ensues. A faulty differentiation arrest in this process leads to transformation and initiation of a Wilms' tumor. Mapping these transitions with respective surface markers affords accessibility to specific cell subpopulations. NCAM1 and CD133 have been previously suggested to mark human renal progenitor populations. Herein, using cell sorting, RNA sequencing, in vitro studies with serum-free media and in vivo xenotransplantation we demonstrate a sequential map that links human kidney development and tumorigenesis; In nephrogenesis, NCAM1(+)CD133(-) marks SIX2(+) multipotent renal stem cells transiting to NCAM1(+)CD133(+) differentiating segment-specific SIX2(-) epithelial progenitors and NCAM1(-)CD133(+) differentiated nephron cells. In tumorigenesis, NCAM1(+)CD133(-) marks SIX2(+) blastema that includes the ALDH1(+) WT cancer stem/initiating cells, while NCAM1(+)CD133(+) and NCAM1(-)CD133(+) specifying early and late epithelial differentiation, are severely restricted in tumor initiation capacity and tumor self-renewal. Thus, negative selection for CD133 is required for defining NCAM1(+) nephron stem cells in normal and malignant nephrogenesis.

Spirochetal antigens and lymphoid cell surface markers in Lyme synovitis. Comparison with rheumatoid synovium and tonsillar lymphoid tissue.

PubMed

Steere, A C; Duray, P H; Butcher, E C

1988-04-01

Using monoclonal antibodies to spirochetal antigenes and lymphoid cell surface markers, we examined the synovial lesions of 12 patients with Lyme disease, and compared them with rheumatoid synovium and tonsillar lymphoid tissue. The synovial lesions of Lyme disease patients and rheumatoid arthritis patients were similar and often consisted of the elements found in normal organized lymphoid tissue. In both diseases, T cells, predominantly of the helper/inducer subset, were distributed diffusely in subsynovial lining areas, often with nodular aggregates of tightly intermixed T and B cells. IgD-bearing B cells were scattered within the aggregates, and a few follicular dendritic cells and activated germinal center B cells were sometimes present. Outside the aggregates, many plasma cells, high endothelial venules, scattered macrophages, and a few dendritic macrophages were found. HLA-DR and DQ expression was intense throughout the lesions. In 6 of the 12 patients with Lyme arthritis, but in none of those with rheumatoid arthritis, a few spirochetes and globular antigen deposits were seen in and around blood vessels in areas of lymphocytic infiltration. Thus, in Lyme arthritis, a small number of spirochetes are probably the antigenic stimulus for chronic synovial inflammation.

Cosmos 2229 immunology study (Experiment K-8-07)

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

1993-01-01

The purpose of the current study was to further validate use of the rhesus monkey as a model for humans in future space flight testing. The areas of immunological importance examined in the Cosmos 2229 flight were represented by two sets of studies. The first set of studies determined the effect of space flight on the ability of bone marrow cells to respond to granulocyte/monocyte colony stimulating factor (GM-CSF). GM-CSF is an important regulator in the differentiation of bone marrow cells of both monocyte/macrophage and granulocyte lineages and any change in the ability of these cells to respond to GM-CSF can result in altered immune function. A second set of studies determined space flight effects on the expression of cell surface markers on both spleen and bone marrow cells. Immune cell markers included in this study were those for T-cell, B-cell, natural killer cell, and interleukin-2 populations. Variations from a normal cell population percentage, as represented by these markers, can be correlated with alterations in immunological function. Cells were stained with fluorescein-labelled antibodies directed against the appropriate antigens, and then analyzed using a flow cytometer.

Delivery of siRNA using ternary complexes containing branched cationic peptides: the role of peptide sequence, branching and targeting.

PubMed

Kudsiova, Laila; Welser, Katharina; Campbell, Frederick; Mohammadi, Atefeh; Dawson, Natalie; Cui, Lili; Hailes, Helen C; Lawrence, M Jayne; Tabor, Alethea B

2016-03-01

Ternary nanocomplexes, composed of bifunctional cationic peptides, lipids and siRNA, as delivery vehicles for siRNA have been investigated. The study is the first to determine the optimal sequence and architecture of the bifunctional cationic peptide used for siRNA packaging and delivery using lipopolyplexes. Specifically three series of cationic peptides of differing sequence, degrees of branching and cell-targeting sequences were co-formulated with siRNA and vesicles prepared from a 1 : 1 molar ratio of the cationic lipid DOTMA and the helper lipid, DOPE. The level of siRNA knockdown achieved in the human alveolar cell line, A549-luc cells, in both reduced serum and in serum supplemented media was evaluated, and the results correlated to the nanocomplex structure (established using a range of physico-chemical tools, namely small angle neutron scattering, transmission electron microscopy, dynamic light scattering and zeta potential measurement); the conformational properties of each component (circular dichroism); the degree of protection of the siRNA in the lipopolyplex (using gel shift assays) and to the cellular uptake, localisation and toxicity of the nanocomplexes (confocal microscopy). Although the size, charge, structure and stability of the various lipopolyplexes were broadly similar, it was clear that lipopolyplexes formulated from branched peptides containing His-Lys sequences perform best as siRNA delivery agents in serum, with protection of the siRNA in serum balanced against efficient release of the siRNA into the cytoplasm of the cell.

Advanced bifunctional electrocatalyst generated through cobalt phthalocyanine tetrasulfonate intercalated Ni2Fe-layered double hydroxides for a laminar flow unitized regenerative micro-cell

NASA Astrophysics Data System (ADS)

Zhong, Haihong; Tian, Ran; Gong, Xiaoman; Li, Dianqing; Tang, Pinggui; Alonso-Vante, Nicolas; Feng, Yongjun

2017-09-01

We fabricated a NiFeOx/CoNy-C nanocomposite derived from CoPcTs-intercalated Ni2Fe-layered double hydroxides (Ni2Fe-CoPcTs-LDH), which served as high-efficiency, low-cost, and long-durability bifunctional oxygen electrocatalyst in half-cell, and a H2-O2 laminar flow unitized regenerative micro-cell (LFURMC) in alkaline media. Based on the synergistic effect between Co-Ny and NiFeOx centers, the non-noble hybrid catalyst NiFeOx/CoNy-C achieves a ΔE (η@jOER,10 - η@jORR,-3) = 0.84 V in alkaline solution, outperforming the commercial Pt/C, and very close to that of IrOx/C. In the fuel cell mode, the performance of NiFeOx/CoNy-C with the maximum power density of 56 mW cm-2 is similar to that of Pt/C (63 mW cm-2) and IrOx/C (58 mW cm-2); in the electrolysis mode, the calculated maximum electrical power consumed on NiFeOx/CoNy-C (237 mW cm-2) is more than 3 times that on Pt/C (73 mW cm-2), similar with that of IrOx/C. More importantly, the NiFeOx/CoNy-C shows a remarkable stability in alternating modes in a LFURMC system.

Engineering of a novel tri-functional enzyme with MnSOD, catalase and cell-permeable activities.

PubMed

Luangwattananun, Piriya; Yainoy, Sakda; Eiamphungporn, Warawan; Songtawee, Napat; Bülow, Leif; Ayudhya, Chartchalerm Isarankura Na; Prachayasittikul, Virapong

2016-04-01

Cooperative function of superoxide dismutase (SOD) and catalase (CAT), in protection against oxidative stress, is known to be more effective than the action of either single enzyme. Chemical conjugation of the two enzymes resulted in molecules with higher antioxidant activity and therapeutic efficacy. However, chemical methods holds several drawbacks; e.g., loss of enzymatic activity, low homogeneity, time-consuming, and the need of chemical residues removal. Yet, the conjugated enzymes have never been proven to internalize into target cells. In this study, by employing genetic and protein engineering technologies, we reported designing and production of a bi-functional protein with SOD and CAT activities for the first time. To enable cellular internalization, cell penetrating peptide from HIV-1 Tat (TAT) was incorporated. Co-expression of CAT-MnSOD and MnSOD-TAT fusion genes allowed simultaneous self-assembly of the protein sequences into a large protein complex, which is expected to contained one tetrameric structure of CAT, four tetrameric structures of MnSOD and twelve units of TAT. The protein showed cellular internalization and superior protection against paraquat-induced cell death as compared to either complex bi-functional protein without TAT or to native enzymes fused with TAT. This study not only provided an alternative strategy to produce multifunctional protein complex, but also gained an insight into the development of therapeutic agent against oxidative stress-related conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Synergistic Interaction within Bifunctional Ruthenium Nanoparticle/SILP Catalysts for the Selective Hydrodeoxygenation of Phenols.

PubMed

Luska, Kylie L; Migowski, Pedro; El Sayed, Sami; Leitner, Walter

2015-12-21

Ruthenium nanoparticles immobilized on acid-functionalized supported ionic liquid phases (Ru NPs@SILPs) act as efficient bifunctional catalysts in the hydrodeoxygenation of phenolic substrates under batch and continuous flow conditions. A synergistic interaction between the metal sites and acid groups within the bifunctional catalyst leads to enhanced catalytic activities for the overall transformation as compared to the individual steps catalyzed by the separate catalytic functionalities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lgr5(+ve) stem/progenitor cells contribute to nephron formation during kidney development.

PubMed

Barker, Nick; Rookmaaker, Maarten B; Kujala, Pekka; Ng, Annie; Leushacke, Marc; Snippert, Hugo; van de Wetering, Marc; Tan, Shawna; Van Es, Johan H; Huch, Meritxell; Poulsom, Richard; Verhaar, Marianne C; Peters, Peter J; Clevers, Hans

2012-09-27

Multipotent stem cells and their lineage-restricted progeny drive nephron formation within the developing kidney. Here, we document expression of the adult stem cell marker Lgr5 in the developing kidney and assess the stem/progenitor identity of Lgr5(+ve) cells via in vivo lineage tracing. The appearance and localization of Lgr5(+ve) cells coincided with that of the S-shaped body around embryonic day 14. Lgr5 expression remained restricted to cell clusters within developing nephrons in the cortex until postnatal day 7, when expression was permanently silenced. In vivo lineage tracing identified Lgr5 as a marker of a stem/progenitor population within nascent nephrons dedicated to generating the thick ascending limb of Henle's loop and distal convoluted tubule. The Lgr5 surface marker and experimental models described here will be invaluable for deciphering the contribution of early nephron stem cells to developmental defects and for isolating human nephron progenitors as a prerequisite to evaluating their therapeutic potential. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

A potential germ cell-specific marker in Japanese flounder, Paralichthys olivaceus: identification and characterization of lymphocyte antigen 75 (Ly75/CD205)

NASA Astrophysics Data System (ADS)

Yang, Yang; Liu, Qinghua; Ma, Daoyuan; Song, Zongchen; Li, Jun

2018-04-01

Some germ cell marker genes, such as vasa, nanos, and dead end (dnd), have been identified in fish. Recently, lymphocyte antigen 75 (Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder ly75 homolog (ly75) was cloned and its expression pattern in gonads was analyzed. The full-length cDNA of ly75 was 7 346 bp, with an open reading frame (ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 kDa. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.

Dynamics associated with spontaneous differentiation of ovarian stem cells in vitro

PubMed Central

2014-01-01

Background Recent studies suggest that ovarian germ line stem cells replenish oocyte-pool in adult stage, and challenge the central doctrine of ‘fixed germ cell pool’ in mammalian reproductive biology. Two distinct populations of spherical stem cells with high nucleo-cytoplasmic ratio have been recently identified in the adult mammalian ovary surface epithelium (OSE) including nuclear OCT-4A positive very small embryonic-like (VSELs) and cytoplasmic OCT-4 expressing ovarian germ stem cells (OGSCs). Three weeks culture of scraped OSE cells results in spontaneous differentiation of the stem cells into oocyte-like, parthenote-like, embryoid body-like structures and also embryonic stem cell-like colonies whereas epithelial cells attach and transform into a bed of mesenchymal cells. Present study was undertaken, to further characterize ovarian stem cells and to comprehend better the process of spontaneous differentiation of ovarian stem cells into oocyte-like structures in vitro. Methods Ovarian stem cells were enriched by immunomagnetic sorting using SSEA-4 as a cell surface marker and were further characterized. Stem cells and clusters of OGSCs (reminiscent of germ cell nests in fetal ovaries), were characterized by immuno-localization for stem and germ cell specific markers and spontaneous differentiation in OSE cultures was studied by live cell imaging. Results Differential expression of markers specific for pluripotent VSELs (nuclear OCT-4A, SSEA-4, CD133), OGSCs (cytoplasmic OCT-4) primordial germ cells (FRAGILIS, STELLA, VASA) and germ cells (DAZL, GDF-9, SCP-3) were studied. Within one week of culture, stem cells became bigger in size, developed abundant cytoplasm, differentiated into germ cells, revealed presence of Balbiani body-like structure (mitochondrial cloud) and exhibited characteristic cytoplasmic streaming. Conclusions Presence of germ cell nests, Balbiani body-like structures and cytoplasmic streaming extensively described during fetal ovary development, are indeed well recapitulated during in vitro oogenesis in adult OSE cultures along with characteristic expression of stem/germ cell/oocyte markers. Further studies are required to assess the genetic integrity of in vitro derived oocytes before harnessing their clinical potential. Advance in our knowledge about germ cell differentiation from stem cells will enable researchers to design better in vitro strategies which in turn may have relevance to reproductive biology and regenerative medicine. PMID:24568237

Association of Regulatory T Cells with Diabetes Type-1 and Its Renal and Vascular Complications Based on the Expression of Forkhead Box Protein P3 (FoxP3), Helios and Neurophilin-1.

PubMed

Khamechian, Tahereh; Irandoust, Behnaz; Mohammadi, Hanieh; Nikoueinejad, Hassan; Akbari, Hossein

2018-04-01

In recent years, it has been recognized that regulatory T cells (Tregs) play a critical role in maintaining immune tolerance. Moreover, the expression of two markers named Helios and neurophilin-1 (NRP-1) has been highlighted in such cells. Helios, an intracellular transcription marker, largely differentiates twomost operative sub group of Tregs, namely naturally occurring (nTreg) and induced (iTreg) Tregs, and NRP-1 is reckoned as a membranous activity marker of Tregs. We aimed to count peripheral mononuclear cells expressing such markers in a group of type 1 diabetes patients to elucidate the possible role of Tregs in the pathogenesis of such disease and its complications. Blood samples from 61 adult patients with type 1 diabetes and 61 sex and age-matched healthy controls were tested to count two types of Tregs, namely naturally occurring and inducible types, according to the expression of cell surface markers of CD4/CD25/CD47-FITC/PE/APC and intracellular markers of FoxP3/Helios-PE-CY5/eFlour450 by flow cytometry, respectively.We also investigated the relation between expression of such markers with HbA1c, urine albumin/creatinine ratio (UACR), and common carotid intima thickness (CIMT). The circulatory frequency of both Helios+ and Helios- T-cells were significantly decreased in patients compared to those in healthy controls (p<0.001). There was also a significant decrease in circulatory frequency of Helios+ NRP-1+ and Helios- NRP-1+ cells in the patients compared to controls (p=0.029). According to expression of Helios and NRP-1 markers, the number and function of both Tregs were decreased in diabetic patients. Moreover, the neurophilin expression was inversely associated with complications of type 1 diabetes.

Investigation of Functional Activity of Cells in Granulomatous Inflammatory Lesions from Mice with Latent Tuberculous Infection in the New Ex Vivo Model

PubMed Central

2013-01-01

The new ex vivo model system measuring functional input of individual granuloma cells to formation of granulomatous inflammatory lesions in mice with latent tuberculous infection has been developed and described in the current study. Monolayer cultures of cells that migrated from individual granulomas were established in the proposed culture settings for mouse spleen and lung granulomas induced by in vivo exposure to BCG vaccine. The cellular composition of individual granulomas was analyzed. The expression of the leukocyte surface markers such as phagocytic receptors CD11b, CD11c, CD14, and CD16/CD32 and the expression of the costimulatory molecules CD80, CD83, and CD86 were tested as well as the production of proinflammatory cytokines (IFNγ and IL-1α) and growth factors (GM-CSF and FGFb) for cells of individual granulomas. The colocalization of the phagocytic receptors and costimulatory molecules in the surface microdomains of granuloma cells (with and without acid-fast BCG-mycobacteria) has also been detected. It was found that some part of cytokine macrophage producers have carried acid-fast mycobacteria. Detected modulation in dynamics of production of pro-inflammatory cytokines, growth factors, and leukocyte surface markers by granuloma cells has indicated continued processes of activation and deactivation of granuloma inflammation cells during the latent tuberculous infection progress in mice. PMID:24198843

Release of active TGF-β1 from the latent TGF-β1/GARP complex on T regulatory cells is mediated by integrin β8.

PubMed

Edwards, Justin P; Thornton, Angela M; Shevach, Ethan M

2014-09-15

Activated T regulatory cells (Tregs) express latent TGF-β1 on their cell surface bound to GARP. Although integrins have been implicated in mediating the release of active TGF-β1 from the complex of latent TGF-β1 and latent TGF-β1 binding protein, their role in processing latent TGF-β1 from the latent TGF-β1/GARP complex is unclear. Mouse CD4(+)Foxp3(+) Treg, but not CD4(+)Foxp3(-) T cells, expressed integrin β8 (Itgb8) as detected by quantitative RT-PCR. Itgb8 expression was a marker of thymically derived (t)Treg, because it could not be detected on Foxp3(+)Helios(-) Tregs or on Foxp3(+) T cells induced in vitro. Tregs from Itgb8 conditional knockouts exhibited normal suppressor function in vitro and in vivo in a model of colitis but failed to provide TGF-β1 to drive Th17 or induced Treg differentiation in vitro. In addition, Itgb8 knockout Tregs expressed higher levels of latent TGF-β1 on their cell surface consistent with defective processing. Thus, integrin αvβ8 is a marker of tTregs and functions in a cell intrinsic manner in mediating the processing of latent TGF-β1 from the latent TGF-β1/GARP complex on the surface of tTregs.

Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varga, Nora; Vereb, Zoltan; Rajnavoelgyi, Eva

2011-10-28

Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth ofmore » undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.« less

Simultaneous detection of transgenic DNA by surface plasmon resonance imaging with potential application to gene doping detection.

PubMed

Scarano, Simona; Ermini, Maria Laura; Spiriti, Maria Michela; Mascini, Marco; Bogani, Patrizia; Minunni, Maria

2011-08-15

Surface plasmon resonance imaging (SPRi) was used as the transduction principle for the development of optical-based sensing for transgenes detection in human cell lines. The objective was to develop a multianalyte, label-free, and real-time approach for DNA sequences that are identified as markers of transgenosis events. The strategy exploits SPRi sensing to detect the transgenic event by targeting selected marker sequences, which are present on shuttle vector backbone used to carry out the transfection of human embryonic kidney (HEK) cell lines. Here, we identified DNA sequences belonging to the Cytomegalovirus promoter and the Enhanced Green Fluorescent Protein gene. System development is discussed in terms of probe efficiency and influence of secondary structures on biorecognition reaction on sensor; moreover, optimization of PCR samples pretreatment was carried out to allow hybridization on biosensor, together with an approach to increase SPRi signals by in situ mass enhancement. Real-time PCR was also employed as reference technique for marker sequences detection on human HEK cells. We can foresee that the developed system may have potential applications in the field of antidoping research focused on the so-called gene doping.

Flow cytometric characterization of the response of Fanconi's anemia cells to mitomycin C treatment.

PubMed

Kaiser, T N; Lojewski, A; Dougherty, C; Juergens, L; Sahar, E; Latt, S A

1982-03-01

DNA flow histogram analysis, using 33342 Hoechst as a stain, has been used to detect the effect of the potentially bifunctional alkylating agent, mitomycin C (MMC) on dermal fibroblasts from patients with Fanconi's anemia (FA), a hereditary human disease characterized by pancytopenia, hypersensitivity to DNA-crosslinking agents, congenital abnormalities and a predisposition for neoplasia. At 24 or 48 hr after a 2-hr exposure to 0.05 or 0.10 micrograms/ml MMC, (3)HdT incorporation was reduced to a greater extent in FA cells than in normal cells. Cells sorted from the last half of S phase showed a slightly greater inhibition of (3)HdT incorporation than did those sorted from the first half of S. Fanconi's anemia cells exhibited a marked accumulation in the G(2) + M peak of flow histograms following exposure to MMC. Twenty-four hr after treatment with .0.5 micrograms/ml MMC, the G(2) + M fraction of FA cells (eight lines) increased to more than 0.5 from a control value of approximately 0.02. Both normals (six lines) and heterozygotes (eight lines) showed, on the average, much less of a G(2) + M increment than did FA cells, even after exposure to 0.1 micrograms/ml MMC. Examination of cells sorted from the G(2) + M peak revealed that MMC-treated FA cells were blocked prior to mitosis. To determine whether the response of FA cells was specific for bifunctional alkylating agent, cells were also treated with ethylmethanesulfonate, a monofunctional agent. Twenty-four hours after exposure to 0.25 or 0.5 mg/ml ethylmethanesulfonate, FA and normal cells showed similar, small increases in the G(2) + M peak. The results suggest the utility of flow cytometry in the diagnostic evaluation of fibroblasts from patients suspected of having Fanconi's anemia.

Self-assembled bifunctional surface mimics an enzymatic and templating protein for the synthesis of a metal oxide semiconductor

PubMed Central

Kisailus, David; Truong, Quyen; Amemiya, Yosuke; Weaver, James C.; Morse, Daniel E.

2006-01-01

The recent discovery and characterization of silicatein, a mineral-synthesizing enzyme that assembles to form the filamentous organic core of the glassy skeletal elements (spicules) of a marine sponge, has led to the development of new low-temperature synthetic routes to metastable semiconducting metal oxides. These protein filaments were shown in vitro to catalyze the hydrolysis and structurally direct the polycondensation of metal oxides at neutral pH and low temperature. Based on the confirmation of the catalytic mechanism and the essential participation of specific serine and histidine residues (presenting a nucleophilic hydroxyl and a nucleophilicity-enhancing hydrogen-bonding imidazole nitrogen) in silicatein’s catalytic active site, we therefore sought to develop a synthetic mimic that provides both catalysis and the surface determinants necessary to template and structurally direct heterogeneous nucleation through condensation. Using lithographically patterned poly(dimethylsiloxane) stamps, bifunctional self-assembled monolayer surfaces containing the essential catalytic and templating elements were fabricated by using alkane thiols microcontact-printed on gold substrates. The interface between chemically distinct self-assembled monolayer domains provided the necessary juxtaposition of nucleophilic (hydroxyl) and hydrogen-bonding (imidazole) agents to catalyze the hydrolysis of a gallium oxide precursor and template the condensed product to form gallium oxohydroxide (GaOOH) and the defect spinel, gamma-gallium oxide (γ-Ga2O3). Using this approach, the production of patterned substrates for catalytic synthesis and templating of semiconductors for device applications can be envisioned. PMID:16585518

The PSO4 gene is responsible for an error-prone recombinational DNA repair pathway in Saccharomyces cerevisiae.

PubMed

de Andrade, H H; Marques, E K; Schenberg, A C; Henriques, J A

1989-06-01

The induction of mitotic gene conversion and crossing-over in Saccharomyces cerevisiae diploid cells homozygous for the pso4-1 mutation was examined in comparison to the corresponding wild-type strain. The pso4-1 mutant strain was found to be completely blocked in mitotic recombination induced by photoaddition of mono- and bifunctional psoralen derivatives as well as by mono- (HN1) and bifunctional (HN2) nitrogen mustards or 254 nm UV radiation in both stationary and exponential phases of growth. Concerning the lethal effect, diploids homozygous for the pso4-1 mutation are more sensitive to all agents tested in any growth phase. However, this effect is more pronounced in the G2 phase of the cell cycle. These results imply that the ploidy effect and the resistance of budding cells are under the control of the PSO4 gene. On the other hand, the pso4-1 mutant is mutationally defective for all agents used. Therefore, the pso4-1 mutant has a generalized block in both recombination and mutation ability. This indicates that the PSO4 gene is involved in an error-prone repair pathway which relies on a recombinational mechanism, strongly suggesting an analogy between the pso4-1 mutation and the RecA or LexA mutation of Escherichia coli.

Contribution of the Staphylococcus aureus Atl AM and GL murein hydrolase activities in cell division, autolysis, and biofilm formation.

PubMed

Bose, Jeffrey L; Lehman, McKenzie K; Fey, Paul D; Bayles, Kenneth W

2012-01-01

The most prominent murein hydrolase of Staphylococcus aureus, AtlA, is a bifunctional enzyme that undergoes proteolytic cleavage to yield two catalytically active proteins, an amidase (AM) and a glucosaminidase (GL). Although the bifunctional nature of AtlA has long been recognized, most studies have focused on the combined functions of this protein in cell wall metabolism and biofilm development. In this study, we generated mutant derivatives of the clinical S. aureus isolate, UAMS-1, in which one or both of the AM and GL domains of AtlA have been deleted. Examination of these strains revealed that each mutant exhibited growth rates comparable to the parental strain, but showed clumping phenotypes and lysis profiles that were distinct from the parental strain and each other, suggesting distinct roles in cell wall metabolism. Given the known function of autolysis in the release of genomic DNA for use as a biofilm matrix molecule, we also tested the mutants in biofilm assays and found both AM and GL necessary for biofilm development. Furthermore, the use of enzymatically inactive point mutations revealed that both AM and GL must be catalytically active for S. aureus to form a biofilm. The results of this study provide insight into the relative contributions of AM and GL in S. aureus and demonstrate the contribution of Atl-mediated lysis in biofilm development.

Lgr proteins in epithelial stem cell biology.

PubMed

Barker, Nick; Tan, Shawna; Clevers, Hans

2013-06-01

The ultimate success of global efforts to exploit adult stem cells for regenerative medicine will depend heavily on the availability of robust, highly selective stem cell surface markers that facilitate the isolation of stem cells from human tissues. Any subsequent expansion or manipulation of isolated stem cells will also require an intimate knowledge of the mechanisms that regulate these cells, to ensure maintenance of their regenerative capacities and to minimize the risk of introducing undesirable growth traits that could pose health risks for patients. A subclass of leucine-rich repeat-containing G-protein-coupled receptor (Lgr) proteins has recently gained prominence as adult stem cell markers with crucial roles in maintaining stem cell functions. Here, we discuss the major impact that their discovery has had on our understanding of adult stem cell biology in various self-renewing tissues and in accelerating progress towards the development of effective stem cell therapies.

Segregation of Two Spectrin Isoforms: Polarized Membrane-binding Sites Direct Polarized Membrane Skeleton Assembly

PubMed Central

Dubreuil, Ronald R.; Maddux, Pratumtip Boontrakulpoontawee; Grushko, Tanya A.; Macvicar, Gary R.

1997-01-01

Spectrin isoforms are often segregated within specialized plasma membrane subdomains where they are thought to contribute to the development of cell surface polarity. It was previously shown that ankyrin and β spectrin are recruited to sites of cell–cell contact in Drosophila S2 cells expressing the homophilic adhesion molecule neuroglian. Here, we show that neuroglian has no apparent effect on a second spectrin isoform (αβH), which is constitutively associated with the plasma membrane in S2 cells. Another membrane marker, the Na,K-ATPase, codistributes with ankyrin and αβ spectrin at sites of neuroglian-mediated contact. The distributions of these markers in epithelial cells in vivo are consistent with the order of events observed in S2 cells. Neuroglian, ankyrin, αβ spectrin, and the Na,K-ATPase colocalize at the lateral domain of salivary gland cells. In contrast, αβH spectrin is sorted to the apical domain of salivary gland and somatic follicle cells. Thus, the two spectrin isoforms respond independently to positional cues at the cell surface: in one case an apically sorted receptor and in the other case a locally activated cell–cell adhesion molecule. The results support a model in which the membrane skeleton behaves as a transducer of positional information within cells. PMID:9348534

Characterization of the corneal surface in limbal stem cell deficiency and after transplantation of cultured allogeneic limbal epithelial cells.

PubMed

Chen, Peng; Zhou, Qingjun; Wang, Junyi; Zhao, Xiaowen; Duan, Haoyun; Wang, Yao; Liu, Ting; Xie, Lixin

2016-09-01

The objective of this study was to characterize the changes that occur in the cornea during Limbal Stem Cell Deficiency (LSCD) and on the corneal surface after transplantation of ex vivo cultured allogeneic limbal epithelial transplantation (CALET). Forty-one pannus were analyzed to characterize the changes found in the cornea in LSCD. Nineteen impression cytology samples, including 14 pannus and five corneal buttons, obtained during subsequent procedures from patients who had undergone CALET were examined to assess the effect of CALET and to determine the long-term fate of donor cells. The presence of donor and recipient epithelial cells in each sample was determined by short tandem repeat (STR) amplification and fluorescent-multiplex polymerase chain reaction (PCR). Phenotypic analysis of the epithelium was performed by immunohistochemistry and real-time PCR. The expression of lineage markers was similar between pannus and conjunctivae, but not to corneas. Objective long-term benefits from the transplantation were recorded in most cases. After CALET, the lineage markers in the excised corneal buttons and pannus showed a limbus phenotype. DNA analysis of the 19 cases showed no donor cells present on the ocular surface beyond three months after CALET. LSCD was characterized by ingrowth of abnormal, inflamed tissue with a conjunctival phenotype. CALET was a useful technique for restoring the ocular surface in LSCD. However, such benefits did not necessarily correlate with survival of measurable numbers of donor cells on the ocular surface. The absence of donor DNA beyond three months raises questions regarding the period of ongoing immunosuppression and the origin of the regenerated corneal epithelium.

High-Resolution FRET Microscopy of Cholera Toxin B-Subunit and GPI-anchored Proteins in Cell Plasma Membranes

PubMed Central

Kenworthy, Anne K.; Petranova, Nadezda; Edidin, Michael

2000-01-01

“Lipid rafts” enriched in glycosphingolipids (GSL), GPI-anchored proteins, and cholesterol have been proposed as functional microdomains in cell membranes. However, evidence supporting their existence has been indirect and controversial. In the past year, two studies used fluorescence resonance energy transfer (FRET) microscopy to probe for the presence of lipid rafts; rafts here would be defined as membrane domains containing clustered GPI-anchored proteins at the cell surface. The results of these studies, each based on a single protein, gave conflicting views of rafts. To address the source of this discrepancy, we have now used FRET to study three different GPI-anchored proteins and a GSL endogenous to several different cell types. FRET was detected between molecules of the GSL GM1 labeled with cholera toxin B-subunit and between antibody-labeled GPI-anchored proteins, showing these raft markers are in submicrometer proximity in the plasma membrane. However, in most cases FRET correlated with the surface density of the lipid raft marker, a result inconsistent with significant clustering in microdomains. We conclude that in the plasma membrane, lipid rafts either exist only as transiently stabilized structures or, if stable, comprise at most a minor fraction of the cell surface. PMID:10793141

Niche matters: The comparison between bone marrow stem cells and endometrial stem cells and stromal fibroblasts reveal distinct migration and cytokine profiles in response to inflammatory stimulus

PubMed Central

Sorjamaa, Anna; Kangasniemi, Marika; Sutinen, Meeri; Salo, Tuula; Liakka, Annikki; Lehenkari, Petri; Tapanainen, Juha S.; Vuolteenaho, Olli; Chen, Joseph C.; Lehtonen, Siri; Piltonen, Terhi T.

2017-01-01

Objective Intrinsic inflammatory characteristics play a pivotal role in stem cell recruitment and homing through migration where the subsequent change in niche has been shown to alter these characteristics. The bone marrow mesenchymal stem cells (bmMSCs) have been demonstrated to migrate to the endometrium contributing to the stem cell reservoir and regeneration of endometrial tissue. Thus, the aim of the present study was to compare the inflammation-driven migration and cytokine secretion profile of human bmMSCs to endometrial mesenchymal stem cells (eMSCs) and endometrial fibroblasts (eSFs). Materials and methods The bmMSCs were isolated from bone marrow aspirates through culturing, whereas eMSCs and eSFs were FACS-isolated. All cell types were tested for their surface marker, proliferation profiles and migration properties towards serum and inflammatory attractants. The cytokine/chemokine secretion profile of 35 targets was analysed in each cell type at basal level along with lipopolysaccharide (LPS)-induced state. Results Both stem cell types, bmMSCs and eMSCs, presented with similar stem cell surface marker profiles as well as possessed high proliferation and migration potential compared to eSFs. In multiplex assays, the secretion of 16 cytokine targets was detected and LPS stimulation expanded the cytokine secretion pattern by triggering the secretion of several targets. The bmMSCs exhibited higher cytokine secretion of vascular endothelial growth factor (VEGF)-A, stromal cell-derived factor-1 alpha (SDF)-1α, interleukin-1 receptor antagonist (IL-1RA), IL-6, interferon-gamma inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)1α and RANTES compared to eMSCs and/or eSFs after stimulation with LPS. The basal IL-8 secretion was higher in both endometrial cell types compared to bmMSCs. Conclusion Our results highlight that similar to bmMSCs, the eMSCs possess high migration activity while the differentiation process towards stromal fibroblasts seemed to result in loss of stem cell surface markers, minimal migration activity and a subtler cytokine profile likely contributing to normal endometrial function. PMID:28419140

Isolation of circulating tumor cells from pancreatic cancer by automated filtration

PubMed Central

Brychta, Nora; Drosch, Michael; Driemel, Christiane; Fischer, Johannes C.; Neves, Rui P.; Esposito, Irene; Knoefel, Wolfram; Möhlendick, Birte; Hille, Claudia; Stresemann, Antje; Krahn, Thomas; Kassack, Matthias U.; Stoecklein, Nikolas H.; von Ahsen, Oliver

2017-01-01

It is now widely recognized that the isolation of circulating tumor cells based on cell surface markers might be hindered by variability in their protein expression. Especially in pancreatic cancer, isolation based only on EpCAM expression has produced very diverse results. Methods that are independent of surface markers and therefore independent of phenotypical changes in the circulating cells might increase CTC recovery also in pancreatic cancer. We compared an EpCAM-dependent (IsoFlux) and a size-dependent (automated Siemens Healthineers filtration device) isolation method for the enrichment of pancreatic cancer CTCs. The recovery rate of the filtration based approach is dramatically superior to the EpCAM-dependent approach especially for cells with low EpCAM-expression (filtration: 52%, EpCAM-dependent: 1%). As storage and shipment of clinical samples is important for centralized analyses, we also evaluated the use of frozen diagnostic leukapheresis (DLA) as source for isolating CTCs and subsequent genetic analysis such as KRAS mutation detection analysis. Using frozen DLA samples of pancreatic cancer patients we detected CTCs in 42% of the samples by automated filtration. PMID:29156783

Isolation of circulating tumor cells from pancreatic cancer by automated filtration.

PubMed

Brychta, Nora; Drosch, Michael; Driemel, Christiane; Fischer, Johannes C; Neves, Rui P; Esposito, Irene; Knoefel, Wolfram; Möhlendick, Birte; Hille, Claudia; Stresemann, Antje; Krahn, Thomas; Kassack, Matthias U; Stoecklein, Nikolas H; von Ahsen, Oliver

2017-10-17

It is now widely recognized that the isolation of circulating tumor cells based on cell surface markers might be hindered by variability in their protein expression. Especially in pancreatic cancer, isolation based only on EpCAM expression has produced very diverse results. Methods that are independent of surface markers and therefore independent of phenotypical changes in the circulating cells might increase CTC recovery also in pancreatic cancer. We compared an EpCAM-dependent (IsoFlux) and a size-dependent (automated Siemens Healthineers filtration device) isolation method for the enrichment of pancreatic cancer CTCs. The recovery rate of the filtration based approach is dramatically superior to the EpCAM-dependent approach especially for cells with low EpCAM-expression (filtration: 52%, EpCAM-dependent: 1%). As storage and shipment of clinical samples is important for centralized analyses, we also evaluated the use of frozen diagnostic leukapheresis (DLA) as source for isolating CTCs and subsequent genetic analysis such as KRAS mutation detection analysis. Using frozen DLA samples of pancreatic cancer patients we detected CTCs in 42% of the samples by automated filtration.

Quaternary FeCoNiMn-Based Nanocarbon Electrocatalysts for Bifunctional Oxygen Reduction and Evolution: Promotional Role of Mn Doping in Stabilizing Carbon

DOE PAGES

Gupta, Shiva; Zhao, Shuai; Wang, Xiao Xia; ...

2017-10-31

The intrinsic instability of carbon largely limits its use for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as a bifunctional catalyst in reversible fuel cells or water electrolyzers. In this paper, we discovered that Mn doping has a promotional role in stabilizing nanocarbon catalysts for the ORR/OER in alkaline media. Stable nanocarbon composites are derived from an inexpensive carbon/nitrogen precursor (i.e., dicyandiamide) and quaternary FeCoNiMn alloy via a template-free carbonization process. In addition to FeCoNiMn metal alloys/oxides, the carbon composites comprise substantial carbon tube forests growing on a thick and dense graphitic substrate. The dense carbon substratemore » with high degree of graphitization results from Mn doping, while active nitrogen-doped carbon tubes stem from FeCoNi. Catalyst structures and performance are greatly dependent on the doping content of Mn. Various accelerated stress tests (AST) and life tests verify the encouraging ORR/OER stability of the nanocarbon composite catalyst with optimal Mn doping. Extensive characterization before and after ASTs elucidates the mechanism of stability enhancement resulting from Mn doping, which is attributed to (i) hybrid carbon nanostructures with enhanced resistance to oxidation and (ii) the in situ formation of the β-MnO 2 and FeCoNi-based oxides capable of preventing carbon corrosion and promoting activity. Note that the improvement in stability due to Mn doping is accompanied by a slight activity loss due to a decrease in surface area. Finally, this work provides a strategy to stabilize carbon catalysts by appropriately integrating transition metals and engineering carbon structures.« less

Quaternary FeCoNiMn-Based Nanocarbon Electrocatalysts for Bifunctional Oxygen Reduction and Evolution: Promotional Role of Mn Doping in Stabilizing Carbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Shiva; Zhao, Shuai; Wang, Xiao Xia

The intrinsic instability of carbon largely limits its use for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) as a bifunctional catalyst in reversible fuel cells or water electrolyzers. In this paper, we discovered that Mn doping has a promotional role in stabilizing nanocarbon catalysts for the ORR/OER in alkaline media. Stable nanocarbon composites are derived from an inexpensive carbon/nitrogen precursor (i.e., dicyandiamide) and quaternary FeCoNiMn alloy via a template-free carbonization process. In addition to FeCoNiMn metal alloys/oxides, the carbon composites comprise substantial carbon tube forests growing on a thick and dense graphitic substrate. The dense carbon substratemore » with high degree of graphitization results from Mn doping, while active nitrogen-doped carbon tubes stem from FeCoNi. Catalyst structures and performance are greatly dependent on the doping content of Mn. Various accelerated stress tests (AST) and life tests verify the encouraging ORR/OER stability of the nanocarbon composite catalyst with optimal Mn doping. Extensive characterization before and after ASTs elucidates the mechanism of stability enhancement resulting from Mn doping, which is attributed to (i) hybrid carbon nanostructures with enhanced resistance to oxidation and (ii) the in situ formation of the β-MnO 2 and FeCoNi-based oxides capable of preventing carbon corrosion and promoting activity. Note that the improvement in stability due to Mn doping is accompanied by a slight activity loss due to a decrease in surface area. Finally, this work provides a strategy to stabilize carbon catalysts by appropriately integrating transition metals and engineering carbon structures.« less

Cell type specific gene expression analysis of prostate needle biopsies resolves tumor tissue heterogeneity

PubMed Central

Krönig, Malte; Walter, Max; Drendel, Vanessa; Werner, Martin; Jilg, Cordula A.; Richter, Andreas S.; Backofen, Rolf; McGarry, David; Follo, Marie; Schultze-Seemann, Wolfgang; Schüle, Roland

2015-01-01

A lack of cell surface markers for the specific identification, isolation and subsequent analysis of living prostate tumor cells hampers progress in the field. Specific characterization of tumor cells and their microenvironment in a multi-parameter molecular assay could significantly improve prognostic accuracy for the heterogeneous prostate tumor tissue. Novel functionalized gold-nano particles allow fluorescence-based detection of absolute mRNA expression levels in living cells by fluorescent activated flow cytometry (FACS). We use of this technique to separate prostate tumor and benign cells in human prostate needle biopsies based on the expression levels of the tumor marker alpha-methylacyl-CoA racemase (AMACR). We combined RNA and protein detection of living cells by FACS to gate for epithelial cell adhesion molecule (EPCAM) positive tumor and benign cells, EPCAM/CD45 double negative mesenchymal cells and CD45 positive infiltrating lymphocytes. EPCAM positive epithelial cells were further sub-gated into AMACR high and low expressing cells. Two hundred cells from each population and several biopsies from the same patient were analyzed using a multiplexed gene expression profile to generate a cell type resolved profile of the specimen. This technique provides the basis for the clinical evaluation of cell type resolved gene expression profiles as pre-therapeutic prognostic markers for prostate cancer. PMID:25514598

Universal Surface-initiated Polymerization of Antifouling Zwitterionic Brushes Using A Mussel-Mimetic Peptide Initiator

PubMed Central

Kuang, Jinghao; Messersmith, Phillip B.

2012-01-01

We report a universal method for the surface-initated polymerization (SIP) of a antifouling polymer brush on various classes of surfaces, including noble metals, metal oxides and inert polymers. Inspired by the versatility of mussel adhesive proteins, we synthesized a novel bifunctional tripeptide bromide (BrYKY) which combines an atom transfer radical polymerization (ATRP) initiating alkyl bromide with l-3,4-dihydroxyphenylalanine (DOPA) and lysine. Simple dip-coating of substrates with variable wetting properties and compositions, including Teflon®, in a BrYKY solution at pH 8.5 led to formation of a thin film of cross-linked BrYKY. Subsequently, we showed that the BrYKY layer initiated the ATRP of a zwitterionic monomer, sulfobetaine methacrylate (SBMA) on all substrates, resulting in high density antifouling pSBMA brushes. Both BrYKY deposition and pSBMA grafting were unambiguously confirmed by ellipsometry, X-ray photoelectron spectroscopy and goniometry. All substrates that were coated with BrYKY/pSBMA dramatically reduced bacterial adhesion for 24 h and also resisted mammalian cell adhesion for at least 4 months, demonstrating the long-term stability of the BrYKY anchoring and antifouling properties of pSBMA. The use of BrYKY as a primer and polymerization initiator has the potential to be widely employed in surface grafted polymer brush modifications for biomedical and other applications. PMID:22506651

Chlorophyll-a analogues conjugated with aminobenzyl-DTPA as potential bifunctional agents for magnetic resonance imaging and photodynamic therapy.

PubMed

Li, Guolin; Slansky, Adam; Dobhal, Mahabeer P; Goswami, Lalit N; Graham, Andrew; Chen, Yihui; Kanter, Peter; Alberico, Ronald A; Spernyak, Joseph; Morgan, Janet; Mazurchuk, Richard; Oseroff, Allan; Grossman, Zachary; Pandey, Ravindra K

2005-01-01

A clinically relevant photosensitizer, 3-devinyl-3-(1-hexyloxyethyl)pyropheophorbide-a (HPPH, a chlorophyll-a derivative), was conjugated with Gd(III)-aminobenzyl-diethylenetriaminepentaacetic acid (DTPA), an experimental magnetic resonance (MR) imaging agent. In vivo reflectance spectroscopy confirmed tumor uptake of HPPH-aminobenzyl-Gd(III)-DTPA conjugate was higher than free HPPH administered intraveneously (iv) to C3H mice with subcutaneously (sc) implanted radiation-induced fibrosarcoma (RIF) tumor cells. In other experiments, Sprague-Dawley (SD) rats with sc implanted Ward Colon Carcinoma cells yielded markedly increased MR signal intensities from tumor regions-of-interest (ROIs) 24 h post-iv injection of HPPH-aminobenzyl-Gd(III)-DTPA conjugate as compared to unconjugated HPPH. In both in vitro (RIF tumor cells) and in vivo (mice bearing RIF tumors and rats bearing Ward Colon tumors) the conjugate produced significant increases in tumor conspicuity at 1.5 T and retained therapeutic efficacy following PDT. Also synthesized were a series of novel bifunctional agents containing two Gd(III) atoms per HPPH molecule that remained tumor-avid and PDT-active and yielded improved MR tumor conspicuity compared to their corresponding mono-Gd(III) analogues. Administered iv at a MR imaging dose of 10 micromol/kg, these conjugates produced severe skin phototoxicity. However, by replacing the hexyl group of the pyropheophorbide-a with a tri(ethylene glycol) monomethyl ether (PEG-methyl ether), these conjugates produced remarkable MR tumor enhancement at 8 h post-iv injection, significant tumoricidal activity (80% of mice were tumor-free on day 90), and reduced skin phototoxicity compared to their corresponding hexyl ether analogues. The poor water-solubility characteristic of these conjugates was resolved by incorporation into a liposomal formulation. This paper presents the synthesis of tumor-avid contrast enhancing agents for MR imaging and thus represents an important milestone toward improving cancer diagnosis and tumor characterization. More importantly, this paper describes a new family of bifunctional agents that combine two modalities into a single cost-effective "see and treat" approach, namely, a single agent that can be used for contrast agent-enhanced MR imaging followed by targeted photodynamic therapy.

Production of a Recombinant Antibody Specific for i Blood Group Antigen, a Mesenchymal Stem Cell Marker

PubMed Central

Suila, Heli; Tiitinen, Sari; Natunen, Suvi; Laukkanen, Marja-Leena; Kotovuori, Annika; Reinman, Mirka; Satomaa, Tero; Alfthan, Kaija; Laitinen, Saara; Takkinen, Kristiina; Räbinä, Jarkko; Valmu, Leena

2013-01-01

Abstract Multipotent mesenchymal stem/stromal cells (MSCs) offer great promise for future regenerative and anti-inflammatory therapies. Panels of functional and phenotypical markers are currently used in characterization of different therapeutic stem cell populations from various sources. The i antigen (linear poly-N-acetyllactosamine) from the Ii blood group system has been suggested as a marker for MSCs derived from umbilical cord blood (UCB). However, there are currently no commercially available antibodies recognizing the i antigen. In the present study, we describe the use of antibody phage display technology to produce recombinant antibodies recognizing a structure from the surface of mesenchymal stem cells. We constructed IgM phage display libraries from the lymphocytes of a donor with an elevated serum anti-i titer. Antibody phage display technology is not dependent on immunization and thus allows the generation of antibodies against poorly immunogenic molecules, such as carbohydrates. Agglutination assays utilizing i antigen–positive red blood cells (RBCs) from UCB revealed six promising single-chain variable fragment (scFv) antibodies, three of which recognized epitopes from the surface of UCB-MSCs in flow cytometric assays. The amino acid sequence of the VH gene segment of B12.2 scFv was highly similar to the VH4.21 gene segment required to encode anti-i specificities. Further characterization of binding properties revealed that the binding of B12.2 hyperphage was inhibited by soluble linear lactosamine oligosaccharide. Based on these findings, we suggest that the B12.2 scFv we have generated is a prominent anti-i antibody that recognizes i antigen on the surface of both UCB-MSCs and RBCs. This binder can thus be utilized in UCB-MSC detection and isolation as well as in blood group serology. PMID:24083089

Regulatory role of hexosamine biosynthetic pathway on hepatic cancer stem cell marker CD133 under low glucose conditions

NASA Astrophysics Data System (ADS)

Lin, Shu-Hai; Liu, Tengfei; Ming, Xiaoyan; Tang, Zhi; Fu, Li; Schmitt-Kopplin, Philippe; Kanawati, Basem; Guan, Xin-Yuan; Cai, Zongwei

2016-02-01

Cancer was hypothesized to be driven by cancer stem cells (CSCs), but the metabolic determinants of CSC-like phenotype still remain elusive. Here, we present that hexosamine biosynthetic pathway (HBP) at least in part rescues cancer cell fate with inactivation of glycolysis. Firstly, metabolomic analysis profiled cellular metabolome in CSCs of hepatocellular carcinoma using CD133 cell-surface marker. The metabolic signatures of CD133-positive subpopulation compared to CD133-negative cells highlighted HBP as one of the distinct metabolic pathways, prompting us to uncover the role of HBP in maintenance of CSC-like phenotype. To address this, CSC-like phenotypes and cell survival were investigated in cancer cells under low glucose conditions. As a result, HBP inhibitor azaserine reduced CD133-positive subpopulation and CD133 expression under high glucose condition. Furthermore, treatment of N-Acetylglucosamine in part restores CD133-positive subpopulation when either 2.5 mM glucose in culture media or glycolytic inhibitor 2-deoxy-D-glucose in HCC cell lines was applied, enhancing CD133 expression as well as promoting cancer cell survival. Together, HBP might be a key metabolic determinant in the functions of hepatic CSC marker CD133.

Obesity Determines the Immunophenotypic Profile and Functional Characteristics of Human Mesenchymal Stem Cells From Adipose Tissue

PubMed Central

Pachón-Peña, Gisela; Serena, Carolina; Ejarque, Miriam; Petriz, Jordi; Duran, Xevi; Oliva-Olivera, W.; Simó, Rafael; Tinahones, Francisco J.

2016-01-01

Adipose tissue is a major source of mesenchymal stem cells (MSCs), which possess a variety of properties that make them ideal candidates for regenerative and immunomodulatory therapies. Here, we compared the immunophenotypic profile of human adipose-derived stem cells (hASCs) from lean and obese individuals, and explored its relationship with the apparent altered plasticity of hASCs. We also hypothesized that persistent hypoxia treatment of cultured hASCs may be necessary but not sufficient to drive significant changes in mature adipocytes. hASCs were obtained from subcutaneous adipose tissue of healthy, adult, female donors undergoing abdominal plastic surgery: lean (n = 8; body mass index [BMI]: 23 ± 1 kg/m2) and obese (n = 8; BMI: 35 ± 5 kg/m2). Cell surface marker expression, proliferation and migration capacity, and adipogenic differentiation potential of cultured hASCs at two different oxygen conditions were studied. Compared with lean-derived hASCs, obese-derived hASCs demonstrated increased proliferation and migration capacity but decreased lipid droplet accumulation, correlating with a higher expression of human leukocyte antigen (HLA)-II and cluster of differentiation (CD) 106 and lower expression of CD29. Of interest, adipogenic differentiation modified CD106, CD49b, HLA-ABC surface protein expression, which was dependent on the donor’s BMI. Additionally, low oxygen tension increased proliferation and migration of lean but not obese hASCs, which correlated with an altered CD36 and CD49b immunophenotypic profile. In summary, the differences observed in proliferation, migration, and differentiation capacity in obese hASCs occurred in parallel with changes in cell surface markers, both under basal conditions and during differentiation. Therefore, obesity is an important determinant of stem cell function independent of oxygen tension. Significance The obesity-related hypoxic environment may have latent effects on human adipose tissue-derived mesenchymal stem cells (hASCs) with potential consequences in mature cells. This study explores the immunophenotypic profile of hASCs obtained from lean and obese individuals and its potential relationship with the altered plasticity of hASCs observed in obesity. In this context, an altered pattern of cell surface marker expression in obese-derived hASCs in both undifferentiated and differentiated stages is demonstrated. Differences in proliferation, migration, and differentiation capacity of hASCs from obese adipose tissue correlated with alterations in cell surface expression. Remarkably, altered plasticity observed in obese-derived hASCs was maintained in the absence of hypoxia, suggesting that these cells might be obesity conditioned. PMID:26956208

Nanosheet Supported Single-Metal Atom Bifunctional Catalyst for Overall Water Splitting.

PubMed

Ling, Chongyi; Shi, Li; Ouyang, Yixin; Zeng, Xiao Cheng; Wang, Jinlan

2017-08-09

Nanosheet supported single-atom catalysts (SACs) can make full use of metal atoms and yet entail high selectivity and activity, and bifunctional catalysts can enable higher performance while lowering the cost than two separate unifunctional catalysts. Supported single-atom bifunctional catalysts are therefore of great economic interest and scientific importance. Here, on the basis of first-principles computations, we report a design of the first single-atom bifunctional eletrocatalyst, namely, isolated nickel atom supported on β 12 boron monolayer (Ni 1 /β 12 -BM), to achieve overall water splitting. This nanosheet supported SAC exhibits remarkable electrocatalytic performance with the computed overpotential for oxygen/hydrogen evolution reaction being just 0.40/0.06 V. The ab initio molecular dynamics simulation shows that the SAC can survive up to 800 K elevated temperature, while enacting a high energy barrier of 1.68 eV to prevent isolated Ni atoms from clustering. A viable experimental route for the synthesis of Ni 1 /β 12 -BM SAC is demonstrated from computer simulation. The desired nanosheet supported single-atom bifunctional catalysts not only show great potential for achieving overall water splitting but also offer cost-effective opportunities for advancing clean energy technology.

Drug screens based on the newly found role of dystroglycan proteolysis and restoration of dystroglycan function thereof

DOEpatents

Bissell, Mina J.; Muschler, John L.

2010-02-23

The present invention provides methods and compositions for the diagnosis and treatment of cells lacking normal growth arresting characteristic. The present invention demonstrates that many tumor cells lack normal cell surface .alpha.-dystroglycan and thereby lack dystroglycan function. Dystroglycan can be lost from the cell surface by proteolytic shedding of a fragment of .alpha.-dystroglycan into the surrounding medium. Upon restoration of dystroglycan function and over-expression of the dystroglycan gene, the once tumorigenic cells revert to non-tumorigenic cells which polarize and arrest cell growth in the presence of basement membrane proteins, demonstrating that dystroglycan functions as a tumor marker and suppressor.

Discovery of novel differentiation markers in the early stage of chondrogenesis by glycoform-focused reverse proteomics and genomics.

PubMed

Ishihara, Takeshi; Kakiya, Kiyoshi; Takahashi, Koji; Miwa, Hiroto; Rokushima, Masatomo; Yoshinaga, Tomoyo; Tanaka, Yoshikazu; Ito, Takaomi; Togame, Hiroko; Takemoto, Hiroshi; Amano, Maho; Iwasaki, Norimasa; Minami, Akio; Nishimura, Shin-Ichiro

2014-01-01

Osteoarthritis (OA) is one of the most common chronic diseases among adults, especially the elderly, which is characterized by destruction of the articular cartilage. Despite affecting more than 100 million individuals all over the world, therapy is currently limited to treating pain, which is a principal symptom of OA. New approaches to the treatment of OA that induce regeneration and repair of cartilage are strongly needed. To discover potent markers for chondrogenic differentiation, glycoform-focused reverse proteomics and genomics were performed on the basis of glycoblotting-based comprehensive approach. Expression levels of high-mannose type N-glycans were up-regulated significantly at the late stage of differentiation of the mouse chondroprogenitor cells. Among 246 glycoproteins carrying this glycotype identified by ConA affinity chromatography and LC/MS, it was demonstrated that 52% are classified as cell surface glycoproteins. Gene expression levels indicated that mRNAs for 15 glycoproteins increased distinctly in the earlier stages during differentiation compared with Type II collagen. The feasibility of mouse chondrocyte markers in human chondrogenesis model was demonstrated by testing gene expression levels of these 15 glycoproteins during differentiation in human mesenchymal stem cells. The results showed clearly an evidence of up-regulation of 5 genes, ectonucleotide pyrophosphatase/phosphodiesterase family member 1, collagen alpha-1(III) chain, collagen alpha-1(XI) chain, aquaporin-1, and netrin receptor UNC5B, in the early stages of differentiation. These cell surface 5 glycoproteins become highly sensitive differentiation markers of human chondrocytes that contribute to regenerative therapies, and development of novel therapeutic reagents. © 2013.

Development of Novel Bifunctional Compounds That Induce Apoptosis in Prostate Cancer Cells

DTIC Science & Technology

2009-03-01

amol 14C/Ag DNA 11h adducts/106 DNA bases amol 14C/Ag DNA 11h adducts/106 DNA bases 1 51 F 5 1.7 F 0.2 4.1 F 1.4 0.14 F 0.05 2 52 F 9 1.7 F 0.3 6.3 F...adduct per million DNA bases was found in LNCaP cells after a 4-hour exposure to 2.5 Amol/L 11h-dichloro in culture. A single dose of 50 mg/kg 11h

The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is necessary for ethanol production in Clostridium thermocellum and Thermoanaerobacterium saccharolyticum.

PubMed

Lo, Jonathan; Zheng, Tianyong; Hon, Shuen; Olson, Daniel G; Lynd, Lee R

2015-04-01

Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are anaerobic thermophilic bacteria being investigated for their ability to produce biofuels from plant biomass. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is present in these bacteria and has been known to be important for ethanol formation in other anaerobic alcohol producers. This study explores the inactivation of the adhE gene in C. thermocellum and T. saccharolyticum. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In both adhE deletion strains, fermentation products shifted from ethanol to lactate production and resulted in lower cell density and longer time to reach maximal cell density. In T. saccharolyticum, the adhE deletion strain lost >85% of alcohol dehydrogenase (ADH) activity. Aldehyde dehydrogenase (ALDH) activity did not appear to be affected, although ALDH activity was low in cell extracts. Adding ubiquinone-0 to the ALDH assay increased activity in the T. saccharolyticum parent strain but did not increase activity in the adhE deletion strain, suggesting that ALDH activity was inhibited. In C. thermocellum, the adhE deletion strain lost >90% of ALDH and ADH activity in cell extracts. The C. thermocellum adhE deletion strain contained a point mutation in the lactate dehydrogenase gene, which appears to deregulate its activation by fructose 1,6-bisphosphate, leading to constitutive activation of lactate dehydrogenase. Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are bacteria that have been investigated for their ability to produce biofuels from plant biomass. They have been engineered to produce higher yields of ethanol, yet questions remain about the enzymes responsible for ethanol formation in these bacteria. The genomes of these bacteria encode multiple predicted aldehyde and alcohol dehydrogenases which could be responsible for alcohol formation. This study explores the inactivation of adhE, a gene encoding a bifunctional alcohol and aldehyde dehydrogenase. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In strains without adhE, we note changes in biochemical activity, product formation, and growth. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

PSMA-Targeted Nano-Conjugates as Dual-Modality (MRI/PET) Imaging Probes for the Non-Invasive Detection of Prostate Cancer

DTIC Science & Technology

2009-10-01

be made. Currently, iodine based compounds are used to enhance contrast of CT which have the limitations of short imaging window due to rapid...number compared to conventionally used iodine compounds . Nanoparticle based CT contrast agents have been demonstrated for vascular imaging, which...constructs with gamma or positron emitting isotopes through a covalent attachment of a bifunctional chelator to the nanoparticles surface. However, in

Structural basis for bifunctional peptide recognition at human δ-opioid receptor

DOE PAGES

Fenalti, Gustavo; Zatsepin, Nadia A.; Betti, Cecilia; ...

2015-02-16

Bi-functional μ- and δ- opioid receptor (OR) ligands are potential therapeutic alternatives to alkaloid opiate analgesics with diminished side effects. We solved the structure of human δ-OR bound to the bi-functional δ-OR antagonist and μ-OR agonist tetrapeptide H-Dmt-Tic-Phe-Phe-NH 2 (DIPP-NH 2) by serial femtosecond crystallography, revealing a cis-peptide bond between H-Dmt and Tic. In summary, the observed receptor-peptide interactions are critical to understand the pharmacological profiles of opioid peptides, and to develop improved analgesics.

Opioid bifunctional ligands from morphine and the opioid pharmacophore Dmt-Tic.

PubMed

Balboni, Gianfranco; Salvadori, Severo; Marczak, Ewa D; Knapp, Brian I; Bidlack, Jean M; Lazarus, Lawrence H; Peng, Xuemei; Si, Yu Gui; Neumeyer, John L

2011-02-01

Bifunctional ligands containing an ester linkage between morphine and the δ-selective pharmacophore Dmt-Tic were synthesized, and their binding affinity and functional bioactivity at the μ, δ and κ opioid receptors determined. Bifunctional ligands containing or not a spacer of β-alanine between the two pharmacophores lose the μ agonism deriving from morphine becoming partial μ agonists 4 or μ antagonists 5. Partial κ agonism is evidenced only for compound 4. Finally, both compounds showed potent δ antagonism. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

NiFe layered double hydroxide/reduced graphene oxide nanohybrid as an efficient bifunctional electrocatalyst for oxygen evolution and reduction reactions

NASA Astrophysics Data System (ADS)

Zhan, Tianrong; Zhang, Yumei; Liu, Xiaolin; Lu, SiSi; Hou, Wanguo

2016-11-01

Highly active and low-cost bifunctional electrocatalysts for oxygen evolution and reduction reactions (OER and ORR) hold a heart position for the renewable energy technologies such as metal-air batteries and fuel cells. Here, we reported the synthesis of NiFe layered double hydroxide/reduced graphene oxide (NiFe-LDH/rGO) nanohybrid via the facile solvothermal method followed by chemical reduction. The template role of surfactant and the hybridization of rGO supplied the NiFe-LDH/rGO catalyst with a porous nanostructure and an enhanced conductivity, favoring both mass transport and charge communication of electrocatalytic reactions. The NiFe-LDH/rGO composite not only displayed highly efficient OER activity in alkaline solution with a low onset overpotential of 240 mV, but also only needed an overpotential of 250 mV to reach the 10 mA cm-2 current density. The NiFe-LDH/rGO nanohybrid also offered excellent ORR catalytic activity with onset potential at 0.796 V in alkaline media. The rotating-disk and rotating-ring-disk electrodes both revealed that the ORR on NiFe-LDH/rGO mainly involved a direct four-electron reaction pathways accompanying part of the two-electron process. The excellent bifunctional activity of the NiFe-LDH/rGO nanohybrid could be attributed to the synergistic effects of rGO and NiFe-LDH components due to the strongly coupled interactions.

Preclinical Biodistribution and Safety Evaluation of a pbi-shRNA STMN1 Lipoplex after Subcutaneous Delivery.

PubMed

Wang, Zhaohui; Jay, Christopher M; Evans, Courtney; Kumar, Padmasini; Phalon, Connor; Rao, Donald D; Senzer, Neil; Nemunaitis, John

2017-02-01

Stathmin-1 (STMN1) is a microtubule-destabilizing protein which is overexpressed in cancer. Its overexpression is associated with poor prognosis and also serves as a predictive marker to taxane therapy. We have developed a proprietary bi-functional shRNA (bi-shRNA) platform to execute RNA interference (RNAi)-mediated gene silencing and a liposome-carrier complex to systemically deliver the pbi-shRNA plasmids. In vitro and in vivo testing demonstrated efficacy and specificity of pbi-shRNA plasmid in targeting STMN1 (Phadke, A. P., Jay, C. M., Wang, Z., Chen, S., Liu, S., Haddock, C., Kumar, P., Pappen, B. O., Rao, D. D., Templeton, N. S., et al. (2011). In vivo safety and antitumor efficacy of bifunctional small hairpin RNAs specific for the human Stathmin 1 oncoprotein. DNA Cell Biol. 30, 715-726.). Biodistribution and toxicology studies in bio-relevant Sprague Dawley rats with pbi-shRNA STMN1 lipoplex revealed that the plasmid DNA was delivered to a broad distribution of organs after a single subcutaneous injection. Specifically, plasmid was detected within the first week using QPCR (threshold 50 copies plasmid/1 µg genomic DNA) at the injection site, lung, spleen, blood, skin, ovary (limited), lymph nodes, and liver. It was not detected in the heart, testis or bone marrow. No plasmid was detected from any organ 30 days after injection. Treatment was well tolerated. Minimal inflammation/erythema was observed at the injection site. Circulating cytokine response was also examined by ELISA. The IL-6 levels were induced within 6 h then declined to the vehicle control level 72 h after the injection. TNFα induction was transiently observed 4 days after the DNA lipoplex treatment. In summary, the pbi-shRNA STMN1 lipoplex was well tolerated and displayed broad distribution after a single subcutaneous injection. The pre-clinical data has been filed to FDA and the pbi-shRNA STMN1 lipoplex is being investigated in a phase I clinical study. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Flow cytometric analysis of cell-surface and intracellular antigens in leukemia diagnosis.

PubMed

Knapp, W; Strobl, H; Majdic, O

1994-12-15

New technology allows highly sensitive flow cytometric detection and quantitative analysis of intracellular antigens in normal and malignant hemopoietic cells. With this technology, the earliest stages of myeloid and lymphoid differentiation can easily and reliably be identified using antibodies directed against (pro-)myeloperoxidase/MPO, CD22 and CD3 antigens, respectively. Particularly for the analysis of undifferentiated acute myeloblastic leukemia (AML) cells, the immunological demonstration of intracellular MPO or its enzymatically inactive proforms is highly relevant, since other myeloid marker molecules such as CD33, CD13, or CDw65 are either not restricted to the granulomonocytic lineage or appear later in differentiation. By combining MPO staining with staining for lactoferrin (LF), undifferentiated cells can be distinguished from the granulomonocytic maturation compartment in bone marrow, since LF is selectively expressed from the myelocyte stage of differentiation onward. The list of informative intracellular antigens to be used in leukemia cell analysis will certainly expand in the near future. One candidate, intracellular CD68, has already been tested by us, and results are presented. Also dealt within this article are surface marker molecules not (as yet) widely used in leukemia cell analysis but with the potential to provide important additional information. Among them are the surface structures CD15, CD15s, CDw65, CD79a (MB-1), CD79b (B29), CD87 (uPA-R), and CD117 (c-kit).

Mpl traffics to the cell surface through conventional and unconventional routes.

PubMed

Cleyrat, Cédric; Darehshouri, Anza; Steinkamp, Mara P; Vilaine, Mathias; Boassa, Daniela; Ellisman, Mark H; Hermouet, Sylvie; Wilson, Bridget S

2014-09-01

Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin (CALR) mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: human erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the endoplasmic reticulum (ER). Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially colocalize with ER-tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants.

PubMed

Santander, Sonia; Alcaine, Clara; Lyahyai, Jaber; Pérez, Maria Angeles; Rodellar, Clementina; Doblaré, Manuel; Ochoa, Ignacio

2012-01-01

Interaction between cells and implant surface is crucial for clinical success. This interaction and the associated surface treatment are essential for achieving a fast osseointegration process. Several studies of different topographical or chemical surface modifications have been proposed previously in literature. The Biomimetic Advanced Surface (BAS) topography is a combination of a shot blasting and anodizing procedure. Macroroughness, microporosity of titanium oxide and Calcium/Phosphate ion deposition is obtained. Human mesenchymal stem cells (hMCSs) response in vitro to this treatment has been evaluated. The results obtained show an improved adhesion capacity and a higher proliferation rate when hMSCs are cultured on treated surfaces. This biomimetic modification of the titanium surface induces the expression of osteblastic differentiation markers (RUNX2 and Osteopontin) in the absence of any externally provided differentiation factor. As a main conclusion, our biomimetic surface modification could lead to a substantial improvement in osteoinduction in titanium alloy implants.

Atomic force microscopy recognition of protein A on Staphylococcus aureus cell surfaces by labelling with IgG-Au conjugates.

PubMed

Tatlybaeva, Elena B; Nikiyan, Hike N; Vasilchenko, Alexey S; Deryabin, Dmitri G

2013-01-01

The labelling of functional molecules on the surface of bacterial cells is one way to recognize the bacteria. In this work, we have developed a method for the selective labelling of protein A on the cell surfaces of Staphylococcus aureus by using nanosized immunogold conjugates as cell-surface markers for atomic force microscopy (AFM). The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG) allowed the visualization, localization and distribution of protein A-IgG complexes on the surface of S. aureus. The selectivity of the labelling method was confirmed in mixtures of S. aureus with Bacillus licheniformis cells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG-Au conjugates to S. aureus was obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing bacteria, which is useful for AFM indication of pathogenic microorganisms in poly-component associations.

Isolation and Characterization of Human Mesenchymal Stem Cells From Facet Joints and Interspinous Ligaments.

PubMed

Kristjánsson, Baldur; Limthongkul, Worawat; Yingsakmongkol, Wicharn; Thantiworasit, Pattarawat; Jirathanathornnukul, Napaphat; Honsawek, Sittisak

2016-01-01

A descriptive in vitro study on isolation and differentiation of human mesenchymal stem cells (MSCs) derived from the facet joints and interspinous ligaments. To isolate cells from the facet joints and interspinous ligaments and investigate their surface marker profile and differentiation potentials. Lumbar spinal canal stenosis and ossification of the posterior longitudinal ligament are progressive conditions characterized by the hypertrophy and ossification of ligaments and joints within the spinal canal. MSCs are believed to play a role in the advancement of these diseases and the existence of MSCs has been demonstrated within the ligamentum flavum and posterior longitudinal ligament. The aim of this study was to investigate whether these cells could also be found within facet joints and interspinous ligaments. Samples were harvested from 10 patients undergoing spinal surgery. The MSCs from facet joints and interspinous ligaments were isolated using direct tissue explant technique. Cell surface antigen profilings were performed via flow cytometry. Their lineage differentiation potentials were analyzed. The facet joints and interspinous ligaments-derived MSCs have the tri-lineage potential to be differentiated into osteogenic, adipogenic, and chondrogenic cells under appropriate inductions. Flow cytometry analysis revealed both cell lines expressed MSCs markers. Both facet joints and interspinous ligaments-derived MSCs expressed marker genes for osteoblasts, adipocytes, and chondrocytes. The facet joints and interspinous ligaments may provide alternative sources of MSCs for tissue engineering applications. The facet joints and interspinous ligaments-derived MSCs are part of the microenvironment of the human ligaments of the spinal column and might play a crucial role in the development and progression of degenerative spine conditions.

Prolymphocytic leukaemia: surface morphology in 21 cases as seen by scanning electron microscopy and comparison with B-type CLL and CLL in 'prolymphocytoid' transformation.

PubMed

Polliack, A; Leizerowitz, R; Berrebi, A; Gamliel, H; Galili, N; Gurfel, D; Catovsky, D

1984-08-01

The surface architecture of leukaemic cells obtained from 21 cases of proven prolymphocytic leukaemia (PLL) and eight cases of chronic lymphocytic leukaemia (CLL) with 'prolymphocytoid' transformation (PL-CLL) was compared with the cell surface morphology of leukaemic cells obtained from 46 cases of B-type CLL, using the scanning electron microscope (SEM). All cases were defined by cytochemistry, immunological markers and transmission electron microscopy prior to SEM examination. B-CLL cells showed the well-recognized spectrum of surface architecture described in earlier studies. The majority of cells had moderate numbers of short microvilli, although in a minority, cells with relatively smooth surfaces predominated. In seven of the eight cases of PL-CLL, cells were villous in nature and in this respect similar to CLL cells; however, more cells with dense microvilli were seen. The prolymphocytic cells were recognized by their larger size and in 18 of the 19 cases of B-derived PLL, villous cells predominated. Two cases of T-derived PLL showed variable cell surface morphology ranging from smooth to moderately villous. It appears that B-PLL cells are most frequently villous and display more surface microvilli than B-CLL cells. B-prolymphocytes display the surface features regarded as characteristic for neoplastic B-cells as seen in patients with B-type lymphoma and leukaemia.

Physical-mechanical image of the cell surface on the base of AFM data in contact mode

NASA Astrophysics Data System (ADS)

Starodubtseva, M. N.; Starodubtsev, I. E.; Yegorenkov, N. I.; Kuzhel, N. S.; Konstantinova, E. E.; Chizhik, S. A.

2017-10-01

Physical and mechanical properties of the cell surface are well-known markers of a cell state. The complex of the parameters characterizing the cell surface properties, such as the elastic modulus (E), the parameters of adhesive (Fa), and friction (Ff) forces can be measured using atomic force microscope (AFM) in a contact mode and form namely the physical-mechanical image of the cell surface that is a fundamental element of the cell mechanical phenotype. The paper aims at forming the physical-mechanical images of the surface of two types of glutaraldehyde-fixed cancerous cells (human epithelial cells of larynx carcinoma, HEp-2c cells, and breast adenocarcinoma, MCF-7 cells) based on the data obtained by AFM in air and revealing the basic difference between them. The average values of friction, elastic and adhesive forces, and the roughness of lateral force maps, as well as dependence of the fractal dimension of lateral force maps on Z-scale factor have been studied. We have revealed that the response of microscale areas of the HEp-2c cell surface having numerous microvilli to external mechanical forces is less expressed and more homogeneous in comparison with the response of MCF-7 cell surface.

Hollow structured carbon-supported nickel cobaltite nanoparticles as an efficient bifunctional electrocatalyst for the oxygen reduction and evolution reaction

DOE PAGES

Wang, Jie; Han, Lili; Lin, Ruoqian; ...

2016-01-05

Here, the exploration of efficient electrocatalysts for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for fuel cells and metal-air batteries. In this study, we developed 3D hollow-structured NiCo 2O 4/C nanoparticles with interconnected pores as bifunctional electrocatalysts, which are transformed from solid NiCo 2 alloy nanoparticles through the Kirkendall effect. The unique hollow structure of NiCo 2O 4 nanoparticles increases the number of active sites and improves contact with the electrolyte to result in excellent ORR and OER performances. In addition, the hollow-structured NiCo 2O 4/C nanoparticles exhibit superior long-term stability for both themore » ORR and OER compared to commercial Pt/C. The template- and surfactant-free synthetic strategy could be used for the low-cost and large-scale synthesis of hollow-structured materials, which would facilitate the screening of high-efficiency catalysts for energy conversion.« less

Development of a Sono-Assembled, Bifunctional Soy Peptide Nanoparticle for Cellular Delivery of Hydrophobic Active Cargoes.

PubMed

Zhang, Yuanhong; Zhao, Mouming; Ning, Zhengxiang; Yu, Shujuan; Tang, Ning; Zhou, Feibai

2018-04-25

Soy proteins are prone to aggregate upon proteolysis, hindering their sustainable development in food processing. Here, a continuous work on the large insoluble peptide aggregates was carried out, aiming to develop a new type of soy peptide-based nanoparticle (SPN) for active cargo delivery. Sono-assembled SPN in spherical appearance and core-shell structure maintained by noncovalent interactions was successfully fabricated, exhibiting small particle size (103.95 nm) in a homogeneous distribution state (PDI = 0.18). Curcumin as a model cargo was efficiently encapsulated into SPN upon sonication, showing high water dispersity (129.6 mg/L, 10 4 higher than its water solubility) and storage stability. Additionally, the pepsin-resistant SPN contributed to the controlled release of curcumin at the intestinal phase and thus significantly improved the bioaccessibility. Encapsulated curcumin was effective in protecting glutamate-induced toxicity in PC12 cells, where the matrix SPN can simultaneously reduce lipid peroxidation and elevate antioxidant enzymes levels, innovatively demonstrating its bifunctionality during cellular delivery.

Co@Co3O4 Encapsulated in Carbon Nanotube-Grafted Nitrogen-Doped Carbon Polyhedra as an Advanced Bifunctional Oxygen Electrode.

PubMed

Aijaz, Arshad; Masa, Justus; Rösler, Christoph; Xia, Wei; Weide, Philipp; Botz, Alexander J R; Fischer, Roland A; Schuhmann, Wolfgang; Muhler, Martin

2016-03-14

Efficient reversible oxygen electrodes for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are vitally important for various energy conversion devices, such as regenerative fuel cells and metal-air batteries. However, realization of such electrodes is impeded by insufficient activity and instability of electrocatalysts for both water splitting and oxygen reduction. We report highly active bifunctional electrocatalysts for oxygen electrodes comprising core-shell Co@Co3O4 nanoparticles embedded in CNT-grafted N-doped carbon-polyhedra obtained by the pyrolysis of cobalt metal-organic framework (ZIF-67) in a reductive H2 atmosphere and subsequent controlled oxidative calcination. The catalysts afford 0.85 V reversible overvoltage in 0.1 m KOH, surpassing Pt/C, IrO2 , and RuO2 and thus ranking them among one of the best non-precious-metal electrocatalysts for reversible oxygen electrodes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Watt-Level Continuous-Wave Emission from a Bifunctional Quantum Cascade Laser/Detector

PubMed Central

2017-01-01

Bifunctional active regions, capable of light generation and detection at the same wavelength, allow a straightforward realization of the integrated mid-infrared photonics for sensing applications. Here, we present a high performance bifunctional device for 8 μm capable of 1 W single facet continuous wave emission at 15 °C. Apart from the general performance benefits, this enables sensing techniques which rely on continuous wave operation, for example, heterodyne detection, to be realized within a monolithic platform and demonstrates that bifunctional operation can be realized at longer wavelength, where wavelength matching becomes increasingly difficult and that the price to be paid in terms of performance is negligible. In laser operation, the device has the same or higher efficiency compared to the best lattice-matched QCLs without same wavelength detection capability, which is only 30% below the record achieved with strained material at this wavelength. PMID:28540324

Nanostructured Perovskite LaCo1-xMnxO3 as Bifunctional Catalysts for Rechargeable Metal-Air Batteries

NASA Astrophysics Data System (ADS)

Ge, Xiaoming; Li, Bing; Wuu, Delvin; Sumboja, Afriyanti; An, Tao; Hor, T. S. Andy; Zong, Yun; Liu, Zhaolin

2015-09-01

Bifunctional catalyst that is active for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is one of the most important components of rechargeable metal-air batteries. Nanostructured perovskite bifunctional catalysts comprising La, Co and Mn(LaCo1-xMnxO3, LCMO) are synthesized by hydrothermal methods. The morphology, structure and electrochemical activity of the perovskite bifunctional catalysts are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and rotating disk electrode (RDE) techniques. Nanorod, nanodisc and nanoparticle are typical morphologies of LCMO. The electrocatalytic activity of LCMO is significantly improved by the addition of conductive materials such as carbon nanotube. To demonstrate the practical utilization, LCMO in the composition of LaCo0.8Mn0.2O3(LCMO82) is used as air cathode catalysts for rechargeable zinc-air batteries. The battery prototype can sustain 470 h or 40 discharge-charge cycles equivalent.

Continuous fabrication of a MnS/Co nanofibrous air electrode for wide integration of rechargeable zinc-air batteries.

PubMed

Wang, Yang; Fu, Jing; Zhang, Yining; Li, Matthew; Hassan, Fathy Mohamed; Li, Guang; Chen, Zhongwei

2017-10-26

Exploring highly efficient bifunctional electrocatalysts toward the oxygen reduction and evolution reactions is essential for the realization of high-performance rechargeable zinc-air batteries. Herein, a novel nanofibrous bifunctional electrocatalyst film, consisting of metallic manganese sulfide and cobalt encapsulated by nitrogen-doped carbon nanofibers (CMS/NCNF), is prepared through a continuous electrospinning method followed by carbonization treatment. The CMS/NCNF bifunctional catalyst shows both comparable ORR and OER performances to those of commercial precious metal-based catalysts. Furthermore, the free-standing CMS/NCNF fibrous thin film is directly used as the air electrode in a solid-state zinc-air battery, which exhibits superior flexibility while retaining stable battery performance at different bending angles. This study provides a versatile design route for the rational design of free-standing bifunctional catalysts for direct use as the air electrode in rechargeable zinc-air batteries.

Scaling-Relation-Based Analysis of Bifunctional Catalysis: The Case for Homogeneous Bimetallic Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, Mie; Medford, Andrew J.; Norskov, Jens K.

Here, we present a generic analysis of the implications of energetic scaling relations on the possibilities for bifunctional gains at homogeneous bimetallic alloy catalysts. Such catalysts exhibit a large number of interface sites, where second-order reaction steps can involve intermediates adsorbed at different active sites. Using different types of model reaction schemes, we show that such site-coupling reaction steps can provide bifunctional gains that allow for a bimetallic catalyst composed of two individually poor catalyst materials to approach the activity of the optimal monomaterial catalyst. However, bifunctional gains cannot result in activities higher than the activity peak of the monomaterialmore » volcano curve as long as both sites obey similar scaling relations, as is generally the case for bimetallic catalysts. These scaling-relation-imposed limitations could be overcome by combining different classes of materials such as metals and oxides.« less

Scaling-Relation-Based Analysis of Bifunctional Catalysis: The Case for Homogeneous Bimetallic Alloys

DOE PAGES

Andersen, Mie; Medford, Andrew J.; Norskov, Jens K.; ...

2017-04-14

Here, we present a generic analysis of the implications of energetic scaling relations on the possibilities for bifunctional gains at homogeneous bimetallic alloy catalysts. Such catalysts exhibit a large number of interface sites, where second-order reaction steps can involve intermediates adsorbed at different active sites. Using different types of model reaction schemes, we show that such site-coupling reaction steps can provide bifunctional gains that allow for a bimetallic catalyst composed of two individually poor catalyst materials to approach the activity of the optimal monomaterial catalyst. However, bifunctional gains cannot result in activities higher than the activity peak of the monomaterialmore » volcano curve as long as both sites obey similar scaling relations, as is generally the case for bimetallic catalysts. These scaling-relation-imposed limitations could be overcome by combining different classes of materials such as metals and oxides.« less

An authentic imaging probe to track cell fate from beginning to end.

PubMed

Lee, Seung Koo; Mortensen, Luke J; Lin, Charles P; Tung, Ching-Hsuan

2014-10-17

Accurate tracing of cell viability is critical for optimizing delivery methods and evaluating the efficacy and safety of cell therapeutics. A nanoparticle-based cell tracker is developed to image cell fate from live to dead. The particle is fabricated from two types of optically quenched polyelectrolytes, a life indicator and a death indicator, through electrostatic interactions. On incubation with cells, the fabricated bifunctional nanoprobes are taken up efficiently and the first colour is produced by normal intracellular proteolysis, reflecting the healthy status of the cells. Depending on the number of coated layers, the signal can persist for several replication cycles. However, as the cells begin dying, the second colour appears quickly to reflect the new cell status. Using this chameleon-like cell tracker, live cells can be distinguished from apoptotic and necrotic cells instantly and definitively.

Grating coupled SPR microarray analysis of proteins and cells in blood from mice with breast cancer.

PubMed

Mendoza, A; Torrisi, D M; Sell, S; Cady, N C; Lawrence, D A

2016-01-21

Biomarker discovery for early disease diagnosis is highly important. Of late, much effort has been made to analyze complex biological fluids in an effort to develop new markers specific for different cancer types. Recent advancements in label-free technologies such as surface plasmon resonance (SPR)-based biosensors have shown promise as a diagnostic tool since there is no need for labeling or separation of cells. Furthermore, SPR can provide rapid, real-time detection of antigens from biological samples since SPR is highly sensitive to changes in surface-associated molecular and cellular interactions. Herein, we report a lab-on-a-chip microarray biosensor that utilizes grating-coupled surface plasmon resonance (GCSPR) and grating-coupled surface plasmon coupled fluorescence (GCSPCF) imaging to detect circulating tumor cells (CTCs) from a mouse model (FVB-MMTV-PyVT). GCSPR and GCSPCF analysis was accomplished by spotting antibodies to surface cell markers, cytokines and stress proteins on a nanofabricated GCSPR microchip and screening blood samples from FVB control mice or FVB-MMTV-PyVT mice with developing mammary carcinomas. A transgenic MMTV-PyVT mouse derived cancer cell line was also analyzed. The analyses indicated that CD24, CD44, CD326, CD133 and CD49b were expressed in both cell lines and in blood from MMTV-PyVT mice. Furthermore, cytokines such as IL-6, IL-10 and TNF-α, along with heat shock proteins HSP60, HSP27, HSc70(HSP73), HSP90 total, HSP70/HSc70, HSP90, HSP70, HSP90 alpha, phosphotyrosine and HSF-1 were overexpressed in MMTV-PyVT mice.

Hypoxic Three-Dimensional Scaffold-Free Aggregate Cultivation of Mesenchymal Stem Cells in a Stirred Tank Reactor.

PubMed

Egger, Dominik; Schwedhelm, Ivo; Hansmann, Jan; Kasper, Cornelia

2017-05-23

Extensive expansion of mesenchymal stem cells (MSCs) for cell-based therapies remains challenging since long-term cultivation and excessive passaging in two-dimensional conditions result in a loss of essential stem cell properties. Indeed, low survival rate of cells, alteration of surface marker profiles, and reduced differentiation capacity are observed after in vitro expansion and reduce therapeutic success in clinical studies. Remarkably, cultivation of MSCs in three-dimensional aggregates preserve stem cell properties. Hence, the large scale formation and cultivation of MSC aggregates is highly desirable. Besides other effects, MSCs cultivated under hypoxic conditions are known to display increased proliferation and genetic stability. Therefore, in this study we demonstrate cultivation of adipose derived human MSC aggregates in a stirred tank reactor under hypoxic conditions. Although aggregates were exposed to comparatively high average shear stress of 0.2 Pa as estimated by computational fluid dynamics, MSCs displayed a viability of 78-86% and maintained their surface marker profile and differentiation potential after cultivation. We postulate that cultivation of 3D MSC aggregates in stirred tank reactors is valuable for large-scale production of MSCs or their secreted compounds after further optimization of cultivation parameters.

Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants

PubMed Central

Yazici, Hilal; O'Neill, Mary B.; Kacar, Turgay; Wilson, Brandon R.; Oren, E. Emre; Sarikaya, Mehmet; Tamerler, Candan

2016-01-01

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property. PMID:26795060

Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants.

PubMed

Yazici, Hilal; O'Neill, Mary B; Kacar, Turgay; Wilson, Brandon R; Oren, E Emre; Sarikaya, Mehmet; Tamerler, Candan

2016-03-02

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property.

In vivo regulation of Bcl6 and T follicular helper cell development1

PubMed Central

Poholek, Amanda C.; Hansen, Kyle; Hernandez, Sairy G.; Eto, Danelle; Chandele, Anmol; Weinstein, Jason S.; Dong, Xuemei; Odegard, Jared M.; Kaech, Susan M.; Dent, Alexander L.; Crotty, Shane; Craft, Joe

2010-01-01

Follicular helper T (TFH) cells, defined by expression of the surface markers CXCR5 and PD-1 and synthesis of IL-21, require upregulation of the transcriptional repressor Bcl6 for their development and function in B cell maturation in germinal centers. We have explored the role of B cells, and the cytokines IL-6 and IL-21, in the in vivo regulation of Bcl6 expression and TFH cell development. We found that TFH cells are characterized by a Bcl6-dependent downregulation of P-selectin glycoprotein ligand-1 (PSGL1, a CCL19- and CCL21-binding protein), indicating that, like CXCR5 and PD-1 upregulation, modulation of PSGL1 expression is part of the TFH cell program of differentiation. B cells were neither required for initial upregulation of Bcl6 nor PSGL1 downregulation, suggesting these events preceded T-B cell interactions, although they were required for full development of the TFH cell phenotype, including CXCR5 and PD-1 upregulation, and IL-21 synthesis. Bcl6 upregulation and TFH cell differentiation were independent of IL-6 and IL-21, revealing that either cytokine is not absolutely required for development of Bcl6+ TFH cells in vivo. These data increase our understanding of Bcl6 regulation in TFH cells and their differentiation in vivo, and identifies a new surface marker that may be functionally relevant in this subset. PMID:20519643

Feeder & basic fibroblast growth factor-free culture of human embryonic stem cells: Role of conditioned medium from immortalized human feeders.

PubMed

Teotia, Pooja; Sharma, Shilpa; Airan, Balram; Mohanty, Sujata

2016-12-01

Human embryonic stem cell (hESC) lines are commonly maintained on inactivated feeder cells, in the medium supplemented with basic fibroblast growth factor (bFGF). However, limited availability of feeder cells in culture, and the high cost of growth factors limit their use in scalable expansion of hESC cultures for clinical application. Here, we describe an efficient and cost-effective feeder and bFGF-free culture of hESCs using conditioned medium (CM) from immortalized feeder cells. KIND-1 hESC cell line was cultured in CM, collected from primary mouse embryonic fibroblast, human foreskin fibroblast (HFF) and immortalized HFF (I-HFF). Pluripotency of KIND-1 hESC cell line was confirmed by expression of genes, proteins and cell surface markers. In culture, these cells retained normal morphology, expressed all cell surface markers, could differentiate to embryoid bodies upon culture in vitro. Furthermore, I-HFF feeder cells without supplementation of bFGF released ample amount of endogenous bFGF to maintain stemness of hESC cells. The study results described the use of CM from immortalized feeder cells as a consistent source and an efficient, inexpensive feeder-free culture system for the maintenance of hESCs. Moreover, it was possible to maintain hESCs without exogenous supplementation of bFGF. Thus, the study could be extended to scalable expansion of hESC cultures for therapeutic purposes.

Design and validation of a low cost surface plasmon resonance bioanalyzer using microprocessors and a touch-screen monitor.

PubMed

Hu, Jiandong; Hu, Jingfang; Luo, Fukun; Li, Wei; Jiang, Guoliang; Li, Zhengfeng; Zhang, Runna

2009-03-15

An economical and high-performance bioanalyzer, with no use of laptop computer, based on the use of TSPR1k23 biosensors was systematically designed, and validated experimentally for its high performance. The analyzer is composed of a micro-flow cell, a thermoelectric cooler (TEC), a clamp, a touch-screen monitor, and an electronic control unit (ECU) incorporated with photoelectric conversion device. The micro-flow cell is made of stainless steel with high thermal conductivity, and the micro-flow system is based on PID temperature-controlled algorithm to keep the constant temperature (25 degrees C) of the liquid sample via thermal exchange with the clamp. With a peristaltic pump implemented by an injection loop flow system, the bioanalyzer allows the core sensor to be completely exposed to samples. The touch-screen monitor displays the normalized response signal values updated every 0.25s, with a typical noise level less than 5RU (response unit) within 2h. The bioanalyzer was validated using hepatitis B surface antigen (HBsAg) as an example. Anti-HBsAg monoclonal antibody is adhered to the surface of the sensor chip by a bifunctional cross-linker with the technology of self-assembly. The duration of the HBsAg measurement only lasts 5min with a dilution factor ranging from 200 to 1200, optimized with a R-squared value 0.998. The results suggested that the bioanalyzer has higher selectivity, lower cost, expanded detection limit, and shorter measuring time as compared with the HBsAg ELISA kit, especially for low concentrations of analyte.

Failure of in vitro-differentiated mesenchymal stem cells from the synovial membrane to form ectopic stable cartilage in vivo.

PubMed

De Bari, Cosimo; Dell'Accio, Francesco; Luyten, Frank P

2004-01-01

We previously reported the identification in a nude mouse assay of molecular markers predictive of the capacity of articular cartilage-derived cells (ACDCs) to form ectopic stable cartilage that is resistant to vascular invasion and endochondral ossification. In the present study, we investigated whether in vitro-differentiated mesenchymal stem cells (MSCs) from the synovial membrane (SM) express the stable-chondrocyte markers and form ectopic stable cartilage in vivo. Chondrogenesis was induced in micromass culture with the addition of transforming growth factor beta1 (TGFbeta1). After acquisition of the cartilage phenotype, micromasses were implanted subcutaneously into nude mice. Alternatively, cells were released enzymatically and either replated in monolayer or injected intramuscularly into nude mice. Marker analysis was performed by quantitative reverse transcription-polymerase chain reaction. Cell death was detected with TUNEL assay. Cartilage-like micromasses and released cells expressed the stable-chondrocyte markers at levels comparable with those expressed by stable ACDCs. The released cells lost chondrocyte marker expression by 24 hours in monolayer and failed to form cartilage when injected intramuscularly into nude mice. Instead, myogenic differentiation was detected. When intact TGFbeta1-treated micromasses were implanted subcutaneously, they partially lost their cartilage phenotype and underwent cell death and neoangiogenesis within 1 week. At later time points (15-40 days), we retrieved neither cartilage nor bone, and human cells were not detectable. The chondrocyte-like phenotype of human SM MSCs, induced in vitro under specific conditions, appears to be unstable and is not sufficient to obtain ectopic formation of stable cartilage in vivo. Studies in animal models of joint surface defect repair are necessary to evaluate the stability of the SM MSC chondrocyte-like phenotype within the joint environment.

Derivation and characterization of hepatic progenitor cells from human embryonic stem cells.

PubMed

Zhao, Dongxin; Chen, Song; Cai, Jun; Guo, Yushan; Song, Zhihua; Che, Jie; Liu, Chun; Wu, Chen; Ding, Mingxiao; Deng, Hongkui

2009-07-31

The derivation of hepatic progenitor cells from human embryonic stem (hES) cells is of value both in the study of early human liver organogenesis and in the creation of an unlimited source of donor cells for hepatocyte transplantation therapy. Here, we report for the first time the generation of hepatic progenitor cells derived from hES cells. Hepatic endoderm cells were generated by activating FGF and BMP pathways and were then purified by fluorescence activated cell sorting using a newly identified surface marker, N-cadherin. After co-culture with STO feeder cells, these purified hepatic endoderm cells yielded hepatic progenitor colonies, which possessed the proliferation potential to be cultured for an extended period of more than 100 days. With extensive expansion, they co-expressed the hepatic marker AFP and the biliary lineage marker KRT7 and maintained bipotential differentiation capacity. They were able to differentiate into hepatocyte-like cells, which expressed ALB and AAT, and into cholangiocyte-like cells, which formed duct-like cyst structures, expressed KRT19 and KRT7, and acquired epithelial polarity. In conclusion, this is the first report of the generation of proliferative and bipotential hepatic progenitor cells from hES cells. These hES cell-derived hepatic progenitor cells could be effectively used as an in vitro model for studying the mechanisms of hepatic stem/progenitor cell origin, self-renewal and differentiation.

Soft fibrin gels promote selection and growth of tumorigenic cells

NASA Astrophysics Data System (ADS)

Liu, Jing; Tan, Youhua; Zhang, Huafeng; Zhang, Yi; Xu, Pingwei; Chen, Junwei; Poh, Yeh-Chuin; Tang, Ke; Wang, Ning; Huang, Bo

2012-08-01

The identification of stem-cell-like cancer cells through conventional methods that depend on stem cell markers is often unreliable. We developed a mechanical method for selecting tumorigenic cells by culturing single cancer cells in fibrin matrices of ~100 Pa in stiffness. When cultured within these gels, primary human cancer cells or single cancer cells from mouse or human cancer cell lines grew within a few days into individual round colonies that resembled embryonic stem cell colonies. Subcutaneous or intravenous injection of 10 or 100 fibrin-cultured cells in syngeneic or severe combined immunodeficiency mice led to the formation of solid tumours at the site of injection or at the distant lung organ much more efficiently than control cancer cells selected using conventional surface marker methods or cultured on conventional rigid dishes or on soft gels. Remarkably, as few as ten such cells were able to survive and form tumours in the lungs of wild-type non-syngeneic mice.

Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells

PubMed Central

Xiong, Jimin; Menicanin, Danijela; Marino, Victor

2016-01-01

The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein “spots” were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells.

PubMed

Xiong, Jimin; Menicanin, Danijela; Zilm, Peter S; Marino, Victor; Bartold, P Mark; Gronthos, Stan

2016-01-01

The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein "spots" were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population.

BIFUNCTIONAL ALUMINUN: A PERMEABLE BARRIER MATERIAL FOR THE DEGRADATION OF MTBE

EPA Science Inventory

Bifunctional aluminum is an innovative remedial material for the treatment of gasoline oxygenates in permeable reactive barriers (PRBs). PRBs represent a promising environmental technology for remediation of groundwater contamination. Although zero-valent metals (ZVM) have been...

Boosting Bifunctional Oxygen Electrolysis for N-Doped Carbon via Bimetal Addition.

PubMed

Wang, Jian; Ciucci, Francesco

2017-04-01

The addition of transition metals, even in a trace amount, into heteroatom-doped carbon (M-N/C) is intensively investigated to further enhance oxygen reduction reaction (ORR) activity. However, the influence of metal decoration on the electrolysis of the reverse reaction of ORR, that is, oxygen evolution reaction (OER), is seldom reported. Moreover, further improving the bifunctional activity and corrosion tolerance for carbon-based materials remains a big challenge, especially in OER potential regions. Here, bimetal-decorated, pyridinic N-dominated large-size carbon tubes (MM'-N/C) are proposed for the first time as highly efficient and durable ORR and OER catalysts. FeFe-N/C, CoCo-N/C, NiNi-N/C, MnMn-N/C, FeCo-N/C, NiFe-N/C, FeMn-N/C, CoNi-N/C, MnCo-N/C, and NiMn-N/C are systematically investigated in terms of their structure, composition, morphology, surface area, and active site densities. In contrast to conventional monometal and N-decorated carbon, small amounts of bimetal (≈2 at%) added during the one-step template-free synthesis contribute to increased pyridinic N content, much longer and more robust carbon tubes, reduced metal particle size, and stronger coupling between the encapsulated metals and carbon support. The synergy of those factors accounts for the dramatically improved ORR and OER activity and stability. By comparison, NiFe-N/C and MnCo-N/C stand out and achieve superior bifunctional oxygen catalytic performance, exceeding most of state-of-the-art catalysts. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Initial testing of two DEMI (Driesbach Electromotive Inc. ) Model 4E zinc-air rechargeable cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardin, J.E.; Martin, M.E.

1989-10-23

The purpose of this document is to report the results of INEL laboratory testing of two DEMI 4E Aerobic Power Battery Cells (collectively designated Pack 46 in INEL records). The 4E Aerobic Power Battery is a secondary battery developed privately by Driesbach Electromotive Inc. (DEMI). The battery employs zinc as the anode and a bifunctional air cathode. This testing was performed as the first phase of a cooperative agreement between INEL and DEMI leading to the construction and testing of electric vehicle-size cells, to be followed eventually by a battery pack. 3 refs., 3 figs., 5 tabs.

Uncovering stem-cell heterogeneity in the microniche with label-free microfluidics

NASA Astrophysics Data System (ADS)

Sohn, Lydia L.

2013-03-01

Better suited for large number of cells from bulk tissue, traditional cell-screening techniques, such as fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS), cannot easily screen stem or progenitor cells from minute populations found in their physiological niches. Furthermore, they rely upon irreversible antibody binding, potentially altering cell properties, including gene expression and regenerative capacity. We have developed a label-free, single-cell analysis microfluidic platform capable of quantifying cell-surface marker expression of functional organ stem cells directly isolated from their micro-anatomical niche. With this platform, we have screened single quiescent muscle stem (satellite) cells derived from single myofibers, and we have uncovered an important heterogeneity in the surface-marker expression of these cells. By sorting the screened cells with our microfluidic device, we have determined what this heterogeneity means in terms of muscle stem-cell functionality. For instance, we show that the levels of beta1-integrin can predict the differentiation capacity of quiescent satellite cells, and in contrast to recent literature, that some CXCR4 + cells are not myogenic. Our results provide the first direct demonstration of a microniche-specific variation in gene expression in stem cells of the same lineage. Overall, our label-free, single-cell analysis and cell-sorting platform could be extended to other systems involving rare-cell subsets. This work was funded by the W. M. Keck Foundation, NIH, and California Institute of Regenerative Medicine

Characterization of hair-follicle side population cells in mouse epidermis and skin tumors

PubMed Central

Kim, Sun Hye; Sistrunk, Christopher; Miliani de Marval, Paula L.; Rodriguez-Puebla, Marcelo L.

2017-01-01

A subset of cells, termed side-population (SP), which have the ability to efflux Hoeschst 33342, have previously been demonstrated to act as a potential method to isolate stem cells. Numerous stem/progenitor cells have been localized in different regions of the mouse hair follicle (HF). The present study identified a SP in the mouse HF expressing the ABCG2 transporter and MTS24 surface marker. These cells are restricted to the upper isthmus of the HF and have previously been described as progenitor cells. Consistent with their SP characteristic, they demonstrated elevated expression of ABCG2 transporter, which participates in the dye efflux. Analysis of tumor epidermal cell lines revealed a correlation between the number of SP keratinocytes and the grade of malignancy, suggesting that the SP may play a role in malignant progression. Consistent with this idea, the present study observed an increased number of cells expressing ABCG2 and MTS24 in chemically induced skin tumors and skin tumor cell lines. This SP does not express the CD34 surface marker detected in the multipotent stem cells of the bulge region of the HF, which have been defined as tumor initiation cells. The present study concluded that a SP with properties of progenitor cells is localized in the upper isthmus of the HF and is important in mouse skin tumor progression. PMID:29181098

In Vivo Rat T-Lymphocyte Pig-a Assay: Detection and Expansion of Cells Deficient in the GPI-Anchored CD48 Surface Marker for Analysis of Mutation in the Endogenous Pig-a Gene.

PubMed

Dobrovolsky, Vasily N; Revollo, Javier; Petibone, Dayton M; Heflich, Robert H

2017-01-01

The Pig-a assay is being developed as an in vivo gene mutation assay for regulatory safety assessments. The assay is based on detecting mutation in the endogenous Pig-a gene of treated rats by using flow cytometry to measure changes in cell surface markers of peripheral blood cells. Here we present a methodology for demonstrating that phenotypically mutant rat T-cells identified by flow cytometry contain mutations in the Pig-a gene, an important step for validating the assay. In our approach, the mutant phenotype T-cells are sorted into individual wells of 96-well plates and expanded into clones. Subsequent sequencing of genomic DNA from the expanded clones confirms that the Pig-a assay detects exactly what it claims to detect-cells with mutations in the endogenous Pig-a gene. In addition, determining the spectra of Pig-a mutations provides information for better understanding the mutational mechanism of compounds of interest. Our methodology of combining phenotypic antibody labeling, magnetic enrichment, sorting, and single-cell clonal expansion can be used in genotoxicity/mutagenicity studies and in other general immunotoxicology research requiring identification, isolation, and expansion of extremely rare subpopulations of T-cells.

Acute myeloid leukemia stem cell markers in prognosis and targeted therapy: potential impact of BMI-1, TIM-3 and CLL-1.

PubMed

Darwish, Noureldien H E; Sudha, Thangirala; Godugu, Kavitha; Elbaz, Osama; Abdelghaffar, Hasan A; Hassan, Emad E A; Mousa, Shaker A

2016-09-06

Acute myeloid leukemia (AML) patients show high relapse rates and some develop conventional chemotherapy resistance. Leukemia Stem Cells (LSCs) are the main player for AML relapses and drug resistance. LSCs might rely on the B-cell-specific Moloney murine leukemia virus integration site-1 (BMI-1) in promoting cellular proliferation and survival. Growth of LSCs in microenvironments that are deprived of nutrients leads to up-regulation of the signaling pathways during the progression of the disease, which may illustrate the sensitivity of LSCs to inhibitors of those signaling pathways as compared to normal cells. We analyzed the expression of LSC markers (CD34, CLL-1, TIM-3 and BMI-1) using quantitative RT-PCR in bone marrow samples of 40 AML patients of different FAB types (M1, M2, M3, M4, M5, and M7). We also studied the expression of these markers in 2 AML cell lines (Kasumi-1 and KG-1a) using flow cytometry and quantitative RT-PCR. The overexpression of TIM-3, CLL-1, and BMI-1 was markedly correlated with poor prognosis in these patients. Our in vitro findings demonstrate that targeting BMI-1, which markedly increased in the leukemic cells, was associated with marked decrease in leukemic burden. This study also presents results for blocking LSCs' surface markers CD44, CLL-1, and TIM-3. These markers may play an important role in elimination of AML. Our study indicates a correlation between the expression of markers TIM-3, CLL-1, and especially of BMI-1 and the aggressiveness of AML and thus the potential impact of prognosis and therapies that target LSCs on improving the cure rates.

Release of active TGF-β1 from the Latent TGF-β1/GARP complex on T regulatory cells is mediated by Integrin β81

PubMed Central

Edwards, Justin P.; Thornton, Angela M.; Shevach, Ethan M.

2014-01-01

Activated T regulatory cells (Treg) express latent TGF-β1 on their cell surface bound to GARP. Although integrins have been implicated in mediating the release of active TGF-β1 from the complex of latent TGF-β1 and latent TGF-β1 binding protein, their role in processing latent TGF-β1 from the latent TGF-β1/GARP complex is unclear. Mouse CD4+Foxp3+ Treg, but not CD4+Foxp3− T cells, expressed integrin β8 (Itgb8) as detected by qRT-PCR. Itgb8 expression was a marker of thymically-derived (t)Treg, as it could not be detected on Foxp3+Helios− Tregs or on Foxp3+ T cells induced in vitro. Tregs from Itgb8 conditional knockouts exhibited normal suppressor function in vitro and in vivo in a model of colitis, but failed to provide TGF-β1 to drive Th17 or iTreg differentiation in vitro. In addition, Itgb8 knockout Tregs expressed higher levels of latent TGF-β1 on their cell surface consistent with defective processing. Thus, integrin αvβ8 is a marker of tTregs and functions in a cell intrinsic manner in mediating the processing of latent TGF-β1 from the latent TGF-β1/GARP complex on the surface of tTregs. PMID:25127859

(Fe0.2Ni0.8)0.96S tubular spheres supported on Ni foam as an efficient bifunctional electrocatalyst for overall water splitting.

PubMed

Xu, Peiman; Li, Jingwei; Luo, Jiaxian; Wei, Licheng; Zhang, Dawei; Zhou, Dan; Xu, Weiming; Yuan, Dingsheng

2018-06-21

Earth-abundant and efficient bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly significant for renewable energy systems. However, the performance of existing electrocatalysts is usually restricted by the low electroic conductivity and the limited amount of exposed active sites. In this work, (Fe 0.2 Ni 0.8 ) 0.96 S tubular spheres supported on Ni foam have been prepared by a sulfuration of FeNi layered double hydroxide spheres grown on Ni foam. Benefiting from the unique tubular sphere architecture, the rich inner defects and the enhanced electron interactions between Fe, Ni and S, this electrocatalyst shows low overpotential of 48 mV for HER at 10 mA cm -2 in 1.0 mol L -1 KOH solution, which is one of the lowest value of non-previous electrocatalyts for HER in alkaline electrolyte. Furthermore, assembled this versatile electrode as an alkaline electrolyzer for overall water splitting, a current density of 10 mA cm -2 is achieved at a low cell voltage of 1.56 V, and reach up to 30 mA cm -2 only at an operating cell voltage of 1.65 V.

Predicting biomaterial property-dendritic cell phenotype relationships from the multivariate analysis of responses to polymethacrylates

PubMed Central

Kou, Peng Meng; Pallassana, Narayanan; Bowden, Rebeca; Cunningham, Barry; Joy, Abraham; Kohn, Joachim; Babensee, Julia E.

2011-01-01

Dendritic cells (DCs) play a critical role in orchestrating the host responses to a wide variety of foreign antigens and are essential in maintaining immune tolerance. Distinct biomaterials have been shown to differentially affect the phenotype of DCs, which suggested that biomaterials may be used to modulate immune response towards the biologic component in combination products. The elucidation of biomaterial property-DC phenotype relationships is expected to inform rational design of immuno-modulatory biomaterials. In this study, DC response to a set of 12 polymethacrylates (pMAs) was assessed in terms of surface marker expression and cytokine profile. Principal component analysis (PCA) determined that surface carbon correlated with enhanced DC maturation, while surface oxygen was associated with an immature DC phenotype. Partial square linear regression, a multivariate modeling approach, was implemented and successfully predicted biomaterial-induced DC phenotype in terms of surface marker expression from biomaterial properties with R2prediction = 0.76. Furthermore, prediction of DC phenotype was effective based on only theoretical chemical composition of the bulk polymers with R2prediction = 0.80. These results demonstrated that immune cell response can be predicted from biomaterial properties, and computational models will expedite future biomaterial design and selection. PMID:22136715

Analysis of myelomonocytic leukemic differentiation by a cell surface marker panel including a fucose-binding lectin from Lotus tetragonolobus.

PubMed

Elias, L; Van Epps, D E

1984-06-01

The fucose-binding lectin from Lotus tetragonolobus ( FBL -L) has been previously shown to bind specifically to normal cells of the myeloid and monocytic lineages. The purpose of this study was to explore the utility of fluoresceinated FBL -L as a leukemia differentiation marker in conjunction with a panel of other frequently used surface markers (Fc receptor, HLA-DR, OKM1, and antimonocyte antibody). FBL -L reacted with leukemic cells in 8/9 cases of clinically recognized acute myeloid leukemia, including myeloid blast crisis of chronic granulocytic leukemia, 3/3 cases of chronic phase chronic myelogenous leukemia, and in 2/7 cases of clinically undifferentiated acute leukemia. Correlations were noted between reactivity with FBL -L, and DR and Fc receptor expression. Among continuous cell lines, FBL -L bound with high intensity to a majority of HL-60 and U937 cells. The less well differentiated myeloblast cell lines, KG-1, KG1a , and HL-60 blast II, exhibited less FBL -L binding than HL-60 and U937. A moderate proportion of K562 cells exhibited low level binding of FBL -L. Several lymphoblastic cell lines exhibited a pattern of low intensity binding that was distinguishable from the high intensity binding pattern of the myeloblastic lines. FBL -L reactivity of U937 was enhanced by induction of differentiation with leukocyte conditioned medium, but not dimethylsulfoxide. Such treatments induced contrasting patterns of change of HL-60 and U937 when labeled with OKM1, alpha-Mono, and HLA-DR. These studies demonstrate the application of FBL -L to analysis and quantitation of myelomonocytic leukemic differentiation.

A synthetic urinary probe–coated nanoparticles sensitive to fibroblast activation protein α for solid tumor diagnosis

PubMed Central

Feng, Xinwei; Wang, Qifan; Liao, Yuehua; Zhou, Xie; Wang, Yidan; Liu, Wanli; Zhang, Ge

2017-01-01

We developed fibroblast activation protein α (FAPα)-sensitive magnetic iron oxide nanoparticles (MNPs) by conjugating a substrate-reporter tandem peptide as a synthetic biomarker to the surface of MNPs (marker-MNPs). In vitro, the marker-MNPs showed stability when treated with serum or urine and exhibited high susceptibility and specificity for FAPα enzyme and 3T3/FAPα cell line. Furthermore, the marker-MNPs were administered to esophageal squamous cell carcinoma xenograft tumor mice; they reached the tumor tissues in the mice, where they were cleaved effectively by the local overexpressed FAPα to release the reporter peptide and filter it into the urine. The tumor targeting and biodistribution of marker-MNPs were verified by in vivo imaging. The cleaved reporter peptides in urine detected by enzyme-linked immunosorbent assay have high diagnostic accuracy for esophageal squamous cell carcinoma (area under the receiver-operating characteristic curve =1.0). Our study implies a promising strategy of utilizing the low-cost and noninvasive synthetic urinary probe–coated nanoparticles for the diagnosis of FAPα-positive solid tumors, except for in renal cancer. PMID:28794628

Isolation of plasma membrane fractions from the intestinal epithelial model T84.

PubMed

Kaoutzani, P; Parkos, C A; Delp-Archer, C; Madara, J L

1993-05-01

The human intestinal epithelial cell line T84 is widely used as a model for studies of Cl- secretion and crypt cell biology. We report a fractionation approach that permits separation of purified apical and basolateral T84 plasma membrane domains. T84 cellular membranes were isolated by nitrogen cavitation and differential centrifugation from monolayers grown on permeable supports. Membranes were then fractionated by isopycnic sucrose density gradient sedimentation, and fractions were assessed, using enzymatic and Western blot techniques, for apical (alkaline phosphatase) and basolateral (Na(+)-K(+)-ATPase) plasma membrane markers and for cytosolic, lysosomal, Golgi, and mitochondrial markers. Buffer conditions were defined that permitted separation of enriched apical and basolateral markers. The validity of the selected markers for the apical and basolateral domains was verified by selective apical and basolateral surface labeling studies using trace iodinated wheat germ agglutinin or biotinylation. This approach allows for separation of apical and basolateral plasma membranes of T84 cells for biochemical analyses and should thus be of broad utility in studies of this model polarized and transporting epithelium.

RchyOptimyx: Cellular Hierarchy Optimization for Flow Cytometry

PubMed Central

Aghaeepour, Nima; Jalali, Adrin; O’Neill, Kieran; Chattopadhyay, Pratip K.; Roederer, Mario; Hoos, Holger H.; Brinkman, Ryan R.

2013-01-01

Analysis of high-dimensional flow cytometry datasets can reveal novel cell populations with poorly understood biology. Following discovery, characterization of these populations in terms of the critical markers involved is an important step, as this can help to both better understand the biology of these populations and aid in designing simpler marker panels to identify them on simpler instruments and with fewer reagents (i.e., in resource poor or highly regulated clinical settings). However, current tools to design panels based on the biological characteristics of the target cell populations work exclusively based on technical parameters (e.g., instrument configurations, spectral overlap, and reagent availability). To address this shortcoming, we developed RchyOptimyx (cellular hieraRCHY OPTIMization), a computational tool that constructs cellular hierarchies by combining automated gating with dynamic programming and graph theory to provide the best gating strategies to identify a target population to a desired level of purity or correlation with a clinical outcome, using the simplest possible marker panels. RchyOptimyx can assess and graphically present the trade-offs between marker choice and population specificity in high-dimensional flow or mass cytometry datasets. We present three proof-of-concept use cases for RchyOptimyx that involve 1) designing a panel of surface markers for identification of rare populations that are primarily characterized using their intracellular signature; 2) simplifying the gating strategy for identification of a target cell population; 3) identification of a non-redundant marker set to identify a target cell population. PMID:23044634

A novel multiplex bead-based platform highlights the diversity of extracellular vesicles

PubMed Central

Koliha, Nina; Wiencek, Yvonne; Heider, Ute; Jüngst, Christian; Kladt, Nikolay; Krauthäuser, Susanne; Johnston, Ian C. D.; Bosio, Andreas; Schauss, Astrid; Wild, Stefan

2016-01-01

The surface protein composition of extracellular vesicles (EVs) is related to the originating cell and may play a role in vesicle function. Knowledge of the protein content of individual EVs is still limited because of the technical challenges to analyse small vesicles. Here, we introduce a novel multiplex bead-based platform to investigate up to 39 different surface markers in one sample. The combination of capture antibody beads with fluorescently labelled detection antibodies allows the analysis of EVs that carry surface markers recognized by both antibodies. This new method enables an easy screening of surface markers on populations of EVs. By combining different capture and detection antibodies, additional information on relative expression levels and potential vesicle subpopulations is gained. We also established a protocol to visualize individual EVs by stimulated emission depletion (STED) microscopy. Thereby, markers on single EVs can be detected by fluorophore-conjugated antibodies. We used the multiplex platform and STED microscopy to show for the first time that NK cell–derived EVs and platelet-derived EVs are devoid of CD9 or CD81, respectively, and that EVs isolated from activated B cells comprise different EV subpopulations. We speculate that, according to our STED data, tetraspanins might not be homogenously distributed but may mostly appear as clusters on EV subpopulations. Finally, we demonstrate that EV mixtures can be separated by magnetic beads and analysed subsequently with the multiplex platform. Both the multiplex bead-based platform and STED microscopy revealed subpopulations of EVs that have been indistinguishable by most analysis tools used so far. We expect that an in-depth view on EV heterogeneity will contribute to our understanding of different EVs and functions. PMID:26901056

Ordered PdCu-Based Nanoparticles as Bifunctional Oxygen-Reduction and Ethanol-Oxidation Electrocatalysts

DOE PAGES

Jiang, Kezhu; Wang, Pengtang; Guo, Shaojun; ...

2016-06-02

Here, the development of superior non-platinum electrocatalysts for enhancing the electrocatalytic activity and stability for the oxygen-reduction reaction (ORR) and liquid fuel oxidation reaction is very important for the commercialization of fuel cells,but still agreat challenge.Herein, we demonstrate a new colloidal chemistry technique for making structurally ordered PdCu-based nanoparticles (NPs) with composition control from PdCu to PdCuNi and PtCuCo.Under the dual tuning on the composition and intermetallic phase,the ordered PdCuCo NPs exhibit better activity and much enhanced stability for ORR and ethanol-oxidation reaction (EOR)than those of disordered PdCuM NPs,the commercial Pt/Cand Pd/C catalysts.The density functional theory (DFT)calculations reveal that themore » improved ORR activity on the PdCuM NPs stems from the catalytically active hollow sites arising from the ligand effect and the compressive strain on thePd surface owing to the smaller atomic size of Cu, Co,and Ni.« less

Stabilization of ultrathin (hydroxy)oxide films on transition metal substrates for electrochemical energy conversion

DOE PAGES

Zeng, Zhenhua; Chang, Kee-Chul; Kubal, Joseph; ...

2017-05-08

Design of cost-effective electrocatalysts with enhanced stability and activity is of paramount importance for the next generation of energy conversion systems, including fuel cells and electrolyzers. However, electrocatalytic materials generally improve one of these properties at the expense of the other. Here, using Density Functional Theory calculations and electrochemical surface science measurements, we explore atomic-level features of ultrathin (hydroxy)oxide films on transition metal substrates and demonstrate that these films exhibit both excellent stability and activity for electrocatalytic applications. The films adopt structures with stabilities that significantly exceed bulk Pourbaix limits, including stoichiometries not found in bulk and properties that aremore » tunable by controlling voltage, film composition, and substrate identity. Using nickel (hydroxy)oxide/Pt(111) as an example, we further show how the films enhance activity for hydrogen evolution through a bifunctional effect. Finally, the results suggest design principles for a new class of electrocatalysts with simultaneously enhanced stability and activity for energy conversion.« less

Stabilization of ultrathin (hydroxy)oxide films on transition metal substrates for electrochemical energy conversion

NASA Astrophysics Data System (ADS)

Zeng, Zhenhua; Chang, Kee-Chul; Kubal, Joseph; Markovic, Nenad M.; Greeley, Jeffrey

2017-06-01

Design of cost-effective electrocatalysts with enhanced stability and activity is of paramount importance for the next generation of energy conversion systems, including fuel cells and electrolysers. However, electrocatalytic materials generally improve one of these properties at the expense of the other. Here, using density functional theory calculations and electrochemical surface science measurements, we explore atomic-level features of ultrathin (hydroxy)oxide films on transition metal substrates and demonstrate that these films exhibit both excellent stability and activity for electrocatalytic applications. The films adopt structures with stabilities that significantly exceed bulk Pourbaix limits, including stoichiometries not found in bulk and properties that are tunable by controlling voltage, film composition, and substrate identity. Using nickel (hydroxy)oxide/Pt(111) as an example, we further show how the films enhance activity for hydrogen evolution through a bifunctional effect. The results suggest design principles for this class of electrocatalysts with simultaneously enhanced stability and activity for energy conversion.

Incombustible resin composition

NASA Technical Reports Server (NTRS)

Akima, T.

1982-01-01

Incombustible resin compositions composed of aromatic compounds were obtained through (1) combustion polymer material and (2) bisphenol A or halogenated bisphenol A and bisphenol A diglycidl ether or halogenated bisphenol A diglycidyl ether. The aromatic compound is an adduct of bifunctional phenols and bifunctional epoxy resins.

Recovery of Uranium from Seawater: Modified Polyacrylonitrile Fibers as Selective Extractants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexandratos, Spiro D.

2017-03-15

A new bifunctional fiber has been prepared and found to have a significant loading capacity of uranium from real seawater. The fiber support is polyacrylonitrile and bifunctionality is provided by amidoxime and either diethylenetriamine (DETA) or ethylenediamine (EDA) ligands. The key feature is adjusting the hydrophilic /lipophilic balance within the fiber and this was best accomplished by partially acetylating or carboxylating EDA ligands. The bifunctional carboxylated EDA /AO fiber had a loading capacity of 3.83 mg U/g fiber at the Pacific Northwest National Laboratory with a 21 day contact time in real seawater.

Embedded Disposable Functionalized Electrochemical Biosensor with a 3D-Printed Flow Cell for Detection of Hepatic Oval Cells (HOCs).

PubMed

Damiati, Samar; Peacock, Martin; Leonhardt, Stefan; Damiati, Laila; Baghdadi, Mohammed A; Becker, Holger; Kodzius, Rimantas; Schuster, Bernhard

2018-02-14

Hepatic oval cells (HOCs) are considered the progeny of the intrahepatic stem cells that are found in a small population in the liver after hepatocyte proliferation is inhibited. Due to their small number, isolation and capture of these cells constitute a challenging task for immunosensor technology. This work describes the development of a 3D-printed continuous flow system and exploits disposable screen-printed electrodes for the rapid detection of HOCs that over-express the OV6 marker on their membrane. Multiwall carbon nanotube (MWCNT) electrodes have a chitosan film that serves as a scaffold for the immobilization of oval cell marker antibodies (anti-OV6-Ab), which enhance the sensitivity of the biomarker and makes the designed sensor specific for oval cells. The developed sensor can be easily embedded into the 3D-printed flow cell to allow cells to be exposed continuously to the functionalized surface. The continuous flow is intended to increase capture of most of the target cells in the specimen. Contact angle measurements were performed to characterize the nature and quality of the modified sensor surface, and electrochemical measurements (cyclic voltammetry (CV) and square wave voltammetry (SWV)) were performed to confirm the efficiency and selectivity of the fabricated sensor to detect HOCs. The proposed method is valuable for capturing rare cells and could provide an effective tool for cancer diagnosis and detection.

Cationic Zn-Porphyrin Polymer Coated onto CNTs as a Cooperative Catalyst for the Synthesis of Cyclic Carbonates.

PubMed

Jayakumar, Sanjeevi; Li, He; Chen, Jian; Yang, Qihua

2018-01-24

The development of solid catalysts containing multiple active sites that work cooperatively is very attractive for biomimetic catalysis. Herein, we report the synthesis of bifunctional catalysts by supporting cationic porphyrin-based polymers on carbon nanotubes (CNTs) using the direct reaction of 5,10,15,20-tetrakis(4-pyridyl)porphyrin zinc(II), di(1H-imidazol-1-yl)methane, and 1,4-bis(bromomethyl)benzene in the presence of CNTs. The bifunctional catalysts could efficiently catalyze the cycloaddition reaction of epoxides and CO 2 under solvent-free conditions with porphyrin zinc(II) as the Lewis acid site and a bromine anion as a nucleophilic agent working in a cooperative way. Furthermore, a relative amount of porphyrin zinc(II) and quaternary ammonium bromide could be facilely adjusted for facilitating cooperative behavior. The bifunctional catalyst with a TOF up to 2602 h -1 is much more active than the corresponding homogeneous counterpart and is one of the most active heterogeneous catalysts ever reported under cocatalyst-free conditions. The high activity is mainly attributed to the enhanced cooperation effect of the bifunctional catalyst. With a wide substrate scope, the bifunctional catalyst could be stably recycled. This work demonstrates a new approach for the generation of a cooperative activation effect for solid catalysts.

Targeting of drugs and nanoparticles to tumors

PubMed Central

Bhatia, Sangeeta N.; Sailor, Michael J.

2010-01-01

The various types of cells that comprise the tumor mass all carry molecular markers that are not expressed or are expressed at much lower levels in normal cells. These differentially expressed molecules can be used as docking sites to concentrate drug conjugates and nanoparticles at tumors. Specific markers in tumor vessels are particularly well suited for targeting because molecules at the surface of blood vessels are readily accessible to circulating compounds. The increased concentration of a drug in the site of disease made possible by targeted delivery can be used to increase efficacy, reduce side effects, or achieve some of both. We review the recent advances in this delivery approach with a focus on the use of molecular markers of tumor vasculature as the primary target and nanoparticles as the delivery vehicle. PMID:20231381