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1.
J Chromatogr A ; 1623: 461211, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505295

RESUMO

This is the second of a two-part study in which we explore the concept of batch chromatography with recycle lag, concluding with the design, construction, and experimental validation of a prototype-an eluate recycling device (ERD)-that embodies the physical realization of this concept. The ERD implements an approximate "first in, first out" method of organizing and manipulating the to-be-recycled fractions of eluate collected from the chromatography column, where the oldest (first) amount fluid, or 'head' of the fraction, is the first to exit and be recycled back to the column. Moreover, the apparatus is simple to set up in particular in view of large-scale applications. Here we detail the construction of the ERD and assembly of a setup to interconnect the ERD and a chromatography column. Through the coordinated operation of two-way valves and two-position six-port switching valves it is possible to implement a diverse set of configurations or operating modes interconnecting the chromatography column and the ERD. The setup is validated experimentally with success using the separation of a nucleoside mixture by reversed phase chromatography as a model problem. It is also shown that by redesigning the fluid distributor using 3D printing technology the ERD performance can be improved.


Assuntos
Cromatografia de Fase Reversa/métodos , Reciclagem , Simulação por Computador , Hidrodinâmica , Nucleosídeos/análise , Impressão Tridimensional , Reprodutibilidade dos Testes , Rodaminas/química , Fatores de Tempo
2.
Phys Rev Lett ; 124(15): 158102, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32357050

RESUMO

We analyze the nonequilibrium shape fluctuations of giant unilamellar vesicles encapsulating motile bacteria. Owing to bacteria-membrane collisions, we experimentally observe a significant increase in the magnitude of membrane fluctuations at low wave numbers, compared to the well-known thermal fluctuation spectrum. We interrogate these results by numerically simulating membrane height fluctuations via a modified Langevin equation, which includes bacteria-membrane contact forces. Taking advantage of the lengthscale and timescale separation of these contact forces and thermal noise, we further corroborate our results with an approximate theoretical solution to the dynamical membrane equations. Our theory and simulations demonstrate excellent agreement with nonequilibrium fluctuations observed in experiments. Moreover, our theory reveals that the fluctuation-dissipation theorem is not broken by the bacteria; rather, membrane fluctuations can be decomposed into thermal and active components.


Assuntos
Vesículas Citoplasmáticas/química , Lipídeos de Membrana/química , Modelos Biológicos , Modelos Químicos , Bacillus subtilis/química , Bacillus subtilis/citologia , Bacillus subtilis/metabolismo , Vesículas Citoplasmáticas/metabolismo , Locomoção , Lipídeos de Membrana/metabolismo , Fosfatidiletanolaminas/química , Rodaminas/química , Termodinâmica , Lipossomas Unilamelares/química , Lipossomas Unilamelares/metabolismo
3.
Chemosphere ; 256: 127082, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32450350

RESUMO

Significant degradation of organic contaminants in biochar sorption systems has recently been reported, demonstrating a promising potential application of biochar in pollution control. We hypothesized that the degradation of organic chemicals by biochar may be further enhanced under irradiation by UV light due to the photocatalytic activities of carbonaceous materials. Our results confirmed that UV conditions increased the degradation of rhodamine B (RhB) by up to three times compared to dark conditions. Washing biochar with ultrapure water further increased RhB photodegradation by up to ten times. This photodegradation increase was the highest for biochar produced at 1000 °C. HF treatment and the addition of biochar supernatant did not increase RhB photodegradation. Therefore, the biochar properties mediating RhB photodegradation may be related to solid particles, mostly the combination of graphite structures and organic functional groups. Based on XPS and FTIR analysis, we propose that the quinoid CO in biochar may play an essential role in RhB photodegradation. Further research on identifying the photoactive components of biochar will be fundamental for improved biochar manufacture and application.


Assuntos
Carvão Vegetal/química , Recuperação e Remediação Ambiental , Rodaminas/química , Adsorção , Poluição Ambiental , Compostos Orgânicos , Fotólise , Raios Ultravioleta
4.
PLoS Comput Biol ; 16(5): e1007890, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453720

RESUMO

The biconcave disk shape of the mammalian red blood cell (RBC) is unique to the RBC and is vital for its circulatory function. Due to the absence of a transcellular cytoskeleton, RBC shape is determined by the membrane skeleton, a network of actin filaments cross-linked by spectrin and attached to membrane proteins. While the physical properties of a uniformly distributed actin network interacting with the lipid bilayer membrane have been assumed to control RBC shape, recent experiments reveal that RBC biconcave shape also depends on the contractile activity of nonmuscle myosin IIA (NMIIA) motor proteins. Here, we use the classical Helfrich-Canham model for the RBC membrane to test the role of heterogeneous force distributions along the membrane and mimic the contractile activity of sparsely distributed NMIIA filaments. By incorporating this additional contribution to the Helfrich-Canham energy, we find that the RBC biconcave shape depends on the ratio of forces per unit volume in the dimple and rim regions of the RBC. Experimental measurements of NMIIA densities at the dimple and rim validate our prediction that (a) membrane forces must be non-uniform along the RBC membrane and (b) the force density must be larger in the dimple than the rim to produce the observed membrane curvatures. Furthermore, we predict that RBC membrane tension and the orientation of the applied forces play important roles in regulating this force-shape landscape. Our findings of heterogeneous force distributions on the plasma membrane for RBC shape maintenance may also have implications for shape maintenance in different cell types.


Assuntos
Deformação Eritrocítica , Membrana Eritrocítica/fisiologia , Eritrócitos/citologia , Miosinas/química , Citoesqueleto de Actina/química , Reagentes para Ligações Cruzadas/química , Glicoforinas/química , Humanos , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Microscopia de Fluorescência , Cadeias Pesadas de Miosina/química , Faloidina/química , Rodaminas/química , Estresse Mecânico
5.
Food Chem ; 327: 127058, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32464462

RESUMO

A "turn-on" fluorescence sensor was developed for total detection of fumonisin B1, B2 and B3 (FB1, FB2 and FB3) in maize samples. Rhodamine B isothiocyanate (RBITC) and gold nanoparticles (AuNPs) were employed as the energy donor-acceptor pairs. The intensity of restored fluorescence was inversely proportional to the concentration of the FBs. The limit of detection (LOD) of the sensor for FB1 was 23.80 pg/mL. The coefficient of variation (CV) was both less than 7% for intra- and inter-assay. The linear range was from 51.39 to 2125.92 pg/mL. The average recoveries of FBs from maize samples were ranged from 88.7% to 107.2%. The correlation coefficient of the results between the developed sensor and LC-MS/MS was 0.9970. To fulfill the procedure of the assay, only 46 min was needed. These results suggest that the fluorescence "turn-on" sensor has great potential applications in the analysis of FBs in maize samples.


Assuntos
Cisteamina/química , Fumonisinas/análise , Espectrometria de Fluorescência/métodos , Contaminação de Alimentos/análise , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Rodaminas/química , Zea mays/química , Zea mays/metabolismo
6.
Chemosphere ; 253: 126655, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32302899

RESUMO

The degradation kinetics and mechanisms of Rhodamine B (RhB) dye by •OH and SO4•- based advanced oxidation processes were investigated. The •OH and SO4•- radicals were generated by UV photolysis of hydrogen peroxide and persulfate (i.e., UV/H2O2 and UV/PS), respectively. The effects of initial solution pH, RhB concentration, oxidant dosage, Fe2+ concentration, and water matrices were examined. The results showed that the degradation of RhB followed pseudo-first-order kinetics in both processes, with the UV/H2O2 process exhibiting better performance than that of the UV/PS process. Acidic conditions were favorable to the degradation of RhB in both systems. Increasing the oxidant dosage or decreasing the contaminant concentration could enhance the degradation of RhB. Photo-Fenton-like processes accelerated the performance when Fe2+ was added into both systems. The removal efficiency of RhB was inhibited upon the addition of humic substances. The addition of Cl- displayed no significant effect and promoted RhB degradation in UV/H2O2 and UV/PS systems, respectively. The presence of NO3- promoted RhB degradation, while H2PO4- and C2O42- showed an inhibitory effect on both UV/H2O2 and UV/PS processes. Radical scavenging tests revealed the dominant role of SO4•- radicals in the UV/PS system. Furthermore, the evolution of low molecular weight organic acids and NH4+ during the degradation of RhB in these two processes were compared. Both UV/H2O2 and UV/PS systems led to similar formation trends of NH4+ and some ring-opening products (e.g., formic acid, acetic acid, and oxalic acid), suggesting some analogies in the decay pathways of RhB by •OH and SO4•--induced oxidation processes.


Assuntos
Rodaminas/química , Poluentes Químicos da Água/química , Substâncias Húmicas , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Cinética , Compostos Orgânicos , Oxirredução , Processos Fotoquímicos , Fotólise , Sulfatos/química , Raios Ultravioleta , Poluentes Químicos da Água/análise
7.
Chemistry ; 26(35): 7912-7917, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32274865

RESUMO

A series of phosphine oxide-bridged rhodamines (P-rhodamines) bearing various acyclic and cyclic amine moieties, including dimethyl- and diethylamine, azetidine, pyrrolidine and 7-azabicyclo[2,2,1]heptane (7ABH), have been synthesized. The photophysical properties as well as chemical and photostability of these dyes have been studied in detail. Among these dyes, the 7ABH-substituted dye shows stronger fluorescence in the near-infrared (NIR) region, relative to the other P-rhodamines. This dye could be applied to live-cell imaging, wherein lysosomes were selectively stained in a pH-independent manner. It was also found that the ring fusion of the amine moieties gives rise to remarkably redshifted spectra, with absorption and emission maxima at 770 and 820 nm, respectively, spectrally close to that of indocyanine green (ICG). Importantly, the ring-fused P-rhodamines showed much higher photostability than ICG, indicative of their promising utility as the NIR-emissive dyes.


Assuntos
Aminas/química , Lisossomos/química , Rodaminas/química , Fluorescência , Verde de Indocianina
8.
Phys Chem Chem Phys ; 22(14): 7516-7523, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32219241

RESUMO

The chiroptical properties of multi-chromophoric systems are governed by the intermolecular arrangement of the monomeric units. We report on a computational and experimental study of the linear optical properties and supramolecular structure of a rhodamine heterodimer assembled on a DNA scaffold. The experimental absorption and circular dichroism (CD) profiles confirm the dimer formation. Computationally, starting from low-cost DFT/TDDFT simulations of the bare dimer we attribute the measured -/+ CD sign sequence of the S1/S2 bands to a specific chiral conformation of the heterodimer. In the monomers, as typical for rhodamine dyes, the electric transition dipole of the lowest π-π* transition is parallel to the long axis of the xanthene planes. We show that in the heterodimer the sign sequence of the two CD bands is related to the orientation of these long axes. To account explicitly for environment effects, we use molecular dynamics (MD) simulations for characterizing the supramolecular structure of the two optical isomers tethered on DNA. Average absorption and CD-profiles were modeled using ab initio TDDFT calculations at the geometries sampled along a few nanosecond MD run. The absorption profiles computed for both optical isomers are in good agreement with the experimental absorption spectrum and do not allow one to discriminate between them. The computed averaged CD profiles provide the orientation of monomers in the enantiomer that is dominant under the experimental conditions.


Assuntos
DNA/química , Modelos Moleculares , Rodaminas/química , Dicroísmo Circular , Química Computacional , Simulação de Dinâmica Molecular , Estrutura Molecular
9.
Int J Nanomedicine ; 15: 1745-1758, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32214808

RESUMO

Purpose: Solid lipid nanoparticles are largely used in biomedical research and are characterized by high stability and biocompatibility and are also able to improve the stability of various loaded molecules. In vitro studies demonstrated that these nanoparticles are low cytotoxic, while in vivo studies proved their efficiency as nanocarriers for molecules characterized by a low bioavailability. However, to our knowledge, no data on the systemic biodistribution and organ accumulation of solid lipid nanoparticles in itself are presently available. Methods: In this view, we investigated the solid lipid nanoparticles biodistribution by a multimodal imaging approach correlating in vivo and ex vivo analyses. We loaded solid lipid nanoparticles with two different fluorophores (cardiogreen and rhodamine) to observe them with an optical imager in the whole organism and in the excised organs, and with fluorescence microscopy in tissue sections. Light and transmission electron microscopy analyses were also performed to evaluate possible structural modification or damage due to nanoparticle administration. Results: Solid lipid nanoparticles loaded with the two fluorochromes showed good optic characteristics and stable polydispersity. After in vivo administration, they were clearly detectable in the organism. Four  hours after the injection, the fluorescent signal occurred in anatomical districts corresponding to the liver and this was confirmed by the ex vivo acquisitions of excised organs. Brightfield, fluorescence and transmission electron microscopy confirmed solid lipid nanoparticles accumulation in hepatocytes without structural damage. Conclusion: Our results support the systemic biocompatibility of solid lipid nanoparticles and demonstrate their detailed biodistribution from the whole organism to organs until the cells.


Assuntos
Nanopartículas/análise , Nanopartículas/química , Animais , Disponibilidade Biológica , Corantes Fluorescentes/química , Verde de Indocianina/química , Lipídeos/química , Fígado/efeitos dos fármacos , Fígado/ultraestrutura , Masculino , Camundongos Nus , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Imagem Multimodal/métodos , Rodaminas/química , Distribuição Tecidual
10.
Chem Commun (Camb) ; 56(21): 3183-3186, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32067022

RESUMO

A novel nanoarchitecture (MSN-Tb-UbR) was prepared by modifying rhodamine B-labelled Ubs (Ub-Rs) on the surface of mesoporous silica nanoparticles (MSNs) loaded with Tb3+-complexes. The MSN-Tb-UbR exhibits ratiometric sensing ability for DUB (UCH-L1) with good sensitivity and selectivity.


Assuntos
Nanopartículas/química , Dióxido de Silício/química , Ubiquitina Tiolesterase/análise , Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Porosidade , Rodaminas/química , Propriedades de Superfície , Térbio/química
11.
J Environ Sci (China) ; 90: 180-188, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081314

RESUMO

A novel N,N-dithenoyl-rhodamine based fluorescent and colorimetric Fe3+ probe 1 was designed and synthesized by only one step from Rhodamine B hydrazide and 2-thiophenecarbonyl chloride. The structure of probe 1 was characterized by 1H NMR/13C NMR spectroscopy, IR spectroscopy, and HRMS spectrometry. Accompanying with significant changes in visual color and fluorescent spectrum, probe 1 displayed good sensitivity for Fe3+ with an abroad pH span. The detection limit (3.76 µmol/L, 0.2 mg/L) for Fe3+ was lower than WHO recommended value (0.3 mg/L) for drinking water. Using two thiophene carbonyl groups as coordinating functional recognition group, probe 1 showed excellent selectivity towards Fe3+ over diverse coexistent metal ions and anions. The sensing mechanism between dithenoyl-substituted probe 1 and Fe3+ was further confirmed by 1H NMR and IR titration experiments, binding constants study, and Job's plot analysis. Furthermore, probe 1 also exhibited good cell membrane permeability and could be used as an efficient Fe3+ probe in living human cells.


Assuntos
Corantes Fluorescentes , Humanos , Íons , Ferro/química , Limite de Detecção , Rodaminas/química , Água
12.
Food Chem ; 316: 126378, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32066074

RESUMO

Rhodamine B (RhB), which is vividly colored, although illegal and potentially carcinogenic, has been reported widely as present in various foods, including chili powder, preserved plums, sausage and sweets, presenting a significant health risk. In this work, solid-phase extraction (SPE), coupled with direct fluorescence detection on the same extraction medium, is proposed for rapid onsite screening for RhB in food without sample pretreatment. Parameters that affected extraction of RhB were explored. The lowest amount of RhB, detected on glass, was 2 ng and the lowest detectable concentration in food samples was 0.5 mg/kg, as verified by HPLC. The analysis time was less than 5 min, including sampling. In addition, the recovery rate of this method was found to be triple of that from the cotton gauze reported in literature. The proposed method has promise as a rapid, onsite screening protocol for food safety.


Assuntos
Análise de Alimentos , Rodaminas/análise , Cromatografia Líquida de Alta Pressão , Fluorescência , Hidrogéis/química , Rodaminas/química , Extração em Fase Sólida
13.
Chemosphere ; 243: 125423, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995878

RESUMO

Transition metal and nanocarbon-based composites with high activity and stability draw great attention in electro-Fenton system for organic pollutants removal. In this study, HKUST-1-derived Cu@C nanoparticles embedded within three-dimensional reduced graphene oxide (rGO) network (denoted as 3DG/Cu@C) is synthesized through a simple strategy. The prepared catalyst shows ordered 3D porous carbon structure and Cu@C NPs are uniformly dispersed in the matrix. The 3DG/Cu@C is used as heterogeneous electro-Fenton (hetero-EF) catalyst and shows outstanding performance in various persistent organic pollutants removal. High concentration Rhodamine B (RhB) (40 mg L-1) can achieve a complete decolorization within 150 min with 25 mg L-1 3DG/Cu@C catalyst, which is one of the lowest catalyst dosages in hetero-EF for RhB removal. More importantly, the 3DG/Cu@C achieves high RhB mineralization efficiency of 81.5% and exhibits high catalytic performance in a wide pH window from 3 to 9. The 3DG/Cu@C also remains high efficiency after five successive reaction cycles. The working mechanism study shows that RhB is mainly oxidized by •OH and O2•- radicals through hetero-EF and anodic oxidation processes. The high stability and outstanding performance of 3DG/Cu@C provide new insights in organic pollutants removal by hetero-EF process with transition metal and nanocarbon-based catalysts.


Assuntos
Corantes Fluorescentes/química , Grafite/química , Peróxido de Hidrogênio/química , Rodaminas/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Cobre/química , Eletrodos , Ferro/química , Nanopartículas Metálicas/química , Estruturas Metalorgânicas/química , Oxirredução
14.
Mater Sci Eng C Mater Biol Appl ; 108: 110463, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923983

RESUMO

Direct real-time measurement of nitric oxide (NO) in living cells has proven quite challenging, owing in part to the lack of tools that are selective and sensitive to measure intracellular concentrations of NO. Herein we report the synthesis and characterization of polyvinyl alcohol (PVA) based nanosensors for fluorescence imaging of cytosolic NO using an o-phenylenediamine-rhodamine (OPD-RhB) platform. More specifically, thiol-functionalized PVA incorporating RhB conjugated OPD was disulfide crosslinked to yield NO-responsive nanosensors. The polymeric nanosensors were anionic, averaged 170 nm in hydrodynamic size, and exhibited linear increases in fluorescence intensity (FLI) to micro- and nanomolar concentrations of NO in a sodium nitroprusside (SNP) concentration-dependent manner. In the presence of SNP, the engineered nanosensors demonstrated physical stability at extracellular glutathione (GSH) conditions, while favoring NO detection at cytoplasmic GSH conditions. In addition, the PVA-based nanosensors were non-cytotoxic, cell membrane-permeable and demonstrated hydrogen peroxide-dependent FL increases upon incubation with activated synoviocytes in vitro. Most notably, NO-induced cell FLIs correlated strongly with total nitrite/nitrate content of conventional Griess assays with Pearson correlation coefficients of 0.96. Comprehensively, our results show that OPD-RhB-conjugated PVA nanosensors offer real-time imaging of NO with high sensitivity in living cells that can be employed for direct quantification of NO.


Assuntos
Nanoestruturas/química , Óxido Nítrico/metabolismo , Rodaminas , Animais , Glutationa/metabolismo , Células Hep G2 , Humanos , Peróxido de Hidrogênio/metabolismo , Microscopia de Fluorescência , Fenilenodiaminas/química , Fenilenodiaminas/farmacologia , Coelhos , Rodaminas/química , Rodaminas/farmacologia
15.
J Nanobiotechnology ; 18(1): 14, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941495

RESUMO

BACKGROUND: In orthopedics, the treatment of implant-associated infections represents a high challenge. Especially, potent antibacterial effects at implant surfaces can only be achieved by the use of high doses of antibiotics, and still often fail. Drug-loaded magnetic nanoparticles are very promising for local selective therapy, enabling lower systemic antibiotic doses and reducing adverse side effects. The idea of the following study was the local accumulation of such nanoparticles by an externally applied magnetic field combined with a magnetizable implant. The examination of the biodistribution of the nanoparticles, their effective accumulation at the implant and possible adverse side effects were the focus. In a BALB/c mouse model (n = 50) ferritic steel 1.4521 and Ti90Al6V4 (control) implants were inserted subcutaneously at the hindlimbs. Afterwards, magnetic nanoporous silica nanoparticles (MNPSNPs), modified with rhodamine B isothiocyanate and polyethylene glycol-silane (PEG), were administered intravenously. Directly/1/7/21/42 day(s) after subsequent application of a magnetic field gradient produced by an electromagnet, the nanoparticle biodistribution was evaluated by smear samples, histology and multiphoton microscopy of organs. Additionally, a pathohistological examination was performed. Accumulation on and around implants was evaluated by droplet samples and histology. RESULTS: Clinical and histological examinations showed no MNPSNP-associated changes in mice at all investigated time points. Although PEGylated, MNPSNPs were mainly trapped in lung, liver, and spleen. Over time, they showed two distributional patterns: early significant drops in blood, lung, and kidney and slow decreases in liver and spleen. The accumulation of MNPSNPs on the magnetizable implant and in its area was very low with no significant differences towards the control. CONCLUSION: Despite massive nanoparticle capture by the mononuclear phagocyte system, no significant pathomorphological alterations were found in affected organs. This shows good biocompatibility of MNPSNPs after intravenous administration. The organ uptake led to insufficient availability of MNPSNPs in the implant region. For that reason, among others, the nanoparticles did not achieve targeted accumulation in the desired way, manifesting future research need. However, with different conditions and dimensions in humans and further modifications of the nanoparticles, this principle should enable reaching magnetizable implant surfaces at any time in any body region for a therapeutic reason.


Assuntos
Portadores de Fármacos/química , Compostos Férricos/química , Nanopartículas de Magnetita/química , Próteses e Implantes , Dióxido de Silício/química , Animais , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/toxicidade , Feminino , Corantes Fluorescentes/química , Membro Posterior , Nanopartículas de Magnetita/toxicidade , Camundongos Endogâmicos BALB C , Ortopedia , Polietilenoglicóis/química , Porosidade , Rodaminas/química , Silanos/química , Distribuição Tecidual
16.
Chemosphere ; 243: 125387, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995867

RESUMO

Hollow porous carbon has attracted a great deal of interest as catalyst-support because of its high surface area, low density and large pore volume. Herein, we develop a layer-by-layer assembly method to effectively load Pt nanoparticles on hollow porous carbon nanospheres (Pt/HPC) through using modified-SiO2 nanospheres as the template and agar as the carbon resource. The gel properties of agar (e.g., sensitivity to temperature and high mechanical strength) makes the Pt nanoparticles well crosslink with carbon, as well as endows the carbon nanospheres with robust stability. The synthesized Pt/HPC was employed as a catalyst in the hydrogenation reduction of rhodamine B (RhB). The catalytic results demonstrate that Pt/HPC is very promising for RhB hydrogenation as compared to commercial Pt/C catalyst. It is proven that such excellent activity of Pt/HPC can be attributed to the combined merits of hollow porous architecture and well combination between HPC and Pt nanoparticles.


Assuntos
Ágar/química , Nanosferas/química , Platina/química , Rodaminas/química , Carbono/química , Catálise , Reagentes para Ligações Cruzadas/química , Hidrogenação , Nanopartículas Metálicas/química , Porosidade , Dióxido de Silício , Temperatura
17.
Chem Commun (Camb) ; 56(16): 2455-2458, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31996872

RESUMO

A group of asymmetric Si-rhodamine scaffolds was designed for protease-activated NIR probes. Dual pH-inertia for both spirocyclized fluorescent probes and fluorescent products of zwitterions form over a wide range of pH (4.0-11.0). Leucine aminopeptidase (LAP) and γ-glutamyl transpeptidase (GGT) were monitored by fluorescent imaging in vivo.


Assuntos
Corantes Fluorescentes/química , Imagem Óptica , Peptídeo Hidrolases/análise , Rodaminas/química , Silício/química , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/metabolismo , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Estrutura Molecular , Peptídeo Hidrolases/metabolismo , Rodaminas/metabolismo , Silício/metabolismo , Espectrometria de Fluorescência
18.
BMC Cancer ; 20(1): 64, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992267

RESUMO

BACKGROUND: It is still difficult to detect and diagnose early adenocarcinoma of the esophagogastric junction (EGJ) using conventional endoscopy or image-enhanced endoscopy. A glutamylprolyl hydroxymethyl rhodamine green (EP-HMRG) fluorescent probe that can be enzymatically activated to become fluorescent after the cleavage of a dipeptidyl peptidase (DPP)-IV-specific sequence has been developed and is reported to be useful for the detection of squamous cell carcinoma of the head and neck, and esophagus; however, there is a lack of studies that focuses on detecting EGJ adenocarcinoma by fluorescence molecular imaging. Therefore, we investigated the visualization of early EGJ adenocarcinoma by applying EP-HMRG and using clinical samples resected by endoscopic submucosal dissection (ESD). METHODS: Fluorescence imaging with EP-HMRG was performed in 21 clinical samples resected by ESD, and the fluorescence intensity of the tumor and non-tumor regions of interest was prospectively measured. Immunohistochemistry was also performed to determine the expression of DPP-IV. RESULTS: Fluorescence imaging of the clinical samples showed that the tumor lesions were visualized within a few minutes after the application of EP-HMRG, with a sensitivity, specificity, and accuracy of 85.7, 85.7, and 85.7%, respectively. However, tumors with a background of intestinal metaplasia did not have a sufficient contrast-to-background ratio since complete intestinal metaplasia also expresses DPP-IV. Immunohistochemistry measurements revealed that all fluorescent tumor lesions expressed DPP-IV. CONCLUSIONS: Fluorescence imaging with EP-HMRG could be useful for the detection of early EGJ adenocarcinoma lesions that do not have a background of intestinal metaplasia.


Assuntos
Adenocarcinoma/diagnóstico , Dipeptidil Peptidase 4/metabolismo , Neoplasias Esofágicas/diagnóstico , Junção Esofagogástrica/patologia , Corantes Fluorescentes/farmacologia , Rodaminas/farmacologia , Adenocarcinoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Detecção Precoce de Câncer , Neoplasias Esofágicas/metabolismo , Junção Esofagogástrica/metabolismo , Feminino , Corantes Fluorescentes/química , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Molecular , Imagem Óptica , Estudos Prospectivos , Rodaminas/química , Sensibilidade e Especificidade
19.
Environ Sci Pollut Res Int ; 27(9): 9152-9166, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31916156

RESUMO

A novel adsorbent derived from banyan aerial roots was prepared via modification and employed to aqueous gentian violet (GV) and rhodamine B (RhB) removal. The surface morphology and physicochemical properties of modified banyan aerial roots (MBARs) were investigated by SEM, EDS, N2 adsorption/desorption, zeta potential, XRD, and FT-IR characterization experiments. Adsorption factors were tested, and the optimal conditions for GV and RhB removal were pH of 6 and 3, doses of 0.02 g and 0.03 g, and reaction time of 540 min. Adsorption isotherm simulation illustrated that theoretical monolayer adsorption capacities of GV and RhB were 456.64 mg/g and 115.23 mg/g, respectively. Kinetics data was assessed with pseudo-first-order and pseudo-second-order models, and the latter described GV and RhB adsorption better at 288 K, 298 K, 308 K, and 318 K. Thermodynamic analysis indicated that GV and RhB adsorption processes were endothermic and spontaneous. From the research results, it could be inferred that GV adsorption was mainly dominated by electrostatic interaction, while RhB adsorption might be primarily attributed to electrostatic interaction and hydrogen bonding. The study based on full utilization of waste plant fibers facilitates recycling of biomass resources, and due to simplicity, safety, and eco-friendliness of the preparation, as well as low cost and high efficiency of the application, MBARs may be potential absorbents for the treatment of dyestuff wastewater.


Assuntos
Rodaminas/química , Poluentes Químicos da Água , Purificação da Água , Adsorção , Violeta Genciana , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
20.
Talanta ; 209: 120436, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892062

RESUMO

pH regulates the function of many organelles and plays a pivotal role in requiring multitud cellular behaviors. Compared with single fluorescent probes, ratio fluorescent probes have higher sensitivity and immunity to interference. Herein, a novel Janus ratio nanoprobe was developed for intracellular pH detection. Modified rhodamine B probe and fluorescein isothiocyanate (FITC) were individually encapsulated in the independent hemispheres of Janus microparticles fabricated via Pickering emulsion. Moreover, it exhibits a satasified ratiometric detection of pH compared to the previous core-shell structure and organic small molecule probe. Accordingly, the Janus nanoprobe possesses many important features as an attractive sensor, including high anti-jamming capability, excellent stability, good reversibility and low cytotoxicity. Variations of the two fluorescence intensities (Fgreen/Fred) resulted in a ratiometric pH fluorescent sensor, which can respond to wide range of pH values from 3 to 8. To be more specific, with a single excitation wavelength of 488 nm, there are dual emission bands centered at 538 nm and 590 nm. Also the Janus nanoprobe displays a excellent linear relationship in the physiologically relevant pH range of 4.0-6.0. Consequently, detecting of pH and imaging was successfully achieved in living cells, which provides a simple and reliable method for detecting intracelluar pH and other similar substances.


Assuntos
Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Nanopartículas/química , Rodaminas/química , Linhagem Celular Tumoral , Sobrevivência Celular , Fluoresceína-5-Isotiocianato/toxicidade , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Microscopia de Fluorescência , Nanopartículas/toxicidade , Rodaminas/síntese química , Rodaminas/toxicidade , Dióxido de Silício/química , Espectrometria de Fluorescência
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